Hammes-Schiffer, Sharon
Proton-coupled electron transfer reactions in solution: Molecular dynamics with quantum transitions A general minimal model for proton-coupled electron transfer PCET reactions in solution is presented. This model consists of three coupled degrees of freedom that represent an electron, a proton, and a solvent
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
Solution-Processed Graphene Electronics,” Nano Letters, vol.applications,” Organic Electronics, vol. 12, no. 2, pp. 249-design in organic electronics by dual-gate technology,” in
PIA - Savannah River Nuclear Solutions Electronic Safeguards...
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Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic Safeguards Security System (E3S) PIA - Savannah River Nuclear Solutions Electronic...
Schwerdtfeger, Christine A.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon, E-mail: shs3@illinois.edu [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)] [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)
2014-01-21
The development of efficient theoretical methods for describing electron transfer (ET) reactions in condensed phases is important for a variety of chemical and biological applications. Previously, dynamical dielectric continuum theory was used to derive Langevin equations for a single collective solvent coordinate describing ET in a polar solvent. In this theory, the parameters are directly related to the physical properties of the system and can be determined from experimental data or explicit molecular dynamics simulations. Herein, we combine these Langevin equations with surface hopping nonadiabatic dynamics methods to calculate the rate constants for thermal ET reactions in polar solvents for a wide range of electronic couplings and reaction free energies. Comparison of explicit and implicit solvent calculations illustrates that the mapping from explicit to implicit solvent models is valid even for solvents exhibiting complex relaxation behavior with multiple relaxation time scales and a short-time inertial response. The rate constants calculated for implicit solvent models with a single solvent relaxation time scale corresponding to water, acetonitrile, and methanol agree well with analytical theories in the Golden rule and solvent-controlled regimes, as well as in the intermediate regime. The implicit solvent models with two relaxation time scales are in qualitative agreement with the analytical theories but quantitatively overestimate the rate constants compared to these theories. Analysis of these simulations elucidates the importance of multiple relaxation time scales and the inertial component of the solvent response, as well as potential shortcomings of the analytical theories based on single time scale solvent relaxation models. This implicit solvent approach will enable the simulation of a wide range of ET reactions via the stochastic dynamics of a single collective solvent coordinate with parameters that are relevant to experimentally accessible systems.
Ultrafast studies of solution dynamics
Woodruff, W.H.; Dyer, R.B.; Callender, R.H.
1997-10-01
This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Fast chemical dynamics generally must be initiated photochemically. This limits the applicability of modern laser methods for following the structural changes that occur during chemical and biological reactions to those systems that have an electronic chromophore that has a significant yield of photoproduct when excited. This project has developed a new and entirely general approach to ultrafast initiation of reactions in solution: laser-induced temperature jump (T-jump). The results open entire new fields of study of ultrafast molecular dynamics in solution. The authors have demonstrated the T-jump technique on time scales of 50 ps and longer, and have applied it to study of the fast events in protein folding. They find that a general lifetime of alpha-helix formation is ca 100 ns, and that tertiary folds (in apomyoglobin) form in ca 100 {mu}s.
Dynamic Transmission Electron Microscopy
Evans, James E.; Jungjohann, K. L.; Browning, Nigel D.
2012-10-12
Dynamic transmission electron microscopy (DTEM) combines the benefits of high spatial resolution electron microscopy with the high temporal resolution of ultrafast lasers. The incorporation of these two components into a single instrument provides a perfect platform for in situ observations of material processes. However, previous DTEM applications have focused on observing structural changes occurring in samples exposed to high vacuum. Therefore, in order to expand the pump-probe experimental regime to more natural environmental conditions, in situ gas and liquid chambers must be coupled with Dynamic TEM. This chapter describes the current and future applications of in situ liquid DTEM to permit time-resolved atomic scale observations in an aqueous environment, Although this chapter focuses mostly on in situ liquid imaging, the same research potential exists for in situ gas experiments and the successful integration of these techniques promises new insights for understanding nanoparticle, catalyst and biological protein dynamics with unprecedented spatiotemporal resolution.
Solution of Large Eigenvalue Problems in Electronic Structure Calculations \\Lambda
Stathopoulos, Andreas
Solution of Large Eigenvalue Problems in Electronic Structure Calculations \\Lambda Y. Saad y , A the structural and electronic properties of complex systems is one of the outstanding problems in condensed external perturbations. For example, it may be desirable in certain cases to follow the dynamics of atoms/electrons
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
Conductors for Flexible Electronics,” Journal of Thefor low-cost and flexible electronics. Parts of his workwidespread use in flexible electronics. From an economic
Bokarev, Sergey I; Suljoti, Edlira; Kühn, Oliver; Aziz, Emad F
2013-01-01
Non-radiative decay channels in the L-edge fluorescence spectra from transition metal-aqueous solutions give rise to spectral dips in X-ray transmission spectra. Their origin is unraveled here using partial and inverse partial fluorescence yields on the micro-jet combined with multi-reference ab initio electronic structure calculations. Comparing Fe2+, Fe3+, and Co2+ systems we demonstrate unequivocally that spectral dips are due to a state-dependent electron delocalization within the manifold of d-orbitals.
Dynamic imaging with electron microscopy
Campbell, Geoffrey; McKeown, Joe; Santala, Melissa
2014-05-30
Livermore researchers have perfected an electron microscope to study fast-evolving material processes and chemical reactions. By applying engineering, microscopy, and laser expertise to the decades-old technology of electron microscopy, the dynamic transmission electron microscope (DTEM) team has developed a technique that can capture images of phenomena that are both very small and very fast. DTEM uses a precisely timed laser pulse to achieve a short but intense electron beam for imaging. When synchronized with a dynamic event in the microscope's field of view, DTEM allows scientists to record and measure material changes in action. A new movie-mode capability, which earned a 2013 R&D 100 Award from R&D Magazine, uses up to nine laser pulses to sequentially capture fast, irreversible, even one-of-a-kind material changes at the nanometer scale. DTEM projects are advancing basic and applied materials research, including such areas as nanostructure growth, phase transformations, and chemical reactions.
Kurnikova, Maria
and the metal cation. Conductivity measure- ments and ab initio electronic structure calculations are used structure and the solute dynamics occur for ionic solute molecules. Both experimental4-10 and theoretical11 of experimental studies, ab initio electronic struc- ture, and molecular dynamics (MD) simulation is used
Electron Transfer Dynamics in Photocatalytic CO2 Conversion ...
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Electron Transfer Dynamics in Photocatalytic CO2 Conversion Electron Transfer Dynamics in Photocatalytic CO2 Conversion Coal is the workhorse of our power industry, responsible for...
Organic electronic devices with multiple solution-processed layers
Forrest, Stephen R.; Lassiter, Brian E.; Zimmerman, Jeramy D.
2015-08-04
A method of fabricating a tandem organic photosensitive device involves depositing a first layer of an organic electron donor type material film by solution-processing of the organic electron donor type material dissolved in a first solvent; depositing a first layer of an organic electron acceptor type material over the first layer of the organic electron donor type material film by a dry deposition process; depositing a conductive layer over the interim stack by a dry deposition process; depositing a second layer of the organic electron donor type material over the conductive layer by solution-processing of the organic electron donor type material dissolved in a second solvent, wherein the organic electron acceptor type material and the conductive layer are insoluble in the second solvent; depositing a second layer of an organic electron acceptor type material over the second layer of the organic electron donor type material film by a dry deposition process, resulting in a stack.
Charge Dynamics in Solution-Processed Nanocrystalline CuInS¬2 Solar Cells
Halpert, Jonathan E.; Morgenstern, Frederik S. F.; Ehrler, Bruno; Vaynzof, Yana; Credgington, Dan; Greenham, Neil C.
2015-05-07
We investigate charge dynamics in solar cells constructed using solution-processed layers of CuInS2 (CIS) nanocrystals (NCs) as the electron donor and CdS as the electron acceptor. By using time-resolved spectroscopic techniques, we are able...
Brownian Dynamics Simulation of Protein Solutions: Structural and Dynamical Properties
Mereghetti, Paolo; Gabdoulline, Razif; Wade, Rebecca C.
2010-12-01
The study of solutions of biomacromolecules provides an important basis for understanding the behavior of many fundamental cellular processes, such as protein folding, self-assembly, biochemical reactions, and signal transduction. Here, we describe a Brownian dynamics simulation procedure and its validation for the study of the dynamic and structural properties of protein solutions. In the model used, the proteins are treated as atomically detailed rigid bodies moving in a continuum solvent. The protein-protein interaction forces are described by the sum of electrostatic interaction, electrostatic desolvation, nonpolar desolvation, and soft-core repulsion terms. The linearized Poisson-Boltzmann equation is solved to compute electrostatic terms. Simulations of homogeneous solutions of three different proteins with varying concentrations, pH, and ionic strength were performed. The results were compared to experimental data and theoretical values in terms of long-time self-diffusion coefficients, second virial coefficients, and structure factors. The results agree with the experimental trends and, in many cases, experimental values are reproduced quantitatively. There are no parameters specific to certain protein types in the interaction model, and hence the model should be applicable to the simulation of the behavior of mixtures of macromolecules in cell-like crowded environments.
Packaging solution for VLSI electronic photonic chips
Lee, Chieh-feng
2007-01-01
As the demand of information capacity grows, the adoption of optical technology will increase. The issue of resistance and capacitance is limiting the electronic transmission bandwidth while fiber optic delivers data at ...
Dynamics around solutes and solutesolvent complexes in mixed solvents
Fayer, Michael D.
Dynamics around solutes and solutesolvent complexes in mixed solvents Kyungwon Kwak, Sungnam Park-IR spectroscopy of the hydroxyl stretch of phenol-OD in three solvents, CCl4, mesitylene (1, 3, 5 trimethyl- benzene), and the mixed solvent of mesitylene and CCl4 (0.83 mole fraction CCl4), are used to study solute-solvent
Efficient electronic structure calculation for molecular ionization dynamics at high x-ray intensity
Hao, Yajiang; Hanasaki, Kota; Son, Sang-Kil; Santra, Robin
2015-01-01
We present the implementation of an electronic-structure approach dedicated to ionization dynamics of molecules interacting with x-ray free-electron laser (XFEL) pulses. In our scheme, molecular orbitals for molecular core-hole states are represented by linear combination of numerical atomic orbitals that are solutions of corresponding atomic core-hole states. We demonstrate that our scheme efficiently calculates all possible multiple-hole configurations of molecules formed during XFEL pulses. The present method is suitable to investigate x-ray multiphoton multiple ionization dynamics and accompanying nuclear dynamics, providing essential information on the chemical dynamics relevant for high-intensity x-ray imaging.
Theoretical examination of picosecond phenol migration dynamics in phenylacetylene solution
Rappe, Andrew M.
Theoretical examination of picosecond phenol migration dynamics in phenylacetylene solution Lucas to simulate 2D-IR echo spectra using Fourier analysis. The resulting dynamics yields a phenol migration time between the two primary binding sites on phenylacetylene of 35 ps in excellent agreement with experiment
Title of Dissertation: LONGITUDINAL DYNAMICS OF AN INTENSE ELECTRON BEAM
Anlage, Steven
ABSTRACT Title of Dissertation: LONGITUDINAL DYNAMICS OF AN INTENSE ELECTRON BEAM John Richardson fusion, spallation neutron sources, free-electron lasers, and other applications. In addition, all beams beams. #12;LONGITUDINAL DYNAMICS OF AN INTENSE ELECTRON BEAM By John Richardson Harris. Dissertation
Electron Dynamics in a Beating Electrostatic Wave Magnetic Null Thruster
Electron dynamics in a beating-electrostatic-wave-powered magnetic null thruster are explored in orderElectron Dynamics in a Beating Electrostatic Wave Magnetic Null Thruster Matthew S. Feldman and Edgar Y. Choueiri Electric Propulsion and Plasma Dynamics Laboratory, Princeton, New Jersey, 08544, USA
A Dynamic Solar Core model: the SSM-like solution
Attila Grandpierre
1998-08-31
I point out that the all the arguments against an astrophysical solution do not exclude a yet not recognised class of solar models, in which an explosive energy source is present in the solar core besides the standard pp and CNO cycle. It is shown from first principle physics that stars have a non-pp,CNO source: local thermonuclear runaways. I derive a model independent inequality, which shows that the problem of the missing beryllium neutrinos lies in that the SuperKamiokande contains a term arising from neutrinos from a runaway source which can produce high-energy electrons and high-energy axions, and muon and tau neutrinos. I point out, that the temperature dependence of the individual neutrino fluxes is related to pure nuclear physics but the usual luminosity constraint is model dependent and actually is a questionable assumption. Allowing non-pp,CNO reaction chains a new approach arises to interpret the neutrino detector data. The explicit temperature dependence leads to $\\Phi_{pp} \\propto T^4$ instead of the usual $\\Phi_{pp} \\propto T^{-1/2}$ for the SSM luminosity constraint. I assume a Sun analogue to the SSM with a different $T_c$. The separate neutrino detector equations lead to separate detector-related temperatures with the neutrino detector data. The results show a slightly lower than standard central temperature. I attempt to show that helioseismology is not in a necessary conflict with the dynamic solar model presented here. The results of the calculations may propose solutions to the problems of solar and atmospheric neutrino oscillations without an ad hoc introduction of sterile neutrinos and present predictions to Borexino and SNO measurements. {\\it PACS numbers}: 26.65+t, 26.30.+k, 96.60Jw, 95.30.Cq
Saha, Asit E-mail: prasantachatterjee1@rediffmail.com; Pal, Nikhil; Chatterjee, Prasanta E-mail: prasantachatterjee1@rediffmail.com
2014-10-15
The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index ? on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.
Repeated Auction Games and Learning Dynamics in Electronic Logistics Marketplaces
Bertini, Robert L.
Repeated Auction Games and Learning Dynamics in Electronic Logistics Marketplaces: Complexity still satisfy the customer's level of service demands. Specifically, this chapter considers the reverse
Chemerisov, Sergey; Gromov, Roman; Makarashvili, Vakho; Heltemes, Thad; Sun, Zaijing; Wardle, Kent E.; Bailey, James; Quigley, Kevin; Stepinski, Dominique; Vandegrift, George
2014-10-01
Argonne is assisting SHINE Medical Technologies in developing SHINE, a system for producing fission-product ^{99}Mo using a D/T-accelerator to produce fission in a non-critical target solution of aqueous uranyl sulfate. We have developed an experimental setup for studying thermal-hydraulics and bubble formation in the uranyl sulfate solution to simulate conditions expected in the SHINE target solution during irradiation. A direct electron beam from the linac accelerator will be used to irradiate a 20 L solution (sector of the solution vessel). Because the solution will undergo radiolytic decomposition, we will be able to study bubble formation and dynamics and effects of convection and temperature on bubble behavior. These experiments will serve as a verification/ validation tool for the thermal-hydraulic model. Utilization of the direct electron beam for irradiation allows homogeneous heating of a large solution volume and simplifies observation of the bubble dynamics simultaneously with thermal-hydraulic data collection, which will complement data collected during operation of the miniSHINE experiment. Irradiation will be conducted using a 30-40 MeV electron beam from the high-power linac accelerator. The total electron-beam power will be 20 kW, which will yield a power density on the order of 1 kW/L. The solution volume will be cooled on the front and back surfaces and central tube to mimic the geometry of the proposed SHINE solution vessel. Also, multiple thermocouples will be inserted into the solution vessel to map thermal profiles. The experimental design is now complete, and installation and testing are in progress.
Linear Boltzmann equation as the long time dynamics of an electron weakly coupled to a phonon eld
Linear Boltzmann equation as the long time dynamics of an electron weakly coupled to a phonon #12 that in the weak coupling limit the Wigner distribution of the electron density matrix converges to the solution of the linear Boltzmann equation globally in time. The collision kernel is identi#12;ed as the sum
FEATURE ARTICLE Femtosecond Dynamics of Electrons Photoinjected into Organic Semiconductors at
Harris, Charles B.
FEATURE ARTICLE Femtosecond Dynamics of Electrons Photoinjected into Organic Semiconductors, 2001 The layer dependent evolution of the unoccupied electronic structure and electron dynamics be assigned as either image potential states or electron affinity (EA) levels, but rather as hybridized EA
Drabold, David
]. The electronic structure calculations are based upon "FIREBALL96" of Sankey and co-workers [7]. Mat. Res. Soc of the electron dynamics of localized edge states in a-Si at room temperature by integrating the time dependent be computed by directly dealing with the electron dynamics from the time- dependent SchrÃ¶dinger equation
Multi-electron dynamics in the tunnel ionization of correlated quantum systems
Hollstein, Maximilian
2015-01-01
The importance of multi-electron dynamics during the tunnel ionization of a correlated quantum system is investigated. By comparison of the solution of the time-dependent Schr\\"odinger equation (TDSE) with the time-dependent configuration interaction singles approach (TDCIS), we demonstrate the importance of a multi-electron description of the tunnel ionization process especially for weakly confined quantum systems. Within this context, we observe that adiabatic driving by an intense light field can even enhance the correlations between still trapped electrons.
The dynamics of polymers in solution with hydrodynamic memory
V. Lisy; J. Tothova; B. Brutovsky; A. V Zatovsky
2005-09-15
The theory of the dynamics of polymers in solution is developed coming from the hydrodynamic theory of the Brownian motion (BM) and the Rouse-Zimm (RZ) model. It is shown that the time correlation functions describing the polymer motion essentially differ from those in the previous RZ models based on the Einstein theory of BM. The MSD of the polymer coil is at short times proportional to t^2 (instead of t). At long times it contains additional (to the Einstein term) contributions, the leading of which is ~ t^{1/2}. The relaxation of the internal normal modes of the polymer differs from the traditional exponential decay. This is displayed in the tails of their correlation functions, the longest-lived being ~ t^{-3/2} in the Rouse limit and t^{-5/2} in the Zimm case when the hydrodynamic interaction is strong. It is discussed that the found peculiarities, in particular a slower diffusion of the coil, should be observable in dynamic scattering experiments. The dynamic structure factor and the first cumulant of the polymer coil are calculated. The theory is extended to the situation when the dynamics of the studied polymer is influenced by the presence of other polymers in dilute solution.
Electronic Structure, Phonon Dynamical Properties, and CO2 Capture...
Office of Scientific and Technical Information (OSTI)
Electronic Structure, Phonon Dynamical Properties, and CO2 Capture Capability of Na2-xMxZrO3 ( MLi ,K): Density-Functional Calculations and Experimental Validations Citation...
Electronic Structure, Phonon Dynamical Properties, and CO2 Capture...
Office of Scientific and Technical Information (OSTI)
Journal Article: Electronic Structure, Phonon Dynamical Properties, and CO2 Capture Capability of Na2-xMxZrO3 ( MLi ,K): Density-Functional Calculations and Experimental...
Electronic Relaxation Dynamics in Coupled Metal Nanoparticles
Scherer, Norbert F.
that takes into account two competing phenomena: electron inelastic surface scattering (ISS), which tends the ultrafast response to optical excitation. For example, they have promise as optical switches and as sources of hot electrons for photoelectrochemical processes, including solar energy conversion or organic waste
Structure and dynamics of aqueous solution of uranyl ions
Chopra, Manish; Choudhury, Niharendu
2014-04-24
The present work describes a molecular dynamics simulation study of structure and dynamics of aqueous solution of uranyl ions in water. Structural properties of the system in terms of radial distribution functions and dynamical characteristics as obtained through velocity autocorrelation function and mean square displacements have been analyzed. The results for radial distribution functions show the oxygen of water to form the first solvation shell at 2.4 Å around the uranium atom, whereas the hydrogen atoms of water are distributed around the uranium atom with the major peak at around 3.0 Å. Analyses of transport behaviors of ions and water through MSD indicates that the diffusion of the uranyl ion is much less as compared to that of the water molecules. It is also observed that the dynamical behavior of water molecules gets modified due to the presence of uranyl ion. The effect of increase in concentration of uranyl ions on the structure and dynamics of water molecules is also studied.
DYNAMIC MODELLING OF LIVING ANIONIC SOLUTION POLYMERIZATION OF STYRENE/BUTADIENE/DIVINYLBENZENE
Schittkowski, Klaus
DYNAMIC MODELLING OF LIVING ANIONIC SOLUTION POLYMERIZATION OF STYRENE/BUTADIENE model for the living anionic solution polymerization of styrene/butadiene/divinylbenzene in a continuous kinetic reactor model for the living anionic solution polymerization of styrene/butadiene
Electron dynamics, gamma and electron-positron production by colliding laser pulses
Jirka, M; Bulanov, S V; Esirkepov, T Zh; Gelfer, E; Bulanov, S S; Weber, S; Korn, G
2015-01-01
The dynamics of an electron bunch irradiated by two focused colliding super-intense laser pulses and the resulting gamma and electron-positron production are studied. Due to attractors of electron dynamics in a standing wave created by colliding pulses the photon emission and pair production, in general, are more efficient with linearly polarized pulses than with circularly polarized ones. The dependence of the key parameters on the laser intensity and wavelength allows to identify the conditions for the cascade development and gamma-electron-positron plasma creation.
Sader, Charles Avery
2015-01-01
Electronic Structure Theory Calculations and Molecular DynamicsElectronic Structure Theory Calculations and Molecular Dynamicsdynamics simulation requires identification of an electronic structure calculation
Molecular Dynamics Simulations of Solutions at Constant Chemical Potential
Perego, Claudio; Parrinello, Michele
2015-01-01
Molecular Dynamics studies of chemical processes in solution are of great value in a wide spectrum of applications, that range from nano-technology to pharmaceutical chemistry. However, these calculations are affected by severe finite-size effects, such as the solution being depleted as the chemical process proceeds, that influence the outcome of the simulations. To overcome these limitations, one must allow the system to exchange molecules with a macroscopic reservoir, thus sampling a Grand-Canonical ensemble. Despite the fact that different remedies have been proposed, this still represents a key challenge in molecular simulations. In the present work we propose the C$\\mu$MD method, which introduces an external force that controls the environment of the chemical process of interest. This external force, drawing molecules from a finite reservoir, maintains the chemical potential constant in the region where the process takes place. We have applied the C$\\mu$MD method to the paradigmatic case of urea crystall...
Molecular dynamics of a dilute solution of hydrogen in palladium
Pratt, L. R.; Eckert, J.
1989-06-15
Molecular-dynamics results on a dilute solution of H in Pd are presentedand compared with available incoherent inelastic neutron-scattering results.The embedded-atom model adopted here does a good job of describing the H-Pdatomic forces probed by incoherent inelastic neutron scattering. The timecorrelation functions associated with the computed spectra are strongly dampedand indicative of the anharmonicity that has been suggested as the principalcontribution to the anomalous isotope dependence of the superconductingtransition temperature in PdH. These results highlight the fact that the H-atomvibrations in Pd-H solutions are low-frequency, large-amplitude vibrationsrelative to vibrations of H atoms in usual covalent interactions. The rmsdisplacement of the H atom from its mean position in the center of the Pdoctahedron compares favorably with the available neutron-diffraction results.
Asymptotic Solution to the Rayleigh Problem of Dynamic Soaring
Bousquet, Gabriel D; Slotine, Jean-Jacques E
2015-01-01
It is believed that albatrosses power their flight through dynamic soaring, a technique where energy is extracted from horizontally blowing shear winds. The Rayleigh model of dynamic soaring, also called the two layer model, makes a 2-dimensional approximation of the wind field and glider trajectory. This note considers the "Rayleigh problem" of finding the minimum wind necessary for the existence of energy neutral gliding cycles. We utilize a 3-degree of freedom glider model with quadratic drag. Asymptotic solutions in the limit of large glide ratios are obtained. The optimal motion is a traveling trajectory constituted of a succession of small partial turns. It is over 50% more efficient at preserving airspeed than full half-turn based trajectories.
Hammes-Schiffer, Sharon
2011-06-16
Proton-coupled electron transfer (PCET) reactions play an important role in a wide range of biological and chemical processes. The motions of the electrons, transferring protons, solute nuclei, and solvent nuclei occur on a wide range of time scales and are often strongly coupled. As a result, the theoretical description of these processes requires a combination of quantum and classical methods. This Perspective discusses three of the current theoretical challenges in the field of PCET. The first challenge is the calculation of electron proton nonadiabatic effects, which are significant for these reactions because the hydrogen tunneling is often faster than the electronic transition. The second challenge is the modeling of electron transfer coupled to proton transport along hydrogen-bonded networks. The third challenge is the simulation of the ultrafast dynamics of nonequilibrium photoinduced PCET reactions in solution. Insights provided by theoretical studies may assist in the design of more effective catalysts for energy conversion processes. The proton relay portion of this review is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.
Dobranskis, R. R.; Zharkova, V. V., E-mail: valentina.zharkova@northumbria.ac.uk [Department of Mathematics and Information Sciences, University of Northumbria, Newcastle upon Tyne NE1 2XP (United Kingdom)
2014-06-10
The original continuity equation (CE) used for the interpretation of the power law energy spectra of beam electrons in flares was written and solved for an electron beam flux while ignoring an additional free term with an electron density. In order to remedy this omission, the original CE for electron flux, considering beam's energy losses in Coulomb collisions, was first differentiated by the two independent variables: depth and energy leading to partial differential equation for an electron beam density instead of flux with the additional free term. The analytical solution of this partial differential continuity equation (PDCE) is obtained by using the method of characteristics. This solution is further used to derive analytical expressions for mean electron spectra for Coulomb collisions and to carry out numeric calculations of hard X-ray (HXR) photon spectra for beams with different parameters. The solutions revealed a significant departure of electron densities at lower energies from the original results derived from the CE for the flux obtained for Coulomb collisions. This departure is caused by the additional exponential term that appeared in the updated solutions for electron differential density leading to its faster decrease at lower energies (below 100 keV) with every precipitation depth similar to the results obtained with numerical Fokker-Planck solutions. The effects of these updated solutions for electron densities on mean electron spectra and HXR photon spectra are also discussed.
Electron Dynamics in Nanostructures in Strong Laser Fields
Kling, Matthias
2014-09-11
The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.
Study of the Electron Beam Dynamics in the FERMI @ ELETTRA Linac
2006-01-01
STUDY OF THE ELECTRON BEAM DYNAMICS IN THE FERMI @ ELETTRAAbstract A study of the electron beam dynamics in the linacused to direct the electron beam into one of two undulator
Electron dynamics in parallel electric and magnetic fields
Christian Bracher; Tobias Kramer; John B. Delos
2005-10-13
We examine the spatial distribution of electrons generated by a fixed energy point source in uniform, parallel electric and magnetic fields. This problem is simple enough to permit analytic quantum and semiclassical solution, and it harbors a rich set of features which find their interpretation in the unusual and interesting properties of the classical motion of the electrons: For instance, the number of interfering trajectories can be adjusted in this system, and the turning surfaces of classical motion contain a complex array of singularities. We perform a comprehensive analysis of both the semiclassical approximation and the quantum solution, and we make predictions that should serve as a guide for future photodetachment experiments.
Simulation of the relativistic electron dynamics and acceleration in a linearly-chirped laser pulse
Jisrawi, Najeh M; Salamin, Yousef I
2014-01-01
Theoretical investigations are presented, and their results are discussed, of the laser acceleration of a single electron by a chirped pulse. Fields of the pulse are modeled by simple plane-wave oscillations and a $\\cos^2$ envelope. The dynamics emerge from analytic and numerical solutions to the relativistic Lorentz-Newton equations of motion of the electron in the fields of the pulse. All simulations have been carried out by independent Mathematica and Python codes, with identical results. Configurations of acceleration from a position of rest as well as from injection, axially and sideways, at initial relativistic speeds are studied.
John A. Parkhill; Thomas Markovich; David G. Tempel; Alan Aspuru-Guzik
2012-10-02
In this work we develop a theory of correlated many-electron dynamics dressed by the presence of a finite-temperature harmonic bath. The theory is based on the ab-initio Hamiltonian, and thus well-defined apart from any phenomenological choice of collective basis states or electronic coupling model. The equation-of-motion includes some bath effects non-perturbatively, and can be used to simulate line- shapes beyond the Markovian approximation and open electronic dynamics which are subjects of renewed recent interest. Energy conversion and transport depend critically on the ratio of electron-electron coupling to bath-electron coupling, which is a fitted parameter if a phenomenological basis of many-electron states is used to develop an electronic equation of motion. Since the present work doesn't appeal to any such basis, it avoids this ambiguity. The new theory produces a level of detail beyond the adiabatic Born-Oppenheimer states, but with cost scaling like the Born-Oppenheimer approach. While developing this model we have also applied the time-convolutionless perturbation theory to correlated molecular excitations for the first time. Resonant response properties are given by the formalism without phenomenological parameters. Example propagations with a developmental code are given demonstrating the treatment of electron-correlation in absorption spectra, vibronic structure, and decay in an open system.
van Stokkum, Ivo
J. Phys. Chem. 1994, 98, 10539-10549 10539 Excited-State Conformational Dynamics of Flexibly and Semirigidly Bridged Electron Donor- Acceptor Systems in Solution. Influence of Temperature and Solvent was either a flexible trimethylene chain or a semirigid piperidine ring. Photoexcitation of the semirigidly
Cammers, Arthur
Kinetic Precipitation of Solution-Phase Polyoxomolybdate Followed by Transmission Electron} keplerate after three days revealed large species (r=20±30 nm) in the co- precipitate, whereas {Mo132
Photocathode Optimization for a Dynamic Transmission Electron Microscope: Final Report
Ellis, P; Flom, Z; Heinselman, K; Nguyen, T; Tung, S; Haskell, R; Reed, B W; LaGrange, T
2011-08-04
The Dynamic Transmission Electron Microscope (DTEM) team at Harvey Mudd College has been sponsored by LLNL to design and build a test setup for optimizing the performance of the DTEM's electron source. Unlike a traditional TEM, the DTEM achieves much faster exposure times by using photoemission from a photocathode to produce electrons for imaging. The DTEM team's work is motivated by the need to improve the coherence and current density of the electron cloud produced by the electron gun in order to increase the image resolution and contrast achievable by DTEM. The photoemission test setup is nearly complete and the team will soon complete baseline tests of electron gun performance. The photoemission laser and high voltage power supply have been repaired; the optics path for relaying the laser to the photocathode has been finalized, assembled, and aligned; the internal setup of the vacuum chamber has been finalized and mostly implemented; and system control, synchronization, and data acquisition has been implemented in LabVIEW. Immediate future work includes determining a consistent alignment procedure to place the laser waist on the photocathode, and taking baseline performance measurements of the tantalum photocathode. Future research will examine the performance of the electron gun as a function of the photoemission laser profile, the photocathode material, and the geometry and voltages of the accelerating and focusing components in the electron gun. This report presents the team's progress and outlines the work that remains.
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
novel silicon graphene composite material that will substantially improve battery cycle life. When combined with other advanced battery materials, it could effectively lower...
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
to recover and reclaim clean water from engines powered by diesel, gasoline or natural gas. Military and commercial applications include transport and stationery power plants,...
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
Laboratory 10147 likes SH Coatings, based in Dallas, Texas, employs Super Hydrophobic Coating (SHC) technology that protects power systems by preventing ice accumulation on power...
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nA Guide toIMPROVEMENT OFBarriersInstitutional changeWebVPNof333 likes
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nA Guide toIMPROVEMENT OFBarriersInstitutional changeWebVPNof333 likes333
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nA Guide toIMPROVEMENT OFBarriersInstitutional changeWebVPNof333 likes333333
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
Broader source: Energy.gov (indexed) [DOE]
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nA Guide toIMPROVEMENT OFBarriersInstitutional changeWebVPNof333
Integrated Dynamic Electron Solutions, Inc. | Department of Energy
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergy HeadquartersFuelBConservationEnergy5975-01 REPORT ONInstitutionalIntegrated2011
Study of the nanobubble phase of aqueous NaCl solutions by dynamic light scattering
Bunkin, N F; Shkirin, A V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Burkhanov, I S; Chaikov, L L [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Lomkova, A K [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation)
2014-11-30
Aqueous NaCl solutions with different concentrations have been investigated by dynamic scattering of laser radiation. It is experimentally shown that these solutions contain scattering particles with a wide size distribution in a range of ?10 – 100 nm. The experimental results indirectly confirm the existence of quasi-stable gas nanobubbles in the bulk of aqueous ionic solutions. (light scattering)
Quantum Chemical Analysis of the Excited State Dynamics of Hydrated Electrons
P. O. J. Scherer; Sighart F. Fischer
2006-02-01
Quantum calculations are performed for an anion water cluster representing the first hydration shell of the solvated electron in solution. The absorption spectra from the ground state, the instant excited states and the relaxed excited states are calculated including CI-SD interactions. Analytic expressions for the nonadiabatic relaxation are presented. It is shown that the 50fs dynamics recently observed after s->p excitation is best accounted for if it is identified with the internal conversion, preceded by an adiabatic relaxation within the excited p state. In addition, transient absorptions found in the infrared are qualitatively reproduced by these calculations .
Hydrogen bond dynamics in aqueous NaBr solutions Sungnam Park
Fayer, Michael D.
Hydrogen bond dynamics in aqueous NaBr solutions Sungnam Park and M. D. FayerÂ§ Department. D. Fayer, August 19, 2007 (sent for review July 27, 2007) Hydrogen bond dynamics of water in Na pumpÂprobe experiments. The hydrogen bond structural dynamics are observed by measuring spectral
Alexander Studenikin
2008-04-09
We present quite a powerful method in investigations of different phenomena that can appear when neutrinos and electrons propagate in background matter. This method implies use of exact solutions of modified Dirac equations that contain the correspondent effective potentials accounting for the matter influence on particles. For several particular cases the exact solutions of modified Dirac and Dirac-Pauli equations for a neutrino and an electron in the background environment of different composition are obtained (the case of magnetized matter is also considered). Neutrino reflection, trapping, neutrino pair creation and annihilation in matter and neutrino energy quantization in a rotating medium are discussed. The neutrino Green functions in matter are also derived. The two recently proposed mechanisms of electromagnetic radiation by a neutrino and an electron in matter (the spin light of neutrino and electron, $SL\
Self-Interacting Electron as a Nonlinear Dynamical System
Vladimir A. Manasson
2006-09-15
We have proposed a simple one-dimensional model of internal particle dynamics. The model is based on the assumption that self-interaction can be represented by a nonlinear feedback and described by a quadratic recurrent map. Charge plays the role of a generalized dynamical variable and a feedback coupling parameter. The model suggests that charge and action quantization stem from the system's dissipative quality and from a hierarchy of supercycle orbits located between period-doubling bifurcations on the Feigenbaum tree. Among the numerical results, we have discovered a link between the quantum of action and the elementary charge. We also found that the fine structure constant can with a good accuracy be expressed exclusively through mathematical constants, including the Feigenbaum delta. We have introduced dimensionless numbers that describe the relative role of the internal particle dynamics when both internal and external dynamics are taken into consideration. We have found these numbers to be close to the electron, proton, and neutron g-factors known from the experiment.
Frequency dependent dynamical electromechanical response of mixed ionic-electronic conductors
Chen, Long-Qing
Frequency dependent dynamical electromechanical response of mixed ionic-electronic conductors A. N dependent dynamical electromechanical response of mixed ionic-electronic conductors A. N. Morozovska,1,a) E online 9 January 2012) Frequency dependent dynamic electromechanical response of the mixed ionic
Zhigilei, Leonid V.
Brine Rejection from Freezing Salt Solutions: A Molecular Dynamics Study Lubos Vrbka and Pavel process of brine rejection from freezing salt solutions is investigated with atomic resolution using. The presence of salt slows down the freezing process, which leads to the formation of an almost neat ice next
U31: Vehicle Stability and Dynamics: Electronic Stability Control
Petrolino, Joseph; Spezia, Tony; Arant, Michael; Delorenzis, Damon; LaClair, Tim J; Lim, Alvin; Pape, Doug
2011-01-01
A team led by NTRCI is working to improve the roll and yaw stability of heavy duty combination trucks through developing stability algorithms, assembling demonstration hardware, and investigating robust wireless communication. Modern electronic stability control (ESC) products automatically slow a vehicle rounding a corner too quickly or apply individual brakes when necessary to improve the steering characteristics of a vehicle. Air brake systems in North America provide no electronic communication between a tractor and semitrailer, limiting the degree to which control systems can be optimized. Prior research has demonstrated stability improvements where dynamic measurements and control commands are communicated between units of a vehicle. Three related activities were undertaken: (1) Develop an algorithm for the optimum yaw and roll control of a combination vehicle. Vehicle state parameters needed to control the vehicle and the proper brake response were determined. An integrated stability control for the tractor and semitrailer requires communication between the two units. Dynamic models were used to assess the algorithm. (2) Implement the ESC algorithm in the laboratory. Hardware components suitable for the harsh environment for measurement, sensor-to-controller communication, and semitrailer-to-tractor communication and brake actuation were specified and assembled as a working system. The goal was to collect the needed vehicle state information, transmit the information to the ESC system, and then actuate the brakes in response to controller commands. (3) Develop a wireless network with the data rate and reliability necessary to communicate dynamic signals for a vehicle stability control system. Adaptive connectivity-aware, multi-hop routing was selected because it can perform in the harsh environment where packet collisions and fading often will exist. The protocol is to give high priority to urgent messages.
Orientational and Translational Dynamics of Polyether/Water Solutions Adam L. Sturlaugson,
Fayer, Michael D.
solvency.3 Applications of PEO include polymer electrolyte membranes and gels,46 ion chromatogra- phy,7Orientational and Translational Dynamics of Polyether/Water Solutions Adam L. Sturlaugson, Kendall is changed. In contrast to the rotational dynamics, the translational diffusion data show a distinct
Collective Dynamics and Coherent Diagnostics of Microbunched Relativistic Electron Beams
Marinelli, Agostino
2012-01-01
Brightness Relativistic Electron Beams for Free-Electrona Thermal Relativistic Electron Beam: Eigenvalue/Eigenmodemicrobunching in the electron beam. The microbunched
Collective Dynamics and Coherent Diagnostics of Microbunched Relativistic Electron Beams
Marinelli, Agostino
2012-01-01
in the diagnostic of compressed electron beams and free-imaging and diagnostics of high-brightness electron beamsfor the diagnostics of compressed electron beams, such as
Matyushov, Dmitry
Effects of Solvent and Solute Polarizability on the Reorganization Energy of Electron Transfer of the effect of solute and solvent polarizability on the solvent reorganization energy of intramolecular electron transfer. In the first set of simulations, the polarizability of the solvent is varied at constant
Dynamical thickening transition in plate coating with concentrated surfactant solutions
Jérôme Delacotte; Lorraine Montel; Frédéric Restagno; Benoît Scheid; Benjamin Dollet; Howard A. Stone; Dominique Langevin; Emmanuelle Rio
2011-06-10
We present a large range of experimental data concerning the influence of surfactants on the well-known Landau-Levich-Derjaguin experiment where a liquid film is generated by pulling a solid plate out of a bath. The thickness h of the film was measured as a function of the pulling velocity V for different kind of surfactant and at various concentrations. Measuring the thickening factor $\\alpha=h/h_{LLD}$, where hLLD is obtained for a pure liquid, in a wide range of capillary ($Ca=\\eta V/\\gamma$), two regimes of constant thickening can be identified: at small capillary number, $\\alpha$ is large due to a confinement and surface elasticity (or Marangoni) effects and at large Ca, $\\alpha$ is slightly higher than unity, due to surface viscous effects. At intermediate Ca, $\\alpha$ decreases as Ca increases along a "dynamic transition". In the case of non-ionic surfactants, the dynamic transition occurs at a fixed Ca, independently of the surfactant concentration, while for ionic surfactants, the dynamic transition depends on the concentration due to the existence of an electrostatic barrier. The control of physico-chemical parameters allowed us to elucidate the nature of the dynamic transition and to relate it to surface rheology.
Transverse dynamics of a relativistic electron beam in an underdense plasma channel
Transverse dynamics of a relativistic electron beam in an underdense plasma channel Andrew A electron beam in a plasma less dense than the beam is analyzed, with particular attention to the electronV electron beam in a 1.5 m plasma cell, with the amplification of beam-centroid offsets on the order of 100
Dunin-Borkowski, Rafal E.
Dynamic studies of catalysts for biofuel synthesis in an Environmental Transmission Electron@cen.dtu.dk Keywords: Biofuel, catalysis, environmental TEM The development of transportation fuels from sustainable
Egorov, E. N. Koronovskii, A. A.; Kurkin, S. A.; Hramov, A. E.
2013-11-15
Results of numerical simulations and analysis of the formation and nonlinear dynamics of the squeezed state of a helical electron beam in a vircator with a magnetron injection gun as an electron source and with additional electron deceleration are presented. The ranges of control parameters where the squeezed state can form in such a system are revealed, and specific features of the system dynamics are analyzed. It is shown that the formation of a squeezed state of a nonrelativistic helical electron beam in a system with electron deceleration is accompanied by low-frequency longitudinal dynamics of the space charge.
Keinan, Ehud
). The sample solution was sonicated in the absence of uranyl acetate. Figure 2. Electron micrograph of didodecyldimethylammonium bromide vesicles. (240 000 X). The sample solution was sonicated in the presence of uranyl acetate solution of didode- cyldimethylammonium bromide was mixed with an equal amount of the uranyl acetate
Diffusion Dynamics of Water Molecules in a LiCl Solution: a Low-Temperature Crossover
Mamontov, Eugene [ORNL
2009-01-01
A quasielastic neutron scattering experiment probing the dynamics of water molecules on the pico- to nanosecond time scale in an aqueous solution of lithium chloride has detected a crossover at about 220-230 K between the high-temperature non-Arrhenius and low-temperature Arrhenius behavior. This is the first experiment where the crossover in the dynamics of water molecules is detected in bulk rather than in confinement. The results suggest that the dynamic crossover observed in the current and many recent experiments is not linked to the specific properties of water; instead, it may represent a more general dynamic transition.
Hammes-Schiffer, Sharon
Model Proton-Coupled Electron Transfer Reactions in Solution: Predictions of Rates, Mechanisms isotope effects for proton-coupled electron transfer (PCET) reactions. These studies are based, the solvent is represented as a dielectric continuum, and the active electrons and transferring protons
Electron beam simulation from gun to collector: Towards a complete solution
Mertzig, R. Shornikov, A. Wenander, F.; Beebe, E.; Pikin, A.
2015-01-09
An electron-beam simulation technique for high-resolution complete EBIS/T modelling is presented. The technique was benchmarked on the high compression HEC{sup 2} test-stand with an electron beam current, current density and energy of 10 A, 10 kA/cm{sup 2} and 49.2 keV, and on the immersed electron beam at REXEBIS for electron beam characteristics of 0.4 A, 200 A/cm{sup 2} and 4.5 keV. In both Brillouin-like and immersed beams the electron-beam radius varies from several millimeters at the gun, through some hundreds of micrometers in the ionization region to a few centimeters at the collector over a total length of several meters. We report on our approach for finding optimal meshing parameters, based on the local beam properties such as magnetic field-strength, electron energy and beam radius. This approach combined with dividing the problem domain into sub-domains, and subsequent splicing of the local solutions allowed us to simulate the beam propagation in EBISes from the gun to the collector using a conventional PC in about 24–36 h. Brillouin-like electron beams propagated through the complete EBIS were used to analyze the beam behavior within the collector region. We checked whether elastically reflected paraxial electrons from a Brillouin-like beam will escape from the collector region and add to the loss current. We have also studied the power deposition profiles as function of applied potentials using two electrode geometries for a Brillouin-like beam including the effects of backscattered electrons.
Matyushov, Dmitry
Dynamical Arrest of Electron Transfer in Liquid Crystalline Solvents Vitaliy Kapko and Dmitry V Form: May 3, 2006 We argue that electron transfer reactions in slowly relaxing solvents proceed in the nonergodic regime, making the reaction activation barrier strongly dependent on the solvent dynamics
Dynamics of excess electrons in atomic and molecular clusters
Young, Ryan Michael
2011-01-01
A. V. Davis et al. , J. Electron Spec. 108, 203 (2000). O.and M. Anbar, The Hydrated Electron (Wiley-Interscience, Newand M. Anbar, The Hydrated Electron (Wiley-Interscience, New
2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003
Elliot Bernstein
2004-09-10
The Gordon Research Conference (GRC) on 2003 Electronic Spectroscopy and Dynamics - July 6-11, 2003 was held at Bates College, Lewiston, Maine, July 6-11, 2003. The Conference was well-attended with 103 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, ''free time'' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.
von der Linde, D.
Ultrafast dynamics of nonequilibrium electrons in metals under femtosecond laser irradiation B with an ultrashort laser pulse leads to a disturbance of the free-electron gas out of thermal equilibrium. We investigate theoretically the transient evolution of the distribution function of the electron gas in a metal
Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love
Devoret, Michel H.
.4 Tunneling Rates in the single Electron Trap . . . . . . . . . . . . . . . . . . . . . . . 49 5 CotunnellingAbstract Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love 2007 This thesis presents measurements of time resolved single electron tunneling events in a metallic thin film
Structure of Earth's outer radiation belt inferred from long-term electron flux dynamics
Vassiliadis, Dimitrios
mapped the radiation-belt structure by quantifying the electron flux variability over the entire radialStructure of Earth's outer radiation belt inferred from long-term electron flux dynamics D September 2003; published 15 October 2003. [1] We map the spatial structure of the electron belts over
Jony
Qurz 2 SOLUTIONS, SECTION ALL. (10 pts.) Find the length of the curve. Solution. Using the formula for the arclength, of a curve onthe interval [0, 2],. 0. (5 pts.) ...
Fayer, Michael D.
Dynamics of Hemoglobin in Human Erythrocytes and in Solution: Influence of Viscosity Studied by Ultrafast Vibrational Echo Experiments Brian L. McClain, Ilya J. Finkelstein, and M. D. Fayer* Contribution experiments are used to measure the vibrational dephasing of the CO stretching mode of hemoglobin-CO (Hb
Water Dynamics in Salt Solutions Studied with Ultrafast Two-Dimensional Infrared (2D IR)
Fayer, Michael D.
Water Dynamics in Salt Solutions Studied with Ultrafast Two-Dimensional Infrared (2D IR. Many of these species are charged. In the ocean, water interacts with dissolved salts. In biological systems, water interacts with dissolved salts as well as charged amino acids, the zwitterionic head groups
Huang, Jianbin
Salt Effect on Microstructures in Cationic Gemini Surfactant Solutions as Studied by Dynamic Light, C12C12C12(Et) underwent a typical "ordinary-to-extraordinary (o-e) transition" with decreasing salt concentration to zero. At higher salt concentration, a single relaxation mode, corresponding to the diffusion
Business Commitments for Dynamic E-business Solution Management: Concept and Specification
Li, Haifei
BPCL (Business Process Commitment Language) has been proposed to declaratively model the relationshipsBusiness Commitments for Dynamic E-business Solution Management: Concept and Specification Haifei 134 Yorktown Heights, NY 10598, USA ABSTRACT Nowadays, enterprises have treated e-business
Electron beam dynamics for the ISIS bremsstrahlung beam generation system
Block, Robert E. (Robert Edward)
2011-01-01
An electron beam transport system was designed for use in the Bremsstrahlung Beam Generation System of the Integrated Stand-off Inspection System (ISIS). The purpose of this electron transport system was to provide for ...
Electronic and Magnetization Dynamics of Cobalt Substituted Iron Oxide Nanocrystals
Chen, Tai-Yen
2011-02-22
Knowledge of energy dissipation and relaxation in electron, spin, and lattice degrees of freedom is of fundamental importance from both a technological and scientific point of view. In this dissertation, the electronic and ...
Probing Electron Dynamics with the Laplacian of the Momentum Density
Sukumar, N.; MacDougall, Preston J.; Levit, M. Creon
2012-09-24
This chapter in the above-titled monograph presents topological analysis of the Laplacian of the electron momentum density in organic molecules. It relates topological features in this distribution to chemical and physical properties, particularly aromaticity and electron transport.
Molecular dynamics study of salt–solution interface: Solubility and surface charge of salt in water
Kobayashi, Kazuya; Liang, Yunfeng E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Matsuoka, Toshifumi E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Sakka, Tetsuo
2014-04-14
The NaCl salt–solution interface often serves as an example of an uncharged surface. However, recent laser-Doppler electrophoresis has shown some evidence that the NaCl crystal is positively charged in its saturated solution. Using molecular dynamics (MD) simulations, we have investigated the NaCl salt–solution interface system, and calculated the solubility of the salt using the direct method and free energy calculations, which are kinetic and thermodynamic approaches, respectively. The direct method calculation uses a salt–solution combined system. When the system is equilibrated, the concentration in the solution area is the solubility. In the free energy calculation, we separately calculate the chemical potential of NaCl in two systems, the solid and the solution, using thermodynamic integration with MD simulations. When the chemical potential of NaCl in the solution phase is equal to the chemical potential of the solid phase, the concentration of the solution system is the solubility. The advantage of using two different methods is that the computational methods can be mutually verified. We found that a relatively good estimate of the solubility of the system can be obtained through comparison of the two methods. Furthermore, we found using microsecond time-scale MD simulations that the positively charged NaCl surface was induced by a combination of a sodium-rich surface and the orientation of the interfacial water molecules.
Ultrafast Electron Dynamics at Alkali/Ice Structures
Wolf, Martin
trapping sites, i.e. at local potential minima, are formed. Photoinjection of excess electrons into these alkali-ion covered amorphous ice layers, results in the trapping of a solvated electron at an alkali, i.e. pump-probe time delay, the electron transfer is mediated by tunneling through a potential
High Resolution Simulation of Beam Dynamics in Electron Linacs for Free Electron Lasers
Ryne, R.D.; Venturini, M.; Zholents, A.A.; Qiang, J.
2009-01-05
In this paper we report on large scale multi-physics simulation of beam dynamics in electron linacs for next generation free electron lasers (FELs). We describe key features of a parallel macroparticle simulation code including three-dimensional (3D) space-charge effects, short-range structure wake fields, longitudinal coherent synchrotron radiation (CSR) wake fields, and treatment of radiofrequency (RF) accelerating cavities using maps obtained from axial field profiles. A macroparticle up-sampling scheme is described that reduces the shot noise from an initial distribution with a smaller number of macroparticles while maintaining the global properties of the original distribution. We present a study of the microbunching instability which is a critical issue for future FELs due to its impact on beam quality at the end of the linac. Using parameters of a planned FEL linac at Lawrence Berkeley National Laboratory (LBNL), we show that a large number of macroparticles (beyond 100 million) is needed to control numerical shot noise that drives the microbunching instability. We also explore the effect of the longitudinal grid on simulation results. We show that acceptable results are obtained with around 2048 longitudinal grid points, and we discuss this in view of the spectral growth rate predicted from linear theory. As an application, we present results from simulations using one billion macroparticles of the FEL linac under design at LBNL. We show that the final uncorrelated energy spread of the beam depends not only on the initial uncorrelated energy spread but also depends strongly on the shape of the initial current profile. By using a parabolic initial current profile, 5 keV initial uncorrelated energy spread at 40 MeV injection energy, and improved linac design, those simulations demonstrate that a reasonable beam quality can be achieved at the end of the linac, with the final distribution having about 100 keV energy spread, 2.4 GeV energy, and 1.2 kA peak current.
Aeschlimann, Martin
relaxation dynamics is played by the electronic structure of the system close to the Fermi level. For exampleExcited electron dynamics in bulk ytterbium: Time-resolved two-photon photoemission and GW+T ab November 2007 The excited electron dynamics in ytterbium is investigated by means of the time-resolved two
Small Polaron Hopping in LixFePO4 Solid Solutions: Coupled Lithium-Ion and Electron Mobility
Ryan, Dominic
Small Polaron Hopping in LixFePO4 Solid Solutions: Coupled Lithium-Ion and Electron Mobility Brian recognized as very promising electrodes for lithium-ion batteries because of their energy storage capacity the factors governing electron and ion transport within the lattice. Lithium extraction from LiFePO4 results
Turner, Daniel B.
We use fifth-order two-dimensional electronic spectroscopy to measure coherent four-particle dynamics in a semiconductor nanostructure. By using optical polarization control in two-quantum measurements enabled by the COLBERT ...
Single-Particle Dynamics in Electron Storage Rings with Extremely...
Office of Scientific and Technical Information (OSTI)
order of reduction is expected. This requirement of ultra-low emittance presents many design challenges in beam dynamics, including better analysis of maps and improvement of...
Pan, Heng
2009-01-01
Electronics and Photovoltaics by Heng Pan A dissertationcost Electronics and Photovoltaics Copyright © 2009 By HengLow-cost Electronics and Photovoltaics by Heng Pan Doctor of
Pan, Heng
2009-01-01
Fig. 1. 1 Flexible electronics and flexible solar cells. Inof metal oxide based electronics on heat sensitive flexibleNanoparticles for Low-cost Electronics and Photovoltaics by
Roland Cristopher F. Caballar; Eric A. Galapon
2010-05-14
We address the multiplicity of solutions to the time-energy canonical commutation relation for a given Hamiltonian. Specifically, we consider a particle spatially confined in a potential free interval, where it is known that two distinct self-adjoint and compact time operators conjugate to the system Hamiltonian exist. The dynamics of the eigenvectors of these operators indicate that different time operators posses distinguishing properties that can unambiguously associate them to specific aspects of the quantum time problem.
Dynamical Mechanism of Two-Dimensional Plasmon Launching by Swift Electrons
Xiao Lin; Xihang Shi; Fei Gao; Ido Kaminer; Zhaoju Yang; Zhen Gao; Hrvoje Buljan; John D. Joannopoulos; Marin Solja?i?; Hongsheng Chen; Baile Zhang
2015-07-30
Launching of surface plasmons by swift electrons has long been utilized to investigate plasmonic properties of ultrathin, or two-dimensional (2D), electron systems, including graphene plasmons recently. However, spatio-temporal dynamics of this process has never been clearly revealed. This is because the impact of an electron will generate not only plasmons, but also photons, demanding both space and time. Here we address this issue within the framework of classical electromagnetics by showing the dynamical process of 2D plasmon launching by swift electrons on graphene. The launching of 2D plasmons on graphene is not immediate, but is delayed after a hydrodynamic splashing-like process, which occurs during the formation time of transition radiation caused by the electron's impact. This newly revealed process also implies that all previous estimates on the yields of graphene plasmons in electron-energy-loss-spectroscopy have been overestimated.
Dynamic Nuclear Polarization with Single Electron Spins J. R. Petta,1,2
Yacoby, Amir
Dynamic Nuclear Polarization with Single Electron Spins J. R. Petta,1,2 J. M. Taylor,1,3 A. C Barbara, California 93106, USA (Received 6 September 2007; published 11 February 2008) We polarize nuclear'' an electron spin and ``flopping'' a nuclear spin. The resulting Overhauser field approaches 80 m
PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal
Goddard III, William A.
2012-01-01
PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal Patrick L-dynamics simulations of the single shock Hugoniot are reported for a crystalline polyethylene (PE) model. The e. INTRODUCTION The material response of polyethylene (PE) to shock and its behavior in the warm dense matter (WDM
Southern California, University of
Electronic processes in fast thermite chemical reactions: A first-principles molecular dynamics composites. We have investigated the thermite reaction of Fe2O3 with aluminum by molecular dynamics as thermite reaction, is widely utilized in the synthesis and processing of materials 1 . In addition
2015-02-09
Tank Mania! (1) Consider a 200 liter tank used to hold a dye solution with a concentration of 1g/liter. The tank needs to be rinsed with fresh water flowing in a
Jony
2011-09-04
Quiz 2, Section 11. P1. Find the cosine of the angle between the vectors bbb. AB and bbb. AC, where A = (2,b1,3), B = (1,1,2),. C = (3,1,0). Solution: First, we ...
2011-09-09
Solution: We're looking for the presale cost of the shirt, so let x be the price of ... The sale price is $10 and we've called the presale price x, so we need to solve.
Sutter, Eli A.; Sutter, Peter W.
2014-11-19
In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?_{aq} created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?_{aq} generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?_{aq}]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?_{aq}] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Sutter, Eli A.; Sutter, Peter W.
2014-11-19
In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pdmore »deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.« less
Correlated electron dynamics with time-dependent quantum Monte...
Office of Scientific and Technical Information (OSTI)
Our results for the dipole response and the ionization of an atom with un-correlated electrons are in good agreement with the predictions of the conventional time-dependent...
Monopole and topological electron dynamics in adiabatic spintronic and graphene systems
Tan, S.G.; Jalil, M.B.A.; Fujita, T.
2010-08-15
A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin's fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.
Monopole and Topological Electron Dynamics in Adiabatic Spintronic and Graphene Systems
S. G. Tan; M. B. A. Jalil; Takashi Fujita
2009-01-22
A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.
Ultrafast optical studies of electronic dynamics in semiconductors
Ruzicka, Brian Andrew
2012-05-31
The dynamics of charge carriers in semiconductors are of fundamental importance for semiconductor applications. This includes studies of energy relaxation, carrier recombination, and carrier transport (both diffusive and ballistic). Due...
Dynamics of Solvated Electrons in Clusters Ryan M. Young,
Neumark, Daniel M.
in Water-Based Cluster Anions 5561 3.3. Dynamics in Halide-Water Clusters 5563 4. Methanol 5564 5. Ammonia 5567 6. Acetonitrile and Primary Amides 5568 7. Benzene, Toluene, and Other Aromatic Solvents 5571 8
Jony
sz 6, SECTION 171, T 2:30 PM. P1. Find the points in the cone 22 = x2 + y2 that are closest to the point (4, 2, 0). Solution 1: First, we note that given the point (4, ...
Phase-space dynamics of runaway electrons in tokamaks Xiaoyin Guan, Hong Qin, and Nathaniel J. Fisch
Phase-space dynamics of runaway electrons in tokamaks Xiaoyin Guan, Hong Qin, and Nathaniel J of runaway electrons is studied, including the influence of loop voltage, radiation damping, and collisions to simulate the long-term dynamics of a runaway electron. The variational symplectic integrator is able
Chu, Shih-I
and structures PACS 85.65.+h Molecular electronic devices PACS 71.15.Pd Molecular dynamics calculations (Carr for electron transport dynamics in molecular devices Zhongyuan Zhou(a) and Shih-I Chu Department of Chemistry. The electron wave function is calculated by solving this equation in a finite P-space volume. This approach
Heatherman, William Joseph
2008-01-01
dynamic" solutions: the UNET-based solver in HEC-RAS and the National Weather Service's FLDWAV program. The four models were tested on four natural streams in northeastern Kansas. Detailed procedures for creating "equivalent reaches" were developed...
Pan, Heng
2009-01-01
etc. Fig. 1. 1 Flexible electronics and flexible solarFig. 3.3 Fig. 3.4 Flexible electronics and flexible solarEnergy Harvesting Devices Flexible electronics refers to the
Osterloh, Frank
Calcium niobate nanosheets as a novel electron transport material for solution-processed multi-junction polymer solar cells Lilian Chang,a Michael A. Holmes,b Mollie Waller,b Frank E. Osterlohb and Adam J-processed tandem polymer solar cells are demonstrated using stacked perovskite, (TBA,H) Ca2Nb3O10 (CNO
Influence of different focusing solutions for the TESLA X-ray FEL's on debunching of the electron), Notkestr. 85, 22607 Hamburg, Germany Abstract For SASE-FELs the total undulator length increases different types of focusing for the TESLA X-ray FEL parameters will be discussed. 1. Introduction The TESLA
Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser wakefield
Umstadter, Donald
Detailed dynamics of electron beams self-trapped and accelerated in a self-modulated laser 1999 The electron beam generated in a self-modulated laser-wakefield accelerator is characterized, was measured for 2 MeV electrons. The electron beam was observed to have a multicomponent beam profile
Dynamic Void Growth and Shrinkage in Mg under Electron Irradiation
Xu, W. Z. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering; Zhang, Y. F. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cheng, G. M. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering; Jian, W. W. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering; Millett, P. C. [Univ. of Arkansas, Fayetteville, AR (United States). Dept. of Mecanical Engineering; Koch, C. C. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering; Mathaudhu, S. N. [U.S. Army Research Office, Research Triangle Park, NC (United States). Materials Science Division; Zhu, Y. T. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering
2014-04-30
We report in-situ atomic-scale investigation of void evolution, including growth, coalescence and shrinkage, under electron irradiation. With increasing irradiation dose, the total volume of voids increased linearly, while nucleation rate of new voids decreased slightly, and the total number of voids decreased. Some voids continued to grow while others shrank to disappear, depending on the nature of their interactions with nearby self-interstitial loops. For the first time, surface diffusion of adatoms was observed largely responsible for the void coalescence and thickening. These findings provide fundamental understanding to help with the design and modeling of irradiation-resistant materials.
Large dynamic range diagnostics for high current electron LINACs
Evtushenko, Pavel [JLAB
2013-11-01
The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.
Large dynamic range diagnostics for high current electron LINACs
Evtushenko, P., E-mail: Pavel.Evtushenko@jlab.org [Thomas Jefferson National Accelerator Facility 12000 Jefferson Avenue, Newport News, VA 23606 (United States)
2013-11-07
The Jefferson Lab FEL driver accelerator - Energy Recovery Linac has provided a beam with average current of up to 9 mA and beam energy of 135 MeV. The high power beam operations have allowed developing and testing methods and approaches required to set up and tune such a facility simultaneously for the high beam power and high beam quality required for high performance FEL operations. In this contribution we briefly review this experience and outline problems that are specific to high current - high power non-equilibrium linac beams. While the original strategy for beam diagnostics and tuning have proven to be quite successful, some shortcomings and unresolved issues were also observed. The most important issues are the non-equilibrium (non-Gaussian) nature of the linac beam and the presence of small intensity - large amplitude fraction of the beam a.k.a. beam halo. Thus we also present a list of the possible beam halo sources and discuss possible mitigations means. We argue that for proper understanding and management of the beam halo large dynamic range (>10{sup 6}) transverse and longitudinal beam diagnostics can be used. We also present results of transverse beam profile measurements with the dynamic range approaching 10{sup 5} and demonstrate the effect the increased dynamic range has on the beam characterization, i.e., emittance and Twiss parameters measurements. We also discuss near future work planned in this field and where the JLab FEL facility will be used for beam tests of the developed of new diagnostics.
2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012
Kohler, Bern
2012-07-27
Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.
Electronic power conditioning for dynamic power conversion in high-power space systems
Hansen, James Michael
1991-01-01
power conversion allows for improved methods of power conditioning. A block diagram of one such system that uses dynamic power conversion is shown in Fig. 4. The blocks labeled Energy Source, Primary Heat Rejection, snd User's Load are the same...ELECTRONIC POWER CONDITIONING FOR DYNAMIC POWER CONVERSION IN HIGH ? POWER SPACE SYSTEMS A Thesis by JAMES MICHAEL HANSEN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...
Photodissociation and photoisomerization dynamics of CH{sub 2}=CHCHO in solution
Wu Weiqiang; Yang Chunfan; Zhao Hongmei; Liu Kunhui; Su Hongmei
2010-03-28
By means of time-resolved Fourier transform infrared absorption spectroscopy, we have investigated the 193 nm photodissociation and photoisomerization dynamics of the prototype molecule of {alpha},{beta}-enones, acrolein (CH{sub 2}=CHCHO) in CH{sub 3}CN solution. The primary photolysis channels and absolute branching ratios are determined. The most probable reaction mechanisms are clarified by control experiments monitoring the product yields varied with the triplet quencher addition. The predominant channel is the 1,3-H migration yielding the rearrangement product CH{sub 3}CH=C=O with a branching ratio of 0.78 and the less important channel is the {alpha} cleavage of C-H bond yielding radical fragments CH{sub 2}=CHCO+H with a branching ratio of only 0.12. The 1,3-H migration is strongly suggested to correlate with the triplet {sup 3}({pi}{pi}{sup *}) state rather than the ground S{sub 0} state and the {alpha} cleavage of C-H bond is more likely to proceed in the singlet S{sub 1} {sup 1}(n{pi}{sup *}) state. From the solution experiments we have not only acquired clues clarifying the previous controversial mechanisms, but also explored different photochemistry in solution. Compared to the gas phase photolysis which is dominated by photodissociation channels, the most important channel in solution is the photoisomerization of 1,3-H migration. The reason leading to the different photochemistry in solution is further ascribed to the solvent cage effect.
V. N. Zirakashvili; F. Aharonian
2007-10-26
%context {Recent observations of hard X-rays and very high energy gamma-rays from a number of young shell type supernova remnants indicate the importance of detailed quantitative studies of energy spectra of relativistic electrons formed via diffusive shock acceleration accompanied by intense nonthermal emission through synchrotron radiation and inverse Compton scattering.} %aim {The aim of this work was derivation of exact asymptotic solutions of the kinetic equation which describes the energy distribution of shock-accelerated electrons for an arbitrary energy-dependence of the diffusion coefficient.} %method {The asymptotic solutions at low and very high energy domains coupled with numerical calculations in the intermediate energy range allow analytical presentations of energy spectra of electrons for the entire energy region.} %results {Under the assumption that the energy losses of electrons are dominated by synchrotron cooling, we derived the exact asymptotic spectra of electrons without any restriction on the diffusion coefficient. We also obtained simple analytical approximations which describe, with accuracy better than ten percent, the energy spectra of nonthermal emission of shock-accelerated electrons due to the synchrotron radiation and inverse Compton scattering.} %conclusions {The results can be applied for interpretation of X-ray and gamma-ray observations of shell type supernova remnants, as well as other nonthermal high energy source populations like microquasars and large scale synchrotron jets of active galactic nuclei.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Xue, Guobiao; Xin, Huolin L.; Wu, Jiake; Fan, Congcheng; Liu, Shuang; Huang, Zhuoting; Liu, Yujing; Shan, Bowen; Miao, Qian; Chen, Hongzheng; et al
2015-10-29
Enhancing electron transport to match with the development in hole transport is critical for organic electronics in the future. As electron motion is susceptible to extrinsic factors, seeking these factors and avoiding their negative effects have become the central challenge. Here, the existence of polar solvent residues in solution-grown single-crystals of 6,13-bis(triisopropylsilylethynyl)-5,7,12,14-tetraazapentacene is identified as a factor detrimental to electron motion. Field-effect transistors of the crystals exhibit electron mobility boosted by about 60% after the residues are removed. The average electron mobility reaches up to 8.0 ± 2.2 cm2 V–1 s–1 with a highest value of 13.3 cm2 V–1 s–1;more »these results are significantly higher than those obtained previously for the same molecule (1.0–5.0 cm2 V–1 s–1). Furthermore, the achieved mobility is also higher than the maximum reported electron mobility for organic materials (11 cm2 V–1 s–1). As a result, this work should greatly accelerate the advancement of organic electron-transporting materials.« less
Figueroa, C.; Brizuela, H.; Heluani, S. P.
2014-05-21
The backscattering coefficient is a magnitude whose measurement is fundamental for the characterization of materials with techniques that make use of particle beams and particularly when performing microanalysis. In this work, we report the results of an analytic method to calculate the backscattering and absorption coefficients of electrons in similar conditions to those of electron probe microanalysis. Starting on a five level states ladder model in 3D, we deduced a set of integro-differential coupled equations of the coefficients with a method know as invariant embedding. By means of a procedure proposed by authors, called method of convergence, two types of approximate solutions for the set of equations, namely complete and simple solutions, can be obtained. Although the simple solutions were initially proposed as auxiliary forms to solve higher rank equations, they turned out to be also useful for the estimation of the aforementioned coefficients. In previous reports, we have presented results obtained with the complete solutions. In this paper, we present results obtained with the simple solutions of the coefficients, which exhibit a good degree of fit with the experimental data. Both the model and the calculation method presented here can be generalized to other techniques that make use of different sorts of particle beams.
Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids
Peinke, Joachim
focus on advanced control of ultrafast electron dynamics with shaped femtosecond laser pulses of a femtosecond laser pulse, in addition to its temporal envelope and phase. Before we present some recent the photoionization of potassium atoms with a phase-coherent double pulse sequence. Building on this simple example we
PHYSICAL REVIEW B 85, 184301 (2012) Spin-lattice-electron dynamics simulations of magnetic materials
2012-01-01
of experiments on laser-induced demagnetization of iron thin films, and estimate the rates of heat transfer of a magnetic material. They evaluated the total free energies and heat capacities of Fe, Co, and Ni usingPHYSICAL REVIEW B 85, 184301 (2012) Spin-lattice-electron dynamics simulations of magnetic
Miller, William H.
Semiclassical theory of electronically nonadiabatic dynamics: Results of a linearized approximation, California 94720 Received 6 May 1998; accepted 31 July 1998 A linearized approximation to the semiclassical easier to apply than the full SC-IVR because it linearizes the phase difference between interfering
DYNAMICS OF DECAY ELECTRONS AND SYNCHROTRON RADIATION IN A TEV MUON COLLIDER*
McIntyre, Peter
) in a TeV muon col- lider present major challenges as heat loads to the super- conducting magnetsDYNAMICS OF DECAY ELECTRONS AND SYNCHROTRON RADIATION IN A TEV MUON COLLIDER* P. McIntyre and A problems are mitigated. 1 MUON DECAY IN A MUON COLLIDER Ankenbrandt et al. [1] summarize the design
Electron-nuclear correlations for photo-induced dynamics in molecular dimers
of the nuclear equilibrium upon photoexcitation. In the limiting case of resonance between the electronic energy with the overall nuclear wave packet width. The demonstrated quantum relaxation features of the photoinduced dynamics in molecular systems, which play domi- nant roles in a variety of problems in physics, technology
Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.
2012-07-25
This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research mission. This workshop built on previous workshops and included three breakout sessions identifying scientific challenges in biology, biogeochemistry, catalysis, and materials science frontier areas of fundamental science that underpin energy and environmental science that would significantly benefit from ultrafast transmission electron microscopy (UTEM). In addition, the current status of time-resolved electron microscopy was examined, and the technologies that will enable future advances in spatio-temporal resolution were identified in a fourth breakout session.
Juven Wang; Jiunn-Wei Chen
2015-01-08
Fundamental properties of macroscopic gene-mating dynamic evolutionary systems are investigated. A model is proposed to describe a large class of systems within population genetics. We focus on a single locus, arbitrary number alleles in a two-gender dioecious population. Our governing equations are time-dependent continuous differential equations labeled by a set of genotype frequencies. The full parameter space consists of all allowed genotype frequencies. Our equations are uniquely derived from four fundamental assumptions within any population: (1) a closed system; (2) average-and-random mating process (mean-field behavior); (3) Mendelian inheritance; (4) exponential growth and exponential death. Even though our equations are non-linear with time evolutionary dynamics, we have an exactly solvable model. Our findings are summarized from phenomenological and mathematical viewpoints. From the phenomenological viewpoint, any initial genotype frequency of a closed system will eventually approach a stable fixed point. Under time evolution, we show (1) the monotonic behavior of genotype frequencies, (2) any genotype or allele that appears in the population will never become extinct, (3) the Hardy-Weinberg law, and (4) the global stability without chaos in the parameter space. To demonstrate the experimental evidence, as an example, we show a mapping from the blood type genotype frequencies of world ethnic groups to our stable fixed-point solutions. From the mathematical viewpoint, the equilibrium solutions consist of a base manifold as a global stable attractor, attracting any initial point in a Euclidean fiber bundle to the fixed point where the fiber is attached. We can define the genetic distance of two populations as their geodesic distance on the equilibrium manifold. In addition, the modification of our theory under the process of natural selection and mutation is addressed.
Morzan, Uriel N.; Ramírez, Francisco F.; Scherlis, Damián A. E-mail: mcgl@qb.ffyb.uba.ar; Lebrero, Mariano C. González E-mail: mcgl@qb.ffyb.uba.ar
2014-04-28
This article presents a time dependent density functional theory (TDDFT) implementation to propagate the Kohn-Sham equations in real time, including the effects of a molecular environment through a Quantum-Mechanics Molecular-Mechanics (QM-MM) hamiltonian. The code delivers an all-electron description employing Gaussian basis functions, and incorporates the Amber force-field in the QM-MM treatment. The most expensive parts of the computation, comprising the commutators between the hamiltonian and the density matrix—required to propagate the electron dynamics—, and the evaluation of the exchange-correlation energy, were migrated to the CUDA platform to run on graphics processing units, which remarkably accelerates the performance of the code. The method was validated by reproducing linear-response TDDFT results for the absorption spectra of several molecular species. Two different schemes were tested to propagate the quantum dynamics: (i) a leap-frog Verlet algorithm, and (ii) the Magnus expansion to first-order. These two approaches were confronted, to find that the Magnus scheme is more efficient by a factor of six in small molecules. Interestingly, the presence of iron was found to seriously limitate the length of the integration time step, due to the high frequencies associated with the core-electrons. This highlights the importance of pseudopotentials to alleviate the cost of the propagation of the inner states when heavy nuclei are present. Finally, the methodology was applied to investigate the shifts induced by the chemical environment on the most intense UV absorption bands of two model systems of general relevance: the formamide molecule in water solution, and the carboxy-heme group in Flavohemoglobin. In both cases, shifts of several nanometers are observed, consistently with the available experimental data.
Dynamic nuclear polarization with simultaneous excitation of electronic and nuclear transitions
G. W. Morley; K. Porfyrakis; A. Ardavan; J. van Tol
2008-05-28
Dynamic nuclear polarization transfers spin polarization from electrons to nuclei. We have achieved this by a new method, simultaneously exciting transitions of electronic and nuclear spins. The efficiency of this technique improves with increasing magnetic field. Experimental results are shown for N@C60 with continuous-wave microwaves, which can be expected to produce even higher polarization than the corresponding pulsed techniques for electron spins greater than 1/2. The degree of nuclear polarization in this case can be easily monitored through the intensities of the well resolved hyperfine components in the EPR spectrum. The nuclear spin-lattice relaxation time is orders of magnitude longer than that of the electrons.
Dynamics of semi-flexible polymer solutions in the highly entangled regime
Manlio Tassieri; R. M. L. Evans; Lucian Barbu-Tudoran; G. Nasir Khan; John Trinick; Tom A. Waigh
2008-10-17
We present experimental evidence that the effective medium approximation (EMA), developed by D.C. Morse [Phys. Rev. E {\\bf 63}, 031502, (2001)], provides the correct scaling law of the macroscopic plateau modulus $G^{0}\\propto\\rho^{4/3}L^{-1/3}_{p}$ (where $\\rho$ is the contour length per unit volume and $L_{p}$ is the persistence length) of semi-flexible polymer solutions, in the highly entangled concentration regime. Competing theories, including a self-consistent binary collision approximation (BCA), have instead predicted $G^{0}\\propto\\rho^{7/5}L^{-1/5}_{p}$. We have tested both the EMA and BCA scaling predictions using actin filament (F-actin) solutions which permit experimental control of $L_p$ independently of other parameters. A combination of passive video particle tracking microrheology and dynamic light scattering yields independent measurements of the elastic modulus $G$ and $L_{p}$ respectively. Thus we can distinguish between the two proposed laws, in contrast to previous experimental studies, which focus on the (less discriminating) concentration functionality of $G$.
A multi-term solution of the space-time Boltzmann equation for electrons in gaseous and liquid Argon
Boyle, G J; Tattersall, W J; McEachran, R P; White, R D
2015-01-01
In a recent paper [1] the scattering and transport of excess electrons in liquid argon in the hydrodynamic regime was investigated, generalizing the seminal works of Lekner and Cohen [2,3] with modern scattering theory techniques and kinetic theory. In this paper, the discussion is extended to the non-hydrodynamic regime through the development of a full multi-term space-time solution of Boltzmann's equation for electron transport in gases and liquids using a novel operator-splitting method. A Green's function formalism is considered that enables flexible adaptation to various experimental systems. The spatio-temporal evolution of electrons in liquids in the hydrodynamic regime is studied for a benchmark model Percus-Yevick liquid as well as for liquid argon. The temporal evolution of Franck-Hertz oscillations are observed for liquids, with striking differences in the spatio-temporal development of the velocity distribution function components between the uncorrelated gas and true liquid approximations in arg...
Dynamics of a delayed-feedback semiconductor laser depending on the number of stationary solutions
Napartovich, A P; Sukharev, Aleksandr G [State Research Center of Russian Federation 'Troitsk Institute for Innovation and Fusion Research', Troitsk, Moscow Region (Russian Federation)
2004-07-31
The lasing regimes of a diode laser with an external mirror are studied using the Lang - Kobayashi (LK) equations in the limit of a small distance from the mirror. The system of LK equations is integrated directly with the help of a program package developed. In addition, the instability and bifurcation points of solutions are found by calculating numerically the contour integral and the spectrum of Lyapunov exponents is calculated. The hysteresis zones of the lasing dynamics are found, which appear when the phase of a reflected signal changes. The parameters are determined at which two or three attractors corresponding to different dynamic regimes coexist in the phase space. It is shown that, when the rest of parameters are fixed, an increase in the pump power leads to a chaotic regime according to a classical scenario via period-doubling bifurcations. The regions of parameters are found in which packets of regular pulsations are generated, and the transition of these packets to the chaotic regime is observed. (lasers, active media)
Electron nuclear dynamics of proton collisions with methane at 30 eV D. Jacquemin,a)
Morales, Jorge Alberto
Electron nuclear dynamics of proton collisions with methane at 30 eV D. Jacquemin,a) J. A. Morales nuclear dynamics END . The results from this theoretical approach, which does not invoke the BornOppenheimer approximation and does not impose any constraints on the nuclear dynamics, are compared to the results from time
Shlomo E. Sklarz; David J. Tannor; Navin Khaneja
2004-02-19
We study the problem of optimal control of dissipative quantum dynamics. Although under most circumstances dissipation leads to an increase in entropy (or a decrease in purity) of the system, there is an important class of problems for which dissipation with external control can decrease the entropy (or increase the purity) of the system. An important example is laser cooling. In such systems, there is an interplay of the Hamiltonian part of the dynamics, which is controllable and the dissipative part of the dynamics, which is uncontrollable. The strategy is to control the Hamiltonian portion of the evolution in such a way that the dissipation causes the purity of the system to increase rather than decrease. The goal of this paper is to find the strategy that leads to maximal purity at the final time. Under the assumption that Hamiltonian control is complete and arbitrarily fast, we provide a general framework by which to calculate optimal cooling strategies. These assumptions lead to a great simplification, in which the control problem can be reformulated in terms of the spectrum of eigenvalues of $\\rho$, rather than $\\rho$ itself. By combining this formulation with the Hamilton-Jacobi-Bellman theorem we are able to obtain an equation for the globaly optimal cooling strategy in terms of the spectrum of the density matrix. For the three-level $\\Lambda$ system, we provide a complete analytic solution for the optimal cooling strategy. For this system it is found that the optimal strategy does not exploit system coherences and is a 'greedy' strategy, in which the purity is increased maximally at each instant.
Dynamical characteristics of Rydberg electrons released by a weak electric field
Diesen, Elias; Richter, Martin; Kunitski, Maksim; Dörner, Reinhard; Rost, Jan M
2015-01-01
The dynamics of ultra-slow electrons in the combined potential of an ionic core and a static electric field is discussed. With state-of-the-art detection it is possible to create such electrons through strong intense-field photo-absorption and to detect them via high-resolution time-of-flight spectroscopy despite their very low kinetic energy. The characteristic feature of their momentum spectrum, which emerges at the same position for different laser orientations, is derived and could be revealed experimentally with an energy resolution of the order of 1meV.
Centrifugal separation and equilibration dynamics in an electron-antiproton plasma
G. B. Andresen; M. D. Ashkezari; M. Baquero-Ruiz; W. Bertsche; P. D. Bowe; E. Butler; C. L. Cesar; S. Chapman; M. Charlton; A. Deller; S. Eriksson; J. Fajans; T. Friesen; M. C. Fujiwara; D. R. Gill; A. Gutierrez; J. S. Hangst; W. N. Hardy; M. E. Hayden; A. J. Humphries; R. Hydomako; S. Jonsell; N. Madsen; S. Menary; P. Nolan; A. Olin; A. Povilus; P. Pusa; F. Robicheaux; E. Sarid; D. M. Silveira; C. So; J. W. Storey; R. I. Thompson; D. P. van der Werf; J. S. Wurtele; Y. Yamazaki
2011-04-26
Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.
Chunara, Rumi
2010-01-01
Microfabricated transducers have enabled new approaches for detection of biomolecules and cells. Integration of electronics with these tools simplify systems and provide platforms for robust use outside of the laboratory ...
Excited states and electron transfer in solution : models based on density functional theory
Kowalczyk, Timothy Daniel
2012-01-01
Our understanding of organic materials for solar energy conversion stands to benefit greatly from accurate, computationally tractable electronic structure methods for excited states. Here we apply two approaches based on ...
Broader source: Energy.gov [DOE]
This guide will show how DC power optimizers and microinverters (both known as module-level power electronics) are being used in new and/or retrofit, single and multifamily homes.
Technology Solutions Case Study: Photovoltaic Systems with Module-Level Power Electronics
Tim Merrigan
2015-09-01
This guide will show how DC power optimizers and microinverters (both known as module-level power electronics) are being used in new and/or retrofit, single and multifamily homes.
Controlling high-frequency collective electron dynamics via single-particle complexity
N. Alexeeva; M. T. Greenaway; A. G. Balanov; O. Makarovsky; A. Patanè; M. B. Gaifullin; F. Kusmartsev; T. M. Fromhold
2012-07-21
We demonstrate, through experiment and theory, enhanced high-frequency current oscillations due to magnetically-induced conduction resonances in superlattices. Strong increase in the ac power originates from complex single-electron dynamics, characterized by abrupt resonant transitions between unbound and localized trajectories, which trigger and shape propagating charge domains. Our data demonstrate that external fields can tune the collective behavior of quantum particles by imprinting configurable patterns in the single-particle classical phase space.
Truong, Thanh N.
-flux correlation function for calculating the thermal rate constants of chemical reactions in solution in this study would provide a complete tool for studying the quantum dynamics of chemical reactions the thermal chemical reaction rate constants. Furthermore, we also employ an efficient and accurate quantum
Stixrude, Lars
First-principles calculations of the structural, dynamical, and electronic properties of liquid Mg first-principles study,10 the structural, dynamic, and electronic properties of the liquid state are yet, dynamical, and electronic properties of liquid MgO have been investigated over a wide range of pressure 0
Rekik, Najeh; Freedman, Holly; Hanna, Gabriel [Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 (Canada); Hsieh, Chang-Yu [Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)
2013-04-14
We apply two approximate solutions of the quantum-classical Liouville equation (QCLE) in the mapping representation to the simulation of the laser-induced response of a quantum subsystem coupled to a classical environment. These solutions, known as the Poisson Bracket Mapping Equation (PBME) and the Forward-Backward (FB) trajectory solutions, involve simple algorithms in which the dynamics of both the quantum and classical degrees of freedom are described in terms of continuous variables, as opposed to standard surface-hopping solutions in which the classical degrees of freedom hop between potential energy surfaces dictated by the discrete adiabatic state of the quantum subsystem. The validity of these QCLE-based solutions is tested on a non-trivial electron transfer model involving more than two quantum states, a time-dependent Hamiltonian, strong subsystem-bath coupling, and an initial energy shift between the donor and acceptor states that depends on the strength of the subsystem-bath coupling. In particular, we calculate the time-dependent population of the photoexcited donor state in response to an ultrafast, on-resonance pump pulse in a three-state model of an electron transfer complex that is coupled asymmetrically to a bath of harmonic oscillators through the optically dark acceptor state. Within this approach, the three-state electron transfer complex is treated quantum mechanically, while the bath oscillators are treated classically. When compared to the more accurate QCLE-based surface-hopping solution and to the numerically exact quantum results, we find that the PBME solution is not capable of qualitatively capturing the population dynamics, whereas the FB solution is. However, when the subsystem-bath coupling is decreased (which also decreases the initial energy shift between the donor and acceptor states) or the initial shift is removed altogether, both the PBME and FB results agree better with the QCLE-based surface-hopping results. These findings highlight the challenges posed by various conditions such as a time-dependent external field, the strength of the subsystem-bath coupling, and the degree of asymmetry on the accuracy of the PBME and FB algorithms.
On the electron dynamics during island coalescence in asymmetric magnetic reconnection
Cazzola, Emanuele; Markidis, Stefano; Goldman, Martin V; Newman, David L; Lapenta, Giovanni
2015-01-01
We present an analysis of the electron dynamics during rapid island merging in asymmetric magnetic reconnection. We consider a doubly periodic system with two asymmetric transitions. The upper layer is an asymmetric Harris sheet initially perturbed to promote a single reconnection site. The lower layer is a tangential discontinuity that promotes the formation of many X-points, separated by rapidly merging islands. Across both layers the magnetic field and the density have a strong jump, but the pressure is held constant. Our analysis focuses on the consequences of electron energization during island coalescence. We focus first on the parallel and perpendicular components of the electron temperature to establish the presence of possible anisotropies and non-gyrotropies. Thanks to the direct comparison between the two different layers simulated, we can distinguish three main types of behavior characteristic of three different regions of interest. The first type represents the regions where traditional asymmetri...
Dynamics of an electron in a relativistically intense laser field including radiaion reaction
Galkin, A. L., E-mail: galkin@kapella.gpi.ru [Prokhorov General Physics Institute of the Russian Academy of Science (Russian Federation)
2012-08-15
The dynamics of an electron in a relativistically intense laser pulse field is described with the radiation reaction being taken into account. The study is based on solving the Newton equation with the Lorentz and the radiation reaction forces. Validation is provided for an iteration technique which makes it possible to remove the discrepancies found in the theoretical models of radiation reaction. It is demonstrated that an electron having a high initial velocity and colliding head-on with a laser pulse sheds a considerable part of its kinetic energy due to the radiation reaction. A broadening of the electromagnetic pulse emitted by the electron occurs as a result of the same effect. The findings obtained can be used to experimentally verify the effect of radiation reaction.
Dodin, Amro; Brumer, Paul
2015-01-01
We present closed-form analytic solutions to non-secular Bloch-Redfield master equations for quantum dynamics of a V-type system driven by weak coupling to a thermal bath. We focus on noise-induced Fano coherences among the excited states induced by incoherent driving of the V-system initially in the ground state. For suddenly turned-on incoherent driving, the time evolution of the coherences is determined by the damping parameter $\\zeta=\\frac{1}{2}(\\gamma_1+\\gamma_2)/\\Delta_p$, where $\\gamma_i$ are the radiative decay rates of the excited levels $i=1,2$, and $\\Delta_p=\\sqrt{\\Delta^2 + (1-p^2)\\gamma_1\\gamma_2}$ depends on the excited-state level splitting $\\Delta>0$ and the angle between the transition dipole moments in the energy basis. The coherences oscillate as a function of time in the underdamped limit ($\\zeta\\gg1$), approach a long-lived quasi-steady state in the overdamped limit ($\\zeta\\ll 1$), and display an intermediate behavior at critical damping ($\\zeta= 1$). The sudden incoherent turn-on generat...
Wopperer, P; Reinhard, P -G; Suraud, E
2014-01-01
Various ways to analyze the dynamical response of clusters and molecules to electromagnetic perturbations exist. Particularly rich information can be obtained from measuring the properties of electrons emitted in the course of the excitation dynamics. Such an analysis of electron signals covers total ionization, Photo-Electron Spectra, Photoelectron Angular Distributions, and ideally combined PES/PAD, with a long history in molecular physics, also increasingly used in cluster physics. Recent progress in the design of new light sources (high intensity and/or frequency, ultra short pulses) opens new possibilities for measurements and thus has renewed the interest on the analysis of dynamical scenarios through these observables, well beyond a simple access to a density of states. This, in turn, has motivated many theoretical investigations of the dynamics of electronic emission for molecules and clusters. A theoretical tool of choice is here Time-Dependent Density Functional Theory (TDDFT) propagated in real tim...
E. J. C. Dias; N. M. R. Peres
2015-02-25
Using a Green's function formalism we derive analytical expressions for the electronic transmittance through a benzene ring. To motivate the approach we first solve the resonant level system and then extend the method to the benzene case. These results can be used to validate numerical methods.
Israel Quiros; Ricardo Garcia-Salcedo; Tonatiuh Matos; Claudia Moreno
2008-12-09
We apply the dynamical systems tools to study the linear dynamics of a self-interacting scalar field trapped on a DGP brane. The simplest kinds of self-interaction potentials are investigated: a) constant potential, and b) exponential potential. It is shown that the dynamics of DGP models can be very rich and complex. One of the most interesting results of this study shows that dynamical screening of the scalar field self-interaction potential, occuring within the Minkowski cosmological phase of the DGP model and mimetizing 4D phantom behaviour, is an attractor solution for a constant self-interaction potential but not for the exponential one. In the latter case gravitational screening is not even a critical point of the corresponding autonomous system of ordinary differential equations.
California at San Diego, University of
FA12 Nanoscale Devices & Systems MS Exam Solution 1. For small semiconductor quantum dot structures, the single-electron charging energy can become comparable to the quantum confinement energies in the dot effective mass 0 * 5.0 mmp , where m0 is the free electron mass. An infinite potential energy barrier
Optics solutions for pp operation with electron lenses at 100 GeV
White, S.; Fischer, W.; Luo, Y.
2014-07-12
Electron lenses for head-on compensation are currently under commissioning and foreseen to be operational for the 2015 polarized proton run. These devices will provide a partial compensation of head-on beam-beam effects and allow to double the RHIC proton luminosity. This note reviews the optics constraints related to beam-beam compensation and summarizes the current lattice options for proton operation at 100 GeV.
Hall-effect-controlled gas dynamics in protoplanetary disks. I. Wind solutions at the inner disk
Bai, Xue-Ning
2014-08-20
The gas dynamics of protoplanetary disks (PPDs) is largely controlled by non-ideal magnetohydrodynamic (MHD) effects including Ohmic resistivity, the Hall effect, and ambipolar diffusion. Among these the role of the Hall effect is the least explored and most poorly understood. In this series, we have included, for the first time, all three non-ideal MHD effects in a self-consistent manner to investigate the role of the Hall effect on PPD gas dynamics using local shearing-box simulations. In this first paper, we focus on the inner region of PPDs, where previous studies (Bai and Stone 2013; Bai 2013) excluding the Hall effect have revealed that the inner disk up to ?10 AU is largely laminar, with accretion driven by a magnetocentrifugal wind. We confirm this basic picture and show that the Hall effect modifies the wind solutions depending on the polarity of the large-scale poloidal magnetic field B{sub 0} threading the disk. When B{sub 0}??>0, the horizontal magnetic field is strongly amplified toward the disk interior, leading to a stronger disk wind (by ?50% or less in terms of the wind-driven accretion rate). The enhanced horizontal field also leads to much stronger large-scale Maxwell stress (magnetic braking) that contributes to a considerable fraction of the wind-driven accretion rate. When B{sub 0}??<0, the horizontal magnetic field is reduced, leading to a weaker disk wind (by ? 20%) and negligible magnetic braking. Under fiducial parameters, we find that when B{sub 0}??>0, the laminar region extends farther to ?10-15 AU before the magnetorotational instability sets in, while for B{sub 0}??<0, the laminar region extends only to ?3-5 AU for a typical accretion rate of ?10{sup –8} to10{sup –7} M {sub ?} yr{sup –1}. Scaling relations for the wind properties, especially the wind-driven accretion rate, are provided for aligned and anti-aligned field geometries.
Effects of energy loss on interaction dynamics of energetic electrons with plasmas C. K. Li and R for energetic electrons interacting with plasmas. This model rigorously treats the effects of energy loss upon and energy loss--which previous calculations had erroneously treated as independent in cases where
Boyer, Edmond
Dynamical mean-field theory using Wannier functions: A flexible route to electronic structure materials with different degrees of structural and electronic complexity, SrVO3 and BaVS3, are investigated calculations of strongly correlated materials F. Lechermann,1,2, * A. Georges,1 A. Poteryaev,1 S. Biermann,1 M
ON QUIET-TIME SOLAR WIND ELECTRON DISTRIBUTIONS IN DYNAMICAL EQUILIBRIUM WITH LANGMUIR TURBULENCE
Zaheer, S.; Yoon, P. H.
2013-10-01
A recent series of papers put forth a self-consistent theory of an asymptotically steady-state electron distribution function and Langmuir turbulence intensity. The theory was developed in terms of the ? distribution which features Maxwellian low-energy electrons and a non-Maxwellian energetic power-law tail component. The present paper discusses a generalized ? distribution that features a Davydov-Druyvesteyn type of core component and an energetic power-law tail component. The physical motivation for such a generalization is so that the model may reflect the influence of low-energy electrons interacting with low-frequency kinetic Alfvénic turbulence as well as with high-frequency Langmuir turbulence. It is shown that such a solution and the accompanying Langmuir wave spectrum rigorously satisfy the balance requirement between the spontaneous and induced emission processes in both the particle and wave kinetic equations, and approximately satisfy the similar balance requirement between the spontaneous and induced scattering processes, which are nonlinear. In spite of the low velocity modification of the electron distribution function, it is shown that the resulting asymptotic velocity power-law index ?, where f{sub e} ? v {sup –?} is close to the average index observed during the quiet-time solar wind condition, i.e., ? ? O(6.5) whereas ?{sub average} ? 6.69, according to observation.
Tseng, Te-Yu; Yang, Chiu-Sheng; Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Tsai, Tsung-Hua [Department of Dermatology, Far Eastern Memorial Hospital, New Taipei City, Taiwan (China); Dong, Chen-Yuan, E-mail: cydong@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan (China); Center for Optoelectronic Biomedicine, National Taiwan University, Taipei, Taiwan (China)
2014-10-20
In this letter, we propose an efficient methodology of investigating dynamic properties of sulforhodamine B and rhodamine B hexyl ester molecules transporting across ex-vivo human stratum corneum with and without oleic acid enhancement. Three-dimensional, time-lapse fluorescence images of the stratum corneum can be obtained using two-photon fluorescence microscopy. Furthermore, temporal quantifications of transport enhancements in diffusion parameters can be achieved with the use of Fick's second law. Dynamic characterization of solutes transporting across the stratum corneum is an effective method for understanding transient phenomena in transdermal delivery of probe molecules, leading to improved delivery strategies of molecular species for therapeutic purposes.
Dynamics of Longitudinal Phase-Space Modulations in an rf Compressor for Electron Beams
Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.
2010-05-21
Free Electron Lasers (FELs) operating in the UV or x-ray radiation spectrum require peak beam currents that are generally higher than those obtainable by present electron sources, thus making bunch compression necessary. Compression, however, may heighten the effects of collective forces and degrade the beam quality. In this paper they provide a framework for investigating some of these effects in rf compressors by focusing on the longitudinal dynamics of small-amplitude density perturbations, which have the potential to cause the disruptive appearance of the so-called microbunching instability. They develop a linear theory valid for low-to-moderate compression factors under the assumption of a 1D impedance model of longitudinal space charge and provide validation against macroparticle simulations.
Haxton, Dan; Adaniya, Hidihito; Slaughter, Dan; Rudek, B.; Osipov, Timur; Weber, Thorsten; Rescigno, Tom; McCurdy, Bill; Belkacem, Ali
2011-06-08
Following prior work on the lower-energy resonances, we apply techniques of momentum imaging and ab initio scattering calculations to the process of dissociative electron attachment to water via the highest-energy {sup 2}B{sub 2} resonance. We focus on the H{sup -} anion fragment, which is produced via dynamics passing through and avoiding the conical intersection with the lower A{sub 1} state, leading to OH ((sup 2}{Pi}#5;) and OH ({sup 2}{Sigma}#6;), respectively. The momentum imaging technique, when combined with theoretical calculations on the attachment amplitude and dissociation dynamics, demonstrates that the angular distributions provide a signature of the location of the conical intersection in the space of nuclear con#12;gurations.
Abdoli-Arani, A.; Jazi, B. [Department of Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute, G. C. Shahid Beheshti University, Tehran (Iran, Islamic Republic of)
2013-02-15
The dynamics and energy gain of an electron in the field of a transverse magnetic wave propagating inside an elliptical degenerate plasma waveguide is analytically investigated by finding the field components of the TM{sub mr} mode in this waveguide. Besides, by solving the relativistic momentum and energy equations the deflection angle and the acceleration gradient of the electron in the waveguide are obtained. Furthermore, the field components of the hybrid mode and the transferred power in the presence of the magnetic field in this waveguide are found. Also by applying the boundary conditions at the plasma-conductor interface, we calculate the dispersion relation. It is shown that the cutoff frequency of this mode is dependent on the plasma density but independent of the magnetic field. Then, a single-electron model for numerical calculations of the electron deflection angle and acceleration gradient inside the magnetized plasma-filled elliptical waveguide is generally presented to be used as a cascading process for the acceleration purposes.
Interfacial electron transfer dynamics of ru(II)-polypy6ridine sensitized TiO2
Jakubikova, Elena [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Batista, Enrique R [Los Alamos National Laboratory; Snoeberger, Robert C [YALE UNIV.; Batista, Victor S [YALE UNIV.
2009-01-01
Quantum dynamics simulations combined with density functional theory calculations are applied to study interfacial electron transfer (IET) from pyridine-4-phosphonic acid, [Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 2+} and [Ru(tpy)(bpy)(H{sub 2}O)-Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 4+} into the (101) surface of anatase TiO{sub 2}. IET rate from pyridine-4-phosphonic acid attached to the nanoparticle in bidentate mode ({tau} {approx} 100 fs) is an order of magnitude faster than the IET rate of the adsorbate attached in the monodentate mode ({tau} {approx} 1 ps). Upon excitation with visible light, [Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 2+} attached to TiO{sub 2} in bidentate binding mode will undergo IET with the rate of {approx} 1-10 ps, which is competitive with the excited state decay into the ground state. The probability of electron injection from [Ru(tpy)(bpy)(H{sub 2}O)-Ru(tpy)(tpy(PO{sub 3}H{sub 2}))]{sup 4+} is rather low, as the excitation with visible light localizes the excited electron in the tpy-tpy bridge, which does not have favorable coupling with the TiO{sub 2} nanoparticle. The results are relevant to better understanding of the adsorbate features important for promoting efficient interfacial electron transfer into the semiconductor.
Hot electron dynamics in graphene (Thesis/Dissertation) | SciTech Connect
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Dynamical Stability of an Ion in a Linear Trap as a Solid-State Problem of Electron Localization
G. P. Berman; A. R. Bishop; D. F. V. James; R. J. Hughes; D. I. Kamenev
2000-12-18
When an ion confined in a linear ion trap interacts with a coherent laser field, the internal degrees of freedom, related to the electron transitions, couple to the vibrational degree of freedom of the ion. As a result of this interaction, quantum dynamics of the vibrational degree of freedom becomes complicated, and in some ranges of parameters even chaotic. We analyze the vibrational ion dynamics using a formal analogy with the solid-state problem of electron localization. In particular, we show how the resonant approximation used in analysis of the ion dynamics, leads to a transition from a two-dimensional (2D) to a one-dimensional problem (1D) of electron localization. The localization length in the solid-state problem is estimated in cases of weak and strong interaction between the cites of the 2D cell by using the methods of resonance perturbation theory, common in analysis of 1D time-dependent dynamical systems.
Faghaninia, Alireza; Lo, Cynthia S
2015-01-01
Accurate models of carrier transport are essential for describing the electronic properties of semiconductor materials. To the best of our knowledge, the current models following the framework of the Boltzmann transport equation (BTE) either rely heavily on experimental data (i.e., semi-empirical), or utilize simplifying assumptions, such as the constant relaxation time approximation (BTE-cRTA). While these models offer valuable physical insights and accurate calculations of transport properties in some cases, they often lack sufficient accuracy -- particularly in capturing the correct trends with temperature and carrier concentration. We present here a general transport model for calculating low-field electrical drift mobility and Seebeck coefficient of n-type semiconductors, by explicitly considering all relevant physical phenomena (i.e. elastic and inelastic scattering mechanisms). We first rewrite expressions for the rates of elastic scattering mechanisms, in terms of ab initio properties, such as the ban...
Electronic-excitation energy transfer in heterogeneous dye solutions under laser excitation
Levshin, L.V.; Mukushev, B.T.; Saletskii, A.M.
1995-10-01
An experimental study has been made of electronic-excitation energy transfer (EEET) among dye molecules of different types for different exciting-fight wavelengths and temperatures. Upon selective laser excitation of the donor, the inhomogeneous broadening of molecular levels increases the probability of EEET from the donor to acceptor molecules. The efficiency of this process is directly proportional to the acceptor molecule concentration and is temperature dependent. The EEET is accompanied by the spectral migration of energy among donor molecules, which reduces the fluorescence quantum efficiency of the donor. Increasing the frequency of the exciting light decreases in the donor fluorescence quantum efficiency. An increase in the acceptor molecule concentration results in a decrease of the spectral migration of excitation in the donor molecule system. 5 refs., 5 figs.
Sutter, Eli A.; Sutter, Peter W.
2014-11-19
In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?_{aq} created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?_{aq} generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?_{aq}]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?_{aq}] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Sutter, Eli A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sutter, Peter W. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2014-12-03
In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.
Suzuoka, Daiki; Takahashi, Hideaki Morita, Akihiro
2014-04-07
We developed a perturbation approach to compute solvation free energy ?? within the framework of QM (quantum mechanical)/MM (molecular mechanical) method combined with a theory of energy representation (QM/MM-ER). The energy shift ? of the whole system due to the electronic polarization of the solute is evaluated using the second-order perturbation theory (PT2), where the electric field formed by surrounding solvent molecules is treated as the perturbation to the electronic Hamiltonian of the isolated solute. The point of our approach is that the energy shift ?, thus obtained, is to be adopted for a novel energy coordinate of the distribution functions which serve as fundamental variables in the free energy functional developed in our previous work. The most time-consuming part in the QM/MM-ER simulation can be, thus, avoided without serious loss of accuracy. For our benchmark set of molecules, it is demonstrated that the PT2 approach coupled with QM/MM-ER gives hydration free energies in excellent agreements with those given by the conventional method utilizing the Kohn-Sham SCF procedure except for a few molecules in the benchmark set. A variant of the approach is also proposed to deal with such difficulties associated with the problematic systems. The present approach is also advantageous to parallel implementations. We examined the parallel efficiency of our PT2 code on multi-core processors and found that the speedup increases almost linearly with respect to the number of cores. Thus, it was demonstrated that QM/MM-ER coupled with PT2 deserves practical applications to systems of interest.
Chen, Dongcheng; Zhou, Hu; Cai, Ping; Sun, Shi; Ye, Hua; Su, Shi-Jian Cao, Yong
2014-02-03
A triazine- and pyridinium-containing water-soluble material of 1,1?,1?-(4,4?,4?-(1,3,5-triazine-2,4,6-triyl)tris(benzene-4,1-diyl)) tris(methylene)tripyridinium bromide (TzPyBr) was developed as an organic electron-selective layer in solution-processed inverted organic solar cells due to its strong anti-erosion capacity against non-polar organic solvents commonly used for the active layer. Ohmic-like contact with the adjacent active materials like fullerene derivatives is speculated to be formed, as confirmed by the work-function measurements with scanning Kelvin probe and ultraviolet photoelectron spectroscopy techniques. Besides, considering the deep highest occupied molecular orbital energy level of TzPyBr, excellent hole-blocking property of the electron-selective layer is also anticipated. The inverted organic photovoltaic devices based on the TzPyBr/ITO (indium tin oxide) bilayer cathode exhibit dramatically enhanced performance compared to the control devices with bare ITO as the cathode and even higher efficiency than the conventional type devices with ITO and Al as the electrodes.
Dynamics of highly concentrated protein solutions around the denaturing Marcus Hennig,ab
Schreiber, Frank
is applicable to other colloid systems exhibiting both center-of-mass and internal dynamics. 1 Introduction addressed by simulation,15 concluding that crowding can enhance the structural stability, but experimentally are not clear. Only few experimental results on the microscopic dynamics of protein suspensions around
Ultrafast myoglobin structural dynamics observed with an X-ray free-electron laser
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Levantino, Matteo; Schirò, Giorgio; Lemke, Henrik Till; Cottone, Grazia; Glownia, James Michael; Zhu, Diling; Chollet, Mathieu; Ihee, Hyotcherl; KAIST, Daejeon; Cupane, Antonio; et al
2015-04-02
Light absorption can trigger biologically relevant protein conformational changes. The light induced structural rearrangement at the level of a photoexcited chromophore is known to occur in the femtosecond timescale and is expected to propagate through the protein as a quake-like intramolecular motion. Here we report direct experimental evidence of such ‘proteinquake’ observed in myoglobin through femtosecond X-ray solution scattering measurements performed at the Linac Coherent Light Source X-ray free-electron laser. An ultrafast increase of myoglobin radius of gyration occurs within 1 picosecond and is followed by a delayed protein expansion. As the system approaches equilibrium it undergoes damped oscillations withmore »a ~3.6-picosecond time period. Our results unambiguously show how initially localized chemical changes can propagate at the level of the global protein conformation in the picosecond timescale.« less
A study of structure and dynamics of polyelectrolyte solutions using flow birefringence measurements
Chen, Shih Ping
1996-01-01
Stress optical data from polyelectrolytes (sodium polystyrenesulfonate) in aqueous solutions have been determined using flow birefringence. The stress optical rule was found to be violated in the semidilute unentangled concentration regime...
Baglioni, P [University of Florence; Chen, Wei-Ren [ORNL; Falus, Peter [ORNL; Faraone, Antonio [National Institute of Standards and Technology (NIST); Fratini, Emiliano [University of Florence; Hong, Kunlun [ORNL; Liu, Yun [National Institute of Standards and Technology (NIST); Porcar, L. [National Institute of Standards and Technology (NIST)
2012-01-01
Recently experiments that combine both small angle neutron scattering (SANS) and Neutron Spin Echo (NSE) have demonstrated that dynamic clusters can form in concentrated lysozyme solutions when there is a right combination of a short-ranged attraction and a long-ranged electrostatic repulsion. In this paper, we study the temperature effect on the dynamic cluster formation and try to pinpoint the transition concentration from a monomer phase to a cluster phase. Interestingly at even a relatively high concentration (10 % mass fraction), despite the significant change of the SANS patterns that are associated with the change of the short-ranged attraction among proteins, the normalized short-time self-diffusion coefficient is not affected. This is interpreted due to the fact that there is no cluster formation at this condition. However, at larger concentrations such as 17.5 % and 22.5 % mass fraction, we show that the average hydrodynamic radius increase significantly and causes a large decrease of the normalized self-diffusion coefficient when the temperature is changed from 25 oC to 5 oC indicating the formation of dynamic clusters in solution.
E. N. Egorov; A. E. Hramov
2006-06-27
The effect of the strength of the focusing magnetic field on chaotic dynamic processes occurring inan electron beam with a virtual cathode, as well as on the processes whereby the structures form in the beamand interact with each other, is studied by means of two-dimensional numerical simulations based on solving a self-consistent set of Vlasov-Maxwell equations. It is shown that, as the focusing magnetic field is decreased,the dynamics of an electron beam with a virtual cathode becomes more complicated due to the formation andinteraction of spatio-temporal longitudinal and transverse structures in the interaction region of a vircator. The optimum efficiency of the interaction of an electron beam with the electromagnetic field of the vircator isachieved at a comparatively weak external magnetic field and is determined by the fundamentally two-dimensional nature of the motion of the beam electrons near the virtual cathode.
Boyer, Edmond
University of Arak, Arak, Iran The motion of a relativistic test electron in a free-electron laser dynamics in free-electron lasers with coaxial wiggler B. Farokhi and S. Mobarakabadi Islamic Azad orbits. Earlier investigations of chaos in free electron lasers have focused on chaotic behavior
Dabhi, Shweta D. [Department of Physics, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar 364001 (India); Gupta, Sanjay D. [V. B. Institute of Science, Department of Physics, C. U. Shah University, Wadhwan City - 363030, Surendranagar (India); Jha, Prafulla K., E-mail: prafullaj@yahoo.com [Department of Physics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390002 (India)
2014-05-28
We report the results of a theoretical study on the structural, electronic, mechanical, and vibrational properties of some graphene oxide models (GDO, a-GMO, z-GMO, ep-GMO and mix-GMO) at ambient pressure. The calculations are based on the ab-initio plane-wave pseudo potential density functional theory, within the generalized gradient approximations for the exchange and correlation functional. The calculated values of lattice parameters, bulk modulus, and its first order pressure derivative are in good agreement with other reports. A linear response approach to the density functional theory is used to derive the phonon frequencies. We discuss the contribution of the phonons in the dynamical stability of graphene oxides and detailed analysis of zone centre phonon modes in all the above mentioned models. Our study demonstrates a wide range of energy gap available in the considered models of graphene oxide and hence the possibility of their use in nanodevices.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; et al
2015-03-04
Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobicmore »environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.« less
Dynamics of soft Nanomaterials captured by transmission electron microscopy in liquid water
Proetto, Maria T.; Rush, Anthony M.; Chien, Miao-Ping; Abellan Baeza, Patricia; Patterson, Joseph P.; Thompson, Matthew P.; Olson, Norman H.; Moore, Curtis E.; Rheingold, Arnold L.; Andolina, Christopher; Millstone, Jill; Howell, Stephen B.; Browning, Nigel D.; Evans, James E.; Gianneschi, Nathan C.
2014-01-14
In this paper we present in situ transmission electron microscopy (TEM) of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterization of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerization of an oxaliplatin analog, designed for an ongoing program in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point toward key design parameters that enable this new characterization approach for organic nanomaterials. We describe the preparation of the synthetic micellar nanoparticles to- gether with their characterization in liquid water.
Huse, Nils; Khalil, Munira; Kim, Tae Kyu; Smeigh, Amanda L.; Jamula, Lindsey; McCusker, James K.; Schoenlein, Robert W.
2009-05-24
We report measurements of the photo-induced Fe(II) spin crossover reaction dynamics in solution via time-resolved x-ray absorption spectroscopy. EXAFS measurements reveal that the iron?nitrogen bond lengthens by 0.21+-0.03 Angstrom in the high-spin transient excited state relative to the ground state. XANES measurements at the Fe L-edge show directly the influence of the structural change on the ligand-field splitting of the Fe(II) 3d orbitals associated with the spin transition.
Mendive-Tapia, David; Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A.
2013-07-28
Coupled electron-nuclear dynamics, implemented using the Ehrenfest method, has been used to study charge migration with fixed nuclei, together with charge transfer when nuclei are allowed to move. Simulations were initiated at reference geometries of neutral benzene and 2-phenylethylamine (PEA), and at geometries close to potential energy surface crossings in the cations. Cationic eigenstates, and the so-called sudden approximation, involving removal of an electron from a correlated ground-state wavefunction for the neutral species, were used as initial conditions. Charge migration without coupled nuclear motion could be observed if the Ehrenfest simulation, using the sudden approximation, was started near a conical intersection where the states were both strongly coupled and quasi-degenerate. Further, the main features associated with charge migration were still recognizable when the nuclear motion was allowed to couple. In the benzene radical cation, starting from the reference neutral geometry with the sudden approximation, one could observe sub-femtosecond charge migration with a small amplitude, which results from weak interaction with higher electronic states. However, we were able to engineer large amplitude charge migration, with a period between 10 and 100 fs, corresponding to oscillation of the electronic structure between the quinoid and anti-quinoid cationic electronic configurations, by distorting the geometry along the derivative coupling vector from the D{sub 6h} Jahn-Teller crossing to lower symmetry where the states are not degenerate. When the nuclear motion becomes coupled, the period changes only slightly. In PEA, in an Ehrenfest trajectory starting from the D{sub 2} eigenstate and reference geometry, a partial charge transfer occurs after about 12 fs near the first crossing between D{sub 1}, D{sub 2} (N{sup +}-Phenyl, N-Phenyl{sup +}). If the Ehrenfest propagation is started near this point, using the sudden approximation without coupled nuclear motion, one observes an oscillation of the spin density – charge migration – between the N atom and the phenyl ring with a period of 4 fs. When the nuclear motion becomes coupled, this oscillation persists in a damped form, followed by an effective charge transfer after 30 fs.
Swenson, Jan Elamin, Khalid; Chen, Guo; Lohstroh, Wiebke; Sakai, Victoria Garcia
2014-12-07
The molecular dynamics of solutions of di-propylene glycol methylether (2PGME) and H{sub 2}O (or D{sub 2}O) confined in 28 Å pores of MCM-41 have been studied by quasielastic neutron scattering and differential scanning calorimetry over the concentration range 0–90 wt.% water. This system is of particular interest due to its pronounced non-monotonic concentration dependent dynamics of 2PGME in the corresponding bulk system, showing the important role of hydrogen bonding for the dynamics. In this study we have elucidated how this non-monotonic concentration dependence is affected by the confined geometry. The results show that this behaviour is maintained in the confinement, but the slowest diffusive dynamics of 2PGME is now observed at a considerably higher water concentration; at 75 wt.% water in MCM-41 compared to 30 wt.% water in the corresponding bulk system. This difference can be explained by an improper mixing of the two confined liquids. The results suggest that water up to a concentration of about 20 wt.% is used to hydrate the hydrophilic hydroxyl surface groups of the silica pores, and that it is only at higher water contents the water becomes partly mixed with 2PGME. Hence, due to this partial micro-phase separation of the two liquids larger, and thereby slower relaxing, structural entities of hydrogen bonded water and 2PGME molecules can only be formed at higher water contents than in the bulk system. However, the Q-dependence is unchanged with confinement, showing that the nature of the molecular motions is preserved. Thus, there is no indication of localization of the dynamics at length scales of less than 20 Å. The dynamics of both water and 2PGME is strongly dominated by translational diffusion at a temperature of 280 K.
Non-existence of Physical Classical Solutions to Euler's Equations of Rigid Body Dynamics
Mark Wilkinson
2015-11-23
We prove that one cannot construct, for arbitrary initial data, global-in-time physical classical solutions to Euler's equations of continuum rigid body mechanics when the constituent rigid bodies are not perfect spheres. By 'physical' solutions, we mean those that conserve the total linear momentum, angular momentum and kinetic energy of any given initial datum. The reason for absence of classical solutions is due to the non-existence of velocity scattering maps which resolve a collision between two non-spherical rigid bodies in such a way that (i) they do not interpenetrate, and (ii) total linear momentum, angular momentum and kinetic energy of the bodies are conserved through collision. In particular, this implies that when solving Euler's equations, it is necessary to deal with rigid body trajectories which experience infinitely-many collisions in a finite time interval.
Hassell, Joel Andre
1968-01-01
vector associated with K is called a check vector. Ordering the so]ation vector so that S. & S. ?. . . S. il ? i2 ? ''' ? im' a comparison is m de between the S. . and the coluam entries a . , j = I, ij kj' . . . , m from the checl vector. If S. . & a... PI B'k. - R. j I ~ Kch [t+ I] Now, i f some S. . for the local optimum is greater than or equal to 1] ak. for the first chock vector at level t+1, the solut! on is the kj optimal solution. This condition may be veri fied as a sufficient condi...
Colby, Ralph H.
of small-angle neutron scattering, small-angle X-ray scattering, and rheometry. Semidilute solutions and the viscosity remains small until a relatively high concentration at which the globules start to overlap. Once structures have also been found.19,20 HMPEs are charged copolymers, containing hydro- phobic comonomers
Condensation dynamics of L-proline and L-hydroxyproline in solution
Epstein, Irving R.
general, occurring in chiral derivatives of acetic, propionic, and butyric acids with a chiral center behavior of L-Pro, L-Hyp, and L-ProL-Hyp in 70% aqueous methanol. The individual amino acid solutions show in an oscillatory fashion in low molecular weight carboxylic acids dissolved in aqueous and non-aqueous abiotic
Dynamics of Magnesite Formation at Low-Temperature and High pCO2 in Aqueous Solution
Qafoku, Odeta; Dixon, David A.; Rosso, Kevin M.; Schaef, Herbert T.; Bowden, Mark E.; Arey, Bruce W.; Felmy, Andrew R.
2015-09-17
Like many metal carbonate minerals, despite conditions of supersaturation, precipitation of magnesite from aqueous solution is kinetically hindered at low temperatures, for reasons that remain poorly understood. The present study examines precipitation products from reaction of Mg(OH)2 in aqueous solutions saturated with supercritical CO2 at high pressures (90 atm and 110 atm) and low temperatures (35 °C and 50 °C). Traditional bulk characterization (X-ray diffraction) of the initial solid formed indicated the presence of hydrated magnesium carbonates (hydromagnesite and nesquehonite), thermodynamically metastable phases that were found to slowly react during ageing to the more stable anhydrous form, magnesite, at temperatures as low as 35 °C (135-140 days) and at a faster rate at 50 °C (56 days). Undetected by bulk measurements, detailed examination of the precipitates by scanning electron microscopy (SEM) showed that magnesite is present as a minor component at relatively early reaction times (7 days) at 50 °C. In addition to magnesite dominating the solid phases over time, we find that mangesite nucleation and growth occurs more quickly with increasing partial pressure of CO2, and in electrolyte solutions with high bicarbonate content. Furthermore, formation of magnesite was found to be enhanced in sulfate-rich solutions, compared to chloride-rich solutions. We speculate that much of this behavior is possibly due to sulfate serving as sink of protons generated during carbonation reactions. These results support the importance of integrating magnesite as an equilibrium phase in reactive transport calculations of the effects of carbon dioxide sequestration on subsurface formations at long time scales.
Demkin, V. P.; Mel'nichuk, S. V.
2014-09-15
In the present work, results of investigations into the dynamics of secondary electrons with helium atoms in the presence of the reverse electric field arising in the flare of a high-voltage pulsed beam-type discharge and leading to degradation of the primary electron beam are presented. The electric field in the discharge of this type at moderate pressures can reach several hundred V/cm and leads to considerable changes in the kinetics of secondary electrons created in the process of propagation of the electron beam generated in the accelerating gap with a grid anode. Moving in the accelerating electric field toward the anode, secondary electrons create the so-called compensating current to the anode. The character of electron motion and the compensating current itself are determined by the ratio of the field strength to the concentration of atoms (E/n). The energy and angular spectra of secondary electrons are calculated by the Monte Carlo method for different ratios E/n of the electric field strength to the helium atom concentration. The motion of secondary electrons with threshold energy is studied for inelastic collisions of helium atoms and differential analysis is carried out of the collisional processes causing energy losses of electrons in helium for different E/n values. The mechanism of creation and accumulation of slow electrons as a result of inelastic collisions of secondary electrons with helium atoms and selective population of metastable states of helium atoms is considered. It is demonstrated that in a wide range of E/n values the motion of secondary electrons in the beam-type discharge flare has the character of drift. At E/n values characteristic for the discharge of the given type, the drift velocity of these electrons is calculated and compared with the available experimental data.
Excited-State Dynamics of Diindenoperylene in Liquid Solution and in Solid Films
Schreiber, Frank
are used in electronic devices ranging from transistors to solar cells. One advantage of organic is dominated by an intrinsic exciton that decays on a time scale of 166 ps. Emission from lower energy excimer for the function of DIP in organic solar cells are discussed. INTRODUCTION Organic molecular semiconductors
Fischer, Ingo
IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 42, NO. 4, APRIL 2006 381 Self-Pulsation Dynamics in Narrow Stripe Semiconductor Lasers Pascal Landais, Member, IEEE, Stephen A. Lynch, Senior Member, IEEE, James O'Gorman, Ingo Fischer, and Wolfgang Elsäßer, Senior Member, IEEE Abstract--In this paper, we
Vibrational Spectra of Water Solutions of Azoles from QM/MM Calculations: Effects of Solvation
Guidoni, Leonardo
the decomposition of the vibrational density of states of the gas phase and solution dynamics. The calculated shifts the structural and dynamical aspects of water solutions. X-ray as well as neutron diffraction are the main source and electronic structure of the molecule.1 We expect therefore that also its vibrational properties could
Noll, Daniel; Stancari, Giulio
2015-11-17
An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.
Higher-order solutions to non-Markovian quantum dynamics via hierarchical functional derivative
Da-Wei Luo; Chi-Hang Lam; Lian-Ao Wu; Ting Yu; Hai-Qing Lin; J. Q. You
2015-09-08
Solving realistic quantum systems coupled to an environment is a challenging task. Here we develop a hierarchical functional derivative (HFD) approach for efficiently solving the non-Markovian quantum trajectories of an open quantum system embedded in a bosonic bath. An explicit expression for arbitrary order HFD equation is derived systematically. Moreover, it is found that for an analytically solvable model, this hierarchical equation naturally terminates at a given order and thus becomes exactly solvable. This HFD approach provides a systematic method to study the non-Markovian quantum dynamics of an open system coupled to a bosonic environment.
A Nonlinear $sl(2)$ Dynamics and New Quasiclassical Solutions for a Class of Quantum Coupled Systems
Valery P. Karassiov
1997-10-02
Hamiltonians of a wide-spread class of strongly coupled quantum system models are expressed as nonlinear functions of $sl(2)$ generators. It enables us to use the $sl(2)$ formalism, in particular, $sl(2)$ generalized coherent states (GCS) for solving both spectral and evolution tasks. In such a manner, using standard variational schemes with $sl(2)$ GCS as trial functions we find new analytical expressions for energy spectra and non-linear evolution equations for cluster dynamics variables in mean-field approximations which are beyond quasi-harmonic ones obtained earlier. General results are illustrated on certain concrete models of quantum optics and laser physics.
Vibrational relaxation of CH3I in the gas phase and in solution
Elles, Christopher G.; Cox, M. Jocelyn; Crim, F. Fleming
2004-03-30
Transient electronic absorption measurements reveal the vibrational relaxation dynamics of CH(3)I following excitation of the C–H stretch overtone in the gas phase and in liquid solutions. The isolated molecule relaxes through two stages...
Linear Boltzmann equation as the long time dynamics of an electron weakly coupled to a phonon field
Laszlo Erdos
2001-08-29
We consider the long time evolution of a quantum particle weakly interacting with a phonon field. We show that in the weak coupling limit the Wigner distribution of the electron density matrix converges to the solution of the linear Boltzmann equation globally in time. The collision kernel is identified as the sum of an emission and an absorption term that depend on the equilibrium distribution of the free phonon modes.
Meyer, Arne [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); Dierks, Karsten [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); XtalConcepts, Marlowring 19, 22525 Hamburg (Germany); Hussein, Rana [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany); Brillet, Karl [ESBS, Pôle API, 300 Boulevard Sébastien Brant, CS10413, 67412 Illkirch CEDEX (France); Brognaro, Hevila [São Paulo State University, UNESP/IBILCE, Caixa Postal 136, São José do Rio Preto-SP, 15054 (Brazil); Betzel, Christian, E-mail: christian.betzel@uni-hamburg.de [University of Hamburg, c/o DESY, Building 22a, Notkestrasse 85, 22603 Hamburg (Germany)
2015-01-01
Application of in situ dynamic light scattering to solutions of protein–detergent complexes permits characterization of these complexes in samples as small as 2 µl in volume. Detergents are widely used for the isolation and solubilization of membrane proteins to support crystallization and structure determination. Detergents are amphiphilic molecules that form micelles once the characteristic critical micelle concentration (CMC) is achieved and can solubilize membrane proteins by the formation of micelles around them. The results are presented of a study of micelle formation observed by in situ dynamic light-scattering (DLS) analyses performed on selected detergent solutions using a newly designed advanced hardware device. DLS was initially applied in situ to detergent samples with a total volume of approximately 2 µl. When measured with DLS, pure detergents show a monodisperse radial distribution in water at concentrations exceeding the CMC. A series of all-transn-alkyl-?-d-maltopyranosides, from n-hexyl to n-tetradecyl, were used in the investigations. The results obtained verify that the application of DLS in situ is capable of distinguishing differences in the hydrodynamic radii of micelles formed by detergents differing in length by only a single CH{sub 2} group in their aliphatic tails. Subsequently, DLS was applied to investigate the distribution of hydrodynamic radii of membrane proteins and selected water-insoluble proteins in presence of detergent micelles. The results confirm that stable protein–detergent complexes were prepared for (i) bacteriorhodopsin and (ii) FetA in complex with a ligand as examples of transmembrane proteins. A fusion of maltose-binding protein and the Duck hepatitis B virus X protein was added to this investigation as an example of a non-membrane-associated protein with low water solubility. The increased solubility of this protein in the presence of detergent could be monitored, as well as the progress of proteolytic cleavage to separate the fusion partners. This study demonstrates the potential of in situ DLS to optimize solutions of protein–detergent complexes for crystallization applications.
Multiscale Gyrokinetics for Rotating Tokamak Plasmas II: Reduced Models for Electron Dynamics
Abel, I G
2012-01-01
In this paper, we extend the multiscale approch developed in [Abel et. al., Rep. Prog. Phys., in press] by exploiting the scale separation between ions and the electrons. The gyrokinetic equation is expanded in powers of the electron to ion mass ratio, which provides a rigorous method for deriving the reduced electron model. We prove that ion-scale electromagnetic turbulence cannot change the magnetic topology, and argue that to lowest order the magnetic field lies on fluctuating flux surfaces. These flux surfaces are used to construct magnetic coordinates, and in these coordinates a closed system of equations for the electron response to ion-scale turbulence is derived. All fast electron timescales have been eliminated from these equations. We also use these magnetic surfaces to construct transport equations for electrons and for electron heat in terms of the reduced electron model.
Electron fishbone dynamics studies in tokamaks using the XHMGC code , S. Briguglio1
Vlad, Gregorio
by suprathermal electrons. Ion fish- bones were first observed experimentally (PDX) [1], opening the path to full
Microwave Heating of Water, Ice and Saline Solution: Molecular Dynamics Study
Motohiko Tanaka; Motoyasu Sato
2006-09-24
In order to study the heating process of water by the microwaves of 2.5-20GHz frequencies, we have performed molecular dynamics simulations by adopting a non-polarized water model that have fixed point charges on rigid-body molecules. All runs are started from the equilibrated states derived from the I$_{c}$ ice with given density and temperature. In the presence of microwaves, the molecules of liquid water exhibit rotational motion whose average phase is delayed from the microwave electric field. Microwave energy is transferred to the kinetic and inter-molecular energies of water, where one third of the absorbed microwave energy is stored as the latter energy. The water in ice phase is scarcely heated by microwaves because of the tight hydrogen-bonded network of water molecules. Addition of small amount of salt to pure water substantially increases the heating rate because of the weakening by defects in the water network due to sloshing large-size negative ions.
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear ProfileMultiferroicAward | DepartmentElectron thermal
Cai, D; Snell, C M; Beardmore, K M; Cai, David; Gronbech-Jensen, Niels; Snell, Charles M.; Beardmore, Keith M.
1996-01-01
It is crucial to have a good phenomenological model of electronic stopping power for modeling the physics of ion implantation into crystalline silicon. In the spirit of the Brandt-Kitagawa effective charge theory, we develop a model for electronic stopping power for an ion, which can be factorized into (i) a globally averaged effective charge taking into account effects of close and distant collisions by target electrons with the ion, and (ii) a local charge density dependent electronic stopping power for a proton. This phenomenological model is implemented into both molecular dynamics and Monte Carlo simulations. There is only one free parameter in the model, namely, the one electron radius rs0 for unbound electrons. By fine tuning this parameter, it is shown that the model can work successfully for both boron and arsenic implants. We report that the results of the dopant profile simulation for both species are in excellent agreement with the experimental profiles measured by secondary-ion mass spectrometry(...
Miyagi, Haruhide; Bojer Madsen, Lars [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)] [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)
2014-04-28
The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell N{sub e}-electron systems, the TD-RASSCF-S wave function can be fully converged using only N{sub e}/2 + 1 ? M ? N{sub e} spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with M = N{sub e} is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.
Morozovska, Anna N.; Morozovsky, Nicholas V.; Eliseev, Eugene A.; Varenyk, Olexandr V.; Kim, Yunseok; Strelcov, Evgheni; Tselev, Alexander; Kalinin, Sergei V.
2014-08-14
We performed self-consistent modelling of nonlinear electrotransport and electromechanical response of thin films of mixed ionic-electronic conductors (MIEC) allowing for steric effects of mobile charged defects (ions, protons, or vacancies), electron degeneration, and Vegard stresses. We establish correlations between the features of the nonlinear space-charge dynamics, current-voltage, and bending-voltage curves for different types of the film electrodes. A pronounced ferroelectric-like hysteresis of the bending-voltage loops and current maxima on the double hysteresis current-voltage loops appear for the electron-transport electrodes. The double hysteresis loop with pronounced humps indicates a memristor-type resistive switching. The switching occurs due to the strong nonlinear coupling between the electronic and ionic subsystems. A sharp meta-stable maximum of the electron density appears near one open electrode and moves to another one during the periodic change of applied voltage. Our results can explain the nonlinear nature and correlation of electrical and mechanical memory effects in thin MIEC films. The analytical expression proving that the electrically induced bending of MIEC films can be detected by interferometric methods is derived.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Canton, Sophie E.; Kjær, Kasper S.; Vankó, György; van Driel, Tim B.; Adachi, Shin -ichi; Bordage, Amélie; Bressler, Christian; Chabera, Pavel; Christensen, Morten; Dohn, Asmus O.; et al
2015-03-02
Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donor–acceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution as compared with storage ring facilities, these measurements constitute the first X-ray-based visualization of a non-equilibrated intramolecular electron transfer process over large interatomic distances.more »Thus experimental and theoretical results establish that mediation through electronically excited molecular states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined.« less
Wolf, Martin
, and transport effects E. Knoesel, A. Hotzel, and M. Wolf Fritz-Haber-Institut der MPG, Faradayweg 4-6, D-14195 calculation, a simulation of the ballistic transport effect and its implication on the observed electron process for a hot electron is scattering with a ``cold'' elec- tron below the Fermi level, because
Yu, J. M.; Balbuena, P. B.; Budzien, J. L.; Leung, Kevin
2011-02-22
We applied static and dynamic hybrid functional density functional theory (DFT) calculations to study the interactions of one and two excess electrons with ethylene carbonate (EC) liquid and clusters. Optimal structures of (EC)_{n} and (EC)_{n}^{-} clusters devoid of Li_{+} ions, n = 1–6, were obtained. The excess electron was found to be localized on a single EC in all cases, and the EC dimeric radical anion exhibits a reduced barrier associated with the breaking of the ethylene carbon–oxygen covalent bond compared to EC_{-}. In ab initio molecular dynamics (AIMD) simulations of EC_{-} solvated in liquid EC, large fluctuations in the carbonyl carbon–oxygen bond lengths were observed. AIMD simulations of a two-electron attack on EC in EC liquid and on Li metal surfaces yielded products similar to those predicted using nonhybrid DFT functionals, except that CO release did not occur for all attempted initial configurations in the liquid state.
Baluka, M.; Edelstein, N.; O'Donnell, T. A.
1980-10-01
Spectra have been recorded for solutions in anhydrous hydrogen fluoride (AHF) of uranium and neptunium in oxidation states (III) to (VI). The spectra for U(III), Np(III) and Np(IV) in AHF are very similar to those in acidified aqueous solution, but that for U(IV) suggests that the cationic species is UF{sub 2}{sup 2+}. The AHF spectra for the elements in oxidation states (V) and (VI) are not comparable with those of the formally analogous aqueous solutions, where the elements exist as well-defined dioxo-cations. However, the AHF spectra can be related to spectra in the gas phase, in the solid state or in non-aqueous solvents for each element in its appropriate oxidation state.
Deymier, Pierre
Ab initio molecular-dynamics method based on the restricted path integral: Application on the discretized path-integral representation of quantum particles. Fermi statistics is automatically generated by an effective exchange potential. This path-integral molecular-dynamics method is able to simulate electron
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Electron beam dynamics in the long-pulse, high-current DARHT-II linear induction accelerator
Ekdahl, Carl A; Abeyta, Epifanio O; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A; Garnett, Robert; Harrison, James F; Johnson, Jeffrey B; Jacquez, Edward B; Mccuistian, Brian T; Montoya, Nicholas A; Nath, Subrato; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rowton, Lawrence; Sanchez, Manolito; Scarpetti, Raymond; Schauer, Martin M; Seitz, Gerald; Schulze, Martin; Bender, Howard A; Broste, William B; Carlson, Carl A; Frayer, Daniel K; Johnson, Douglas E; Tom, C Y; Williams, John; Hughes, Thomas; Anaya, Richard; Caporaso, George; Chambers, Frank; Chen, Yu - Jiuan; Falabella, Steve; Guethlein, Gary; Raymond, Brett; Richardson, Roger; Trainham, C; Weir, John; Genoni, Thomas; Toma, Carsten
2009-01-01
The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. The long risetime of the 6-cell injector current pulse is 0.5 {micro}s, which can be scraped off in a beam-head cleanup zone before entering the 68-cell main accelerator. We discuss our experience with tuning this novel accelerator; and present data for the resulting beam transport and dynamics. We also present beam stability data, and relate these to previous stability experiments at lower current and energy.
Hyeon-Deuk, Kim; Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 ; Ando, Koji
2014-05-07
Liquid para-hydrogen (p-H{sub 2}) is a typical quantum liquid which exhibits strong nuclear quantum effects (NQEs) and thus anomalous static and dynamic properties. We propose a real-time simulation method of wave packet (WP) molecular dynamics (MD) based on non-empirical intra- and inter-molecular interactions of non-spherical hydrogen molecules, and apply it to condensed-phase p-H{sub 2}. The NQEs, such as WP delocalization and zero-point energy, are taken into account without perturbative expansion of prepared model potential functions but with explicit interactions between nuclear and electron WPs. The developed MD simulation for 100 ps with 1200 hydrogen molecules is realized at feasible computational cost, by which basic experimental properties of p-H{sub 2} liquid such as radial distribution functions, self-diffusion coefficients, and shear viscosities are all well reproduced.
Beam dynamics study of a 30?MeV electron linear accelerator to drive a neutron source
Kumar, Sandeep; Yang, Haeryong; Kang, Heung-Sik
2014-02-14
An experimental neutron facility based on 32?MeV/18.47?kW electron linac has been studied by means of PARMELA simulation code. Beam dynamics study for a traveling wave constant gradient electron accelerator is carried out to reach the preferential operation parameters (E?=?30?MeV, P?=?18?kW, dE/E?electron energy is required to produce acceptable neutron flux. The final neutron flux is estimated to be 5?×?10{sup 11}?n/cm{sup 2}/s/mA. Future development will be the real design of a 30?MeV electron linac based on S band traveling wave.
Mentel, ?. M.; Meer, R. van; Gritsenko, O. V.; Baerends, E. J.
2014-06-07
For chemistry an accurate description of bond weakening and breaking is vital. The great advantage of density matrix functionals, as opposed to density functionals, is their ability to describe such processes since they naturally cover both nondynamical and dynamical correlation. This is obvious in the Löwdin-Shull functional, the exact natural orbital functional for two-electron systems. We present in this paper extensions of this functional for the breaking of a single electron pair bond in N-electron molecules, using LiH, BeH{sup +}, and Li{sub 2} molecules as prototypes. Attention is given to the proper formulation of the functional in terms of not just J and K integrals but also the two-electron L integrals (K integrals with a different distribution of the complex conjugation of the orbitals), which is crucial for the calculation of response functions. Accurate energy curves are obtained with extended Löwdin-Shull functionals along the complete dissociation coordinate using full CI calculations as benchmark.
Buß, J. H.; Schaefer, A.; Hägele, D.; Rudolph, J. [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780 Bochum (Germany); Schupp, T.; As, D. J. [Department of Physics, University of Paderborn, Warburger Str. 100, D-33095 Paderborn (Germany)
2014-11-03
The electron spin dynamics in n-doped bulk cubic GaN is investigated for very high temperatures from 293?K up to 500?K by time-resolved Kerr-rotation spectroscopy. We find extraordinarily long spin lifetimes exceeding 1?ns at 500?K. The temperature dependence of the spin relaxation time is in qualitative agreement with predictions of Dyakonov-Perel theory, while the absolute experimental times are an order of magnitude shorter than predicted. Possible reasons for this discrepancy are discussed, including the role of phase mixtures of hexagonal and cubic GaN as well as the impact of localized carriers.
Effects of disorder on electron spin dynamics in a semiconductor quantum well
Loss, Daniel
characterizes the disorder potential. Using our knowledge of the DOS, a simple model estimates the temperature-doped semiconductors2,3 . Previous work also suggested that the spin dephasing rate of the electrons is suppressed
Dynamic electron correlation in interactions of light with matter formulated in b-space
Lev Kaplan; J. H. McGuire
2015-09-02
Scattering of beams of light and matter from multi-electron atomic targets is formulated in the position representation of quantum mechanics. This yields expressions for the probability amplitude, a(b), for a wide variety of processes. Here the spatial parameter b is the distance of closest approach of incoming particles traveling on a straight line with the center of the atomic target. The correlated probability amplitude, a(b), reduces to a relatively simple product of single electron probability amplitudes in the widely used independent electron approximation limit, where the correlation effects of the Coulomb interactions between the atomic electrons disappear. As an example in which a(b} has an explicit dependence on b}, we consider transversely finite vortex beams of twisted photons that lack the translational invariance of infinite plane-wave beams. Some experimental considerations and future applications are briefly considered.
Electron dynamics of the buffer layer and bilayer graphene on SiC
Shearer, Alex J.; Caplins, Benjamin W.; Suich, David E.; Harris, Charles B., E-mail: cbharris@berkeley.edu [Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Johns, James E. [Department of Chemistry, University of Minnesota Twin Cities, Minneapolis, Minnesota 55455 (United States); Hersam, Mark C. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)
2014-06-09
Angle- and time-resolved two-photon photoemission (TPPE) was used to investigate electronic states in the buffer layer of 4H-SiC(0001). An image potential state (IPS) series was observed on this strongly surface-bound buffer layer, and dispersion measurements indicated free-electron-like behavior for all states in this series. These results were compared with TPPE taken on bilayer graphene, which also show the existence of a free-electron-like IPS series. Lifetimes for the n?=?2, and n?=?3 states were obtained from time-resolved TPPE; slightly increased lifetimes were observed in the bilayer graphene sample for the n?=?2 the n?=?3 states. Despite the large band gap of graphene at the center of the Brillouin zone, the lifetime results demonstrate that the graphene layers do not behave as a simple tunneling barrier, suggesting that the buffer layer and graphene overlayers play a direct role in the decay of IPS electrons.
Longitudinal Dynamics of Twin Electron Bunches in a High-energy Linac
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Zhen [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Tsinghua University, Beijing (China); Ding, Yuantao [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Marinelli, Agostino [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Huang, Zhirong [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
2015-03-01
The recent development of two-color x-ray free-electron lasers, as well as the successful demonstration of high-gradient witness bunch acceleration in a plasma, have generated strong interest in electron bunch trains, where two or more electron bunches are generated, accelerated and compressed in the same accelerating bucket. In this paper we give a detailed analysis of a twin-bunch technique in a high-energy linac. This method allows the generation of two electron bunches with high peak current and independent control of time delay and energy separation. We #12;find that the wake#12;fields in the accelerator structures play an important role in the twin-bunch compression, and through analysis show that they can be used to extend the available time delay range. Based on the theoretical model and simulations we propose several methods to achieve larger time delay.
Longitudinal Dynamics of Twin Electron Bunches in a High-energy Linac
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Zhen; Tsinghua University, Beijing; Ding, Yuantao; Marinelli, Agostino; Huang, Zhirong
2015-03-01
The recent development of two-color x-ray free-electron lasers, as well as the successful demonstration of high-gradient witness bunch acceleration in a plasma, have generated strong interest in electron bunch trains, where two or more electron bunches are generated, accelerated and compressed in the same accelerating bucket. In this paper we give a detailed analysis of a twin-bunch technique in a high-energy linac. This method allows the generation of two electron bunches with high peak current and independent control of time delay and energy separation. We #12;find that the wake#12;fields in the accelerator structures play an important role in the twin-bunchmore »compression, and through analysis show that they can be used to extend the available time delay range. Based on the theoretical model and simulations we propose several methods to achieve larger time delay.« less
Aqueous systems from first-principles : structure, dynamics and electron-transfer reactions
Sit, Patrick Hoi Land
2006-01-01
In this thesis, we show for the first time how it is possible to calculated fully from first-principles the diabatic free-energy surfaces of electron-transfer reactions. The excitation energy corresponding to the transfer ...
The structural, electronic and dynamic properties of the L1{sub 2}- type Co{sub 3}Ti alloy
Arikan, Nihat; Özduran, Mustafa
2014-10-06
The structural, electronic and dynamic properties of the cubic Co{sub 3}Ti alloy in L1{sub 2} structure have been investigated using a pseudopotential plane wave (PP-PW) method within the generalized gradient approximation proposed by Perdew–Burke–Ernzerhof (GGA-PBE). The structural properties, including the lattice constant, the bulk modulus and its pressure derivative agree reasonably with the previous results. The density of state (DOS), projected density of state (PDOS) and electronic band structure are also reported. The DOS shows that Co{sub 3}Ti alloy has a metallic character since the energy bands cross the Fermi level. The density of states at Fermi level mainly comes from the Co-3d states. Phonon dispersion curves and their corresponding total densities of states were obtained using a linear response in the framework of the density functional perturbation theory. All computed phonon frequencies are no imaginer and thus, Co{sub 3}Ti alloy is dynamically stable. The zone center phonon modes have been founded to be 9.307, 9.626 and 13.891 THz for Co{sub 3}Ti.
Dynamic Imaging of Au-nanoparticles via Scanning Electron Microscopy in a Graphene Wet Cell
Wayne Yang; Yuning Zhang; Michael Hilke; Walter Reisner
2015-06-10
High resolution nanoscale imaging in liquid environments is crucial for studying molecular interactions in biological and chemical systems. In particular, electron microscopy is the gold-standard tool for nanoscale imaging, but its high-vacuum requirements make application to in-liquid samples extremely challenging. Here we present a new graphene based wet cell device where high resolution SEM (scanning electron microscope) and Energy Dispersive X-rays (EDX) analysis can be performed directly inside a liquid environment. Graphene is an ideal membrane material as its high transparancy, conductivity and mechanical strength can support the high vacuum and grounding requirements of a SEM while enabling maximal resolution and signal. In particular, we obtain high resolution (graphene wet cell and EDX analysis of nanoparticle composition in the liquid enviornment. Our obtained resolution surpasses current conventional silicon nitride devices imaged in both SEM and TEM under much higher electron doses.
Smolka, Linda B.
2006-01-01
J. Non-Newtonian Fluid Mech. 137 (2006) 103109 Charge screening effects on filament dynamics January 2006 Abstract We experimentally investigate the filament dynamics of non-Newtonian drops falling as an order of magnitude with the addition of KCl. The qualitative dynamics of bead formation on the filament
Algwari, Q. Th. [Centre for Plasma Physics, School of Maths and Physics, Queen's University Belfast, University Road, Belfast, Northern Ireland BT7 1NN (United Kingdom); Electronic Department, College of Electronics Engineering, Mosul University, Mosul 41002 (Iraq); O'Connell, D. [Centre for Plasma Physics, School of Maths and Physics, Queen's University Belfast, University Road, Belfast, Northern Ireland BT7 1NN (United Kingdom); York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom)
2011-09-19
The excitation dynamics within the main plasma production region and the plasma jets of a kHz atmospheric pressure dielectric barrier discharge (DBD) jet operated in helium was investigated. Within the dielectric tube, the plasma ignites as a streamer-type discharge. Plasma jets are emitted from both the powered and grounded electrode end; their dynamics are compared and contrasted. Ignition of these jets are quite different; the jet emitted from the powered electrode is ignited with a slight time delay to plasma ignition inside the dielectric tube, while breakdown of the jet at the grounded electrode end is from charging of the dielectric and is therefore dependent on plasma production and transport within the dielectric tube. Present streamer theories can explain these dynamics.
Quantum Shock Waves - the case for non-linear effects in dynamics of electronic liquids
Eldad Bettelheim; Alexander G. Abanov; Paul Wiegmann
2006-06-29
Using the Calogero model as an example, we show that the transport in interacting non-dissipative electronic systems is essentially non-linear. Non-linear effects are due to the curvature of the electronic spectrum near the Fermi energy. As is typical for non-linear systems, propagating wave packets are unstable. At finite time shock wave singularities develop, the wave packet collapses, and oscillatory features arise. They evolve into regularly structured localized pulses carrying a fractionally quantized charge - {\\it soliton trains}. We briefly discuss perspectives of observation of Quantum Shock Waves in edge states of Fractional Quantum Hall Effect and a direct measurement of the fractional charge.
Tunable mega-ampere electron current propagation in solids by dynamic control of lattice melt
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
MacLellan, D.? A.; Carroll, D.? C.; Gray, R.? J.; Booth, N.; Burza, M.; Desjarlais, M.? P.; Du, F.; Neely, D.; Powell, H.? W.; Robinson, A.? P.?L.; et al
2014-10-31
The influence of lattice-melt-induced resistivity gradients on the transport of mega-ampere currents of fast electrons in solids is investigated numerically and experimentally using laser-accelerated protons to induce isochoric heating. Tailoring the heating profile enables the resistive magnetic fields which strongly influence the current propagation to be manipulated. This tunable laser-driven process enables important fast electron beam properties, including the beam divergence, profile, and symmetry to be actively tailored, and without recourse to complex target manufacture.
Zhou, R. J.; Hu, L. Q.; Li, E. Z.; Xu, M.; Zhong, G. Q.; Xu, L. Q.; Lin, S. Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)
2013-03-15
The nature of runaway electrons is such that the confinement and dynamics of the electrons can be strongly affected by magnetic fluctuations in plasma. Experimental results in the HT-7 tokamak indicated significant losses of runaway electrons due to magnetic fluctuations, but the loss processes did not only rely on the fluctuation amplitude. Efficient radial runaway transport required that there were no more than small regions of the plasma volume in which there was very low transport of runaways. A radial runaway diffusion coefficient of D{sub r} Almost-Equal-To 10 m{sup 2}s{sup -1} was derived for the loss processes, and diffusion coefficient near the resonant magnetic surfaces and shielding factor #Greek Upsilon With Hook Symbol#=0.8 were deduced. Test particle equations were used to analyze the effect of magnetic fluctuations on runaway dynamics. It was found that the maximum energy that runaways can gain is very sensitive to the value of {alpha}{sub s} (i.e., the fraction of plasma volume with reduced transport). {alpha}{sub s}=(0.28-0.33) was found for the loss processes in the experiment, and maximum runaway energy could be controlled in the range of E=(4 MeV-6 MeV) in this case. Additionally, to control the maximum runaway energy below 5 MeV, the normalized electric field needed to be under a critical value D{sub {alpha}}=6.8, and the amplitude normalized magnetic fluctuations b(tilde sign) needed to be at least of the order of b(tilde sign) Almost-Equal-To 3 Multiplication-Sign 10{sup -5}.
Nobuyuki Takei; Christian Sommer; Claudiu Genes; Guido Pupillo; Haruka Goto; Kuniaki Koyasu; Hisashi Chiba; Matthias Weidemüller; Kenji Ohmori
2015-04-14
Many-body interactions govern a variety of important quantum phenomena ranging from superconductivity and magnetism in condensed matter to solvent effects in chemistry. Understanding those interactions beyond mean field is a holy grail of modern sciences. AMO physics with advanced laser technologies has recently emerged as a new platform to study quantum many-body systems. One of its latest developments is the study of long-range interactions among ultracold particles to reveal the effects of many-body correlations. Rydberg atoms distinguish themselves by their large dipole moments and tunability of dipolar interactions. Most of ultracold Rydberg experiments have been performed with narrow-band lasers in the Rydberg blockade regime. Here we demonstrate an ultracold Rydberg gas in a complementary regime, where electronic coherence is created using a broadband picosecond laser pulse, thus circumventing the Rydberg blockade to induce strong many-body correlations. The effects of long-range Rydberg interactions have been investigated by time-domain Ramsey interferometry with attosecond precision. This approach allows for the real-time observation of coherent and ultrafast many-body dynamics in which the electronic coherence is modulated by the interaction-induced correlations. The modulation evolves more rapidly than expected for two-body correlations by several orders of magnitude. We have actively controlled such ultrafast many-body dynamics by tuning the principal quantum number and the population of the Rydberg state. The observed Ramsey interferograms are well reproduced by a theoretical model beyond mean-field approximation, which can be relevant to other similar many-body phenomena in condensed matter physics and chemistry. Our new approach opens a new avenue to observe and manipulate nonequilibrium dynamics of strongly-correlated quantum many-body systems on the ultrafast timescale.
Diessel, Oliver
and Instrumentation Oliver Diessel School of Computer Science & Engineering University of New South Wales, Sydney NSW the capabilities of this technology with respect to applications in electronic measurement and instrumentation can be used to implement any digital circuit for which there are sufficient resources available
Nonadiabatic Molecular Dynamics Study of Electron Transfer from Alizarin to the Hydrated Ti4+ Ion
to the more costly traditional solar cell.1-5 It employs organic or transition-metal- based chromophores that forms the basis of the Gra¨tzel type solar cell. The experimental data and electronic structure The dye-sensitized nanocrystalline solar cell, also known as the Gra¨tzel cell, is a promising alternative
Dynamics of an electron confined to a "hybrid plane" and interacting with a magnetic field
Raffaele Carlone; Pavel Exner
2010-12-13
We discuss spectral and resonance properties of a Hamiltonian describing motion of an electron moving on a "hybrid surface" consisting on a halfline attached by its endpoints to a plane under influence of a constant magnetic field which interacts with its spin through a Rashba-type term.
Grapes, Michael D.; LaGrange, Thomas; Reed, Bryan W.; Campbell, Geoffrey H.; Friedman, Lawrence H.; LaVan, David A.; Weihs, Timothy P.
2014-08-15
Nanocalorimetry is a chip-based thermal analysis technique capable of analyzing endothermic and exothermic reactions at very high heating and cooling rates. Here, we couple a nanocalorimeter with an extremely fast in situ microstructural characterization tool to identify the physical origin of rapid enthalpic signals. More specifically, we describe the development of a system to enable in situ nanocalorimetry experiments in the dynamic transmission electron microscope (DTEM), a time-resolved TEM capable of generating images and electron diffraction patterns with exposure times of 30 ns–500 ns. The full experimental system consists of a modified nanocalorimeter sensor, a custom-built in situ nanocalorimetry holder, a data acquisition system, and the DTEM itself, and is capable of thermodynamic and microstructural characterization of reactions over a range of heating rates (10{sup 2} K/s–10{sup 5} K/s) accessible by conventional (DC) nanocalorimetry. To establish its ability to capture synchronized calorimetric and microstructural data during rapid transformations, this work describes measurements on the melting of an aluminum thin film. We were able to identify the phase transformation in both the nanocalorimetry traces and in electron diffraction patterns taken by the DTEM. Potential applications for the newly developed system are described and future system improvements are discussed.
Dynamics of the electric current in an ideal electron gas: a sound mode inside the quasi-particles
Sašo Grozdanov; Janos Polonyi
2015-09-03
We study the equation of motion for the Noether current in an electron gas within the framework of the Schwinger-Keldysh Closed-Time-Path formalism. The equation is shown to be highly non-linear and irreversible even for a non-interacting, ideal gas of electrons at non-zero density. We truncate the linearised equation of motion, written as the Laurent series in Fourier space, so that the resulting expressions are local in time, both at zero and at small finite temperatures. Furthermore, we show that the one-loop Coulomb interactions only alter the physical picture quantitatively, while preserving the characteristics of the dynamics that the electric current exhibits in the absence of interactions. As a result of the composite nature of the Noether current, {\\it composite sound} waves are found to be the dominant IR collective excitations at length scales between the inverse Fermi momentum and the mean free path that would exist in an interacting electron gas. We also discuss the difference and the transition between the hydrodynamical regime of an ideal gas, defined in this work, and the hydrodynamical regime in phenomenological hydrodynamics, which is normally used for the description of interacting gases.
Dynamics of the electric current in an ideal electron gas: a sound mode inside the quasi-particles
Grozdanov, Sašo
2015-01-01
We study the equation of motion for the Noether current in an electron gas within the framework of the Schwinger-Keldysh Closed-Time-Path formalism. The equation is shown to be highly non-linear and irreversible even for a non-interacting, ideal gas of electrons at non-zero density. We truncate the linearised equation of motion, written as the Laurent series in Fourier space, so that the resulting expressions are local in time, both at zero and at small finite temperatures. Furthermore, we show that the one-loop Coulomb interactions only alter the physical picture quantitatively, while preserving the characteristics of the dynamics that the electric current exhibits in the absence of interactions. As a result of the composite nature of the Noether current, composite sound waves are found to be the dominant IR collective excitations at length scales between the inverse Fermi momentum and the mean free path that would exist in an interacting electron gas. We also discuss the difference and the transition betwee...
Abellan Baeza, Patricia; Mehdi, Beata L.; Parent, Lucas R.; Gu, Meng; Park, Chiwoo; Xu, Wu; Zhang, Yaohui; Arslan, Ilke; Zhang, Jiguang; Wang, Chong M.; Evans, James E.; Browning, Nigel D.
2014-03-12
One of the goals in the development of new battery technologies is to find new electrolytes with increased electrochemical stability. In-situ (scanning) transmission electron microscopy ((S)TEM) using an electrochemical fluid cell provides the ability to rapidly and directly characterize electrode/electrolyte interfacial reactions under battery relevant electrochemical conditions. Furthermore, as the electron beam itself causes a localized electrochemical reaction when it interacts with the electrolyte, the breakdown products that occur during the first stages of battery operation can potentially be simulated and characterized using a straightforward in-situ liquid stage (without electrochemical biasing capabilities). In this paper, we have studied the breakdown of a range of inorganic/salt complexes that are used in state-of-the-art Li-ion battery systems. The results of the in-situ (S)TEM experiments matches with previous stability tests performed during battery operation and the breakdown products and mechanisms are also consistent with known mechanisms. This analysis indicates that in-situ liquid stage (S)TEM observations can be used to directly test new electrolyte designs and provide structural insights into the origin of the solid electrolyte interphase (SEI) formation mechanism.
Hu, Y.H.; Ruckenstein, E.
1999-05-15
The carbon deposition due to the CH{sub 4} decomposition at 790 C over NiO/MgO catalysts was investigated by high-resolution transmission electron microscopy. While no deposits could be detected over the catalysts with a NiO content smaller than 9.1 wt%, they were detected over the catalysts with NiO contents of 23 and 50 wt%. The carbon deposits are composed of platelets located at distances of about 0.34 nm, corresponding to the graphitic carbon. Various structures of the deposited carbon were observed: (a) carbon consisting of platelets parallel to the surface of the particle, which covers a catalyst particle, (b) nanotubes composed of platelets parallel to their axis, and (c) carbon vortexes consisting of platelets parallel to their axis.
Akatay, M. Cem; Zvinevich, Yury; Ribeiro, Fabio H. E-mail: estach@bnl.gov; Baumann, Philipp; Stach, Eric A. E-mail: estach@bnl.gov
2014-03-15
A gas mixing manifold system that is capable of delivering a stable pressure stream of a desired composition of gases into an environmental transmission electron microscope has been developed. The system is designed to provide a stable imaging environment upon changes of either the composition of the gas mixture or upon switching from one gas to another. The design of the system is described and the response of the pressure inside the microscope, the sample temperature, and sample drift in response to flow and composition changes of the system are reported.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Feng; Sun, Yang; Ye, Zhuo; Zhang, Yue; Wang, Cai -Zhuang; Mendelev, Mikhail I.; Ott, Ryan T.; Kramer, Matthew J.; Ding, Ze -Jun; Ho, Kai -Ming
2015-05-06
In this study, we have performed molecular dynamics simulations on a typical Al-based alloy Al90Sm10. The short-range and medium-range correlations of the system are reliably produced by ab initio calculations, whereas the long-range correlations are obtained with the assistance of a semi-empirical potential well-fitted to ab initio data. Our calculations show that a prepeak in the structure factor of this system emerges well above the melting temperature, and the intensity of the prepeak increases with increasing undercooling of the liquid. These results are in agreement with x-ray diffraction experiments. The interplay between the short-range order of the system originating frommore »the large affinity between Al and Sm atoms, and the intrinsic repulsion between Sm atoms gives rise to a stronger correlation in the second peak than the first peak in the Sm–Sm partial pair correlation function (PPCF), which in turn produces the prepeak in the structure factor.« less
Electron dynamics inside a vacuum tube diode through linear differential equations
Gonzalez, Gabriel
2013-01-01
In this paper we analyze the motion of charged particles in a vacuum tube diode by solving linear differential equations. Our analysis is based on expressing the volume charge density as a function of the current density and coordinates only, while in the usual scheme the volume charge density is expressed as a function of the current density and electrostatic potential. Our approach gives the well known behavior of the classical current density proportional to the three-halves power of the bias potential and inversely proportional to the square of the gap distance between the electrodes, and does not require the solution of the nonlinear differential equation normally associated with the Child-Langmuir formulation.
Tayebi, Amin; Paladhi, Pavel Roy; Udpa, Lalita; Udpa, Satish; Rothwell, Edward
2015-01-01
An electronically reconfigurable dual-band-reflectarray antenna is presented in this paper. The tunable unit cell, a ring loaded square patch with a single varactor diode connected across the gap between the ring and the patch, is modeled using both a full-wave solver and an equivalent circuit. The parameters of the equivalent circuit are calculated independently of the simulation and experiment using analysis techniques employed in frequency selective surfaces. The reflection phase of the proposed unit cell is shown to provide an excellent phase range of 335$^{\\circ}$ in F band and 340$^{\\circ}$ in S band. Results from the analysis are used to design and build a 10x10 element reflectarray antenna. The high tuning phase range of each element allows the fabricated reflectarray to demonstrate a very broad steering range of up to $\\pm$60$^{\\circ}$ in both frequency bands.
van Stokkum, Ivo
852 J. Phys. Chem. 1994, 98, 852-866 ConformationalDynamics of Flexibly and Semirigidly Bridged Electron Donor-Acceptor Systems As Revealed by Spectrotemporal Parameterization of Fluorescence I. H.M. van: a flexible trimethylene chain and a semirigid piperidine ring. In moderately polar solvents (6 > 3.5) only
Optimizing a dynamical decoupling protocol for solid-state electronic spin ensembles in diamond
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Farfurnik, D.; Jarmola, A.; Pham, L. M.; Wang, Z. H.; Dobrovitski, V. V.; Walsworth, R. L.; Budker, D.; Bar-Gill, N.
2015-08-24
We demonstrate significant improvements of the spin coherence time of a dense ensemble of nitrogen-vacancy (NV) centers in diamond through optimized dynamical decoupling (DD). Cooling the sample down to 77 K suppresses longitudinal spin relaxation T1 effects and DD microwave pulses are used to increase the transverse coherence time T2 from ~0.7ms up to ~30ms. Furthermore, we extend previous work of single-axis (Carr-Purcell-Meiboom-Gill) DD towards the preservation of arbitrary spin states. Following a theoretical and experimental characterization of pulse and detuning errors, we compare the performance of various DD protocols. We also identify that the optimal control scheme for preservingmore »an arbitrary spin state is a recursive protocol, the concatenated version of the XY8 pulse sequence. The improved spin coherence might have an immediate impact on improvements of the sensitivities of ac magnetometry. Moreover, the protocol can be used on denser diamond samples to increase coherence times up to NV-NV interaction time scales, a major step towards the creation of quantum collective NV spin states.« less
Kim, Sang Kyu
Clustering Dynamics of the Metal-Benzene Sandwich Complex: The Role of Microscopic Structure of the Solute In the Bis(6-benzene)chromium ·Arn Clusters (n ) 1-15) Kyo-Won Choi, Sunyoung Choi, Doo-Sik AhnVised Manuscript ReceiVed: June 25, 2008 Ar clustering dynamics around the metal-benzene sandwich complex, bis(6
Tian You Fan
2012-10-05
The observation recently of 12-fold quasicrystals in polymers, nanoparticle mixture and 12-fold and 18-fold quasicrystals in colloidal solutions are important events for the study of quasicrystals. To describe the mechanical behaviour we propose a new solid-liquid phase quasicrystal model for some soft matters including polymers and colloids. The so-called new solid-liquid phase, is a new phase model of anisotropic fluid, but different from liquid crystal phase, here the structure presents quasiperiodic symmetry. Based on the model, the elasticity, fluidity and viscosity of the material have been studied, the relevant mathematical theory has also been proposed. Some mathematical solutions of the theory are discussed.
Torque for electron spin induced by electron permanent electric dipole moment
Senami, Masato E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo E-mail: akitomo@scl.kyoto-u.ac.jp
2014-10-06
The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.
Xiong, Qihua
2014-01-01
on their solar energy conversion efficiency. DOI: 10.1103/PhysRevB.90.035208 PACS number(s): 72.15.Jf, 63.20.kd system could be fur- ther improved [8]. Although device engineering and materials optimization of these lattice dynamics would shed light on the suitability of Sb2S3 as an absorber layer for solar energy
Lu, Ping
2014-10-01
Controlling metallic nanoparticle (NP) interactions plays a vital role in the development of new joining techniques (nanosolder) that bond at lower processing temperatures but remain viable at higher temperatures. The pr imary objective of this project is t o develop a fundamental understanding of the actual reaction processes, associated atomic mechanisms, and the resulting microstructure that occur during thermally - driven bond formation concerning metal - metal nano - scale (<50nm) interfaces. In this LDRD pr oject, we have studied metallic NPs interaction at the elevated temperatures by combining in - situ transmission electron microscopy (TEM ) using an aberration - corrected scanning transmission electron microscope (AC - STEM) and atomic - scale modeling such as m olecular dynamic (MD) simulations. Various metallic NPs such as Ag, Cu and Au are synthesized by chemical routines. Numerous in - situ e xperiments were carried out with focus of the research on study of Ag - Cu system. For the first time, using in - situ STEM he ating experiments , we directly observed t he formation of a 3 - dimensional (3 - D) epitaxial Cu - Ag core - shell nanoparticle during the thermal interaction of Cu and Ag NPs at elevated temperatures (150 - 300 o C). The reaction takes place at temperatures as low as 150 o C and was only observed when care was taken to circumvent the effects of electron beam irradiation during STEM imaging. Atomic - scale modeling verified that the Cu - Ag core - shell structure is energetically favored, and indicated that this phenomenon is a nano - scale effect related to the large surface - to - volume ratio of the NPs. The observation potentially can be used for developing new nanosolder technology that uses Ag shell as the %22glue%22 that stic ks the particles of Cu together. The LDRD has led to several journal publications and numerous conference presentations, and a TA. In addition, we have developed new TEM characterization techniques and phase - field modeling tools that can be used for future materials research at Sandia. Acknowledgeme nts This work was supported by the Laboratory Directed Research and Development (LDRD) program of Sandia National Laboratories. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidia ry of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.
Mondal, Santanu; Chakrabarti, Sandip K
2014-01-01
We study accretion flow dynamics of Galactic transient black hole candidate (BHC) H 1743-322 during its 2010 outburst by analyzing spectral data using Two Component (Keplerian and sub-Keplerian) Advective Flow (TCAF) solution, after its inclusion in XSPEC as a local model. We compare our TCAF solution fitted results with combined disk black body and power-law model fitted results and find a similar smooth variation of thermal (Keplerian or disk black body) and non-thermal (power-law or sub-Keplerian) fluxes/rates in two types of model fits. For a spectral analysis, 2.5-25 keV spectral data from RXTE PCA instrument are used. From the TCAF solution fit, accretion flow parameters, such as Keplerian rate, sub-Keplerian rate, location of centrifugal pressure supported shock and strength of the shock are extracted, thus providing a deeper understanding of accretion process and properties of accretion disks around BHC H 1743-322 during its X-ray outburst. Based on the halo to disk accretion rate ratio (ARR), shock p...
Meng, Da; Zheng, Bin; Lin, Guang; Sushko, Maria L.
2014-08-29
We have developed efficient numerical algorithms for the solution of 3D steady-state Poisson-Nernst-Planck equations (PNP) with excess chemical potentials described by the classical density functional theory (cDFT). The coupled PNP equations are discretized by finite difference scheme and solved iteratively by Gummel method with relaxation. The Nernst-Planck equations are transformed into Laplace equations through the Slotboom transformation. Algebraic multigrid method is then applied to efficiently solve the Poisson equation and the transformed Nernst-Planck equations. A novel strategy for calculating excess chemical potentials through fast Fourier transforms is proposed which reduces computational complexity from O(N2) to O(NlogN) where N is the number of grid points. Integrals involving Dirac delta function are evaluated directly by coordinate transformation which yields more accurate result compared to applying numerical quadrature to an approximated delta function. Numerical results for ion and electron transport in solid electrolyte for Li ion batteries are shown to be in good agreement with the experimental data and the results from previous studies.
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
Graphene Conductors .. 41 Fabrication .. 44 Printing Conditions Optimization 44 ii Experimental Setup and Sample Preparation
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
of plastic- compatible electrolyte, this memory technologylow-cost plastic substrates and makes this technology lesstechnology would require flexible substrates, such as plastics.
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
review,” Solar Energy Materials and Solar Cells, vol. 91,cells,” Solar Energy Materials and Solar Cells, vol. 75, no.conductors as solar energy materials: A panoramic
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
layers for organic diodes and solar cells, and contacts tosensitized solar cells, as well as organic and inorganicorganic semiconductors in both diode (OLED and solar cell)[
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
Ultrasmooth Graphene Nanoribbon Semiconductors,” Science,layer graphene is a zero-bandgap semiconductor, although amade of graphene as a contact for organic semiconductors in
SOLUTION-PROCESSED INORGANIC ELECTRONICS
Bakhishev, Teymur
2011-01-01
4.7. It consists of a solid electrolyte stacked between twoa reactive electrode, a solid electrolyte, and an inert
Electron acoustic wave driven vortices with non-Maxwellian hot electrons in magnetoplasmas
Haque, Q.; Mirza, Arshad M.; Zakir, U.
2014-07-15
Linear dispersion characteristics of the Electron Acoustic Wave (EAW) and the corresponding vortex structures are investigated in a magnetoplasma in the presence of non-Maxwellian hot electrons. In this regard, kappa and Cairns distributed hot electrons are considered. It is noticed that the nonthermal distributions affect the phase velocity of the EAW. Further, it is found that the phase velocity of EAW increases for Cairns and decreases for kappa distributed hot electrons. Nonlinear solutions in the form of dipolar vortices are also obtained for both stationary and non-stationary ions in the presence of kappa distributed hot electrons and dynamic cold electrons. It is found that the amplitude of the nonlinear vortex structures also reduces with kappa factor like the electron acoustic solitons.
J. L. Alonso; J. Clemente-Gallardo; P. Echenique-Robba; J. A. Jover-Galtier
2013-09-02
In spite of the relevance of the proposal introduced in the recent work A. Abedi, N. T. Maitra and E. K. U. Gross, J. Chem. Phys. 137, 22A530, 2012, there is an important ingredient which is missing. Namely, the proof that the norms of the electronic and nuclear wavefunctions which are the solutions to the nonlinear equations of motion are preserved by the evolution. To prove the conservation of these norms is precisely the objective of this Comment.
Vinh, N Q; Allen, S James; George, D K; Rahmani, A J; Plaxco, Kevin W
2015-01-01
Because it is sensitive to fluctuations occurring over femtoseconds to picoseconds, gigahertz-to-terahertz dielectric relaxation spectroscopy can provide a valuable window into water's most rapid intermolecular motions. In response, we have built a vector network analyzer dielectric spectrometer capable of measuring absorbance and index of refraction in this frequency regime with unprecedented precision. Using this to determine the complex dielectric response of water and aqueous salt solutions from 5.9 GHz to 1.12 THz (which we provide in the SI), we have obtained strong new constraints on theories of water's collective dynamics. For example, while the salt-dependencies we observe for water's two slower relaxations (8 and 1 ps) are easily reconciled with suggestions that they arise due to rotations of fully and partially hydrogen bonded molecules, respectively, the salt-dependence of the fastest relaxation (180 fs) appears difficult to reconcile with its prior assignment to liberations of single hydrogen bon...
LaGrange, T; Campbell, G H; Browning, N D; Reed, B W; Grummon, D S
2010-03-01
The crystallization processes of the as-deposited, amorphous NiTi thin films have been studied in detail using techniques such as differential scanning calorimetry and, in-situ TEM. The kinetic data have been analyzed in terms of Johnson-Mehl-Avrami-Kolomogrov (JMAK) semi-empirical formula. The kinetic parameters determined from this analysis have been useful in defining process control parameters for tailoring microstructural features and shape memory properties. Due to the commercial push to shrink thin film-based devices, unique processing techniques have been developed using laser-based annealing to spatially control the microstructure evolution down to sub-micron levels. Nanosecond, pulse laser annealing is particularly attractive since it limits the amount of peripheral heating and unwanted microstructural changes to underlying or surrounding material. However, crystallization under pulsed laser irradiation can differ significantly from conventional thermal annealing, e.g., slow heating in a furnace. This is especially true for amorphous NiTi materials and relevant for shape memory thin film based microelectromechanical systems (MEMS) applications. There is little to no data on the crystallization kinetics of NiTi under pulsed laser irradiation, primarily due to the high crystallization rates intrinsic to high temperature annealing and the spatial and temporal resolution limits of standard techniques. However, with the high time and spatial resolution capabilities of the dynamic transmission electron microscope (DTEM) constructed at Lawrence Livermore National Laboratory, the rapid nucleation events occurring from pulsed laser irradiation can be directly observed and nucleation rates can be quantified. This paper briefly explains the DTEM approach and how it used to investigate the pulsed laser induced crystallization processes in NiTi and to determine kinetic parameters.
Pasciak, Alexander Samuel
2009-05-15
There are two principal techniques for performing Monte Carlo electron transport computations. The first, and least common, is the full track-structure method. This method individually models all physical electron interactions ...
Bourg, Ian C.; Sposito, Garrison
2011-01-01
We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl–CaCl_{2} electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO_{2} or high-level radioactive waste (0.34–1.83 mol_{c} dm^{-3}). Our results confirm the existence of three distinct ion adsorption planes (0-, ?-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the ?- and d-planes are independent of ionic strength or ion type and (2) “indifferent electrolyte” ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl+ ion pairs. Therefore, at concentrations {>=0.34 mol_{c} dm^{-3}}, properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid “ice-like” structures for water on clay mineral surfaces.
Accelerated, energy-conserving BornOppenheimer molecular dynamics via Fock matrix extrapolation
Herbert, John
in order to accelerate convergence of the electronic structure calculations, can suffer from systematicOppenheimer molecular dynamics calculations, especially those that exploit information retained from previous time steps, on a potential energy surface obtained by ``on-the-fly'' solution of the quantum-mechanical electronic structure
Adiabatic electronic flux density: a Born-Oppenheimer Broken Symmetry ansatz
Pohl, Vincent
2015-01-01
The Born-Oppenheimer approximation leads to the counterintuitive result of a vanishing electronic flux density upon vibrational dynamics in the electronic ground state. To circumvent this long known issue, we propose using pairwise anti-symmetrically translated vibronic densities to generate a symmetric electronic density that can be forced to satisfy the continuity equation approximately. The so-called Born-Oppenheimer broken symmetry ansatz yields all components of the flux density simultaneously while requiring only knowledge about the nuclear quantum dynamics on the electronic adiabatic ground state potential energy surface. The underlying minimization procedure is transparent and computationally inexpensive, and the solution can be computed from the standard output of any quantum chemistry program. Taylor series expansion reveals that the implicit electron dynamics originates from non-adiabatic coupling to the explicit Born-Oppenheimer nuclear dynamics. The new approach is applied to the ${\\rm H}_2^+$ mo...
del Alamo, Jesús A.
event is characterized by a fast release of trapped charge through a temperature-independent tunneling-resistance, FET, GaN, high electron-mobility transistor (HEMT), transient, trapping. I. INTRODUCTION IN THE last3190 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 60, NO. 10, OCTOBER 2013 Methodology for the Study
Angulo Wilfredo; Contreras Joyne
2014-12-19
We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.
Wilfredo, Angulo
2014-01-01
We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.
Kluge, T., E-mail: t.kluge@hzdr.de; Huang, L. G.; Metzkes, J.; Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany)] [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Gutt, C. [Universität Siegen, D-57068 Siegen (Germany)] [Universität Siegen, D-57068 Siegen (Germany); Schramm, U.; Cowan, T. E. [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany) [Helmholtz-Zentrum Dresden-Rossendorf e.V., D-01328 Dresden (Germany); Technische Universität Dresden, D-01062 Dresden (Germany)
2014-03-15
We demonstrate the potential of X-ray free-electron lasers (XFEL) to advance the understanding of complex plasma dynamics by allowing for the first time nanometer and femtosecond resolution at the same time in plasma diagnostics. Plasma phenomena on such short timescales are of high relevance for many fields of physics, in particular in the ultra-intense ultra-short laser interaction with matter. Highly relevant yet only partially understood phenomena become directly accessible in experiment. These include relativistic laser absorption at solid targets, creation of energetic electrons and electron transport in warm dense matter, including the seeding and development of surface and beam instabilities, ambipolar expansion, shock formation, and dynamics at the surfaces or at buried layers. In this paper, we focus on XFEL plasma probing for high power laser matter interactions based on quantitative calculations using synthesized data and evaluate the feasibility of various imaging and scattering techniques with special focus on the small angle X-ray scattering technique.
Röder, Beate
Dynamics from Pump-Probe Signals S. Ramakrishna* and F. Willig Hahn-Meitner-Institut, 14109 Berlin, Germany Numerical calculations of pump-probe signals corresponding to excited-state absorption of the molecular to model the pump-probe dynamics. The continuum of semiconductor states, namely, its conduction-band levels
Kanicki, Jerzy
-matrix organic light- emitting display (AM-OLED), bottom gate, corbino, dynamic measurement, dynamic response. INTRODUCTION TO DATE, the active-matrix organic light-emitting dis- play (AM-OLED) has attracted many interests of Normal and Corbino a-Si:H TFTs for AM-OLEDs Hojin Lee, Chun-Sung Chiang, and Jerzy Kanicki, Senior Member
Skovorodko, P. A.; Sharafutdinov, R. G.
2014-12-09
The paper is devoted to experimental and numerical study of the gas jet technical device for obtaining axisymmetric flow with low pressure in its near axis region. The studied geometry of the device is typical of that used in the plasma generator consisting of an electron gun with a hollow (plasma) cathode and a double supersonic ring nozzle. The geometry of the nozzles as well as the relation between the gas flow rates through the nozzles providing the electron beam extraction into the region with increased pressure are tested both experimentally and numerically. The maximum external pressure of about 0.25 bar that does not disturb the electron beam is achieved.
Willingale, L.; Thomas, A. G. R.; Maksimchuk, A; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109 (United States)] [Center for Ultrafast Optical Science, University of Michigan, 2200 Bonisteel Boulevard, Ann Arbor, Michigan 48109 (United States); Morace, A. [University of California-San Diego, La Jolla, California 92093 (United States) [University of California-San Diego, La Jolla, California 92093 (United States); Università di Milano-Biocca, Piazza della Scienza 3, 20126 Milano (Italy); Bartal, T.; Kim, J.; Beg, F. N. [University of California-San Diego, La Jolla, California 92093 (United States)] [University of California-San Diego, La Jolla, California 92093 (United States); Stephens, R. B.; Wei, M. S. [General Atomics, San Diego, California 92121 (United States)] [General Atomics, San Diego, California 92121 (United States)
2013-12-15
Simultaneous experimental measurements of copper K{sub ?} imaging and the maximum target normal sheath acceleration proton energies from the rear target surface are compared for various target thicknesses. For the T-cubed laser (?4 J, 400 fs) at an intensity of ?2 × 10{sup 19} W cm{sup ?2}, the hot electron divergence is determined to be ?{sub HWHM}?22{sup °} using a K{sub ?} imaging diagnostic. The maximum proton energies are measured to follow the expected reduction with increasing target thickness. Numerical modeling produces copper K{sub ?} trends for both signal level and electron beam divergence that are in good agreement with the experiment. A geometric model describing the electron beam divergence reproduces the maximum proton energy trends observed from the experiment and the fast electron density and the peak electric field observed in the numerical modeling.
chsm.Rev. 1992. 92.463-480 463 Dynamical Solvent Effects on Activated Electron-Transfer Reactions
Turro, Nicholas J.
influencesexerted by the solvating environment upon the kinetics of electron- transfer (ET)proteases, either solvent influences upon AG' attributed to the reactionfree energy, AGO, whereas the former describesthe only mildly by the "slow" nuclear solvent modes. In addition to such energetic factors, however, one
Birattari, Mauro
Methods in the Dynamic Assessment of Power Components Loading Capability Domenico Villacci, Member, IEEE loading of power components in the deregulated electricity market demands reliable assessment models- ticular, we focus on the problem of forecasting the hot-spot temper- ature of a mineral
Conjugated Polymer Design and Engineering for Organic Electronics
Woo, Claire Hoi Kar
2011-01-01
W. ; Forrest, S. R. Organic Electronics 2003, 4, 77-87. (24)Aspects of Organic Electronics: From Fundamentals toof solution-processed organic electronics rapidly advancing,
Modeste Nguimdo, Romain, E-mail: Romain.Nguimdo@vub.ac.be [Applied Physics Research Group, APHY, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel (Belgium); Tchitnga, Robert [Laboratory of Electronics, Automation and Signal Processing, Department of Physics, University of Dschang, P.O. Box 67, Dschang (Cameroon)] [Laboratory of Electronics, Automation and Signal Processing, Department of Physics, University of Dschang, P.O. Box 67, Dschang (Cameroon); Woafo, Paul [Laboratory of Modelling and Simulation in Engineering and Biological Physics, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé (Cameroon)] [Laboratory of Modelling and Simulation in Engineering and Biological Physics, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé (Cameroon)
2013-12-15
We numerically investigate the possibility of using a coupling to increase the complexity in simplest chaotic two-component electronic circuits operating at high frequency. We subsequently show that complex behaviors generated in such coupled systems, together with the post-processing are suitable for generating bit-streams which pass all the NIST tests for randomness. The electronic circuit is built up by unidirectionally coupling three two-component (one active and one passive) oscillators in a ring configuration through resistances. It turns out that, with such a coupling, high chaotic signals can be obtained. By extracting points at fixed interval of 10?ns (corresponding to a bit rate of 100?Mb/s) on such chaotic signals, each point being simultaneously converted in 16-bits (or 8-bits), we find that the binary sequence constructed by including the 10(or 2) least significant bits pass statistical tests of randomness, meaning that bit-streams with random properties can be achieved with an overall bit rate up to 10×100 Mb/s =1Gbit/s (or 2×100 Mb/s =200 Megabit/s). Moreover, by varying the bias voltages, we also investigate the parameter range for which more complex signals can be obtained. Besides being simple to implement, the two-component electronic circuit setup is very cheap as compared to optical and electro-optical systems.
Electron Thermodynamics in GRMHD Simulations of Low-Luminosity Black Hole Accretion
Ressler, Sean M; Quataert, Eliot; Chandra, Mani; Gammie, Charles F
2015-01-01
Simple assumptions made regarding electron thermodynamics often limit the extent to which general relativistic magnetohydrodynamic (GRMHD) simulations can be applied to observations of low-luminosity accreting black holes. We present, implement, and test a model that self-consistently evolves an electron entropy equation and takes into account the effects of spatially varying electron heating and relativistic anisotropic thermal conduction along magnetic field lines. We neglect the back-reaction of electron pressure on the dynamics of the accretion flow. Our model is appropriate for systems accreting at $\\ll 10^{-5}$ of the Eddington rate, so radiative cooling by electrons can be neglected. It can be extended to higher accretion rates in the future by including electron cooling and proton-electron Coulomb collisions. We present a suite of tests showing that our method recovers the correct solution for electron heating under a range of circumstances, including strong shocks and driven turbulence. Our initial a...
Pseudopotential for the electron-electron interaction
Lloyd-Williams, J H; Conduit, G J
2015-01-01
We propose a pseudopotential for the electron-electron Coulomb interaction to improve the efficiency of many-body electronic structure calculations. The pseudopotential accurately replicates the scattering properties of the Coulomb interaction, and recovers the analytical solution for two electrons in a parabolic trap. A case study for the homogeneous electron gas using the diffusion Monte Carlo and configuration interaction methods recovers highly accurate values for the ground state energy, and the smoother potential reduces the computational cost by a factor of ~30. Finally, we demonstrate the use of the pseudopotential to study isolated lithium and beryllium atoms.
Takei, Nobuyuki; Genes, Claudiu; Pupillo, Guido; Goto, Haruka; Koyasu, Kuniaki; Chiba, Hisashi; Weidemüller, Matthias; Ohmori, Kenji
2015-01-01
Many-body interactions govern a variety of important quantum phenomena ranging from superconductivity and magnetism in condensed matter to solvent effects in chemistry. Understanding those interactions beyond mean field is a holy grail of modern sciences. AMO physics with advanced laser technologies has recently emerged as a new platform to study quantum many-body systems. One of its latest developments is the study of long-range interactions among ultracold particles to reveal the effects of many-body correlations. Rydberg atoms distinguish themselves by their large dipole moments and tunability of dipolar interactions. Most of ultracold Rydberg experiments have been performed with narrow-band lasers in the Rydberg blockade regime. Here we demonstrate an ultracold Rydberg gas in a complementary regime, where electronic coherence is created using a broadband picosecond laser pulse, thus circumventing the Rydberg blockade to induce strong many-body correlations. The effects of long-range Rydberg interactions h...
Random walk approach to spin dynamics in a two-dimensional electron gas with spin-orbit coupling
Yang, Luyi; Orenstein, J.; Lee, Dung-Hai
2010-09-27
We introduce and solve a semiclassical random walk (RW) model that describes the dynamics of spin polarization waves in zinc-blende semiconductor quantum wells. We derive the dispersion relations for these waves, including the Rashba, linear and cubic Dresselhaus spin-orbit interactions, as well as the effects of an electric field applied parallel to the spin polarization wave vector. In agreement with calculations based on quantum kinetic theory [P. Kleinert and V. V. Bryksin, Phys. Rev. B 76, 205326 (2007)], the RW approach predicts that spin waves acquire a phase velocity in the presence of the field that crosses zero at a nonzero wave vector, q{sub 0}. In addition, we show that the spin-wave decay rate is independent of field at q{sub 0} but increases as (q-q{sub 0}){sup 2} for q {ne} q{sub 0}. These predictions can be tested experimentally by suitable transient spin grating experiments.
Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics
1993-12-31
In the past few years there has been a resurgence of interest in dynamical impurity problems, as a result of developments in the theory of correlated electron systems. The general dynamical impurity problem is a set of conduction electrons interacting with an impurity which has internal degrees of freedom. The simplest and earliest example, the Kondo problem, has attracted interest since the mid-sixties not only because of its physical importance but also as an example of a model displaying logarithmic divergences order by order in perturbation theory. It provided one of the earliest applications of the renormalization group method, which is designed to deal with just such a situation. As we shall see, the antiferromagnetic Kondo model is controlled by a strong-coupling fixed point, and the essence of the renormalization group solution is to carry out the global renormalization numerically starting from the original (weak-coupling) Hamiltonian. In these lectures, we shall describe an alternative route in which we identify an exactly solvable model which renormalizes to the same fixed point as the original dynamical impurity problem. This approach is akin to determining the critical behavior at a second order phase transition point by solving any model in a given universality class.
Electron Cyclotron Resonances in Electron Cloud Dynamics
Celata, C. M.
2008-01-01
z positions in the International Linear Collider positrondesign for the International Linear Collider (ILC). We have
Watching Electrons Transfer from Metals to Insulators using Two Photon Photoemission
Johns, James E.
2010-01-01
principles calculations of hot-electron lifetimes in metals.Harris, Femtosecond studies of electron tunneling at metal-M. , Electronic structure and electron dynamics at Si(100).
Cao Jun; Liu Lihong; Fang Weihai; Xie Zhizhong; Zhang Yong
2013-04-07
Azobenzene is one of the most widely used photoactive units and recently an ethylene-bridged azobenzene (BAB) was reported to have greatly enhanced conversion efficiency, quantum yield, and other favorable properties. As the first step towards exploring its photo-switchable character in real systems, we report here a systematic study on the photoisomerization dynamics between trans (E) and cis (Z) isomers in the gas phase and the CH{sub 3}OH solution, using ab initio based surface hopping and molecular dynamics, which is the first report of dynamics simulation to reveal the environmental effects on BAB photoreactions. Results show that while the relatively faster S{sub 1} relaxation of the photo-induced E{yields}Z process is only mildly affected by the solvent effect, the relatively slower S{sub 1} relaxation of the reverse reaction becomes even slower in the solution compared to the gas phase. The subsequent S{sub 0} dynamics from the conical intersection between S{sub 1} and S{sub 0} (CI{sub E}) to Z is accelerated in solution compared to the gas phase because of avoided re-crossing to the S{sub 1} state, while the S{sub 0} dynamics from the conical intersection between S{sub 1} and S{sub 0} (CI{sub Z}) to E are basically the same in both phases. Overall, the solvent effect was found to enhance the back-and-forth photo-switch efficiency between the Z and E isomers compared to the gas phase, while the quantum yields are reduced. But the solution yields of both the forward and backward photoreactions are still around 0.4. Therefore, BAB may have good photo-responsive properties if used as a photoactive unit in real systems. These results will facilitate future experimental and theoretical studies in this area to help design new azobenzene derivatives as photoactive units in biological processes, nanoscale devices, and photo-responsive materials.
Experimental Investigation of Electron-Acoustic Waves in Electron Plasmas
California at San Diego, University of
Experimental Investigation of Electron-Acoustic Waves in Electron Plasmas Andrey A. Kabantsev , F Electron-acoustic wave (EAW) solutions of the linearized electrostatic Vlasov equations have usually been USA 92093-0319 Dipt. di Fisica and INFM, Univ. della Calabria, 87036 Rende, Italy Abstract. Electron-acoustic
Noda, Masashi; Ishimura, Kazuya; Nobusada, Katsuyuki [Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585 (Japan); Yabana, Kazuhiro; Boku, Taisuke [Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan)
2014-05-15
A highly efficient program of massively parallel calculations for electron dynamics has been developed in an effort to apply the method to optical response of nanostructures of more than ten-nanometers in size. The approach is based on time-dependent density functional theory calculations in real-time and real-space. The computational code is implemented by using simple algorithms with a finite-difference method in space derivative and Taylor expansion in time-propagation. Since the computational program is free from the algorithms of eigenvalue problems and fast-Fourier-transformation, which are usually implemented in conventional quantum chemistry or band structure calculations, it is highly suitable for massively parallel calculations. Benchmark calculations using the K computer at RIKEN demonstrate that the parallel efficiency of the program is very high on more than 60?000 CPU cores. The method is applied to optical response of arrays of C{sub 60} orderly nanostructures of more than 10 nm in size. The computed absorption spectrum is in good agreement with the experimental observation.
Hartmann, S., E-mail: steffen.hartmann@etit.tu-chemnitz.de; Blaudeck, T.; Hermann, S.; Wunderle, B. [Technische Universität Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Hölck, O. [Technische Universität Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Fraunhofer IZM Berlin, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Schulz, S. E.; Gessner, T. [Technische Universität Chemnitz, Reichenhainer Str. 70, 09126 Chemnitz (Germany); Fraunhofer ENAS Chemnitz, Technologie-Campus 3, 09126 Chemnitz (Germany)
2014-04-14
In this paper, we present our results of experimental and numerical pull-out tests on carbon nanotubes (CNTs) embedded in palladium. We prepared simple specimens by employing standard silicon wafers, physical vapor deposition of palladium and deposition of CNTs with a simple drop coating technique. An AFM cantilever with known stiffness connected to a nanomanipulation system was utilized inside a scanning electron microscope (SEM) as a force sensor to determine forces acting on a CNT during the pull-out process. SEM-images of the cantilever attached to a CNT have been evaluated for subsequent displacement steps with greyscale correlation to determine the cantilever deflection. We compare the experimentally obtained pull-out forces with values of numerical investigations by means of molecular dynamics and give interpretations for deviations according to material impurities or defects and their influence on the pull-out data. We find a very good agreement of force data from simulation and experiment, which is 17 nN and in the range of 10–61 nN, respectively. Our findings contribute to the ongoing research of the mechanical characterization of CNT-metal interfaces. This is of significant interest for the design of future mechanical sensors utilizing the intrinsic piezoresistive effect of CNTs or other future devices incorporating CNT-metal interfaces.
Yoon, Hyungsuk Alexander
1996-12-01
Studies of surface structure and dynamics of atoms and molecules on metal surfaces are presented. My research has focused on understanding the nature of adsorbate-adsorbate and adsorbate-substrate interactions through surface studies of coverage dependency and coadsorption using both scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The effect of adsorbate coverage on the surface structures of sulfur on Pt(111) and Rh(111) was examined. On Pt(111), sulfur forms p(2x2) at 0.25 ML of sulfur, which transforms into a more compressed ({radical}3x{radical}3)R30{degrees} at 0.33 ML. On both structures, it was found that sulfur adsorbs only in fcc sites. When the coverage of sulfur exceeds 0.33 ML, it formed more complex c({radical}3x7)rect structure with 3 sulfur atoms per unit cell. In this structure, two different adsorption sites for sulfur atoms were observed - two on fcc sites and one on hcp site within the unit cell.
International Association for Cryptologic Research (IACR)
for Cloud Security Hongwei Li1 , Yuanshun Dai1,2 , Bo Yang1 1 University of Electronic Science comprehensive security solutions to attain assurance of the cloud's treatment of security issues. Independent1 Abstract--Cloud computing is a style of computing in which dynamically scalable and commonly
van Stokkum, Ivo
Use of Ultrafast Dispersed Pump-Dump-Probe and Pump-Repump-Probe Spectroscopies to Explore Form: NoVember 14, 2005 Optical pump-induced dynamics of the highly asymmetric carotenoid peridinin in methanol was studied by dispersed pump-probe, pump-dump-probe, and pump-repump-probe transient absorption
2011-03-27
MA 261 - Quiz 7 (20 minutes). Tuesday, March 8, 2011. Solution. Statistics (out of 20): Section. 23. 24. Average. 14.4 13.4. Standard Deviation 4.5. 4.6. Median.
2001-12-07
Solutions 5. 1. A ring A is called a Boolean ring if x2 = x for all x ? A. (a) Let E be a set and 2E its power set. Show that a Boolean ring structure is defined.
Duan, Yuhua
2014-01-01
The electronic, structural and phonon properties of LiMZrO{sub 3} (M=Na, K) were investigated by the density functional theory and lattice phonon dynamics. Their thermodynamic properties for CO{sub 2} absorption/desorption were analyzed in comparison with the corresponding M{sub 2}ZrO{sub 3}. Two substituted configurations of LiMZrO{sub 3} were created from Li{sub 2}ZrO{sub 3}. Both types of LiNaZrO3 have direct band gaps with values of 3.84 eV and 3.49 eV respectively. While in the case of LiKZrO{sub 3}, one type has an indirect band gap of 3.79 eV between ? and M high symmetric points while another has a direct band gap of 3.12 eV. The phonon dispersions and phonon density of states of LiMZrO{sub 3} were calculated with the direct method. From the calculated thermodynamic properties of LiMZrO{sub 3} reacting with CO{sub 2}, our results showed that by doping Na into Li{sub 2}ZrO{sub 3}, the obtained new solid LiNaZrO{sub 3} has better performance as a CO{sub 2} sorbent applying to post-combustion capture technology. For K doping into Li{sub 2}ZrO{sub 3}, our calculated thermodynamic results showed that the new solid LiKZrO{sub 3} does not gain improvement on its CO{sub 2} capture performance because its regeneration temperature is much higher than Li{sub 2}ZrO{sub 3}.
Henn, T.; Kiessling, T., E-mail: tobias.kiessling@physik.uni-wuerzburg.de; Ossau, W.; Molenkamp, L. W. [Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg (Germany)] [Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg (Germany); Biermann, K.; Santos, P. V. [Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin (Germany)] [Paul-Drude-Institut für Festkörperelektronik, 10117 Berlin (Germany)
2013-12-15
We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast “white light” supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.
Hofer, T.S.; Randolf, B.R.; Shah, S.Adnan Ali; Rode, B.M.; Persson, I.
2009-06-01
The pharmacologically and industrially important palladium(II) ion is usually characterised as square-planar structure in aqueous solution, similar to the platinum(II) ion. Our investigations by means of the most modern experimental and theoretical methods give clear indications, however, that the hydrated palladium(II) ion is hexa-coordinated, with four ligands arranged in a plane at 2.0 {angstrom} plus two additional ligands in axial positions showing an elongated bond distance of 2.7-2.8 A. The second shell consists in average of 8.0 ligands at a mean distance of 4.4 {angstrom}. This structure provides a new basis for the interpretation of the kinetic properties of palladium(II) complexes.
Abolfath, Ramin M; Rajnarayanam, R; Brabec, Thomas; Kodym, Reinhard; Papiez, Lech
2012-01-01
Understanding the damage of DNA bases from hydrogen abstraction by free OH radicals is of particular importance to reveal the effect of hydroxyl radicals produced by the secondary effect of radiation. Previous studies address the problem with truncated DNA bases as ab-initio quantum simulation required to study such electronic spin dependent processes are computationally expensive. Here, for the first time, we employ a multiscale and hybrid Quantum-Mechanical-Molecular-Mechanical simulation to study the interaction of OH radicals with guanine-deoxyribose-phosphate DNA molecular unit in the presence of water where all the water molecules and the deoxyribose-phosphate fragment are treated with the simplistic classical Molecular-Mechanical scheme. Our result illustrates that the presence of water strongly alters the hydrogen-abstraction reaction as the hydrogen bonding of OH radicals with water restricts the relative orientation of the OH-radicals with respective to the the DNA base (here guanine). This results ...
Adiabatic electronic flux density: a Born-Oppenheimer Broken Symmetry ansatz
Vincent Pohl; Jean Christophe Tremblay
2015-10-20
The Born-Oppenheimer approximation leads to the counterintuitive result of a vanishing electronic flux density upon vibrational dynamics in the electronic ground state. To circumvent this long known issue, we propose using pairwise anti-symmetrically translated vibronic densities to generate a symmetric electronic density that can be forced to satisfy the continuity equation approximately. The so-called Born-Oppenheimer broken symmetry ansatz yields all components of the flux density simultaneously while requiring only knowledge about the nuclear quantum dynamics on the electronic adiabatic ground state potential energy surface. The underlying minimization procedure is transparent and computationally inexpensive, and the solution can be computed from the standard output of any quantum chemistry program. Taylor series expansion reveals that the implicit electron dynamics originates from non-adiabatic coupling to the explicit Born-Oppenheimer nuclear dynamics. The new approach is applied to the ${\\rm H}_2^+$ molecular ion vibrating in its ${}^2\\Sigma^+_g$ ground state. The electronic flux density is found to have the correct nodal structure and symmetry properties at all times.
Integrability in the mesoscopic dynamics
Artur Sowa
2004-09-12
The Mesoscopic Mechanics (MeM), which has been introduced in a previous paper, is relevant to the electron gas confined to two spatial dimensions. It predicts a special way of collective response of correlated electrons to the external magnetic field. The dynamic variable of this theory is a finite-dimensional operator, which is required to satisfy the mesoscopic Schr\\"{o}dinger equation (cf. text). In this article, we describe general solutions of the mesoscopic Schr\\"{o}dinger equation. Our approach is specific to the problem at hand. It relies on the unique structure of the equation and makes no reference to any other techniques, with the exception of the geometry of unitary groups. In conclusion, a surprising fact comes to light. Namely, the mesoscopic dynamics "filters" through the (microscopic) Schr\\"odinger dynamics as the latter turns out to be a clearly separable part, in fact an autonomous factor, of the evolution. This is a desirable result also from the physical standpoint.
Krawczyk, Gerhard Erich; Miller, Kevin Michael
2011-07-26
There is provided a method of making a polymer solution comprising polymerizing one or more monomer in a solvent, wherein said monomer comprises one or more ethylenically unsaturated monomer that is a multi-functional Michael donor, and wherein said solvent comprises 40% or more by weight, based on the weight of said solvent, one or more multi-functional Michael donor.
A Review on Ab Initio Approaches for Multielectron Dynamics
Ishikawa, Kenichi L
2015-01-01
In parallel with the evolution of femtosecond and attosecond laser as well as free-electron laser technology, a variety of theoretical methods have been developed to describe the behavior of atoms, molecules, clusters, and solids under the action of those laser pulses. Here we review major ab initio wave-function-based numerical approaches to simulate multielectron dynamics in atoms and molecules driven by intense long-wavelength and/or ultrashort short-wavelength laser pulses. Direct solution of the time-dependent Schr\\"odinger equation (TDSE), though its applicability is limited to He, ${\\rm H}_2$, and Li, can provide an exact description and has been greatly contributing to the understanding of dynamical electron-electron correlation. Multiconfiguration self-consistent-field (MCSCF) approach offers a flexible framework from which a variety of methods can be derived to treat both atoms and molecules, with possibility to systematically control the accuracy. The equations of motion of configuration interactio...
Solvated electron lithium electrode for high energy density battery
Sammels, A.F.
1987-08-04
A solvated electron lithium negative electrode is described containing: containment means holding a solution of lithium dissolved in liquid ammonia to form a solvated electron solution, the solvated electron solution contacting a lithium intercalating membrane and providing lithium to the intercalating membrane during discharge and accepting it from the intercalating membrane during charge.
Uranyl fluoride luminescence in acidic aqueous solutions
Beitz, J.V.; Williams, C.W. [Argonne National Lab., IL (United States). Chemistry Div.
1996-08-01
Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 {+-} 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO{sub 4} at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO{sub 2}F{sub 2}. Studies on the effect of added LiNO{sub 3} or Na{sub 2}WO{sub 4}{center_dot}2H{sub 2}O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF{sub 6} content of WF{sub 6} gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF{sub 6}.
Neupane, Mahesh Raj
2015-01-01
electronic structure calculation package QUANTUM ESPRESSO [311]. MD Calculation Molecular dynamics (
Ab initio simulations of two-dimensional electronic spectra: The SOS//QM/MM approach
Rivalta, I; Nenov, A; Cerullo, G; Mukamel, S; Garavelli, M; Garavelli, M
2013-01-01
calculations. Conclusions Two-dimensional electronic spectroscopy holds great potential for studying structure, dynamics,
Jayanth Kuppambatti; Jaroslav Ban; Timothy Andeen; Peter Kinget; Gustaaf Brooijmans
2013-07-31
The design of a radiation-hard dual channel 12-bit 40 MS/s pipeline ADC with extended dynamic range is presented, for use in the readout electronics upgrade for the ATLAS Liquid Argon Calorimeters at the CERN Large Hadron Collider. The design consists of two pipeline A/D channels with four Multiplying Digital-to-Analog Converters with nominal 12-bit resolution each. The design, fabricated in the IBM 130 nm CMOS process, shows a performance of 68 dB SNDR at 18 MHz for a single channel at 40 MS/s while consuming 55 mW/channel from a 2.5 V supply, and exhibits no performance degradation after irradiation. Various gain selection algorithms to achieve the extended dynamic range are implemented and tested.
Correlated exciton dynamics in semiconductor nanostructures
Wen, Patrick, Ph. D. Massachusetts Institute of Technology
2013-01-01
The absorption and dissipation of energy in semiconductor nanostructures are often determined by excited electron dynamics. In semiconductors, one fundamentally important electronic state is an exciton, an excited electron ...
Gusev, Guennady
, Boite Postale 166, F-38042 Grenoble, France J. C. Portal High Magnetic Field Laboratory CNRS, Boite, Russia Received 30 April 1996 The classical dynamics of a charged particle colliding ballistically around
Merrill, Frank E.; Morris, Christopher
2005-05-17
A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.
Time-periodic solutions of the Benjamin-Ono equation
Ambrose, D.M.
2009-01-01
application to Benjamin Ono equation. Chinese Physics, 14(solutions of Hamiltonian equations. In Dynamics and Pro-quelques generalisations de l’equation de Korteweg-deVries.
Linkping University Electronic Press
Zhao, Yuxiao
Linköping University Electronic Press Activity Summary, 2007 January, 2008 1 #12;1. Organization In March of 2007, Erik Sandewall, E-Press' director, resigned in order to take up a position at the Royal solution was found as part of a larger restructuring of LiU E-Press. As of September 1st , the Board
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Nilson, P. M.; Solodov, A. A.; Davies, J. R.; Theobald, W.; Mileham, C.; Stoeckl, C.; Begishev, I. A.; Zuegel, J. D.; Froula, D. H.; Betti, R.; et al
2015-09-25
Time-resolved K? spectroscopy measurements from high-intensity laser interactions with thin-foil solid targets are reviewed. Thin Cu foils were irradiated with 1- to 10-J, 1-ps pulses at focused intensities from 1018 to 1019 W/cm2. The experimental data show K?-emission pulse widths from 3 to 6 ps, increasing with laser intensity. The time-resolved K?-emission data are compared to a hot-electron transport and K?-production model that includes collisional electron-energy coupling, resistive heating, and electromagnetic field effects. The experimental data show good agreement with the model when a reduced ponderomotive scaling is used to describe the initial mean hot-electron energy over the relevant intensitymore »range.« less
O'Connell, Robert F.
of the Electrostatic Problem for a Single Electron Multijunction Trap [Phys. Rev. Lett. 74, 1839 (1995)] G. Y. Hu and R remark that " . . . there cannot be any real trapped electron . . . " for the system described in Ref. [1) for tunneling and escape are 221 and 29, respectively, which makes clear that the system in Ref. [1] does trap
Yildiz, Bilge
from solid oxide fuel cells (SOFC) at intermediate temperatures. Surface oxygen exchange and oxygen microstructure (3-6). However, the harsh operating environments of the SOFC make it difficult to probe on SOFC cathode surfaces. The material we chose to study is the Sr(Ti1-xFex)O3 (STF) solid solution system
Rajib Basak; Ranjini Bandyopadhyay
2014-06-27
Three drugs, Ibuprofen, Aspirin and Erythromycin, are encapsulated in spherical Pluronic F127 micelles. The shapes and the size distributions of the micelles in dilute, aqueous solutions, with and without drugs, are ascertained using cryo- Scanning Electron Microscopy and Dynamic Light Scattering (DLS) experiments, respectively. Uptake of drugs above a threshold concentration is seen to reduce the critical micellization temperature of the solution. The mean hydrodynamic radii and polydispersities of the micelles are found to increase with decrease in temperature and in the presence of drug molecules. The hydration of the micellar core at lower temperatures is verified using fluorescence measurements. Increasing solution pH leads to the ionization of the drugs incorporated in the micellar cores. This causes rupture of the micelles and release of the drugs into the solution at the highest solution pH value of 11.36 investigated here and is studied using DLS and fluorescence spectrocopy.
Mueser, Martin
" This electronic auxiliary material contains supportive evidence for claims made in the main text. STRUCTURAL PROPERTIES To give an impression of the various systems analyzed in the main part of our letter, a few conditions. In the main part of our manuscript we claim that our model reproduces the correct static features
McCusker, James K.
Solar Cells Amanda L. Smeigh, Jordan E. Katz, Bruce S. Brunschwig,*,,§ Nathan S. Lewis,*, and James K dynamics of dye-sensitized TiO2-based solar cells have been investigated to determine the effects -/I- were fully functional solar cells whose steady-state photocurrents were directly measured. In (n
Equilibrium and dynamics of ionic solutions
Anton, Mihai
2009-01-01
The present work is motivated by the desire to understand the physical mechanism underlying the propagation of nervous influx in neurons as well as the modulation and summation of electrical signals during their progression ...
The anisotropic distribution of the interacting electrons
Boris Bondarev
2013-01-21
The distribution function for a system of interacting electrons in metals is multivalent in a certain region of wave vectors. One solution among many is isotropic. For other solutions the distribution of electrons over the wave vectors is anisotropic. In the simplest case, the anisotropy arises as a result of the repulsion between electrons in states with the wave vectors $\\bf k$ and $-\\hh\\bf k$.
Korshunov, M A
2012-01-01
We measured the small frequencies Raman spectrum of the paradihlorobenzene and paradihlorobenzene solid solution nanoparticles with the size about 100 nanometers. Values of frequencies of lines decrease. The size of nanoparticles was determined by the electronic microscope. Calculations of nanoparticles structure were done using the method of molecular dynamics and histograms of nanoparticles spectra were calculated via the Dyne's method. The result is that the Raman spectrum is the sum of spectra from the central part of the nanoparticle and superficial structures with smaller concentration of paradihlorobenzene.
Hosler, Erik Robert
2013-01-01
dynamics. Tunnel ionization rate determinations are employed to model the pump, while electronic structure calculations
Generalized dilaton-Maxwell cosmic string and wall solutions
John Morris
2006-08-15
The class of static solutions found by Gibbons and Wells for dilaton-electrodynamics in flat spacetime, which describe nontopological strings and walls that trap magnetic flux, is extended to a class of dynamical solutions supporting arbitrarily large, nondissipative traveling waves, using techniques previously applied to global and local topological defects. These solutions can then be used in conjunction with S-duality to obtain more general solitonic solutions for various axidilaton-Maxwell theories. As an example, a set of dynamical solutions is found for axion, dilaton, and Maxwell fields in low energy heterotic string theory using the SL(2,R) invariance of the equations of motion.
A compact electron gun for time-resolved electron diffraction
Robinson, Matthew S.; Lane, Paul D.; Wann, Derek A.
2015-01-15
A novel compact time-resolved electron diffractometer has been built with the primary goal of studying the ultrafast molecular dynamics of photoexcited gas-phase molecules. Here, we discuss the design of the electron gun, which is triggered by a Ti:Sapphire laser, before detailing a series of calibration experiments relating to the electron-beam properties. As a further test of the apparatus, initial diffraction patterns have been collected for thin, polycrystalline platinum samples, which have been shown to match theoretical patterns. The data collected demonstrate the focusing effects of the magnetic lens on the electron beam, and how this relates to the spatial resolution of the diffraction pattern.
Infinite Energy Dyon Solutions
Douglas Singleton
1996-02-18
Three dyon solutions to the SU(2) Yang-Mills-Higgs system are presented. These solutions are obtained from the BPS dyon by allowing the gauge fields to be complex, or by letting the free parameter of the BPS solution become imaginary. In all cases however the physically measurable quantities connected with these new solutions are entirely real. Although the new solutions are mathematically simple variations of the BPS solution, they have one or more physically distinct characteristics.
Approximation of the Time-Dependent Electronic Schrodinger Equation by
Koch, Othmar
], [2]. Large-scale computations of electronic structure and dynamics pose extremely challenging powerful standard tools in electronic structure calculations of atoms and small molecules. Similar to DFT-dependent electronic SchrÂ¨odinger equa- tion (TDSE) arising in ultrafast laser dynamics, which was first proposed in [1
Hane, J.K.
1995-05-01
Wavelength and composition dependence of the time-resolved luminescence were examined. Effects of macroscopic composition gradient and microscopic alloy disorder on e{sup {minus}}-h{sup +} pair dynamics were probed. Materials with both increasing and decreasing S content with distance from the surface were examined, where 0{le} {times} {le}1 over the full range. In these graded materials, the band gap energy also varies with position. The graded semiconductor luminescence shows strong wavelength dependence, showing diffusion in both band gap and concentration gradients. A bottleneck in the diffusion is attributed to localization occurring primarily in the materials with greatest alloy disorder, i.e. around CdS{sub 0.5}Se{sub 0.50}. Homogeneous materials were studied for x = 0, 0.25, 0.50, 0.75, 1; the time-resolved luminescence depends strongly on the composition. The mixed compositions have longer decay constants than CdS and CdSe. Observed lifetimes agree with a picture of localized states induced by the alloy disorder. For a given homogeneous crystal, no wavelength dependence of the time decays was observed. Picosecond luminescence upconversion spectroscopy was used to study further the dependence of the luminescence on composition. Large nonexponential character in the decay functions was observed in the alloys; this long time tail can be attributed to a broad distribution of relaxation times as modeled by the Kohlrausch exponential.
Free-energy functional of the electronic potential for Schrödinger-Poisson theory
Vikram Jadhao; Kaushik Mitra; Francisco J. Solis; Monica Olvera de la Cruz
2014-12-15
In the study of model electronic device systems where electrons are typically under confinement, a key obstacle is the need to iteratively solve the coupled Schr\\"{o}dinger-Poisson (SP) equation. It is possible to bypass this obstacle by adopting a variational approach and obtaining the solution of the SP equation by minimizing a functional. Further, using molecular dynamics methods that treat the electronic potential as a dynamical variable, the functional can be minimized on the fly in conjunction with the update of other dynamical degrees of freedom leading to considerable reduction in computational costs. But such approaches require access to a true free-energy functional, one that evaluates to the equilibrium free energy at its minimum. In this paper, we present a variational formulation of the Schr\\"{o}dinger-Poisson (SP) theory with the needed free-energy functional of the electronic potential. We apply our formulation to semiconducting nanostructures and provide the expression of the free-energy functional for narrow channel quantum wells where the local density approximation yields accurate physics and for the case of wider channels where Thomas-Fermi approximation is valid.
Electron spin motion in the delta-function pulse
Miroslav Pardy
2012-11-26
We formulate the Bargman-Michel-Telegdi (BMT) equation for electron spin motion in a plane wave and in the Dirac delta-function pulse. We compare the BMT solution with the Wolkow solution of the Dirac equation. The Wolkow solution for the spin is not identical with the solution following from the BMT .
Introduction to Accelerated Molecular Dynamics
Perez, Danny [Los Alamos National Laboratory
2012-07-10
Molecular Dynamics is the numerical solution of the equations of motion of a set of atoms, given an interatomic potential V and some boundary and initial conditions. Molecular Dynamics is the largest scale model that gives unbiased dynamics [x(t),p(t)] in full atomistic detail. Molecular Dynamics: is simple; is 'exact' for classical dynamics (with respect to a given V); can be used to compute any (atomistic) thermodynamical or dynamical properties; naturally handles complexity -- the system does the right thing at the right time. The physics derives only from the interatomic potential.
Communication: Quantum molecular dynamics simulation of liquid...
Office of Scientific and Technical Information (OSTI)
Communication: Quantum molecular dynamics simulation of liquid para-hydrogen by nuclear and electron wave packet approach Citation Details In-Document Search Title: Communication:...
Low energy 2+1 string gravity; black hole solutions
A. A. Garcia Diaz; G. Gutierrez Cano
2014-12-17
In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly identified. The stationary generalization, via SL(2;R) transformations, of the static (2+1) Horne Horowitz string black hole solution is given.
Dor Ben-Amotz, PI
2012-08-17
Understanding the fundamental principles governing the structure and dynamics of water - and particularly how water mediates chemical interactions and processes - continues to pose formidable challenges and yield abundant surprises. The focus of this Gordon Research Conference is on identifying key questions, describing emerging understandings, and unveiling surprising discoveries related to water and aqueous solutions. The talks and posters at this meeting will describe studies of water and its interactions with objects such as interfaces, channels, electrons, oils, ions, and proteins; probed using optical, electrical, and particle experiments, and described using classical, quantum, and multi-scale theories.
Superthermal electron distribution measurements from polarized electron cyclotron emission
Luce, T.C.; Efthimion, P.C.; Fisch, N.J.
1988-06-01
Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs.
43 PARTICLE ACCELERATORS; ELECTRON GUNS; BEAM EMITTANCE; CHARGE
Office of Scientific and Technical Information (OSTI)
SPACE 430200* -- Particle Accelerators-- Beam Dynamics, Field Calculations, & Ion Optics The evolution of the electron-beam phase space distribution in laser-driven rf guns is...
Mukamel, Shaul
-acceptor substituted Hexatrienes demonstrate the interplay of electronic structure and dynamics, and the correlation the calculation of the optical response onto the dynam- ics of coupled electronic oscillators and suggests, which in turn controls the electronic dynamics. We further explore which characteristics of the ground
Classical Solutions in the BMN Matrix Model
Joakim Arnlind; Jens Hoppe
2003-12-15
Several reductions of the bosonic BMN matrix model equations to ordinary point particle Hamiltonian dynamics in the plane (or R^3) are given - as well as a few explicit solutions (some of which, as N->infinity, correspond to membranes rotating with constant angular velocity, others to higher dimensional objects).
Including the Effects of Electronic Excitations and Electron-Phonon Coupling in Cascade Simulations
Duffy, Dorothy |
2008-07-01
Radiation damage has traditionally been modeled using cascade simulations however such simulations generally neglect the effects of electron-ion interactions, which may be significant in high energy cascades. A model has been developed which includes the effects of electronic stopping and electron-phonon coupling in Molecular Dynamics simulations by means of an inhomogeneous Langevin thermostat. The energy lost by the atoms to electronic excitations is gained by the electronic system and the energy evolution of the electronic system is modeled by the heat diffusion equation. Energy is exchanged between the electronic system and the atoms in the Molecular Dynamics simulation by means of a Langevin thermostat, the temperature of which is the local electronic temperature. The model is applied to a 10 keV cascade simulation for Fe. (authors)
Non-linear viscoelastic deformation of polymeric solutions
Sanchez Reyes, Javier
2000-01-01
The dynamics of entangled polymeric solutions were studied using drag of borosilicate discs and conventional shear rheometry devices in order to understand the effect of deformation on the relaxation process and the possible ...
A Solution to the Problem of Updating Encyclopedias
Zalta, Edward N.
A Solution to the Problem of Updating Encyclopedias Eric M. Hammer and Edward N. Zalta Center¸caise is still available in loose-leaf format. 1 Eric Hammer and Edward N. Zalta 2 problem, namely, a `dynamic
initio density functional calculations, we trace the governing mechanism back to electronic structure changes in the electronic properties, direct de- termination of lattice structural dynamics from opticalDirect Observation of Optically Induced Transient Structures in Graphite Using Ultrafast Electron
Wiring-up catalytically active metals in solution with sulfonated carbon nanotubes
Schnorr, Jan Markus
Highly water soluble sulfonate MWCNTs were synthesized and could be used to facilitate the electron transfer between Pd and Cu in a Wacker-type oxidation in solution.
Bhuyan, Laxmi N.
4 Solutions Solution 4.1 4.1.1 The values of the signals are as follows: RegWrite MemRead ALUMux MemWrite ALUOp RegMux Branch a. 1 0 0 (Reg) 0 Add 1 (ALU) 0 b. 1 1 1 (Imm) 0 Add 1 (Mem) 0 ALUMux of the ALU and 1 (Mem) selects the output of memory. A value of X is a "don't care" (does not matter
The electromagnetic spike solutions
Ernesto Nungesser; Woei Chet Lim
2013-09-28
The aim of this paper is to use the existing relation between polarized electromagnetic Gowdy spacetimes and vacuum Gowdy spacetimes to find explicit solutions for electromagnetic spikes by a procedure which has been developed by one of the authors for gravitational spikes. We present new inhomogeneous solutions which we call the EME and MEM electromagnetic spike solutions.
I. A. Ar'ev; N. I. Lebovka; E. A. Solovieva
2013-03-03
A method for study of charge-transfer interactions between solute molecules and solvent based on the comparison of the ratios of spectral shifts of different electronic transitions in solute molecules in chemically inert solvent is proposed. The method is applicable to molecules that do not change their dipole moment on excitation. As an example, a presence of charge transfer interactions in higher electronic states of aromatic hydrocarbons (benzene, phenanthrene, and naphthalene) dissolved in water and alcohols was demonstrated.
Dynamic Electronic Control of Catalytic Converters | Department...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Commonalities between Non-road and On-road Diesel Emissions Diesel Injection Shear-Stress Advanced Nozzle (DISSAN) Microstructural Contol of the Porous Si3N4 Ceramics Consisted...
Dynamic characteristics of an oscillating electron tube
Hull, Lewis Madison
1918-01-01
detecting device, whose behavior was shroud ed in mystery and apparently governed by no consistent laws or principles, to a most unique position in the radio field; its immense variety of possible applications in both in laboratory measurements... assumptions have been made: RIf negligible compared with VQ. RCB n " " 1. In practice, when the tube is put in oscillation with this arrangement of inductances a number of harmonic frequencies is present. These frequencies were first detect ed...
Femtosecond Studies of Electron Dynamics at Interfaces
Harris, Charles B.
B. HARRIS*,, Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California at the interface can drastically affect carrier transport properties and the performance of devices. To develop
Dynamics in the quantum Hall effect and the phase diagram of graphene
E. V. Gorbar; V. P. Gusynin; V. A. Miransky; I. A. Shovkovy
2008-08-28
The dynamics responsible for lifting the degeneracy of the Landau levels in the quantum Hall (QH) effect in graphene is studied by utilizing a low-energy effective model with a contact interaction. A detailed analysis of the solutions of the gap equation for Dirac quasiparticles is performed at both zero and nonzero temperatures. The characteristic feature of the solutions is that the order parameters connected with the QH ferromagnetism and magnetic catalysis scenarios necessarily coexist. The solutions reproduce correctly the experimentally observed novel QH plateaus in graphene in strong magnetic fields. The phase diagram of this system in the plane of temperature and electron chemical potential is analyzed. The phase transitions corresponding to the transitions between different QH plateaus in graphene are described.
Suyama, Motohiro (Hamamatsu, JP); Fukasawa, Atsuhito (Hamamatsu, JP); Arisaka, Katsushi (Los Angeles, CA); Wang, Hanguo (North Hills, CA)
2011-12-20
An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.
Method of Linear Invariants for description of beam dynamics of FEL undulator
A. Angelow; D. Trifonov; V. Angelov; H. Hristov
2008-05-23
We propose a new model for description of electrons beam dynamics in Free Electron Laser (FEL) undulator, based on the method of linear time-dependent invariants of quantum-mechanical charge particle. The magnetic field has periodic structure along the undulator. For this problem, described by time-dependent quadratic Hamiltonian, we obtain exact solution. The time-evolutions of the tree quantum fluctuations: covariance cov(q,p), var(q) and var(p) for the charge particle in this case are also determined. This research will help to optimize the FEL undulator: for example, using a 2.5 GeV linear electron accelerator it will be possible to emit radiation at 1.5 nm and shorter length. This method could be applicable also to any device with periodic structure of applied field (e.g. Tokamak, cyclic accelerators) for the case of charge non-relativistic quantum particles.
Influence of solute-solute interactions on membrane filtration
Neale, Peta Anne
2009-01-01
An understanding of solute-solute interactions is essential for aquatic systems as this can affect the fate and behaviour of micropollutants in the environment and engineered systems. Despite the importance of solute-solute ...
Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant
2014-01-21
Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.
Hacker, Randi; Greene, Megan
2009-01-28
. The Japanese: firefly connection goes back to the 8th Century when poets used them to represent human passions. But pollution and development have depleted the number of fireflies. So what's a New Year's reveler to do? Buy Denshi Hotaru, life-sized, electronic...
Magno, Scott (Dublin, CA); Wang, Ruiping (Fremont, CA); Derouane, Eric (Liverpool, GB)
2003-01-01
The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.
Owner
2013-08-16
Apr 18, 2013 ... The annual effective risk free interest rate is 4%. Determine the maximum loss that you could incur on a long 6 month forward contract. Solution:.
jeffb_000
2013-12-02
Nov 19, 2013 ... Calculate the total transaction costs incurred by Patrick and Eric combined. Solution: Ask Price = 30. Bid Ask Spread = 0.50 = Ask Price - Bid ...
Electron spin resonance of nitrogen-vacancy centers in optically trapped nanodiamonds
Horowitz, Viva R; Christle, David J; Cleland, Andrew N; Awschalom, David D
2012-01-01
Using an optical tweezers apparatus, we demonstrate three-dimensional control of nanodiamonds in solution with simultaneous readout of ground-state electron-spin resonance (ESR) transitions in an ensemble of diamond nitrogen-vacancy (NV) color centers. Despite the motion and random orientation of NV centers suspended in the optical trap, we observe distinct peaks in the measured ESR spectra qualitatively similar to the same measurement in bulk. Accounting for the random dynamics, we model the ESR spectra observed in an externally applied magnetic field to enable d.c. magnetometry in solution. We estimate the d.c. magnetic field sensitivity based on variations in ESR line shapes to be ~50 microTesla/Hz^1/2. This technique may provide a pathway for spin-based magnetic, electric, and thermal sensing in fluidic environments and biophysical systems inaccessible to existing scanning probe techniques.
Electron spin resonance of nitrogen-vacancy centers in optically trapped nanodiamonds
Viva R. Horowitz; Benjamín J. Alemán; David J. Christle; Andrew N. Cleland; David D. Awschalom
2012-06-07
Using an optical tweezers apparatus, we demonstrate three-dimensional control of nanodiamonds in solution with simultaneous readout of ground-state electron-spin resonance (ESR) transitions in an ensemble of diamond nitrogen-vacancy (NV) color centers. Despite the motion and random orientation of NV centers suspended in the optical trap, we observe distinct peaks in the measured ESR spectra qualitatively similar to the same measurement in bulk. Accounting for the random dynamics, we model the ESR spectra observed in an externally applied magnetic field to enable d.c. magnetometry in solution. We estimate the d.c. magnetic field sensitivity based on variations in ESR line shapes to be ~50 microTesla/Hz^1/2. This technique may provide a pathway for spin-based magnetic, electric, and thermal sensing in fluidic environments and biophysical systems inaccessible to existing scanning probe techniques.
Voigt, James A. (Corrales, NM); Sipola, Diana L. (Albuquerque, NM); Tuttle, Bruce A. (Albuquerque, NM); Anderson, Mark T. (Woodbury, MN)
1999-01-01
A process for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications.
Voigt, J.A.; Sipola, D.L.; Tuttle, B.A.; Anderson, M.T.
1999-06-01
A process is disclosed for producing powders of perovskite-type compounds which comprises mixing a metal alkoxide solution with a lead acetate solution to form a homogeneous, clear metal solution, adding an oxalic acid/n-propanol solution to this metal solution to form an easily filterable, free-flowing precursor powder and then calcining this powder. This process provides fine perovskite-phase powders with ferroelectric properties which are particularly useful in a variety of electronic applications. 4 figs.
Dispersant solutions for dispersing hydrocarbons
Tyndall, R.L.
1997-03-11
A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.
Dispersant solutions for dispersing hydrocarbons
Tyndall, Richard L. (Clinton, TN)
1997-01-01
A dispersant solution includes a hydrocarbon dispersing solution derived from a bacterium from ATCC 75527, ATCC 75529, or ATCC 55638.
Le Roy, Robert J.
1999 Solutions Euclid Contest (Grade12) for the Awards Canadian Mathematics Competition An activity of The Centre for Education in Mathematics and Computing, University of Waterloo, Waterloo, Ontario © 1999 Waterloo Mathematics Foundation #12;1999 Euclid Solutions 2 1. (a) If x 1 1 1 3 4= + , what
Neace, James C. (Blackville, SC)
1986-01-01
Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.
Neace, J.C.
1984-03-13
A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.
Switched Control of Electron Nuclear Spin Systems
Navin Khaneja
2007-07-11
In this article, we study control of electron-nuclear spin dynamics at magnetic field strengths where the Larmor frequency of the nucleus is comparable to the hyperfine coupling strength. The quantization axis for the nuclear spin differs from the static B_0 field direction and depends on the state of the electron spin. The quantization axis can be switched by flipping the state of electron spin, allowing for universal control on nuclear spin states. We show that by performing a sequence of flips (each followed by a suitable delay), we can perform any desired rotation on the nuclear spins, which can also be conditioned on the state of the electron spin. These operations, combined with electron spin rotations can be used to synthesize any unitary transformation on the coupled electron-nuclear spin system. We discuss how these methods can be used for design of experiments for transfer of polarization from the electron to the nuclear spins.
Design of an Electron Gun using Computer Optimization
Design of an Electron Gun using Computer Optimization B. M. Lewis H. T. Tran Department geometry of the system. This optimization framework, to be considered in the context of electron guns the methods of shape optimization to design the cathode of an electron gun. The dynamical equations modeling
Computing Partial Eigenvalue Sum in Electronic Structure Calculations
Bai, Zhaojun
and CPU time. In the application of electronic structure calculations in molecular dynamics, the newComputing Partial Eigenvalue Sum in Electronic Structure Calculations Z. Bai M. Faheyy G. Golubz M where computation of the total energy of an electronic structure requires the evaluation of partial
The structure of electronic states in amorphous silicon
Drabold, David
the structure and dynamics of electron states in amorphous Si. The nature of the states near the gap at zeroThe structure of electronic states in amorphous silicon David A. Drabold,* Uwe Stephan, Jianjun for amorphous Si, which are of particular interest for efficient ab initio calculation of electronic properties
Krylov, Anna I.
electronic structure calculations with the experimental observables. We aim at establishing a theoretical in molecular solids and model compounds. The electronic structure aspects of SF have received considerable quantities by modeling complicated nonadiabatic dynamics encompassing several interacting electronic states
Integrating Security Solutions to Support nanoCMOS Electronics Research
Sinnott, R.O.
Sinnott,R.O. Asenov,A. Bayliss,C. Davenhall,C. Doherty,T. Harbulot,B. Jones,M. Martin,D. Millar,C. Roy,G. Roy,S. Stewart,G. Watt,J. IEEE International Symposium on Parallel and Distributed Processing Systems with Applications, Sydney Australia, December 2008.
PIA - Savannah River Nuclear Solution SRNS Electronic Document Workflow
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PIA - Savannah River Nuclear Solutions Electronic Safeguards Security
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuelsof EnergyAprilEnergy EEREPlateau Training System PIARECORDSSystem (E3S) |
[Inelastic electron scattering from surfaces]. [Progress report
Not Available
1993-10-01
This program uses ab-initio and multiple scattering to study surface dynamical processes; high-resolution electron-energy loss spectroscopy is used in particular. Off-specular excitation cross sections are much larger if electron energies are in the LEED range (50--300 eV). The analyses have been extended to surfaces of ordered alloys. Phonon eigenvectors and eigenfrequencies were used as inputs to electron-energy-loss multiple scattering cross section calculations. Work on low-energy electron and positron holography is mentioned.
Guo, Shimin Mei, Liquan
2014-08-15
Dust-ion-acoustic (DIA) rogue waves are investigated in a three-dimensional magnetized plasma containing nonthermal electrons featuring Tsallis distribution, both positive and negative ions, and immobile dust grains having both positive and negative charges. Via the reductive perturbation method, a (3?+?1)-dimensional nonlinear Schrödinger (NLS) equation is derived to govern the dynamics of the DIA wave packets. The modulation instability of DIA waves described by the (3?+?1)-dimensional NLS equation is investigated. By means of the similarity transformation and symbolic computation, both the first- and second-order rogue wave solutions of the (3?+?1)-dimensional NLS equation are constructed in terms of rational functions. Moreover, the dynamics properties and the effects of plasma parameters on the nonlinear structures of rogue waves are discussed in detail. The results could be useful for understanding the physical mechanism of rogue waves in laboratory experiments where pair-ion plasmas with electrons and dust grains can be found.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit the followingConcentrating SolarConstruction Review BasicConsumer-Electronics
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear ProfileMultiferroicAward |ElectronFluctuations3 Pierre
Electronic Coupling Dependence of Ultrafast Interfacial Electron...
Office of Scientific and Technical Information (OSTI)
Electron Transfer on Nanocrystalline Thin Films and Single Crystal Lian, Tianquan 14 SOLAR ENERGY The long-term goal of the proposed research is to understand electron transfer...
2013 R&D 100 Award: Movie-mode electron microscope captures nanoscale
Lagrange, Thomas; Reed, Bryan
2014-07-21
A new instrument developed by LLNL scientists and engineers, the Movie Mode Dynamic Transmission Electron Microscope (MM-DTEM), captures billionth-of-a-meter-scale images with frame rates more than 100,000 times faster than those of conventional techniques. The work was done in collaboration with a Pleasanton-based company, Integrated Dynamic Electron Solutions (IDES) Inc. Using this revolutionary imaging technique, a range of fundamental and technologically important material and biological processes can be captured in action, in complete billionth-of-a-meter detail, for the first time. The primary application of MM-DTEM is the direct observation of fast processes, including microstructural changes, phase transformations and chemical reactions, that shape real-world performance of nanostructured materials and potentially biological entities. The instrument could prove especially valuable in the direct observation of macromolecular interactions, such as protein-protein binding and host-pathogen interactions. While an earlier version of the technology, Single Shot-DTEM, could capture a single snapshot of a rapid process, MM-DTEM captures a multiframe movie that reveals complex sequences of events in detail. It is the only existing technology that can capture multiple electron microscopy images in the span of a single microsecond.
or structure--and they generate approximately 15 percent of all green- house gas emissions.2 Excluding staffing management and greenhouse gas emissions. Automated operations management: IBM solutions provide automated
2006-10-24
Assignment 2 Solutions. James Vanderhyde. 1. Problem 7-5. (a) Let x1, x2, and x3 be the three values that are picked at random. Since there are 3! = 6 ways to ...
Apr 25, 2015 ... Math 373. Spring 2015. Quiz 5. April 16, 2015. 1. In a short sale of a stock, there is credit risk. Define credit risk. Solution: Credit risk is the risk ...
Residential Energy Efficiency Solutions
Broader source: Energy.gov [DOE]
Our mission is to increase the availability of high-quality, safe, affordable and workforce housing options. Through innovative reuse and rehabilitation we incorporate economic benefits, environmental stewardship/energy efficiency, and social solutions.
Suslick, Kenneth S.
Solvent Evaporation/ Reactions Precursor Solution Droplet Product Densification Product Collection Production of Nano-Materials microporous shell internal macropores Hierarchically Porous Carbons Brandon Ito (20 ppm) Formaldehyde (20 ppm) Control (50% RH) Maryam SayyahKaty Filson Wei Jiang Mechanoluminescence
2003-11-25
Solutions to Assignment 1. 1. Let G be a finite set with an associative law of composition, and e ? G an element with xe = ex = x for all x ? G. If G has the ...
2006-12-07
Assignment 5 Solutions. James Vanderhyde. 1. Problem 31.2-6. Recall F1 = 0, F2 = 1, and Fk+1 = Fk + Fk?1 for k > 2. By the discussion in the book ...
The chemistry of plutonium(VI) in aqueous carbonate solutions
Stout, B.E.; Choppin, G.R. . Dept. of Chemistry); Sullivan, J.C. )
1990-01-01
The dynamic behavior of carbonate ion as a ligand that interacts with the hexavalent actinyl ions of U, Np, and Pu has been examined by {sup 13}C NMR. The first order rate parameter that describes the exchange between bulk solution and bound carbonate decreases with increasing pH. At a pH of 10.0, 25{degree}C, the respective values of k for the U(VI), Np(VI) and Pu(VI) complexes are 27.1 {plus minus} 0.3, 64.7 {plus minus} 3.3 and 706 {plus minus} 29. The variation of k with temperature was used to calculate the values of {Delta}H{sup +} = 53 and 42 kJ/M; and {Delta}S{sup +} = {minus}40 and {minus}71 J/M-K for the uranyl and neptunyl systems, respectively. A plausible reaction scheme for the exchange reaction is considered. The influence of these slow carbonate exchange reactions on selected electron transfer reactions is noted. 19 refs., 4 figs., 2 tabs.
Caballar, Roland Cristopher F.; Ocampo, Leonard R.; Galapon, Eric A.
2010-06-15
Internal symmetries can be used to classify multiple solutions to the time-energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR possessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.
Roland Cristopher F. Caballar; Leonard R. Ocampo; Eric A. Galapon
2010-05-14
Internal symmetries can be used to classify multiple solutions to the time energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR posessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.
An Exact, Three-Dimensional, Time-Dependent Wave Solution in Local Keplerian Flow
Steven A. Balbus; John F. Hawley
2006-08-21
We present an exact three-dimensional wave solution to the shearing sheet equations of motion. The existence of this solution argues against transient amplification as a route to turbulence in unmagnetized disks. Moreover, because the solution covers an extensive dynamical range in wavenumber space, it is an excellent test of the dissipative properties of numerical codes.
Shear and Extensional Rheology of Cellulose/Ionic Liquid Solutions Simon J. Haward,*,
Sharma, Vivek
Shear and Extensional Rheology of Cellulose/Ionic Liquid Solutions Simon J. Haward,*, Vivek Sharma characterize the shear and extensional rheology of dilute to semidilute solutions of cellulose in the ionic of the semidilute cellulose solutions in a uniaxial extensional ow that mimics the dynamics encountered in the spin
Boltzmann-Electron Model in Aleph.
Hughes, Thomas Patrick; Hooper, Russell
2014-11-01
We apply the Boltzmann-electron model in the electrostatic, particle-in-cell, finite- element code Aleph to a plasma sheath. By assuming a Boltzmann energy distribution for the electrons, the model eliminates the need to resolve the electron plasma fre- quency, and avoids the numerical %22grid instability%22 that can cause unphysical heating of electrons. This allows much larger timesteps to be used than with kinetic electrons. Ions are treated with the standard PIC algorithm. The Boltzmann-electron model re- quires solution of a nonlinear Poisson equation, for which we use an iterative Newton solver (NOX) from the Trilinos Project. Results for the spatial variation of density and voltage in the plasma sheath agree well with an analytic model
Curvature Dependence of Hydrophobic Hydration Dynamics
R. Gregor Weiß; Matthias Heyden; Joachim Dzubiella
2015-04-08
We investigate the curvature-dependence of water dynamics in the vicinity of hydrophobic spherical solutes using molecular dynamics simulations. For both, the lateral and perpendicular diffusivity as well as for H-bond kinetics of water in the first hydration shell, we find a non-monotonic solute-size dependence, exhibiting extrema close to the well-known structural crossover length scale for hydrophobic hydration. Additionally, we find an apparently anomalous diffusion for water moving parallel to the surface of small solutes, which, however, can be explained by topology effects. The intimate connection between solute curvature, water structure and dynamics has implications for our understanding of hydration dynamics at heterogeneous biomolecular surfaces.
Ekdahl, Carl August Jr. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-10-14
Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.
Tong, Xiao-Min; Chu, Shih-I
1998-01-01
We present a self-interaction-free time-dependent density-functional theory (TDDFT) for nonperturbative treatment of multiphoton processes of many-electron atomic systems in intense laser fields. The theory is based on the ...
Chu, Xi; Chu, Shih-I
2001-11-14
We present a time-dependent density-functional theory (TDDFT) with proper asymptotic long-range potential for nonperturbative treatment of multiphoton processes of many-electron molecular systems in intense laser fields. ...
Sandia Energy - Scattering Dynamics
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Scattering Dynamics Home Transportation Energy Predictive Simulation of Engines Combustion Chemistry Chemical Dynamics Scattering Dynamics Scattering DynamicsAshley...
Relativistic Remnants of Non-Relativistic Electrons
Taro Kashiwa; Taisuke Yamaguchi
2014-10-09
Electrons obeying the Dirac equation are investigated under the non-relativistic $c \\mapsto \\infty$ limit. General solutions are given by derivatives of the relativistic invariant functions whose forms are different in the time- and the space-like region, yielding the delta function of $(ct)^2 - x^2$. This light-cone singularity does survive to show that the charge and the current density of electrons travel with the speed of light in spite of their massiveness.
Electronic Structure Methods for Predicting the Properties Materials: Grids in Space
Stathopoulos, Andreas
Electronic Structure Methods for Predicting the Properties Materials: Grids in Space James and glasses small atomic clusters. Many materials properties be predicted accurate solution electronic structure system interest exists. For example, structural properties a material determined the total
Mesoscale modeling of colloidal suspensions with adsorbing solutes
Rei Tatsumi; Osamu Koike; Yukio Yamaguchi
2015-01-14
We construct a mesoscale model of colloidal suspensions that contain solutes reversibly adsorbing onto the colloidal particle surfaces. The present model describes the coupled dynamics of the colloidal particles, the host fluid, and the solutes through the Newton-Euler equations of motion, the hydrodynamic equations, and the advection-diffusion equation, respectively. The solute adsorption is modeled through a square-well potential, which represents a short-range attractive interaction between a particle and a solute molecule. The present model is formulated to be solved through direct numerical simulations. Some numerical results are presented to validate the simulations. The present model enables investigations of solute adsorption effects in the presence of a fluid flow and an inhomogeneous solute concentration distribution.
Automated MAD and MIR structure solution
Terwilliger, Thomas C., E-mail: terwilliger@lanl.gov [Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berendzen, Joel [Biophysics Group, Mail Stop D454, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Structural Biology Group, Mail Stop M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
1999-04-01
A fully automated procedure for solving MIR and MAD structures has been developed using a scoring scheme to convert the structure-solution process into an optimization problem. Obtaining an electron-density map from X-ray diffraction data can be difficult and time-consuming even after the data have been collected, largely because MIR and MAD structure determinations currently require many subjective evaluations of the qualities of trial heavy-atom partial structures before a correct heavy-atom solution is obtained. A set of criteria for evaluating the quality of heavy-atom partial solutions in macromolecular crystallography have been developed. These have allowed the conversion of the crystal structure-solution process into an optimization problem and have allowed its automation. The SOLVE software has been used to solve MAD data sets with as many as 52 selenium sites in the asymmetric unit. The automated structure-solution process developed is a major step towards the fully automated structure-determination, model-building and refinement procedure which is needed for genomic scale structure determinations.
Susmita Roy; Subramanian Yashonath; Biman Bagchi
2015-01-08
A self-consistent mode coupling theory (MCT) with microscopic inputs of equilibrium pair correlation functions is developed to analyze electrolyte dynamics. We apply the theory to calculate concentration dependence of (i) time dependent ion diffusion, (ii) dynamic structure factor of the constituent ions, and (iii) ion solvation dynamics in electrolyte solution. Brownian dynamics (BD) with implicit water molecules and molecular dynamics (MD) method with explicit water are used to check the theoretical predictions. The time dependence of ionic self-diffusion coefficient and the corresponding dynamic structure factor evaluated from our MCT approach show quantitative agreement with early experimental and present Brownian dynamic simulation results. With increasing concentration, the dispersion of electrolyte friction is found to occur at increasingly higher frequency, due to the faster relaxation of the ion atmosphere. The wave number dependence of total dynamic structure factor F(k,t), exhibits markedly different relaxation dynamics at different length scales. At small wave numbers, we find the emergence of a step-like relaxation, indicating the presence of both fast and slow time scales in the system. Such behaviour allows an intriguing analogy with temperature dependent relaxation dynamics of supercooled liquids. We find that solvation dynamics of a tagged ion exhibits a power law decay at long times- the decay can also be fitted to a stretched exponential form. The emergence of the power law in solvation dynamics has been tested by carrying out long Brownian dynamics simulations with varying ionic concentrations. This solvation time correlation and ion-ion dynamic structure factor indeed exhibits highly interesting, non-trivial dynamical behaviour at intermediate to longer times that require further experimental and theoretical studies.
Ford, W.; Marshall, R.S.; Osborn, L.C.; Picard, R.; Thomas, C.C. Jr.
1982-07-01
This report describes the efforts to develop and demonstrate a solution mass measurement system for use at the Los Alamos Plutonium Facility. Because of inaccuracy of load cell measurements, our major effort was directed towards the pneumatic bubbler tube. The differential pressure between the air inlet to the bubbler tube and the glovebox interior is measured and is proportional to the solution mass in the tank. An inexpensive, reliable pressure transducer system for measuring solution mass in vertical, cylindrical tanks was developed, tested, and evaluated in a laboratory test bed. The system can withstand the over- and underpressures resulting from solution transfer operations and can prevent solution backup into the measurement pressure transducer during transfers. Drifts, noise, quantization error, and other effects limit the accuracy to 30 g. A transportable calibration system using a precision machined tank, pneumatic bubbler tubes, and a Ruska DDR 6000 electromanometer was designed, fabricated, tested, and evaluated. Resolution of the system is +-3.5 g out of 50 kg. The calibration error is 5 g, using room-temperature water as the calibrating fluid. Future efforts will be directed towards in-plant test and evaluation of the tank measurement systems. 16 figures, 3 tables.
C. E. Magalhaes Batista; W. Zimdahl
2010-03-18
The dynamics of TeVeS in a homogeneous and isotropic universe is shown to be equivalent to the dynamics of an interacting two-component system, consisting of a scalar field and a "fluid", related to the matter part, with explicitly given coupling term. Scaling solutions (solutions with a constant ratio of the energy densities of both components) in the "Einstein frame" are found which are exponentially expanding or contracting with no remaining freedom for Bekenstein's $F$ function. In the "physical frame" these solutions are of the power-law type. An equivalent General Relativity (GR) picture of the dynamics suggests that it is the scalar field which plays the role of dark matter, while the "matter" has to mimic (phantom-type) dark energy.
structure calculations qualitatively reproduce the experimental observations. From the calculations interest in the kinetics and dynamics of electron transfer (ET) reac- tions, including reactions kinetics and dynamics studies: `how far is the electron transferred?' At first glance, this would appear
Fissile solution measurement apparatus
Crane, T.W.; Collinsworth, P.R.
1984-06-11
An apparatus for determining the content of a fissile material within a solution by detecting delayed fission neutrons emitted by the fissile material after it is temporarily irradiated by a neutron source. The apparatus comprises a container holding the solution and having a portion defining a neutron source cavity centrally disposed within the container. The neutron source cavity temporarily receives the neutron source. The container has portions defining a plurality of neutron detector ports that form an annular pattern and surround the neutron source cavity. A plurality of neutron detectors count delayed fission neutrons emitted by the fissile material. Each neutron detector is located in a separate one of the neutron detector ports.
A. J. John; S. D. Maharaj
2006-02-08
The condition for pressure isotropy is reduced to a recurrence equation with variable, rational coefficients of order three. We prove that this difference equation can be solved in general. Consequently we can find an exact solution to the field equations corresponding to a static spherically symmetric gravitational potential in terms of elementary functions. The metric functions, the energy density and the pressure are continuous and well behaved which implies that this solution could be used to model the interior of a relativistic sphere. The model satisfies a barotropic equation of state in general which approximates a polytrope close to the stellar centre.
Theoretical studies of electronically excited states
Besley, Nicholas A.
2014-10-06
Time-dependent density functional theory is the most widely used quantum chemical method for studying molecules in electronically excited states. However, excited states can also be computed within Kohn-Sham density functional theory by exploiting methods that converge the self-consistent field equations to give excited state solutions. The usefulness of single reference self-consistent field based approaches for studying excited states is demonstrated by considering the calculation of several types of spectroscopy including the infrared spectroscopy of molecules in an electronically excited state, the rovibrational spectrum of the NO-Ar complex, core electron binding energies and the emission spectroscopy of BODIPY in water.
Optically pulsed electron accelerator
Fraser, J.S.; Sheffield, R.L.
1985-05-20
An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.
Optically pulsed electron accelerator
Fraser, John S. (Los Alamos, NM); Sheffield, Richard L. (Los Alamos, NM)
1987-01-01
An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.
Kurnikova, Maria
calculations of electronic couplings, molecular dynamics simulations of molecular geometries, and Poisson exists to interpret electron-transfer (ET) reactions and their dependence upon molecular structure.1Structural Fluctuations, Spin, Reorganization Energy, and Tunneling Energy Control
Offshore Renewable Energy Solutions
Offshore Renewable Energy Solutions #12;Cefas: meeting complex requirements The Centre power to meet its target of achieving 15% of energy consumption from renewable sources by 2020. Cefas and sustainable energy supply. The UK is uniquely placed to harness its natural resources wind, wave and tidal
Drabold, David
upon reasonable calculations of the electron-lattice coupling and molecular dynamic simulationNetwork structure and dynamics of hydrogenated amorphous silicon D.A. Drabold *, T.A. Abtew, F on the network or lattice dynamics of the system, both in the electronic ground state and in an electronic
Electron beam generation in Tevatron electron lenses
Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.; /Novosibirsk, IYF
2006-08-01
New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices.
Non-adiabatic molecular dynamics by accelerated semiclassical Monte Carlo
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
White, Alexander J.; Gorshkov, Vyacheslav N.; Tretiak, Sergei; Mozyrsky, Dmitry
2015-07-07
Non-adiabatic dynamics, where systems non-radiatively transition between electronic states, plays a crucial role in many photo-physical processes, such as fluorescence, phosphorescence, and photoisomerization. Methods for the simulation of non-adiabatic dynamics are typically either numerically impractical, highly complex, or based on approximations which can result in failure for even simple systems. Recently, the Semiclassical Monte Carlo (SCMC) approach was developed in an attempt to combine the accuracy of rigorous semiclassical methods with the efficiency and simplicity of widely used surface hopping methods. However, while SCMC was found to be more efficient than other semiclassical methods, it is not yet as efficientmore »as is needed to be used for large molecular systems. Here, we have developed two new methods: the accelerated-SCMC and the accelerated-SCMC with re-Gaussianization, which reduce the cost of the SCMC algorithm up to two orders of magnitude for certain systems. In many cases shown here, the new procedures are nearly as efficient as the commonly used surface hopping schemes, with little to no loss of accuracy. This implies that these modified SCMC algorithms will be of practical numerical solutions for simulating non-adiabatic dynamics in realistic molecular systems.« less
Choi, Jun-Ho; Lim, Sohee; Chon, Bonghwan; Cho, Minhaeng; Kim, Heejae; Kim, Seongheun
2015-05-28
The vibrational frequency, frequency fluctuation dynamics, and transition dipole moment of the O—D stretch mode of HDO molecule in aqueous solutions are strongly dependent on its local electrostatic environment and hydrogen-bond network structure. Therefore, the time-resolved vibrational spectroscopy the O—D stretch mode has been particularly used to investigate specific ion effects on water structure. Despite prolonged efforts to understand the interplay of O—D vibrational dynamics with local water hydrogen-bond network and ion aggregate structures in high salt solutions, still there exists a gap between theory and experiment due to a lack of quantitative model for accurately describing O—D stretch frequency in high salt solutions. To fill this gap, we have performed numerical simulations of Raman scattering and IR absorption spectra of the O—D stretch mode of HDO in highly concentrated NaCl and KSCN solutions and compared them with experimental results. Carrying out extensive quantum chemistry calculations on not only water clusters but also ion-water clusters, we first developed a distributed vibrational solvatochromic charge model for the O—D stretch mode in aqueous salt solutions. Furthermore, the non-Condon effect on the vibrational transition dipole moment of the O—D stretch mode was fully taken into consideration with the charge response kernel that is non-local polarizability density. From the fluctuating O—D stretch mode frequencies and transition dipole vectors obtained from the molecular dynamics simulations, the O—D stretch Raman scattering and IR absorption spectra of HDO in salt solutions could be calculated. The polarization effect on the transition dipole vector of the O—D stretch mode is shown to be important and the asymmetric line shapes of the O—D stretch Raman scattering and IR absorption spectra of HDO especially in highly concentrated NaCl and KSCN solutions are in quantitative agreement with experimental results. We anticipate that this computational approach will be of critical use in interpreting linear and nonlinear vibrational spectroscopies of HDO molecule that is considered as an excellent local probe for monitoring local electrostatic and hydrogen-bonding environment in not just salt but also other confined and crowded solutions.
Deymier, Pierre
VOLUME 81, NUMBER 15 P H Y S I C A L R E V I E W L E T T E R S 12 OCTOBER 1998 Path-Integral method based on the discretized path integral representation of quantum particles. Fermi statistics is automatically generated by an effective exchange potential. This path-integral molecular dynamics method is able
Two-beam detuned-cavity electron accelerator structure
Jiang, Y.; Hirshfield, J. L. [Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States); Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States) and Omega-P, Inc., New Haven, CT 06510 (United States)
2012-12-21
Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.
Building America Solution Center
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels ResearchofDerivativeColdSealedOverview - 2015August 2011Solution
Solution to the Proton Radius Problem
D. Robson
2015-01-27
The relationship between the electric form factors for the proton in the rest frame and in the Breit momentum frame is used to provide a value for the difference in the mean squared charge radius of the proton evaluated in the two frames. Associating the muonic-hydrogen data analysis for the proton charge radius of 0.84087 fm with the rest frame and associating the electron scattering with the Breit frame yields a prediction 0f 0.87944 fm for the proton radius in the relativistic frame. The most recent value deduced via electron scattering from the proton is 0.877(6)fm so that the frame dependence used here yields a plausible solution to the proton radius puzzle.
Spieler, Helmuth G
2008-01-01
R. Armstrong Contents Electronics 9.1 Introduction 9.2measurements 9.11 Digital electronics 9.11.1 Logic elementsProblems page 1 vii Electronics This chapter was contributed
Casey, Jennifer Ryan
2014-01-01
Cavity and Non-cavity Hydrated Elec- tron at the Air/Waterrelaxation dynamics at water/air interfaces. J. Chem.Electronic states at the water/air interface. J. Phys. Chem.
Chen Lijen; Bessho, Naoki; Bhattacharjee, Amitava; Lefebvre, Bertrand; Vaith, Hans; Puhl-Quinn, Pamela; Torbert, Roy; Asnes, Arne; Fazakerley, Andrew; Khotyaintsev, Yuri; Daly, Patrick
2009-05-15
Open questions concerning structures and dynamics of diffusion regions and electron acceleration in collisionless magnetic reconnection are addressed based on data from the four-spacecraft mission Cluster and particle-in-cell simulations. Using time series of electron distribution functions measured by the four spacecraft, distinct electron regions around a reconnection layer are mapped out to set the framework for studying diffusion regions. A spatially extended electron current sheet (ecs), a series of magnetic islands, and bursts of energetic electrons within islands are identified during magnetotail reconnection with no appreciable guide field. The ecs is collocated with a layer of electron-scale electric fields normal to the ecs and pointing toward the ecs center plane. Both the observed electron and ion densities vary by more than a factor of 2 within one ion skin depth north and south of the ecs, and from the ecs into magnetic islands. Within each of the identified islands, there is a burst of suprathermal electrons whose fluxes peak at density compression sites [L.-J. Chen et al., Nat. Phys. 4, 19 (2008)] and whose energy spectra exhibit power laws with indices ranging from 6 to 7.3. These results indicate that the in-plane electric field normal to the ecs can be of the electron scale at certain phases of reconnection, electrons and ions are highly compressible within the ion diffusion region, and for reconnection involving magnetic islands, primary electron acceleration occurs within the islands.
Stability of the electron cyclotron resonance
Joachim Asch; Olivier Bourget; Cédric Meresse
2015-10-15
We consider the magnetic AC Stark effect for the quantum dynamics of a single particle in the plane under the influence of an oscillating homogeneous electric and a constant perpendicular magnetic field. We prove that the electron cyclotron resonance is insensitive to impurity potentials.
electronic reprint Acta Crystallographica Section B
Vocadlo, Lidunka
electronic reprint Acta Crystallographica Section B Structural Science ISSN 0108-7681 Structures, concluding that a CsCl-type structure would be the thermo- dynamically most stable phase for pressures calculations Lidunka Vocadlo, Geoffrey D. Price and I. G. Wood Copyright © International Union
Controlling Graphene's Electronic Structure
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Controlling Graphene's Electronic Structure Print Wednesday, 25 April 2007 00:00 Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has...
Dirac solutions for quaternionic potentials
De Leo, Stefano Giardino, Sergio
2014-02-15
The Dirac equation is solved for quaternionic potentials, i?V{sub 0} + j?W{sub 0} (V{sub 0}?R , W{sub 0}?C). The study shows two different solutions. The first one contains particle and anti-particle solutions and leads to the diffusion, tunneling, and Klein energy zones. The standard solution is recovered taking the complex limit of this solution. The second solution, which does not have a complex counterpart, can be seen as a V{sub 0}-antiparticle or |W{sub 0}|-particle solution.
High Order Finite Element Solution of Elastohydrodynamic Lubrication Problems
Jimack, Peter
High Order Finite Element Solution of Elastohydrodynamic Lubrication Problems by Hongqiang Lu-dimensional Elastohydro- dynamic Lubrication (EHL) problems (line contact and point contact). This thesis pro- vides an introduction to elastohydrodynamic lubrication, including some history, and a description of the underlying
Towards Computational Resources-Aware Control Solutions for Automotive CPS
Rajkumar, Ragunathan "Raj"
Towards Computational Resources-Aware Control Solutions for Automotive CPS Jonathan Sprinkle and Ricardo G. Sanfelice University of Arizona Abstract Automotive cyber-physical systems will need to address platforms, component based design, dynamic adaptation, and modeling languages and conventions. 2 Current
Generation of Femtosecond Electron Pulses
Jinamoon, V.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Thongbai, C.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Chumphongphan, S.; Wiedemann, H.; /SLAC, SSRL
2005-05-09
At the Fast Neutron Research Facility (FNRF), Chiang Mai University (Thailand), the SURIYA project has been established aiming to produce femtosecond electron pulses utilizing a combination of an S-band thermionic rf gun and a magnetic bunch compressor ({alpha}-magnet). A specially designed rf-gun has been constructed to obtain optimum beam characteristics for the best bunch compression. Simulation results show that bunch lengths as short as about 50 fs rms can be expected at the experimental station. The electron bunch lengths will be determined using autocorrelation of coherent transition radiation (TR) through a Michelson interferometer. The paper discusses beam dynamics studies, design, fabrication and cold tests of the rf-gun as well as presents the project current status and forth-coming experiments.
Iyengar, Srinivasan S.
electronic structure calculations (at the level of density functional theory, Hartree-Fock, post- Hartree approach to treat the simultaneous dynamics of electrons and nuclei. The method is based on a synergy-H-Cl]- and [CH3-H-Cl]- along with simultaneous dynamical treatment of the electrons and classical nuclei, through
Brenner, Donald W.
binding electronic structure calculations, pertur- bation models, and quantum-classical Hamiltonians [6 depends on the degree of approximation used in solving the electronic structure problem, which can add-scale molecular dynamics (MD) simulation is not to model electron dynamics, but rather to numerically solve
Iyengar, Srinivasan S.
Dynamics and Electronic Structure David Hocker, Xiaohu Li, and Srinivasan S. Iyengar* Department) approximates the electronic structure alongside the nuclei to simulate molecular dynamics. When AIMD techniques in electronic structure calculation. The approach is quantum-classical40,57-63 and involves the synergy between
Electron Cloud Effects in Accelerators
Furman, M.A.
2012-11-30
Abstract We present a brief summary of various aspects of the electron-cloud effect (ECE) in accelerators. For further details, the reader is encouraged to refer to the proceedings of many prior workshops, either dedicated to EC or with significant EC contents, including the entire ?ECLOUD? series [1?22]. In addition, the proceedings of the various flavors of Particle Accelerator Conferences [23] contain a large number of EC-related publications. The ICFA Beam Dynamics Newsletter series [24] contains one dedicated issue, and several occasional articles, on EC. An extensive reference database is the LHC website on EC [25].
Electromagnetic space-time crystals. III. Dispersion relations for partial solutions
G. N. Borzdov
2014-10-21
Partial solutions of the Dirac equation describing an electron motion in electromagnetic crystals created by plane waves with linear and circular polarizations are treated. It is shown that the electromagnetic crystal formed by circularly polarized waves possesses the spin birefringence.
Bearwall Energy Efficient Solutions
Sovero,M.
2014-01-01
, 2014 ENERGY EFFICIENT SOLUTIONS ESL-KT-14-11-06 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Brief History of Bearwall… Who We Are: ? Manuel Sovero ? Luis Osorio Energy Conservation Experience: ESL-KT-14-11-06 CATEE 2014...: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Energy Programs… ESL-KT-14-11-06 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 Bearwall Methodology… Introduction of Bearwall to the Local Authorities ESL...
Nerukh, Dmitry
Water network dynamics at the critical moment of a peptide's -turn formation: A molecular dynamics-Enkephalin in aqueous solution have been used to study the role of the water network during the formation of -turns. We give a detailed account of the intramolecular hydrogen bonding, the water-peptide hydrogen bonding
Qurz 10 SOLUTIONS, SECTION ALL
jony2_000
Qurz 10 SOLUTIONS, SECTION ALL. If C is the line segment from (0, 0) to (3, 5), then fc 3x2ds :7. A16 B25 C45 D65 E.75. Solution. To parametrize the line we ...
A tale of coupled vibrations in solution told by coherent two-dimensional infrared spectroscopy
Khalil, Munira, 1975-
2004-01-01
Coherent two-dimensional infrared (2D IR) spectroscopy is used as a tool for investigating the molecular structure and dynamics of coupled vibrations in solution on a picosecond timescale. The strongly coupled asymmetric ...
Bai, Xiaoli
2011-10-21
The solution of initial value problems (IVPs) provides the evolution of dynamic system state history for given initial conditions. Solving boundary value problems (BVPs) requires finding the system behavior where elements of the states are defined...
Flow dynamics and solute transport in unsaturated rock fractures
Su, G.W.
2011-01-01
2.4. Cross-section of flow cell/flange assembly ceramic2.1,2.3 Mariotte bottle Exp.2.2 flow meter o IighttaQt6porous media effecting fluid flow, J. Irrig. Drainage Div.
Flow dynamics and solute transport in unsaturated rock fractures
Su, G.W.
2011-01-01
PDF's of the measured cumulative BTC's at 13 = 45° and theMeasured data and predicted BTC for Experiment 5.3 using5.2. Parameters obtained from the BTC's in Experiments 5.3 -
Low-Cost Solutions for Dynamic Window Material
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURING OFFICE INDUSTRIALU.S.Leadership onProton ConductivityManagement |
Standing electromagnetic solitons in hot ultra-relativistic electron-positron plasmas
Heidari, E.; Aslaninejad, M.; Eshraghi, H.; Rajaee, L.
2014-03-15
Using a one-dimensional self-consistent fluid model, we investigate standing relativistic bright solitons in hot electron-positron plasmas. The positron dynamics is taken into account. A set of nonlinear coupled differential equations describing the evolution of electromagnetic waves in fully relativistic two-fluid plasma is derived analytically and solved numerically. As a necessary condition for the existence of standing solitons the system should be relativistic. For the case of ultra-relativistic plasma, we investigate non-drifting bright solitary waves. Detailed discussions of the acceptable solutions are presented. New single hump non-trivial symmetric solutions for the scalar potential were found, and single and multi-nodal symmetric and anti-symmetric solutions for the vector potential are presented. It is shown that for a fixed value of the fluid velocity excited modes with more zeros in the profile of the vector potential show a higher magnitude for the scalar potential. An increase in the plasma fluid velocity also increases the magnitude of the scalar potential. Furthermore, the Hamiltonian and the first integral of the system are given.
Sandia Energy - SCADA Engineering Solutions
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Engineering Solutions Home Stationary Power Safety, Security & Resilience of Energy Infrastructure Grid Modernization Cyber Security for Electric Infrastructure National...
ELECTRONIC CHARTS INTRODUCTION
New Hampshire, University of
199 CHAPTER 14 ELECTRONIC CHARTS INTRODUCTION 1400. The Importance of Electronic Charts Since. Electronic charts automate the process of integrating real-time positions with the chart display and allow is expected to take and plot a fix every three minutes. An electronic chart system can do it once per second
Brunner, S. Hausammann, L.; Berger, R. L. Cohen, B. I.; Valeo, E. J.
2014-10-15
Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate ? and quasi- wavenumber ?k, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.
Brunner, S.; Berger, R. L.; Cohen, B. I.; Hausammann, L.; Valeo, E. J.
2014-10-01
Kinetic Vlasov simulations of one-dimensional finite amplitude Electron Plasma Waves are performed in a multi-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate ? and quasi- wavenumber ?k, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are successfully compared against numerical and analytical solutions to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] for the Trapped Particle Instability (TPI). A model recently suggested by Dodin et al. [Phys. Rev. Lett. 110, 215006 (2013)], which in addition to the TPI accounts for the so-called Negative Mass Instability because of a more detailed representation of the trapped particle dynamics, is also studied and compared with simulations.
A Corpuscular Picture of Electrons in Chemical Bond
Ando, Koji
2015-01-01
We introduce a theory of chemical bond with a corpuscular picture of electrons. It employs a minimal set of localized electron wave packets with 'floating and breathing' degrees of freedom and the spin-coupling of non-orthogonal valence-bond theory. It accurately describes chemical bonds in ground and excited states of spin singlet and triplet, in a distinct manner from conventional theories, indicating potential for establishing a dynamical theory of electrons in chemical bonds.
Kervalishvili, N A
2015-01-01
The results of experimental investigations of electron ejection from gas-discharge nonneutral electron plasma at the formation and radial oscillations of vortex structure have been presented. The electrons are injected from the vortex structure and the adjacent region of electron sheath in the form of pulses the duration and periodicity of which are determined by the processes of evolution and dynamics of this structure. The possible mechanisms of pulse ejection of electrons are considered. The influence of electron ejection on other processes in discharge electron sheath is analyzed.
Thermodynamics of Electron Flow in the Bacterial Deca-heme Cytochrome MtrF
Breuer, Marian; Zarzycki, Piotr P.; Blumberger, Jochen; Rosso, Kevin M.
2012-07-01
Electron transporting multiheme cytochromes are essential to the metabolism of microbes that inhabit soils and carry out important biogeochemical processes. Recently the first crystal structure of a prototype bacterial deca-heme cytochrome (MtrF) has been resolved and its electrochemistry characterized. However, the molecular details of electron conductance along heme chains in the cytochrome are difficult to access via experiment due to the nearly identical chemical nature of the heme cofactors. Here we employ large-scale molecular dynamics simulations to compute the reduction potentials of the ten hemes of MtrF in aqueous solution. We find that as a whole they fall within a range of about 0.3 V in agreement with experiment. Individual reduction potentials give rise to a free energy profile for electron conduction that is approximately symmetric with respect to the center of the protein. Our calculations indicate that there is no significant potential bias along the orthogonal octa- and tetra-heme chains suggesting that under aqueous conditions MtrF is a nearly reversible two-dimensional conductor.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Zhen; Bane, Karl; Ding, Yantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa
2015-01-30
Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between at metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (#24;100 MeV) and with relatively long bunches (> 1ps). In the parameter regime of the LCLS dechirper, with the corrugation size similar to the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a #12;field matching program to obtain the wakes. Based on the numerical calculations, we #12;fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields - both dipole and quadrupole-are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zhang, Zhen; Bane, Karl; Ding, Yantao; Huang, Zhirong; Iverson, Richard; Maxwell, Timothy; Stupakov, Gennady; Wang, Lanfa
2015-01-30
Electron beam energy chirp is an important parameter that affects the bandwidth and performance of a linac-based, free-electron laser. In this paper we study the wakefields generated by a beam passing between at metallic plates with small corrugations, and then apply such a device as a passive dechirper for the Linac Coherent Light Source (LCLS) energy chirp control with a multi-GeV and femtosecond electron beam. Similar devices have been tested in several places at relatively low energies (#24;100 MeV) and with relatively long bunches (> 1ps). In the parameter regime of the LCLS dechirper, with the corrugation size similar tomore »the gap between the plates, the analytical solutions of the wakefields are no longer applicable, and we resort to a #12;field matching program to obtain the wakes. Based on the numerical calculations, we #12;fit the short-range, longitudinal wakes to simple formulas, valid over a large, useful parameter range. Finally, since the transverse wakefields - both dipole and quadrupole-are strong, we compute and include them in beam dynamics simulations to investigate the error tolerances when this device is introduced in the LCLS.« less
Shimojo, Fuyuki; Hattori, Shinnosuke [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States) [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Kalia, Rajiv K.; Mou, Weiwei; Nakano, Aiichiro; Nomura, Ken-ichi; Rajak, Pankaj; Vashishta, Priya [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States)] [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Kunaseth, Manaschai [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States) [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); National Nanotechnology Center, Pathumthani 12120 (Thailand); Ohmura, Satoshi [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States) [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Shimamura, Kohei [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States) [Collaboratory for Advanced Computing and Simulations, Department of Physics and Astronomy, Department of Computer Science, and Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-0242 (United States); Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Fukuoka 819-0395 (Japan)
2014-05-14
We introduce an extension of the divide-and-conquer (DC) algorithmic paradigm called divide-conquer-recombine (DCR) to perform large quantum molecular dynamics (QMD) simulations on massively parallel supercomputers, in which interatomic forces are computed quantum mechanically in the framework of density functional theory (DFT). In DCR, the DC phase constructs globally informed, overlapping local-domain solutions, which in the recombine phase are synthesized into a global solution encompassing large spatiotemporal scales. For the DC phase, we design a lean divide-and-conquer (LDC) DFT algorithm, which significantly reduces the prefactor of the O(N) computational cost for N electrons by applying a density-adaptive boundary condition at the peripheries of the DC domains. Our globally scalable and locally efficient solver is based on a hybrid real-reciprocal space approach that combines: (1) a highly scalable real-space multigrid to represent the global charge density; and (2) a numerically efficient plane-wave basis for local electronic wave functions and charge density within each domain. Hybrid space-band decomposition is used to implement the LDC-DFT algorithm on parallel computers. A benchmark test on an IBM Blue Gene/Q computer exhibits an isogranular parallel efficiency of 0.984 on 786?432 cores for a 50.3 × 10{sup 6}-atom SiC system. As a test of production runs, LDC-DFT-based QMD simulation involving 16?661 atoms is performed on the Blue Gene/Q to study on-demand production of hydrogen gas from water using LiAl alloy particles. As an example of the recombine phase, LDC-DFT electronic structures are used as a basis set to describe global photoexcitation dynamics with nonadiabatic QMD (NAQMD) and kinetic Monte Carlo (KMC) methods. The NAQMD simulations are based on the linear response time-dependent density functional theory to describe electronic excited states and a surface-hopping approach to describe transitions between the excited states. A series of techniques are employed for efficiently calculating the long-range exact exchange correction and excited-state forces. The NAQMD trajectories are analyzed to extract the rates of various excitonic processes, which are then used in KMC simulation to study the dynamics of the global exciton flow network. This has allowed the study of large-scale photoexcitation dynamics in 6400-atom amorphous molecular solid, reaching the experimental time scales.
Yamazaki, M.; Kasai, Y.; Oishi, K.; Nakazawa, H.; Takahashi, M.
2013-06-15
An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.
Statistics as a dynamical attractor
Michail Zak
2012-08-30
It is demonstrated that any statistics can be represented by an attractor of the solution to a corresponding systen of ODE coupled with its Liouville equation. Such a non-Newtonian representation allows one to reduce foundations of statistics to better established foundations of ODE. In addition to that, evolution to the attractor reveals possible micro-mechanisms driving random events to the final distribution of the corresponding statistical law. Special attention is concentrated upon the power law and its dynamical interpretation: it is demonstrated that the underlying dynamics supports a " violent reputation" of the power law statistics.
Dynamics of Protein Hydration Water
M. Wolf; S. Emmert; R. Gulich; P. Lunkenheimer; A. Loidl
2014-12-08
We present the frequency- and temperature-dependent dielectric properties of lysozyme solutions in a broad concentration regime, measured at subzero temperatures and compare the results with measurements above the freezing point of water and on hydrated lysozyme powder. Our experiments allow examining the dynamics of unfreezable hydration water in a broad temperature range including the so-called No Man's Land (160 - 235 K). The obtained results prove the bimodality of the hydration shell dynamics and are discussed in the context of the highly-debated fragile-to-strong transition of water.
Chiral specific electron vortex beam spectroscopy
J. Yuan; S. M. Lloyd; M. Babiker
2013-07-29
Electron vortex beams carry well-defined orbital angular momentum (OAM) about the propagation axis. Such beams are thus characterised by chirality features which make them potentially useful as probes of magnetic and other chiral materials. An analysis of the inelastic processes in which electron vortex beams interact with atoms and which involve OAM exchange is outlined, leading to the multipolar selection rules governing this chiral specific electron vortex beam spectroscopy. Our results show clearly that the selection rules are dependent on the dynamical state and location of the atoms involved. In the most favorable scenario, this form of electron spectroscopy can induce magnetic sublevel transitions which are commonly probed using circularly polarized photon beams.
ASYMMETRIC ELECTRON DISTRIBUTIONS IN THE SOLAR WIND
Rha, Kicheol; Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Yoon, Peter H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)] [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States)
2013-09-20
A plausible mechanism responsible for producing asymmetric electron velocity distribution functions in the solar wind is investigated by means of one-dimensional electrostatic particle-in-cell (PIC) simulation. A recent paper suggests that the variation in the ion-to-electron temperature ratio influences the nonlinear wave-particle dynamics such that it results in the formation of asymmetric distributions. The present PIC code simulation largely confirms this finding, but quantitative differences between the weak turbulence formalism and the present PIC simulation are also found, suggesting the limitation of the analytical method. The inter-relationship between the asymmetric electron distribution and the ion-to-electron temperature ratio may be a new useful concept for the observation.
Generation of Femtosecond Electron And Photon Pulses
Thongbai, C.; Jinamoon, V.; Kangrang, M.; Kusoljariyakul, K.; Rimjaem, S.; Saisut, J.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Wiedemann, H.; /SLAC
2006-03-17
Femtosecond (fs) electron and photon pulses become a tool of increasing importance to study dynamics in ultrafast processes. Such short electron pulses can be generated from a system consisting of a thermionic-cathode RF-gun and a magnetic bunch compressor. The fs electron pulses can be used directly or used as a source to produce equally short electromagnetic radiation pulses via certain kind of radiation production processes. At the Fast Neutron Research Facility (FNRF), Thailand, we are especially interested in production of radiation in Farinfrared and X-ray regime. In the far-infrared wavelengths, the radiation emitted from fs electron pulses is emitted coherently resulting high intensity radiation. In the X-ray regime, development of fs X-ray sources is crucial for application in ultrafast sciene.
Exciton coherence lifetimes from electronic structure
Parkhill, John; Aspuru-Guzik, Alan
2011-01-01
We model the coherent energy transfer of an electronic excitation within covalently linked aromatic homodimers from first-principles, to answer whether the usual models of the bath calculated via detailed electronic structure calculations can reproduce the key dynamics. For these systems the timescales of coherent transport are experimentally known from time-dependent polarization anisotropy measurements, and so we can directly assess the whether current techniques might be predictive for this phenomenon. Two choices of electronic basis states are investigated, and their relative merits discussed regarding the predictions of the perturbative model. The coupling of the electronic degrees of freedom to the nuclear degrees of freedom is calculated rather than assumed, and the fluorescence anisotropy decay is directly reproduced. Surprisingly we find that although TDDFT absolute energies are routinely in error by orders of magnitude more than the coupling energy, the coherent transport properties of these dimers ...
FEATURE ARTICLE Unified Molecular Picture of the Surfaces of Aqueous Acid, Base, and Salt Solutions
FEATURE ARTICLE Unified Molecular Picture of the Surfaces of Aqueous Acid, Base, and Salt Solutions inorganic ions. Molecular dynamics calculations show that in salt solutions and bases the positively charged, consequently, these acids (unlike bases and salts) reduce the surface tension of water. The results
Measurement and numerical analysis of freezing in solutions enclosed in a small container
Lowengrub, John
Measurement and numerical analysis of freezing in solutions enclosed in a small container the magnitude and dynamics of latent heat during freezing of 14 different pre-nucleated solute laden aqueous the experimentally measured behavior based on the full set of heat and mass transport equations during the freezing
Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons
Pokol, G. I.; Kómár, A.; Budai, A.; Stahl, A.; Fülöp, T.
2014-10-15
Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the 100–1000??s time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.
Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons
Pokol, G I; Budai, A; Stahl, A; Fülöp, T
2014-01-01
Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the $100-1000\\;\\rm \\mu s$ time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.
Horn, Berthold Klaus Paul
Dynamic reconstruction is a method for generating images or image sequences from data obtained using moving radiation detection systems. While coded apertures are used as examples of the underlying information collection ...
Terwilliger, Thomas C [Los Alamos National Laboratory; Adams, Paul D [LBNL; Read, Randy J [UNIV OF CAMBRIDGE; Mccoy, Airlie J [UNIV OF CAMBRIDGE
2008-01-01
Ten measures of experimental electron-density-map quality are examined and the skewness of electron density is found to be the best indicator of actual map quality. A Bayesian approach to estimating map quality is developed and used in the PHENIX AutoSol wizard to make decisions during automated structure solution.
Gu, X.; Altinbas, Z.; Bruno, D.; Binello, S.; Costanzo, M.; Drees, A.; Fischer, W.; Gassner, D. M.; Hock, J.; Hock, K.; Harvey, M.; Luo, Y.; Marusic, A.; Mi, C.; Mernick, K.; Minty, M.; Michnoff, R.; Miller, T. A.; Pikin, A. I.; Robert-Demolaize, G.; Samms, T.; Shrey, T. C.; Schoefer, V.; Tan, Y.; Than, R.; Thieberger, P.; White, S. M.
2015-05-03
In the Relativistic Heavy Ion Collider (RHIC) 100 GeV polarized proton run in 2015, two electron lenses were used to partially compensate for the head-on beam-beam effect for the first time. Here, we describe the design of the current electron lens, detailing the hardware modifications made after the 2014 commissioning run with heavy ions. A new electron gun with 15-mm diameter cathode is characterized. The electron beam transverse profile was measured using a YAG screen and fitted with a Gaussian distribution. During operation, the overlap of the electron and proton beams was achieved using the electron backscattering detector in conjunction with an automated orbit control program.
Interaction of a Polyelectrolyte Solution with an Attractive Surface Kate Barteau
Shell, M. Scott
studied a simplified system of a semi-dilute polymer electrolyte solution and its behavior near an oppositely charged surface using molecular dynamics (MD) simulations. Polymers were simulated as 6-12 Lennard with an attractive wall has been carried out through molecular dynamics simulations. Total charge density along
TheRate: Program for Ab Initio Direct Dynamics Calculations of Thermal and
Truong, Thanh N.
, and the convergence of the rate constants with respect to the number of electronic structure calculations. 1998 John is that such limited potential energy information may be obtained from accurate electronic structure calculations-- --Dynamics Calculations of Thermal and Vibrational
Photoionization dynamics and angular squeezing phenomenon in intense long-wavelength laser fields
Chu, Shih-I; Zhou, Zhongyuan
2011-03-11
We develop a coherent-state Ehrenfest trajectory (CSET) approach for the nonperturbative study of full electronic and nuclear dynamics of molecules interacting with intense laser fields. In this approach, electrons and ...
Zharkova, Valentina V.
THE EFFECT OF A SELF-INDUCED ELECTRIC FIELD ON ELECTRON BEAM DIFFERENTIAL SPECTRA IN FLARING field decrease with depth reduces the electron decelera- tion that allows beam electrons to precipitate. INTRODUCTION The effect of the induced electric field on the dynam- ics of non-thermal electron beams
A high dynamic range data acquisition system for a solid-state...
Office of Scientific and Technical Information (OSTI)
A high dynamic range data acquisition system for a solid-state electron electric dipole moment experiment Citation Details In-Document Search Title: A high dynamic range data...
Dynamics-dependent symmetries in Newtonian mechanics
Peter Holland
2014-09-19
We exhibit two symmetries of one-dimensional Newtonian mechanics whereby a solution is built from the history of another solution via a generally nonlinear and complex potential-dependent transformation of the time. One symmetry intertwines the square roots of the kinetic and potential energies and connects solutions of the same dynamical problem (the potential is an invariant function). The other symmetry connects solutions of different dynamical problems (the potential is a scalar function). The existence of corresponding conserved quantities is examined using Noethers theorem and it is shown that the invariant-potential symmetry is correlated with energy conservation. In the Hamilton-Jacobi picture the invariant-potential transformation provides an example of a field-dependent symmetry in point mechanics. It is shown that this transformation is not a symmetry of the Schroedinger equation.
Imaging Electrons in Few-Electron Quantum Dots
Imaging Electrons in Few-Electron Quantum Dots A thesis presented by Parisa Fallahi to The Division Electrons in Few-Electron Quantum Dots Abstract Electrons in a one-electron quantum dot were imaged the tip-induced shift of the electron energy state in the dot. A technique for extracting the amplitude
Bump formation in the runaway electron tail
Decker, J; Fülöp, T
2015-01-01
Runaway electrons are generated in a magnetized plasma when the parallel electric field exceeds a critical value. For such electrons with energies typically reaching tens of MeV, the Abraham-Lorentz-Dirac (ALD) radiation force, in reaction to the synchrotron emission, is significant and can be the dominant process limiting the electron acceleration. The effect of the ALD-force on runaway electron dynamics in a homogeneous plasma is investigated using the relativistic finite-difference Fokker-Planck codes LUKE [Decker & Peysson, Report EUR-CEA-FC-1736, Euratom-CEA, (2004)] and CODE [Landreman et al, Comp. Phys. Comm. 185, 847 (2014)]. Under the action of the ALD force, we find that a bump is formed in the tail of the electron distribution function if the electric field is sufficiently large. We also observe that the energy of runaway electrons in the bump increases with the electric field amplitude, while the population increases with the bulk electron temperature. The presence of the bump divides the elec...
Large-Scale First-Principles Molecular Dynamics simulations on the BlueGene/L Platform
Franchetti, Franz
. Keywords Electronic structure. Molecular Dynamics. Ab initio simulations. First-principles simulations of the electronic properties of the system. The electronic structure calculation is the most time-consuming part the past three decades to the development of efficient implementations of the electronic structure
Free electron laser with bunched relativistic electron beam and electrostatic longitudinal wiggler
Sepehri Javan, Nasser [Department of Physics, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil (Iran, Islamic Republic of)
2010-06-15
The system of the nonlinear nonstationary equations describing spatial-temporal dynamics of the amplitudes of an undulator radiation and a space charge wave of a relativistic electron beam in the resonator is obtained. The electrostatic longitudinal wiggler is considered. A bunch of the electron beam injects to the resonator, at the ends of which two mirrors are placed. After the interaction of electrons of bunch with radiation in the presence of wiggler and after amplifying electromagnetic pulse, a part of radiation is reflected back by semitransparent mirror. Then, it reaches to the initial of the system where the other mirror is placed. Synchronously, when the pulse is reflecting, the other electron bunch enters to the resonator and interacts with the pulse. This operation has simulated until saturation of growth of the electromagnetic pulse. The dynamics of the problem is simulated by the method of macro particles. The dynamics of pulse amplification, motion of the electrons, and spectra of output radiation in each stage are simulated.
Energy transfer dynamics in trimers and aggregates of light-harvesting...
Office of Scientific and Technical Information (OSTI)
Energy transfer dynamics in trimers and aggregates of light-harvesting complex II probed by 2D electronic spectroscopy Citation Details In-Document Search Title: Energy transfer...
Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)
1982-01-01
A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.
E. L. Koschmieder
2006-09-26
We will show that one half of the rest mass of the electron is equal to the sum of the rest masses of electron neutrinos and that the other half of the rest mass of the electron is given by the energy in the sum of electric oscillations. With this composition we can explain the rest mass, the electric charge, the spin and the magnetic moment of the electron.
Extraordinary vacuum black string solutions
Kim, Hyeong-Chan; Lee, Jungjai
2008-01-15
In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.
Building America Solution Center Webinar
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
with fast, free and reliable building science and efficiency knowledge. At the heart of the Building America Solution Center are the guides -- a compilation of content...
Is Nuclear Energy the Solution?
Saier, Milton H.; Trevors, Jack T.
2010-01-01
009-0270-y Is Nuclear Energy the Solution? Milton H. Saier &in the last 50 years, nuclear energy subsidies have totaledadministration, the Global Nuclear Energy Partnership (GNEP)
PetaScale Calculations of the Electronic Structures of Nanostructures with Hundreds of Thousands in the material science category. The DFT can be used to calculate the electronic structure, the charge density. To understand the electronic structures of such systems and the corresponding carrier dynamics is essential
Time-dependent electron phenomena at surfaces R. Dez Muioa,b
Muiño, Ricardo Díez
, control, and design physical and chemical processes at surfaces. Dynamics of electronic excitations13). As a consequence, deep understanding has been reached about the mechanisms ruling electron decay and electron. Attosecond spectroscopy, for in- stance, is nowadays able to discern the individual elementary steps
Time-optimal polarization transfer from an electron spin to a nuclear spin
Haidong Yuan; Robert Zeier; Nikolas Pomplun; Steffen J. Glaser; Navin Khaneja
2015-09-07
Polarization transfers from an electron spin to a nuclear spin are essential for various physical tasks, such as dynamic nuclear polarization in nuclear magnetic resonance and quantum state transformations on hybrid electron-nuclear spin systems. We present time-optimal schemes for electron-nuclear polarization transfers which improve on conventional approaches and will have wide applications.
Sandini, Giulio
Electron Beam Lithography Marco Salerno #12;Outline · general lithographic concepts · EBL www.cnf.cornell.edu/SPIEBook/SPIE1.HTM #12;Typical Electron Beam Column Zeiss GeminiTM column Types of Electron Beam Columns · no e- cross over no Boersch-effect (additional energy spread) · beam booster
Burra G. Sidharth
2008-08-05
In the light of recent developments in Dark Energy, we consider the electron in a such a background field and show that at the Compton wavelength the electron is stable, in that the Cassini inward pressure exactly counterbalances the outward Coulomb repulsive pressure thus answering a problem of the earlier electron theory.