Artigos de revistas: "Electrons dynamic"

1

Egorov, Vladimir V. "Dynamic Symmetry in Dozy-Chaos Mechanics". Symmetry 12, n.º 11 (11 de novembro de 2020): 1856. http://dx.doi.org/10.3390/sym12111856.

Texto completo da fonte

Resumo:

All kinds of dynamic symmetries in dozy-chaos (quantum-classical) mechanics (Egorov, V.V. Challenges 2020, 11, 16; Egorov, V.V. Heliyon Physics 2019, 5, e02579), which takes into account the chaotic dynamics of the joint electron-nuclear motion in the transient state of molecular “quantum” transitions, are discussed. The reason for the emergence of chaotic dynamics is associated with a certain new property of electrons, consisting in the provocation of chaos (dozy chaos) in a transient state, which appears in them as a result of the binding of atoms by electrons into molecules and condensed matter and which provides the possibility of reorganizing a very heavy nuclear subsystem as a result of transitions of light electrons. Formally, dozy chaos is introduced into the theory of molecular “quantum” transitions to eliminate the significant singularity in the transition rates, which is present in the theory when it goes beyond the Born–Oppenheimer adiabatic approximation and the Franck–Condon principle. Dozy chaos is introduced by replacing the infinitesimal imaginary addition in the energy denominator of the full Green’s function of the electron-nuclear system with a finite value, which is called the dozy-chaos energy γ. The result for the transition-rate constant does not change when the sign of γ is changed. Other dynamic symmetries appearing in theory are associated with the emergence of dynamic organization in electronic-vibrational transitions, in particular with the emergence of an electron-nuclear-reorganization resonance (the so-called Egorov resonance) and its antisymmetric (chaotic) “twin”, with direct and reverse transitions, as well as with different values of the electron–phonon interaction in the initial and final states of the system. All these dynamic symmetries are investigated using the simplest example of quantum-classical mechanics, namely, the example of quantum-classical mechanics of elementary electron-charge transfers in condensed media.

Estilos ABNT, Harvard, Vancouver, APA, etc.

2

Douis, S., e M. T. Meftah. "Correlation function and electronic spectral line broadening in relativistic plasmas". Serbian Astronomical Journal, n.º 186 (2013): 15–23. http://dx.doi.org/10.2298/saj130218002d.

Texto completo da fonte

Resumo:

The electrons dynamics and the time autocorrelation function Cee(t) for the total electric microfield of the electrons on positive charge impurity embedded in a plasma are considered when the relativistic dynamic of the electrons is taken into account. We have, at first, built the effective potential governing the electrons dynamics. This potential obeys a nonlinear integral equation that we have solved numerically. Regarding the electron broadening of the line in plasma, we have found that when the plasma parameters change, the amplitude of the collision operator changes in the same way as the time integral of Cee(t). The electron-impurity interaction is taken at first time as screened Deutsh interaction and at the second time as Kelbg interaction. Comparisons of all interesting quantities are made with respect to the previous interactions as well as between classical and relativistic dynamics of electrons.

Estilos ABNT, Harvard, Vancouver, APA, etc.

3

Yang, Ciann-Dong, e Shiang-Yi Han. "Orbital and Spin Dynamics of Electron’s States Transition in Hydrogen Atom Driven by Electric Field". Photonics 9, n.º 9 (2 de setembro de 2022): 634. http://dx.doi.org/10.3390/photonics9090634.

Texto completo da fonte

Resumo:

State transition in the multiple-levels system has the great potential applications in the quantum technology. In this article we employ a deterministic approach in complex space to analyze the dynamics of the 1s–2p electron transition in the hydrogen atom. The electron’s spin motion is embodied in the framework of quantum Hamilton mechanics that allows us to examine the transition dynamics more precisely. The transition is driven by an oscillating electric field in the z-direction. The electron’s transition process can be visualized by monitoring its motion in the complex space. The quantum potential and the total energy proposed in this paper provide new indices to observe the dynamic changes of electrons in the transition process.

Estilos ABNT, Harvard, Vancouver, APA, etc.

4

Brange, Fredrik, Adrian Schmidt, Johannes C. Bayer, Timo Wagner, Christian Flindt e Rolf J. Haug. "Controlled emission time statistics of a dynamic single-electron transistor". Science Advances 7, n.º 2 (janeiro de 2021): eabe0793. http://dx.doi.org/10.1126/sciadv.abe0793.

Texto completo da fonte

Resumo:

Quantum technologies involving qubit measurements based on electronic interferometers rely critically on accurate single-particle emission. However, achieving precisely timed operations requires exquisite control of the single-particle sources in the time domain. Here, we demonstrate accurate control of the emission time statistics of a dynamic single-electron transistor by measuring the waiting times between emitted electrons. By ramping up the modulation frequency, we controllably drive the system through a crossover from adiabatic to nonadiabatic dynamics, which we visualize by measuring the temporal fluctuations at the single-electron level and explain using detailed theory. Our work paves the way for future technologies based on the ability to control, transmit, and detect single quanta of charge or heat in the form of electrons, photons, or phonons.

Estilos ABNT, Harvard, Vancouver, APA, etc.

5

Mirzanejhad, S., J. Babaei e R. Nasrollahpour. "Electron sheath dynamic in the laser–foil interaction". Laser and Particle Beams 34, n.º 3 (20 de junho de 2016): 440–46. http://dx.doi.org/10.1017/s0263034616000331.

Texto completo da fonte

Resumo:

AbstractIn the interaction of ultra-short and ultra-intense high contrast laser pulse with a dense foil, accelerating electron sheath is formed. The dynamic of this sheath is obtained according to the ponderomotive force of the laser pulse and restoring electrostatic force of the stationary heavy ions. In the transient dynamics, maximum electron sheath displacement is obtained for different interaction parameters. This maximum displacement has an important effect in the explanation of the electron blow out condition. It is shown numerically that the electron sheath maximum displacement increases with increasing laser pulse amplitude or decreasing its rise time, or by decreasing plasma electron density. Recently, backward MeV acceleration of electrons in the interaction of intense laser pulse with solid targets was observed. The ponderomotive force of the compressed reflected laser pulse includes in our formalism and is used for explanation of the electron's backward acceleration. The threshold values of the interaction parameters for the occurrence of this phenomenon are considered. The electron blow out condition and backward acceleration are accompanied with numerical modeling and 1D3V, particle-in-cell simulation code.

Estilos ABNT, Harvard, Vancouver, APA, etc.

6

ZHANG, S. Y., Y. K. HO, Z. CHEN, Y. J. XIE, Z. YAN e J. J. XU. "DYNAMIC TRAJECTORIES OF RELATIVISTIC ELECTRONS INJECTED INTO TIGHTLY-FOCUSED INTENSE LASER FIELDS". Journal of Nonlinear Optical Physics & Materials 13, n.º 01 (março de 2004): 103–12. http://dx.doi.org/10.1142/s0218863504001785.

Texto completo da fonte

Resumo:

Dynamic trajectories of relativistic electrons injected into tightly focused ultra-intense laser field have been investigated. In addition to the previously-reported CAS (Capture and Acceleration Scenario) and IS (Inelastic Scattering) trajectories, a new kind of nonlinear electron trajectory is found when the beam waist radius w0 is small enough (kw0≤30, k is the wave number) and incident angle is small. We shall call it PARM (Penetrate into Axial Region and Move). The basic feature of PARM trajectory shows the strong diffraction effect of a tightly-focused laser field. Part of the incident electrons that experience the strong transversal force from the diffraction edge field as they travel toward the beam waist will follow the PARM trajectory. This force can push the electrons toward the beam center. Thus unlike the CAS and IS electrons, the PARM electrons will move along the region near the beam axis. We also found some of the PARM electrons can gain energy from the field. The conditions for PARM electrons to appear were examined and are presented here. The implication of the presence of PARM to the planned experimental test of the CAS scheme is addressed.

Estilos ABNT, Harvard, Vancouver, APA, etc.

7

Ryzhii, Maxim, Taiichi Otsuji, Victor Ryzhii, Vladimir Mitin, Michael S. Shur, Georgy Fedorov e Vladimir Leiman. "Dynamic Conductivity and Two-Dimensional Plasmons in Lateral CNT Networks". International Journal of High Speed Electronics and Systems 26, n.º 01n02 (17 de fevereiro de 2017): 1740004. http://dx.doi.org/10.1142/s0129156417400043.

Texto completo da fonte

Resumo:

We study theoretically the carrier transport and the plasmonic phenomena in the gated structures with dense lateral carbon nanotube (CNT) networks (CNT “felt”) placed between the highly-conducting slot line electrodes. The CNT networks under consideration consist of a mixture of semiconducting and metallic CNTs. We find the dispersion relations for the two-dimensional plasmons, associated with the collective self-consisted motion of electrons in the individual CNTs, propagating along the electrodes as functions of the net electron density (gate voltage), relative fraction of the semiconducting and metallic CNTs, and the spacing between the electrodes. In a wide range of parameters, the characteristic plasmonic frequencies can fall in the terahertz (THz) range. The structures with lateral CNT networks can used in different THz devices.

Estilos ABNT, Harvard, Vancouver, APA, etc.

8

Wili, Nino, Jan Henrik Ardenkjær-Larsen e Gunnar Jeschke. "Reverse dynamic nuclear polarisation for indirect detection of nuclear spins close to unpaired electrons". Magnetic Resonance 3, n.º 2 (10 de agosto de 2022): 161–68. http://dx.doi.org/10.5194/mr-3-161-2022.

Texto completo da fonte

Resumo:

Abstract. Polarisation transfer schemes and indirect detection are central to magnetic resonance. Using the trityl radical OX063 and a pulse electron paramagnetic resonance spectrometer operating in the Q-band (35 GHz, 1.2 T), we show here that it is possible to use pulsed dynamic nuclear polarisation (DNP) to transfer polarisation from electrons to protons and back. The latter is achieved by first saturating the electrons and then simply using a reverse DNP step. A variable mixing time between DNP and reverse DNP allows us to investigate the decay of polarisation on protons in the vicinity of the electrons. We qualitatively investigate the influence of solvent deuteration, temperature, and electron concentration. We expect reverse DNP to be useful in the investigation of nuclear spin diffusion and envisage its use in electron–nuclear double-resonance (ENDOR) experiments.

Estilos ABNT, Harvard, Vancouver, APA, etc.

9

Issanova, M. K., S. K. Kodanova, T. S. Ramazanov, N. Kh Bastykova, Zh A. Moldabekov e C. V. Meister. "Classical scattering and stopping power in dense plasmas: the effect of diffraction and dynamic screening". Laser and Particle Beams 34, n.º 3 (27 de junho de 2016): 457–66. http://dx.doi.org/10.1017/s026303461600032x.

Texto completo da fonte

Resumo:

AbstractIn the present work, classical electron–ion scattering, Coulomb logarithm, and stopping power are studied taking into account the quantum mechanical diffraction effect and the dynamic screening effect separately and together. The inclusion of the quantum diffraction effect is realized at the same level as the well-known first-order gradient correction in the extended Thomas–Fermi theory. In order to take the effect of dynamic screening into account, the model suggested by Grabowski et al. in 2013 is used. Scattering as well as stopping power of the external electron (ion) beam by plasma ions (electrons) and scattering of the plasma's own electrons (ions) by plasma ions (electrons) are considered differently. In the first case, it is found that in the limit of the non-ideal plasma with a plasma parameter Γ → 1, the effects of quantum diffraction and dynamic screening partially compensate each other. In the second case, the dynamic screening enlarges scattering cross-section, Coulomb logarithm, and stopping power, whereas the quantum diffraction reduces their values. Comparisons with the results of other theoretical methods and computer simulations indicate that the model used in this work gives a good description of the stopping power for projectile velocities $v\,{\rm \lesssim}\, 1.5 v_{{\rm th}}$, where vth is the thermal velocity of the plasma electrons.

Estilos ABNT, Harvard, Vancouver, APA, etc.

10

Yasuda, Hirotsugu, Loic Ledernez, Fethi Olcaytug e Gerald Urban. "Electron dynamics of low-pressure deposition plasma". Pure and Applied Chemistry 80, n.º 9 (1 de janeiro de 2008): 1883–92. http://dx.doi.org/10.1351/pac200880091883.

Texto completo da fonte

Resumo:

When the electric field in the dark gas phase reaches the threshold value, an electron avalanche (breakdown) occurs, which causes dissociation of organic molecules, excitation of chemically reactive molecular gas, and/or ionization of atomic gas, depending on the type of gas involved. The principles that govern these electron-impact reactions are collectively described by the term "electron dynamics". The electron-impact dissociation of organic molecules is the key factor for the deposition plasma. The implications of the interfacial avalanche of the primary electrons on the deposition plasma and also other plasma processes are discussed. The system dependency of low-pressure plasma deposition processes is an extremely important factor that should be reckoned, because the electron dynamic reactions are highly dependent on every aspect of the reaction system. The secondary electron emission from the cathode is a misinterpretation of the interfacial electron avalanche of the primary electrons described in this paper.

Estilos ABNT, Harvard, Vancouver, APA, etc.

11

Astakhova, T. Yu, e G. A. Vinogradov. "Single-Electron Model for Polaron on Dimerized Lattice". Mathematical Biology and Bioinformatics 14, n.º 2 (17 de dezembro de 2019): 625–34. http://dx.doi.org/10.17537/2019.14.625.

Texto completo da fonte

Resumo:

A new approach to modeling the electronic and dynamic properties of dimerized polyacetylene is proposed. Compared to the well-known and widely used approach, where dimerization is formed by the π-electrons of the valence band, in the proposed model the same effect is provided by an additional potential in the dynamic part of the Hamiltonian. In the usually used computational schemes, for a lattice of N sites, N π-electrons have to be used to describe dimerization, so the total number of equations for quantum and classical dynamics is approximately equal to N2/2. The integration step is dictated by the "fast" quantum subsystem and should be small. Both of these reasons make modeling difficult at large times and scales. In the proposed approach, in contrast to the N-electronic model, for describing a polaron on a dimerized lattice, the one-electron approximation is sufficient when the electron occupies the lowest level of the conduction band. Thus, the number of basis functions decreases to 3N, which allows to carry out calculations on large scales and times.

Estilos ABNT, Harvard, Vancouver, APA, etc.

12

Boyko, I. V., e A. M. Gryschyk. "The Influence of Dimensional Static and Dynamic Charge on the Spectral Parameters and Active Dynamic Conductivity of Resonanse Tunnelling Structures with Constant Electric Field". Фізика і хімія твердого тіла 17, n.º 1 (15 de março de 2016): 21–30. http://dx.doi.org/10.15330/pcss.17.1.21-30.

Texto completo da fonte

Resumo:

In the model of effective masses and rectangular potentials obtained self-consistent solution of Poisson and Schrödinger equations for different concentrations of electrons. It has been calculated spectral parameters and active dynamic conductivity for three-well nanostructure as active band of experimental quantum cascade laser. It has been established, that space charge deforms shape dependence of transmission factor of electron energy from Lorentzian shape to quasi-Lorentzian, shifting their maximum value to the high energy region and increasing the lifetimes of electronic quasistationary states. It was shown, that with increasing concentration of electrons energy of laser radiation in quantum transitions and decreases, and the total value of active dynamic conductivity increases so, that it increases the partial contribution component of conductivity, determined by electron flux, directed opposite to the exit of nanostructure.

Estilos ABNT, Harvard, Vancouver, APA, etc.

13

Jeevarajan, A. S., e Richard W. Fessenden. "Unusual chemically-induced dynamic electron polarization of electrons produced by photoionization". Journal of Physical Chemistry 96, n.º 4 (fevereiro de 1992): 1520–23. http://dx.doi.org/10.1021/j100183a003.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

14

Liu, Jingyue. "Imaging and Microanalysis of Non-Conducting Materials in the Lowvoltage FE-SEM: Challenges and Strategies". Microscopy and Microanalysis 6, S2 (agosto de 2000): 754–55. http://dx.doi.org/10.1017/s1431927600036266.

Texto completo da fonte

Resumo:

Under high-energy electron bombardment, electrical charge can rapidly build up in non-conducting materials. The electron-induced charging process is very complex and is still not well understood. Injection of energetic electrons into insulators generates electron-hole pairs which can be localized at pre-existing or newly created charge-trap centers. Charging of insulators results from a balance between the emission of secondary electrons and the diffusion and trapping of incident electrons. In the SEM, charging is usually a dynamic process: the degree of specimen charging depends on the energy and the dose of the incident electrons, the image magnification, the pixel dwell time (PDT), and the history of the electron irradiation of the specimen. Although the degree of charging can be reduced by varying the energy of the incident electrons, charging of non-conducting specimens cannot be completely eliminated due to variations in the local SE yield across the specimen surface and the presence of charge-traps inside the specimen.

Estilos ABNT, Harvard, Vancouver, APA, etc.

15

Walter, Peter, Micheal Holmes, Razib Obaid, Lope Amores, Xianchao Cheng, James P. Cryan, James M. Glownia et al. "The DREAM Endstation at the Linac Coherent Light Source". Applied Sciences 12, n.º 20 (19 de outubro de 2022): 10534. http://dx.doi.org/10.3390/app122010534.

Texto completo da fonte

Resumo:

Free-electron lasers (FEL), with their ultrashort pulses, ultrahigh intensities, and high repetition rates at short wavelength, have provided new approaches to Atomic and Molecular Optical Science. One such approach is following the birth of a photo electron to observe ion dynamics on an ultrafast timescale. Such an approach presents the opportunity to decipher the photon-initiated structural dynamics of an isolated atomic and molecular species. It is a fundamental step towards understanding single- and non-linear multi-photon processes and coherent electron dynamics in atoms and molecules, ultimately leading to coherent control following FEL research breakthroughs in pulse shaping and polarization control. A key aspect for exploring photoinduced quantum phenomena is visualizing the collective motion of electrons and nuclei in a single reaction process, as dynamics in atoms/ions proceed at femtosecond (10−15 s) timescales while electronic dynamics take place in the attosecond timescale (10−18 s). Here, we report on the design of a Dynamic Reaction Microscope (DREAM) endstation located at the second interaction point of the Time-Resolved Molecular and Optical (TMO) instrument at the Linac Coherent Light Source (LCLS) capable of following the photon–matter interactions by detecting ions and electrons in coincidence. The DREAM endstation takes advantage of the pulse properties and high repetition rate of LCLS-II to perform gas-phase soft X-ray experiments in a wide spectrum of scientific domains. With its design ability to detect multi-ions and electrons in coincidence while operating in step with the high repetition rate of LCLS-II, the DREAM endstation takes advantage of the inherent momentum conservation of reaction product ions with participating electrons to reconstruct the original X-ray photon–matter interactions. In this report, we outline in detail the design of the DREAM endstation and its functionality, with scientific opportunities enabled by this state-of-the-art instrument.

Estilos ABNT, Harvard, Vancouver, APA, etc.

16

Guo, Zongshuai. "Radial distribution of electrons rotation moment in hall effect and plasma-ion thrusters". Aerospace technic and technology, n.º 4 (27 de agosto de 2021): 28–34. http://dx.doi.org/10.32620/aktt.2021.4.04.

Texto completo da fonte

Resumo:

The subject matter of the article is the radial distribution of electrons movement parameters inside electric propulsion thrusters with closed electrons drift. The radial magnetic field in Hall effect thrusters is the limits the axial flow of electrons because of interaction with azimuth electron current. In turn, this azimuth current exists as a result of rivalry between the attempt of the magnetic field to transform electrons current completely closed one and the loss of electrons rotation moment in collisions. Similar processes take place in the ionization chamber of plasma-ion thrusters with the radial magnetic field. The attempts to estimate electrons parameters through only collisions with ions and atoms inside volume have given the value of axial electrons current much lower than really being. This phenomenon is called anomalous electrons conductivity, which was tried to be explained as a consequence of various effects including "near-the-wall-conductivity", which was explained as a result of non-mirror reflection of electrons from the Langmuir layer near the walls of the thruster channel. The disadvantage of this name is the fact that the reflection of the electron occurs before reaching the surface from the potential barrier at the plasma boundary with any environment: the wall, but also with the environment vacuum. The potential distribution in the Langmuir layer is non-stationary and inhomogeneous due to the presence of so-called plasma oscillations. The definition of "conductivity" is just as unfortunate in this name, because the collisions are always not a factor of conductivity, but on the contrary – of resistance. The goal is to solve the task of electrons rotation moment distribution in the thruster channel. The methods used are the formulation of the kinetic equation for electrons distribution function over the velocities, radius, and projections of the coordinates of the instantaneous center of cyclotron rotation; solution of this equation and finding with its use the distribution of the gas-dynamic parameters of electrons along the cross-section of the channel. Conclusions. A mathematical model of electrons rotation moment dynamics is proposed, which allows using plasma-dynamics equations to analyze its distribution along the cross-section of thruster channel and to estimate the effect of "near-the-wall-conductivity" using appropriate boundary conditions.

Estilos ABNT, Harvard, Vancouver, APA, etc.

17

Komori, Yosuke, e Tohru Okamoto. "Dynamic nuclear polarization induced by hot electrons". Applied Physics Letters 90, n.º 3 (15 de janeiro de 2007): 032102. http://dx.doi.org/10.1063/1.2431779.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

18

Ermolaev, A. M., S. V. Kofanov e G. I. Rashba. "Electron Gas Dynamic Conductivity Tensor on the Nanotube Surface in Magnetic Field". Advances in Condensed Matter Physics 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/901848.

Texto completo da fonte

Resumo:

Kubo formula was derived for the electron gas conductivity tensor on the nanotube surface in longitudinal magnetic field considering spatial and time dispersion. Components of the degenerate and nondegenerate electron gas conductivity tensor were calculated. The study has showed that under high electron density, the conductivity undergoes oscillations of de Haas-van Alphen and Aharonov-Bohm types with the density of electrons and magnetic field changes.

Estilos ABNT, Harvard, Vancouver, APA, etc.

19

Zhang, Zhekai, Jiyu Tian, Junfei Chen, Yugui He, Chaoyang Liu, Xinmiao Liang e Jiwen Feng. "Li Plating on Carbon Electrode Surface Probed by Low-Field Dynamic Nuclear Polarization ⁷Li NMR". Chinese Physics Letters 38, n.º 12 (1 de dezembro de 2021): 126801. http://dx.doi.org/10.1088/0256-307x/38/12/126801.

Texto completo da fonte

Resumo:

Lithium deposition on graphite electrode not only reduces fast-charging capability of lithium ion batteries but also causes safety trouble. Here, a low-field 7Li dynamic nuclear polarization (DNP) is used to probe Li plating on the surfaces of three types of carbon electrodes: hard carbon, soft carbon and graphite. Owing to the strong Fermi contact interaction between 7Li and conduction electrons, the 7Li nuclear-magnetic-resonance (NMR) signal of Li metal deposited on electrode surface could be selectively enhanced by DNP. It is suggested that low-field 7Li DNP spectroscopy is a sensitive tool for investigating Li deposition on electrodes during charging/discharging processes.

Estilos ABNT, Harvard, Vancouver, APA, etc.

20

Shindo, D., J. J. Kim, W. Xia, K. H. Kim, N. Ohno, Y. Fujii, N. Terada e S. Ohno. "Electron holography on dynamic motion of secondary electrons around sciatic nerve tissues". Journal of Electron Microscopy 56, n.º 1 (12 de janeiro de 2007): 1–5. http://dx.doi.org/10.1093/jmicro/dfl039.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

21

Wang, Xiaojun, Lianshui Zhang, Weidong Lai e Fengliang Liu. "Nitrogen oxide removal dynamic process through 15 Ns DBD technique". Modern Physics Letters B 29, n.º 12 (10 de maio de 2015): 1550053. http://dx.doi.org/10.1142/s0217984915500530.

Texto completo da fonte

Resumo:

Nitrogen oxides exhaust gas assumes the important responsibility on air pollution by forming acid rain. This paper discusses the NO removal mechanism in 15 ns pulse dielectric barrier discharge (DBD) plasma through experimental and simulating method. Emission spectra collected from plasma are evaluated as sourced from N + and O (3 P ). The corresponding zero-dimensional model is established and verified through comparing the simulated concentration evolution and the experimental time-resolved spectra of N +. The electron impact ionization plays major role on NO removal and the produced NO + are further decomposed into N + and O (3 P ) through electron impact dissociative excitation rather than the usual reported dissociative recombination process. Simulation also indicates that the removal process can be accelerated by NO inputted at lower initial concentration or electrons streamed at higher concentration, due to the heightened electron impact probability on NO molecules. The repetitive pulse discharge is a benefit for improving the NO removal efficiency by effectively utilizing the radicals generated from the previous pulse under the condition that the pulse period should be shorter enough to ignore the spatial diffusion of radicals. Finally, slight attenuation on NO removal has been experimentally and simulatively observed after N 2 mixed, due to the competitive consumption of electrons.

Estilos ABNT, Harvard, Vancouver, APA, etc.

22

Fröjdh, E., F. Baruffaldi, A. Bergamaschi, M. Carulla, R. Dinapoli, D. Greiffenberg, J. Heymes et al. "Detection of MeV electrons using a charge integrating hybrid pixel detector". Journal of Instrumentation 17, n.º 12 (1 de dezembro de 2022): C12004. http://dx.doi.org/10.1088/1748-0221/17/12/c12004.

Texto completo da fonte

Resumo:

Abstract Electrons are emerging as a strong complement to X-rays for diffraction based studies. In this paper we investigate the performance of a JUNGFRAU detector with 320 um thick silicon sensor at a pulsed electron source. Originally developed for X-ray detection at free electron lasers, JUNGFRAU features a dynamic range of 120 MeV/pixel (implemented with in-pixel gain switching) which translated to about 1200 incident electrons per pixel and frame in the MeV region. We preset basic characteristics such as energy deposited per incident particle, resulting cluster size and spatial resolution along with dynamic (intensity) range scans. Measurements were performed at 4, 10 and 20 MeV/c. We compare the measurements with GEANT4 based simulations and extrapolate the results to different sensor thicknesses using these simulations.

Estilos ABNT, Harvard, Vancouver, APA, etc.

23

Yurimoto, H., K. Nagashima, T. Kunihiro, I. Takayanagi, J. Nakamura e K. Kosaka. "A Stacked CMOS Active Pixel Image Sensor for Charge Particle Detection and the Application to SIMS". Microscopy and Microanalysis 5, S2 (agosto de 1999): 370–71. http://dx.doi.org/10.1017/s1431927600015178.

Texto completo da fonte

Resumo:

A stacked CMOS active pixel image-sensor (APS) has been developed for detecting various kinds of charged particles and its noise performance has been measured and analyzed. The sensitivity for ions and electrons with keV energy level utilizes for ion microscopy such-as SIMS and electron microscopy, respectively.Charge particles such as ions and electrons with kinetic energy of keV order are useful probes for surface analysis of material. A measurement system which yields two-dimensional image of charge particles is highly demanded. The conventional two-dimensional detection system is composed of a micro channel plate, a florescent plate which receives multiplied secondary electrons and generates a visible image, and a visible image sensor. However, its limited dynamic range and non-linearity in the ion-electron-to-photon conversion process make a quantitative measurement difficult. The proposed system using a stacked CMOS APS has several advantages over the conventional system such as high spatial resolution, no insensitive time, high S/N, wide dynamic range, nondestructive readout capability, high robustness, and low power consumption.

Estilos ABNT, Harvard, Vancouver, APA, etc.

24

VELARDE, M. G., W. EBELING e A. P. CHETVERIKOV. "THERMAL SOLITONS AND SOLECTRONS IN 1D ANHARMONIC LATTICES UP TO PHYSIOLOGICAL TEMPERATURES". International Journal of Bifurcation and Chaos 18, n.º 12 (dezembro de 2008): 3815–23. http://dx.doi.org/10.1142/s0218127408022767.

Texto completo da fonte

Resumo:

We study the thermal excitation of solitons in 1D Toda–Morse lattices in a wide range of temperatures from zero up to physiological level (about 300 K) and their influence on added excess electrons moving on the lattice. The lattice units are treated by classical Langevin equations. The electron distributions are in a first estimate represented by equilibrium adiabatic distributions in the actual fields. Further, the electron dynamics is modeled in the framework of the tight-binding approximation including on-site energy shifts due to electron-lattice coupling and stochastic hopping between the sites. We calculate the electron distributions and discuss the excitations of solectron type (electron-soliton dynamic bound states) and estimate their life times.

Estilos ABNT, Harvard, Vancouver, APA, etc.

25

Kai, Takeshi, Tomohiro Toigawa, Yusuke Matsuya, Yuho Hirata, Tomoya Tezuka, Hidetsugu Tsuchida e Akinari Yokoya. "Initial yield of hydrated electron production from water radiolysis based on first-principles calculation". RSC Advances 13, n.º 11 (2023): 7076–86. http://dx.doi.org/10.1039/d2ra07274b.

Texto completo da fonte

Resumo:

For water radiolysis, conventional simulation methods estimate free radical yields based on the cross-sections. Our results indicated that electron dynamic motion must be further solved to predict the initial yields of hydrated electrons.

Estilos ABNT, Harvard, Vancouver, APA, etc.

26

Fokin, Vladimir, Dmitry Minakov e Pavel Levashov. "Ab Initio Calculations of Transport and Optical Properties of Dense Zr Plasma Near Melting". Symmetry 15, n.º 1 (24 de dezembro de 2022): 48. http://dx.doi.org/10.3390/sym15010048.

Texto completo da fonte

Resumo:

The dynamic electrical conductivity of dense Zr plasma near melting is calculated using ab initio molecular dynamics and the Kubo–Greenwood formula. The antisymmetrization of the electronic wave function is considered with the determinant of one-electron wave functions; exchange and correlation effects are treated via an exchange–correlation functional. Optical properties are restored using the Kramers–Kronig transformation. The influence of computational parameters and inner shell electrons on the results is thoroughly investigated. We demonstrate the convergence of our computations and analyze comparison with experimental data.

Estilos ABNT, Harvard, Vancouver, APA, etc.

27

ROMANOVA, J. Y., e Y. A. ROMANOV. "DYNAMIC LOCALIZATION AND ELECTROMAGNETIC TRANSPARENCY OF SEMICONDUCTOR SUPERLATTICE IN MULTIFREQUENCY ELECTRIC FIELDS". International Journal of Nanoscience 06, n.º 05 (outubro de 2007): 395–98. http://dx.doi.org/10.1142/s0219581x0700450x.

Texto completo da fonte

Resumo:

We consider the dynamics of electrons in semiconductor superlattices in intense multifrequency electric fields. We examine the conditions for dynamic localization and electromagnetic transparency. We investigate processes of formation, destruction, and stabilization of electromagnetic transparency in biharmonic field. The stable states with static fields are determined.

Estilos ABNT, Harvard, Vancouver, APA, etc.

28

Stahl, A., O. Embréus, G. Papp, M. Landreman e T. Fülöp. "Kinetic modelling of runaway electrons in dynamic scenarios". Nuclear Fusion 56, n.º 11 (21 de julho de 2016): 112009. http://dx.doi.org/10.1088/0029-5515/56/11/112009.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

29

Luchinat, Claudio, e Zhicheng Xia. "Paramagnetism and dynamic properties of electrons and nuclei". Coordination Chemistry Reviews 120 (novembro de 1992): 281–307. http://dx.doi.org/10.1016/0010-8545(92)80056-w.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

30

Armstrong, Fraser A., H. Allen O. Hill e Nicholas J. Walton. "Reactions of electron-transfer proteins at electrodes". Quarterly Reviews of Biophysics 18, n.º 3 (agosto de 1985): 261–322. http://dx.doi.org/10.1017/s0033583500000366.

Texto completo da fonte

Resumo:

Studies of electron-transfer reactions of redox proteins have, in recent years, attracted widespread interest and attention. Progress has been evident from both physical and biological standpoints, with the increasing availability of three-dimensional structural data for many small electron-transfer proteins prompting a variety of systematic investigations (Isied, 1985). Most recently, attention has been directed towards questions concerning the elementary transfer of electrons between spatially remote redox sites, and the nature of protein–protein interactions which, for intermolecular processes, stabilize specific precursor complexes which may be optimally juxtaposed for electron-transfer. These and other issues, including the necessary reversibility of protein interfacial interactions and the dynamic properties of proteins as carriers of electrons in biological electron-transport systems, are now being addressed in the rapidly emerging field of direct (unmediated) protein electrochemistry. It is our intention in this article to discuss developments made in this area and highlight points which we believe to have the most bearing on our current understanding of diffusion-dominated, protein-mediated electron transport at electrode surfaces. First we shall outline some basic considerations which are best considered with reference to homogeneous systems.

Estilos ABNT, Harvard, Vancouver, APA, etc.

31

Tkach, M. V., Ju O. Seti, Y. B. Grynyshyn e O. M. Voitsekhivska. "Dynamic Conductivity of Electrons and Electron-Phonon Interaction in Open Three-Well Nanostructures". Acta Physica Polonica A 128, n.º 2 (setembro de 2015): 343–52. http://dx.doi.org/10.12693/aphyspola.128.343.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

32

Lifa, A., S. Dilmi e S. E. Bentridi. "The Influence of Hot Electrons on the Calculation of Ionization Rates". Engineering, Technology & Applied Science Research 12, n.º 6 (1 de dezembro de 2022): 9579–83. http://dx.doi.org/10.48084/etasr.5294.

Texto completo da fonte

Resumo:

Electron-Impact Ionization (EII) is considered one of the most important ionization methods in dynamic systems, in which elements and ions are suddenly exposed to energetic electrons. In many plasma types, it has been observed that some electrons (hot) are governed by a non-Maxwellian energy distribution. This study illustrates the effects of a non-Maxwellian distribution on beryllium and Be+2 emission lines and their effective ionization rate coefficients. The focus on beryllium as an impacted material by electron flux aimed to evaluate the EII rates for Be and generate the corresponding datasets needed for Be+2 data analysis. An interaction cross-section was generated using the Flexible Atomic Code (FAC) and used in the estimation of the EII distribution energy functions to estimate the ionization rates for a non-Maxwellian distribution. The use of non-Maxwellian energy distributions for different fractions of hot electrons showed the sensitivity of these rates to the fraction of hot electrons and the forms of the electron energy distribution. The results were in good agreement with those found in the literature.

Estilos ABNT, Harvard, Vancouver, APA, etc.

33

Coronel-Escamilla, A., J. F. Gómez-Aguilar, E. Alvarado-Méndez, G. V. Guerrero-Ramírez e R. F. Escobar-Jiménez. "Fractional dynamics of charged particles in magnetic fields". International Journal of Modern Physics C 27, n.º 08 (25 de maio de 2016): 1650084. http://dx.doi.org/10.1142/s0129183116500844.

Texto completo da fonte

Resumo:

In many physical applications the electrons play a relevant role. For example, when a beam of electrons accelerated to relativistic velocities is used as an active medium to generate Free Electron Lasers (FEL), the electrons are bound to atoms, but move freely in a magnetic field. The relaxation time, longitudinal effects and transverse variations of the optical field are parameters that play an important role in the efficiency of this laser. The electron dynamics in a magnetic field is a means of radiation source for coupling to the electric field. The transverse motion of the electrons leads to either gain or loss energy from or to the field, depending on the position of the particle regarding the phase of the external radiation field. Due to the importance to know with great certainty the displacement of charged particles in a magnetic field, in this work we study the fractional dynamics of charged particles in magnetic fields. Newton’s second law is considered and the order of the fractional differential equation is [Formula: see text]. Based on the Grünwald–Letnikov (GL) definition, the discretization of fractional differential equations is reported to get numerical simulations. Comparison between the numerical solutions obtained on Euler’s numerical method for the classical case and the GL definition in the fractional approach proves the good performance of the numerical scheme applied. Three application examples are shown: constant magnetic field, ramp magnetic field and harmonic magnetic field. In the first example the results obtained show bistability. Dissipative effects are observed in the system and the standard dynamic is recovered when the order of the fractional derivative is 1.

Estilos ABNT, Harvard, Vancouver, APA, etc.

34

Yao, Zi-Shuo, Zheng Tang e Jun Tao. "Bistable molecular materials with dynamic structures". Chemical Communications 56, n.º 14 (2020): 2071–86. http://dx.doi.org/10.1039/c9cc09238b.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

35

Tikhomirov, S. A. "Ultrafast dynamics and mechanisms of non-stationary absorption in thin gallium selenide samples". Proceedings of the National Academy of Sciences of Belarus. Physics and Mathematics Series 57, n.º 1 (2 de abril de 2021): 99–107. http://dx.doi.org/10.29235/1561-2430-2021-57-1-99-107.

Texto completo da fonte

Resumo:

Herein, the dynamics and mechanisms of induced absorption in thin samples of gallium selenide under various excitation conditions are studied using femtosecond kinetic spectroscopy. We have registered several types of induced changes including induced absorption on free charge carriers (“hot” and thermalized electrons), bleaching and absorption due to the population of near-edge trap or exciton states, as well as rapid changes in the absorption of probing radiation in the region of the overlap of the exciting and probing pulses due to two-quantum two-frequency interband transitions. The time ranges of the relaxation processes are estimated. It is shown that when using relatively low-intensity long-wave excitation (790 nm), the resonant excitation of the near-edge states occurs mainly due to two-quantum two-frequency transitions followed by the formation of the dynamic equilibrium between bound and free electrons in the time range up to 5 ps. When electrons are excited deeply into the conduction band with the formation of hot free electrons and their subsequent thermalization to the bottom of the conduction band in the time range up to 1 ps, the population of the near-edge states and the establishment of the dynamic equilibrium between bound and free electrons is realized in the same time range (5 ps) as when they are excited “from below”.

Estilos ABNT, Harvard, Vancouver, APA, etc.

36

Mann, G., V. N. Melnik, H. O. Rucker, A. A. Konovalenko e A. I. Brazhenko. "Radio signatures of shock-accelerated electron beams in the solar corona". Astronomy & Astrophysics 609 (janeiro de 2018): A41. http://dx.doi.org/10.1051/0004-6361/201730546.

Texto completo da fonte

Resumo:

Context. The Sun’s activity can appear in terms of radio bursts. In the frequency range 8−33 MHz the radio telescope URAN-2 observed special fine structures appearing as a chain of stripes of enhanced radio emission in the dynamic radio spectrum. The chain drifts slowly from 26 to 23 MHz within 4 min. The individual structures consist of a “head” at the high-frequency edge and a “tail” rapidly drifting from the “head” to lower frequencies over an extent of ≈10 MHz within 8 s. Since they resemble the well-known “herring bones” in type II radio bursts, they are interpreted as shock accelerated electron beams. Aims. The electron beams generating these fine structures are considered to be produced by shock drift acceleration (SDA). The beam electrons excite Langmuir waves which are converted into radio waves by nonlinear wave-plasma processes. That is called plasma emission. The aim of this paper is to link the radio spectral data of these fine structures to the theoretical results in order to gain a better understanding of the generation of energetic electrons by shocks in the solar corona. Methods. Adopting SDA for generating energetic electrons, the accelerated electrons establish a beam-like velocity distribution. Plasma emission requires the excitation of Langmuir waves, which is efficient if the velocity of the beam electrons exceeds a few times thermal electron speed. That is the case if the angle between the shock normal and the upstream magnetic field is nearly perpendicular. Hence, the Rankine-Hugoniot relationships, which describe the shock transition in the framework of magnetohydrodynamics, are evaluated for the special case of nearly perpendicular shocks under coronal circumstances. Results. The radio data deduced from the dynamic radio spectrum can be related in the best way to the theoretical results, if the electron beams, which generate these fine structures, are generated via SDA at an almost perpendicular shock, which is traveling nearly horizontally to the surface of the Sun.

Estilos ABNT, Harvard, Vancouver, APA, etc.

37

Lewis, Russell H., Robert A. Wind e G. E. Maciel. "Investigation of cured hydridopolysilazane-derived ceramic fibers via dynamic nuclear polarization". Journal of Materials Research 8, n.º 3 (março de 1993): 649–54. http://dx.doi.org/10.1557/jmr.1993.0649.

Texto completo da fonte

Resumo:

During the pyrolysis of cured hydridopolysilazane (HPZ) polymer to form Si–C–N ceramic fibers, large quantities of unpaired electrons are produced. For such materials dynamic nuclear polarization (DNP) provides a means of enhancing the intensity of the NMR signal, and supplies information on the localization or delocalization of unpaired electrons. 29Si, 1H, and 13C DNP gives enhancements of 250 for 13C and at least 800 for 29Si. 13C and 29Si DNP-DPMAS experiments yield the following results: (i) there are at least two distinct types of carbon, sp2 and sp3; (ii) there is a distribution of sp3 silicon environments; (iii) the unpaired electrons behave as fixed paramagnetic centers; and (iv) the unpaired electrons are distributed homogeneously throughout the sample. Proton DNP spectra can be obtained even though hydrogen is only a trace element in the finished ceramic.

Estilos ABNT, Harvard, Vancouver, APA, etc.

38

Nardi, E., Y. Maron e D. H. H. Hoffmann. "Dynamic screening and charge state of fast ions in plasma and solids". Laser and Particle Beams 27, n.º 2 (22 de abril de 2009): 355–61. http://dx.doi.org/10.1017/s0263034609000469.

Texto completo da fonte

Resumo:

AbstractThis paper addresses the effect of target plasma electrons on the charge state of energetic ions, penetrating a target composed of bound as well as plasma electrons. Dynamic screening of the projectile Coulomb potential by the plasma electrons brings about a depression in the ionization energy of the ionic projectiles, as has been verified experimentally. This in turn makes the ionization cross-sections larger, while making the recombination cross-section smaller, thereby causing an increase in the ion charge state compared to the case of a gas target. The effect of the plasma environment, where the valence electrons are treated as plasma, is illustrated here for a 2 MeV carbon beam penetrating amorphous carbon targets of varying densities.

Estilos ABNT, Harvard, Vancouver, APA, etc.

39

SHARIFIAN, M. "Numerical analysis of monoenergetic electrons energy effect on dynamic potential profile of plasma sheath". Journal of Plasma Physics 79, n.º 5 (10 de janeiro de 2013): 509–12. http://dx.doi.org/10.1017/s0022377812001183.

Texto completo da fonte

Resumo:

AbstractThe dynamic behavior of the electric potential distribution of a plasma sheath region in the presence of monoenergetic electrons with two different values of energy, larger (fast electrons) and smaller (slow electrons) than the cathode potential energy, is examined numerically by the finite difference method. Exploring and comparing the plots of numerical computation results shows that the time evolution of the non-monotonic potential distribution heavily depends on the energy of monoenergetic electrons.

Estilos ABNT, Harvard, Vancouver, APA, etc.

40

BANG, Junhyeok. "Excited Carrier Dynamics in Two-dimensional Materials". Physics and High Technology 29, n.º 9 (30 de setembro de 2020): 15–21. http://dx.doi.org/10.3938/phit.29.032.

Texto completo da fonte

Resumo:

When electrons in materials are excited, they undergo several dynamic processes such as carrier thermalization, transfer, and recombination. These fundamental excited state processes are crucial to understanding the microscopic principles at work in electronic and optoelectronic devices. This article introduces the excited carrier dynamics in a two-dimensional van der Waals material and reveals several interesting phenomena that do not occur in bulk materials. Particularly, the focus will be two dynamic processes: carrier multiplication and ultrafast charge transfer.

Estilos ABNT, Harvard, Vancouver, APA, etc.

41

Khan, Arroj A., I. Zeba e M. Jamil. "Subsonic Potentials in Ultradense Plasmas". Zeitschrift für Naturforschung A 74, n.º 3 (25 de fevereiro de 2019): 207–12. http://dx.doi.org/10.1515/zna-2018-0461.

Texto completo da fonte

Resumo:

AbstractThe existence of the subsonic dynamic potential for a test charge in extremely dense quantum plasmas is pointed out for the first time. The dispersion equation of ion acoustic wave in relativistic plasmas is derived by using the quantum hydrodynamic model. The relativistic electrons obey Fermi statistics, whereas the ions are taken classically. The standard model of wake potential is hereafter applied for the derivation of dynamic potential of the test particle. A usual supersonic potential is found suppressed. However, the oscillatory subsonic wake potential does exist in small length scales. The analytical results are applied in different regions by taking the range of magnetic field as well as the electron number density. It is found that the dynamic potential exists only when vt < Cs, showing the presence of subsonic wake potential contrary to the usual supersonic condition vt > Cs. Here vt is the test particle speed and Cs is the acoustic speed defined by the Fermi temperature of the electrons. This work is significant in order to describe the structure formation in the astrophysical environment and laboratory dense plasmas.

Estilos ABNT, Harvard, Vancouver, APA, etc.

42

Batson, P. E., e J. Bruley. "Dynamic screening of the core exciton by swift electrons in electron-energy-loss scattering". Physical Review Letters 67, n.º 3 (15 de julho de 1991): 350–53. http://dx.doi.org/10.1103/physrevlett.67.350.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

43

Beleggia, M., e G. Pozzi. "Comment on 'Electron holography on dynamic motion of secondary electrons around sciatic nerve tissues'". Journal of Electron Microscopy 57, n.º 5 (25 de julho de 2008): 165–67. http://dx.doi.org/10.1093/jmicro/dfn015.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

44

Khajetoorians, Alexander Ako, Benjamin Baxevanis, Christoph Hübner, Tobias Schlenk, Stefan Krause, Tim Oliver Wehling, Samir Lounis et al. "Current-Driven Spin Dynamics of Artificially Constructed Quantum Magnets". Science 339, n.º 6115 (3 de janeiro de 2013): 55–59. http://dx.doi.org/10.1126/science.1228519.

Texto completo da fonte

Resumo:

The future of nanoscale spin-based technologies hinges on a fundamental understanding and dynamic control of atomic-scale magnets. The role of the substrate conduction electrons on the dynamics of supported atomic magnets is still a question of interest lacking experimental insight. We characterized the temperature-dependent dynamical response of artificially constructed magnets, composed of a few exchange-coupled atomic spins adsorbed on a metallic substrate, to spin-polarized currents driven and read out by a magnetic scanning tunneling microscope tip. The dynamics, reflected by two-state spin noise, is quantified by a model that considers the interplay between quantum tunneling and sequential spin transitions driven by electron spin-flip processes and accounts for an observed spin-transfer torque effect.

Estilos ABNT, Harvard, Vancouver, APA, etc.

45

Tuska, Evelyn, Paul Evenson e Peter Meyer. "Solar modulation of cosmic electrons - Evidence for dynamic regulation". Astrophysical Journal 373 (maio de 1991): L27. http://dx.doi.org/10.1086/186043.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

46

Kim, Chang Sub, e Arkady M. Satanin. "Dynamic confinement of electrons in time-dependent quantum structures". Physical Review B 58, n.º 23 (15 de dezembro de 1998): 15389–92. http://dx.doi.org/10.1103/physrevb.58.15389.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

47

Rivas, Nicolás, Germán Sciaini e Ernesto Marceca. "Static and dynamic scavenging of ammoniated electrons by nitromethane". Physical Chemistry Chemical Physics 21, n.º 39 (2019): 21972–78. http://dx.doi.org/10.1039/c9cp03342d.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

48

Sablikov, V. A., e B. S. Shchamkhalova. "Dynamic conductivity of interacting electrons in open mesoscopic structures". Journal of Experimental and Theoretical Physics Letters 66, n.º 1 (julho de 1997): 41–46. http://dx.doi.org/10.1134/1.567480.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

49

Réveillé, T., P. Bertrand, A. Ghizzo, F. Simonet e N. Baussart. "Dynamic evolution of relativistic electrons in the radiation belts". Journal of Geophysical Research: Space Physics 106, A9 (1 de setembro de 2001): 18883–94. http://dx.doi.org/10.1029/2000ja900177.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

50

Maresch, G. G., R. D. Kendrick, C. S. Yannoni e M. E. Galvin. "Dynamic nuclear polarization via confined electrons in bulk solids". Journal of Magnetic Resonance (1969) 82, n.º 1 (março de 1989): 41–50. http://dx.doi.org/10.1016/0022-2364(89)90163-7.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Artigos de revistas sobre o tema "Electrons dynamic"

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos