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1.
The self-consistent field model is modified to take into account the effect of orientation correlations on the behavior of an electron solvated in a polar liquid. This model is used as the basis for calculating the maximum of the absorption spectrum as well as the temperature dependence of this maximum for an electron sol-vated in water and ammonium. The results are in accord with experimental data and with the results of calcu-lation by the quantum molecular dynamics method. 相似文献
2.
Within the framework of general statistical mechanics of irreversible processes the electrical resistivity of an open electron-phonon system is calculated. By means of the projection operator technique an evolution equation for coupled subsystems in a heat bath is derived and specialized for electrons and longitudinal phonons, the latter being coupled to a bath of transverse phonons. The influence of heating of the electron-phonon system is investigated and the question of validity of the linear response theory with or without inclusion of a dissipative mechanism is discussed. In the balance equation for the total electron momentum, terms of only third (and higher) order in the electrical field strength and the current density appear; consequently, the transverse phonons act only as a “momentum bath”. A general resistivity formula is derived containing the Bloch-Grüneisen law as a special case and including corrections due to phonon drag up to infinite order without a partial summation. 相似文献
3.
Summary Properties of solvated electrons at high dilution in four molten alkali halides are investigated theoretically. A self-consistent
evaluation of the bound ground state of the electron and of the surrounding liquid structure, already developed in a previous
paper, is compared with the results of NMR hyperfine shifts and magnetic-susceptibility measurements. The absorption bands
associated with Franck-Condon 1s→2p and 1s→3p transitions are calculated and compared with the available data of optical absorption, with special emphasis on the detailed
analysis by Yuh and Nachtrieb for molten CsCl. An instability of the excited states against ionic relaxation and the origin
of a finite lifetime for the ground state are also discussed. Finally, the perturbation induced by the solvated electron in
the fundamental absorption of the molten salt is estimated.
Riassunto Il lavoro presenta uno studio teorico di elettroni solvatati a forte diluizione in alogenuri alcalini fusi. Un calcolo autoconsistente dello stato fondamentale è confrontato con dati NMR d'interazioni iperfini e con misure di suscettività magnetica. Le bande di assorbimento ottico dovute a transizioni 1s→2p e 1s→3p sono calcolate in uno schema di Franck-Condon e i risultati sono confrontati con l'evidenza sperimentale, con attenzione particolare all'analisi dello spettro nel CsCl fuso data da Yuh e Nachtrieb. Si discutono quindi un'instabilità degli stati eccitati sotto rilassamento ionico, la vita media dello stato fondamentale nel liquido e lo spostamento dello spettro eccitonico dovuto all'elettrone solvatato.
Резюме Теоретически исследуются свойства сольватированных электронов при высокой степени разведения в четырех расплавленных щелочных галоидах. Самосогласованное вычисление основного состояния связанного электрона и окружающей жидкой структуры сравнивается с данными ЯМР для сверхтонких смещений и с измерениями магнитной восприимчивости. Вычисляются зоны поглощения, связанные с переходами 1s→2p и 1s→3p в схеме Франка-Кондона. Полученные результаты сравниваются с имеющимися экспериментальными данными по оптическому поглощению, причем, особое внимание уделяется анализу спектров для расплавленного CsCl. Также обсуждается неустойчивость возбужденных состояний относительно ионной релаксации и конечное время жизни основного состояния в жидкости. В заключение, оценивается смещение экситонного спектра, обусловленное сольватированным электроном.相似文献
4.
Aleksander Jablonski 《Physica A》1985,129(3):591-600
The parameters describing scattering of electrons by atoms, which usually involve multiple integration of the atomic potentials, may be severely affected by the accuracy of these potentials. In the present work an iterative procedure is proposed providing a sequence of solutions of the Thomas-Fermi equation with increasing accuracy. Such a sequence makes it possible to establish the sensitivity of a given parameter to the accuracy of the atomic potential, and consequently to determine the accurate value of this parameter. Based on the present solutions, the differential scattering cross-sections for the Thomas-Fermi atom are calculated, and are found to deviate from the literature data. 相似文献
5.
A. Rossani A. M. Scarfone 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):295-298
Test particles interact with a medium by means of a
bimolecular reversible chemical reaction. Two species are assumed to
be much more numerous so that they are distributed according to
fixed distributions: Maxwellians and Dirac's deltas. Equilibrium and
its stability are investigated in the first case. For the second
case, a system is constructed, in view of an approximate solution. 相似文献
6.
J. des Cloizeaux 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,8(3):439-443
Dirac equation is reformulated in terms of real local observables, which are mean values of the wave function . The quadrivector current is shown to be a function of the potential vector and of other local observables. The equations
describe the evolution of a four dimensional system T, X, Y, Z, and of two scalars, in the coordinate system ct, x, y, z. The current is proportional to the T vector. The Z vector is associated with the spin of the electron. Energy and gauge transformations correspond to rotations in the plane
(X, Y). In the presence of a static field, the (real) solutions of the equations appear as eigenfunctions associated with energy
eigenvalues.
Received 7 September 1998 相似文献
7.
In this paper we study an ideal electron gas in the presence of a uniform electromagnetic field and confinement by a three-dimensional harmonic potential. We find the partition function of this system and in the sequel we examine the Boltzmann statistics and Fermi-Dirac statistics applying the grand canonical ensemble method. 相似文献
8.
9.
Spontaneous emission by electrons moving in a magnetic field constant in time and periodic in space (with circular polarization) is calculated using exact solutions of the corresponding Dirac equation. In addition to the known transitions we find two harmonics connected with spin flip processes, which are, however, strongly suppressed. The gain of the free electron laser is recalculated from the rate for spontaneous emission. The results obtained by classical methods are corroborated.Supported in part by Deutsche Forschungsgemeinschaft 相似文献
10.
Quantum transitions associated with the radiation of an electron in a weakly focusing magnetic field are analyzed, allowing for betatron oscillations. An expression is derived for the intensity of the synchrotron radiation. The effect of the betatron oscillations on the polarization properties of the radiation is examined.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 60–64, April, 1973.The authors wish to thank A. A. Sokolov for constant interest in this work. 相似文献
11.
The interaction between an electron beam and a retarded electromagnetic field with an accelerating electrostatic field (traveling wave tube with bunching) is considered. An exact steady-state solution of the kinetic equation is found for the case of a zero electrostatic field and an approximate solution is found for the case of a slowly varying electrostatic potential. A theory is constructed for the amplification of the electromagnetic wave; a critical value is indicated for the power of the amplified wave, above which stable amplification is possible. The dependence of the differential efficiency on the power of the amplified wave is calculated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 17–21, April, 1982. 相似文献
12.
Abstract Radiation-induced latchup in commercially available junction-isolated integrated microcircuits is reported. Four different types of construction of integrated microcircuits have been examined. They include quadruplediffused, diffused collector, epitaxial, and epitaxial with buried layer (gold-doped). It was found that pnpn switching could be obtained between isolated components on these devices. In fact, pnpn paths were quite common in all but the last type mentioned. The current gains of the parasitic transistors involved in these pnpn paths were measured and were, in most cases, shown to indicate that pnpn switching should occur. However, important exceptions were seen. Latchup between these isolated components could be induced by a pulse of ionizing radiation even with a reverse bias on the substrate of the microcircuits. As a result of this investigation, it is concluded that the pnpn mechanism, since it is so common, is a majorcause of latchup in junction-isolated integrated microcircuits. 相似文献
13.
V. L. Shablov P. S. Vinitsky Yu. V. Popov O. Chuluunbaatar K. A. Kouzakov 《Physics of Particles and Nuclei》2010,41(2):335-357
In this review, a generalization of few-body quantum scattering theory is given for the case of Coulomb interaction. Since
in this specific case the scattering amplitude, which is a solution to a resolvent-type equation, possesses a singularity
when the complex parameter z tends to the energy shell, a definition of the physical amplitude is provided. A recipe for regularizing integrals (eliminating
divergences), which describe the terms of a perturbation theory series for different perturbing potentials, is formulated.
As an example, the general theory is applied to the calculations of differential cross sections for a quasi-elastic electron
impact ionization reaction on atomic hydrogen. 相似文献
14.
15.
Conclusions Thus, our investigation shows that the character of the instability of an electron beam in a waveguide depends significantly on the state of the magnetization of the ferrite. Thus, in the case of an unsaturated ferrite the spectrum of the excited oscillations is unbounded, in contrast to the case of a longitudinally magnetized ferrite, when the spectrum of the waveguide harmonics is bounded by the frequency
In the case of gyrotropic ferrite waveguide, the frequencies of the excited oscillations increase with increasing longitudinal magnetic field
[see formula (21)], as is well confirmed by measurement results [8].The development of instability leads to a redistribution of the energy over the length of the beam (this effect was observed in experiment [8]), so that ferrite waveguides can be used for self-acceleration of intense electron beams.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 20, No. 3, pp. 444–450, March, 1977 相似文献
16.
We compute the logarithmic deviations from Bjorken scaling for the spin dependent structure functions of deep inelastic electron scattering in an asymptotically free gauge theory. Continuations to the elastic limit and to the Regge region are also considered. 相似文献
17.
It is pointed out that a slight modification of the relativistic quantum theory of a free electron in a uniform wiggler field enables the study of motion in a tapered wiggler field of the form which merits attention. The lower limit of z is 800 cm. The exact relativistic quantum mechanical calculation shows an enhancement in the gain for single pass. The frequencies are up-shifted by amounts depending on the parameter b. 相似文献
18.
19.
Jack Cohn 《International Journal of Theoretical Physics》1974,9(3):179-184
A relativistic, non-quantum theory of electrons is constructed in which the electron is not considered to be composed of any type of distribution of charge. The electron's structurelessness is defined by several assumptions which, together with Maxwell's equations outside the electron, yield the general fields produced by such an arbitrarily movingholistic electron. Several equations of motion for the holistic electron are found to result from the formulation, the Lorentz-Dirac equation being among them. The formulation, by its very nature, avoids the problems of the electron self-energy and the need for normalization. 相似文献