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51.
52.
V. A. Gordeev R. F. Konopleva V. G. Firsov Yu. V. Obukhov Yu. V. Gorelkinskii N. N. Nevinnyi 《Hyperfine Interactions》1990,60(1-4):717-722
Main experimental data on the hydrogen-like states with an anisotropic hyperfine structure forming in silicon single crystals
in the implantation of high energy muons and protons are presented. The characteristics of the “anomalous” muonium (Mu*) and hydrogen-containing silicon AA9 states studied by the muon spin rotation (μSR) and ESR techniques in silicon with a
due inclusion of the isotope effect are shown to be similar, thus suggesting the existence of two equivalent structures in
silicon, Mu* and AA9, differing only in the mass of the paramagnetic center. 相似文献
53.
Most of the experiments on the quantum Hall effect (QHE) were made at approximately the same height above sea level. A future international comparison will determine whether the gravitational field g(x) influences the QHE. In the realm of (1+2)-dimensional phenomenological macroscopic electrodynamics, the Ohm-Hall law is metric independent ("topological"). This suggests that it does not couple to g(x). We corroborate this result by a microscopic calculation of the Hall conductance in the presence of a post-Newtonian gravitational field. 相似文献
54.
Classification of all electrovac specetimes permitting the separation of variables in the Hamilton-Jacobi equation for a charged
test particle is carried out. This separation requires the existence of a complete set consisting of Killing’s vectors and
tensors of a special kind. Every complete set defines its own type of metric and electromagnetic potential in the separable
coordinate system. There exist seven types of separation of variables for electromagnetic spaces. For every type an additional
classification is carried out by transformation of coordinates without any disturbance of the separation conditions, the gradient
transformation of electromagnetic potential and the conformal-constant transformation of metric.
The key step in solving the problem is the extraction of an autonomous subsystem which determines the metric from only the
Einstein-Maxwell equations for every type of separation of variables.
Representatives of all classes of metrics and electromagnetic potential are given for every type of separation of variables
with the exception of the spaces found in the well-known work by Carter.
The problem is solved in terms of metric formalism. The classes of electrovac spacetimes obtained are found to be related
to Petrov’s classification. 相似文献
55.
A. M. Obukhov 《Waves in Random and Complex Media》1994,4(1):9-19
Small-scale inhomogeneities caused by atmospheric turbulence have a considerable effect on sound and light propagation, producing the fluctuations of these wave fields. V A Krasilnikov [1, 2] performed experiments on phase and amplitude variations of a sound wave propagating through the atmosphere. Fluctuations of light-wave parameters occur, for example, in the well known phenomenon of star scintillation, apparently strongly connected with turbulent irregularities of the atmospheric temperature field [3, 4]‡.
Some calculations of phase (arrival angle) and amplitude fluctuations for a wave propagating through a turbulent medium are described by Krasilnikov [1, 3, 8]. All these and similar calculations are based on the geometrical optics (acoustics) approximation, which may be the reason for disagreement between calculation and experimental data in some cases. Thus, for example, amplitude fluctuations in the geometrical approximation turn out to be proportional to the distance of propagation through a turbulent medium to the power of 3/2. However, observations usually show much slower fluctuation growth.
This paper represents an attempt to consider the problem of amplitude and phase variations for a scalar wave field in terms of more general equations including some diffraction effects. Incidentally, the range of validity of geometrical optics theory becomes clear. 相似文献
Some calculations of phase (arrival angle) and amplitude fluctuations for a wave propagating through a turbulent medium are described by Krasilnikov [1, 3, 8]. All these and similar calculations are based on the geometrical optics (acoustics) approximation, which may be the reason for disagreement between calculation and experimental data in some cases. Thus, for example, amplitude fluctuations in the geometrical approximation turn out to be proportional to the distance of propagation through a turbulent medium to the power of 3/2. However, observations usually show much slower fluctuation growth.
This paper represents an attempt to consider the problem of amplitude and phase variations for a scalar wave field in terms of more general equations including some diffraction effects. Incidentally, the range of validity of geometrical optics theory becomes clear. 相似文献
56.
N. Lee S. Obukhov 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,1(3):371-376
We study the configurational statistics of a ring polyampholyte chain made of N randomly charged monomers with elementary charge .To a large extent, the overall structure of a polyampholyte is controlled by a total sum Q of all charges. When the total charge is smaller than , the polyampholyte has a compact globular structure. At charges larger than , the configuration has the form of a ring of small globules (beads) connected by strings. Between Q1 and Q2 we find a remarkable diversity of meta-stable configurations having the shapes of irregular clusters of small globules connected
by the strings. We estimate the number of these configurations and the energy barriers between them. Between Q1 and Q2, the minimum energy configurations are completely controlled by randomness in the charge distribution along the chain. There
are hysteresis effects in the shapes of the clusters. As the total charge increases, the linearly extended configurations
become dynamically more preferable. When the charge decreases, the circular shapes are preferred. We remark on the probable
connection with the multiple phase transitions observed in polyampholyte gels.
Received: 10 July 1997 / Accepted: 13 October 1997 相似文献
57.
The accurate integration of the Einstein—Weyl field equations is considered for the case when the spinor field depends only
on the time, while the metric specifies a uniform space—time of type I in the Bianci classification, i.e., a particular case
of a Steckel space of type (3.0).
Tomsk State Pedagogical University. Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika,
No. 11, pp. 69–78, November, 1998. 相似文献
58.
59.
The problem of integrating the Einstein-Maxwell equations with the additional condition of variable separation in the Hamilton-Jacobi equations is considered. The case where the integrals of motion form isotropic sets is studied in detail. Classes of accurate solution corresponding to the Einstein-Maxwell equations are obtained.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 33–36, December, 1981. 相似文献
60.