Faculty of Physics
M.V.Lomonosov Moscow State University

## Scattering and absorption of small particles by a black hole

### A.B. Gaina, G.A. Chizhov

Moscow University Physics Bulletin 1983. 38. N 2. P. 1

The scattering and absorption processes of weakly relativistic electric and scalar particles in Kerr-Newman fields with an event-horizon radius less than the particle wavelength are considered. Particle absorption by the event horizon is due to polarizational phenomena $\sim r_g/\lambda$ in electron scattering. Corrections of the same order to the differential scattering cross section are obtained, together with expressions for the total absorption cross sections. The general formulas are used to consider analogous processes involving the neutrino.

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## Seeking short-term increases in the heavy-nucleus flux of cosmic rays from the data of measurements on Prognoz spacecraft

### N.N. Volodichev, I.A. Savenko, A.A. Suslov

Moscow University Physics Bulletin 1983. 38. N 2. P. 8

A search is made for short-term increases in the cosmic-ray flux of predominantly heavy nuclei of energy E $\ge$500 MeV/nucleon from the data of measurements on the Prognoz-2 and Prognoz-3 spacecraft. These increases were recorded in the course of the first space flights by Soviet rockets, orbital spacecraft, and the Elektron and Molniya-1 satellites. No such increases were observed by the Prognoz spacecraft. Moreover, the increase on 2 January 1974, observed by the Molniya-1 spacecraft by a telescope consisting of scintillational and Cherenkov counters was not recorded by the analogous devices on the Prognoz-3 spacecraft. Therefore, the nature of the short-term increases in the heavy-nucleus flux remains an open question.

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## Spectral properties of dielectric mirrors on a metallic substrate

### A.V. Tikhonravov

Moscow University Physics Bulletin 1983. 38. N 2. P. 13

Dielectric mirrors on a metallic substrate are investigated taking account of absorption in the layers. Simple formulas are obtained for the reflection coefficient of such mirrors. It is shown that the basic obstacle to the achievement of high values of R is absorption in the dielectric layers, and this is the basis for the selection of the best mirror construction. It is also shown that, under certain conditions, the system consisting of a dielectric mirror on a metallic substrate is a selective absorber of wave energy. Simple expressions are obtained allowing the construction of such an absorber to be calculated and its basic spectral characteristics to be determined.

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## Shock waves excited by a relativistic charged beam in media with dissipation

### V.K. Grishin

Moscow University Physics Bulletin 1983. 38. N 2. P. 18

The possibility of the propagation of electromagnetic waves with a shock profile cophasally related with a beam of relativistic particles and localized at its leading edge is considered. The conditions of dynamic equilibrium are found, when the energy losses of the wave are compensated by its "pumping" with freezing of the fast particles of the beam in the intrinsic field.

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## Prediction of the optical properties of ruby and leucosapphire under conditions of cosmic-plasma action

### A.I. Akishin, T.S. Bessonova, A.I. Sobko, E.M. Akulenok

Moscow University Physics Bulletin 1983. 38. N 2. P. 23

On the basis of the results obtained earlier in the experimental and theoretical investigation of radiation-optical effects in ruby and leucosapphire, methods of practical importance are developed for the computer prediction of the optical transparency of ruby and the luminescent-noise intensity from a leucosapphire lens of a spacecraft under conditions of cosmic-plasma action. The change in optical density of ruby and the level of luminescent noise from the leucosapphire lens of a spacecraft moving in interplanetary space in the course of a solar flare described by the Bailey method is calculated.

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## Conditions of oscillation development in a spin generator

### L.S. Kornienko, A.L. Kotkin, D.M. Litvak, Yu.V. Pavlov, R.M. Umarkhodzhaev

Moscow University Physics Bulletin 1983. 38. N 2. P. 29

"Peak" conditions of transition of a spin generator to a steady level of oscillation, occurring at large feedback-loop amplification factors, are investigated theoretically and experimentally.

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## Analysis of the statistical treatment of a random process on the example of the velocity pulsations of a waterway flow

### V.P. Petrov, O.P. Petrosyan, I.P. Kharchenko

Moscow University Physics Bulletin 1983. 38. N 2. P. 37

A method of statistical treatment is proposed for the random process of velocity pulsation of a waterway flow, allowing the true values of the given process to be obtained in the specified frequency range.

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## Model of the vertical distribution of temperature and dissolved-oxygen concentration in the convective mixing of the upper layer of a reservoir

### V.V. Alekseev, Yu.I. Gorbatov, A.Yu. Loskutov

Moscow University Physics Bulletin 1983. 38. N 2. P. 44

A mathematical model is constructed for the dynamics of water temperature and dissolved-oxygen concentration in the convective mixing of the upper layer of a reservoir. Satisfactory agreement is obtained between the results of the calculation and experimental data. The validity of the theoretical formula for the turbulent transfer coefficient with convection for Grashof numbers of around $10^9$ is verified. The model may be used to predict the water quality of fresh-water reservoirs in the period of autumnal cooling.

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## Simplest hypernuclear systems with $A\le5$ and $\Lambda N$ potential

### N.N. Kolesnikov, V.I. Tarasov

Moscow University Physics Bulletin 1983. 38. N 2. P. 48

A theoretical analysis of the lightest hypernuclear systems with $A\le 5$ is conducted by means of a multiparticle variational procedure. It is shown that the available experimental data may be described by means of pairwise central spin- and charge-dependent $\Lambda N$ potentials, with possible admixture of the Majorana conponent.

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## Conductivity of bounded two-dimensional systems

### I.P. Zvyagin

Moscow University Physics Bulletin 1983. 38. N 2. P. 53

On the basis of scale theory of localization, it is shown that the activational temperature dependence of the conductivity of two-dimensional systems, usually interpreted by means of the concept of a mobility edge, may be due to the finite value of the characteristic length - the dimension of the system or the diffusional length including the free-path time with respect to inelastic collisions.

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## Asymptote of the solution of some boundary problems of singularly perturbed systems of differential equations

### A.A. Shishkin, G.B. Gurov

Moscow University Physics Bulletin 1983. 38. N 2. P. 58

For a singularly perturbed system of differential equations of the theory of semiconductor instruments, three boundary problems are considered. Asymptotic expansions of the solution of these boundary problems with respect to a small parameter are obtained.

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## Recording the classical force acting on a quantum oscillator

### B.A. Grishanin, V.N. Rudenko

Moscow University Physics Bulletin 1983. 38. N 2. P. 63

With the aim of discovering practically realizable operations that satisfy the criterion of a "nonperturbing measurement", quantum analysis is performed of a specific measuring system including a test oscillator and a recording element - an RC sensor. It is shown that the sensitivity to external force may be the best characteristic quantum standard if the oscillator is an excited state. For a vacuum state of the oscillator, quantum fluctuations of the RC sensor limit the sensitivity at the typical level $\tau^{-1}(m\hbar\omega_0)^{1/2}$.

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## Basic laws of the algebra of parallel compounds of N-poles

### V.I. Shestakov

Moscow University Physics Bulletin 1983. 38. N 2. P. 69

Any physical system interacting with the surrounding medium or with N-poles at N points ("poles") is called an N-pole (NP) N(X) in the present work. An autonomous physical system is called a zero-pole (0-pole). Mutually substitutable NP are said to be equivalent NP. Parallel combinations (P combinations) of P are denoted by the previous symbol [1]. On the basis of physical considerations, the basic laws of the algebra of P combinations of NP are taken to be the associative and commutative laws (Al) and (A2), i.e., axioms of each Abelian semigroup. As a consequence of laws (Al) and (A2), formulas analogous to certain axioms of linear algebra are obtained. The relation N(А)$\le$N(В) of shunt neutrality of N(A) with respect to N(B) is determined; a series of formulas expressing its basic properties is presented; it is asserted that they may be used in simplifying P combinations; and it is noted that this ratio is analogous to the inclusion relation $Х\subset Y$ of sets X and Y and also to the relation of partial order in semilattices (semistructures) and, in particular, in Boolean algebra.

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## Diffraction of laser beams with a smooth profile of intensity variation

### P.V. Korolenko, S.N. Markova, A.M. Khapaev

Moscow University Physics Bulletin 1983. 38. N 2. P. 77

The diffraction of laser beams with a smooth profile of the intensity distribution is investigated using a method based on the representation of the diffracted wave in the form of a superposition of TEM free-space modes. The field distribution of waves diffracted at a "soft" diaphragm and at the end of the gas-discharge capillary of a waveguide laser is calculated. The results of the calculation are verified experimentally.

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## Nonlinear aberrations in the self-deviation of a light beam in a moving medium

### V.A. Trofimov

Moscow University Physics Bulletin 1983. 38. N 2. P. 81

A general solution of the problem of optical-radiation propagation in a moving medium is constructed in the approximation of nonlinear geometric optics. The beam distortion is analyzed for homogeneous and bell-shaped intensity distributions.

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## Investigation of strontium sulfide in the near-IR regio

### M.-L.Yu. Allsalu, V.V. Mikhailin, E.Yu. Pedak, M.A. Rozhdestvenskii, I.V. Tereshchenko

Moscow University Physics Bulletin 1983. 38. N 2. P. 84

The near-IR luminescence of preliminarily undeformed SrS phosphors is investigated. It is shown that it belongs to the luminescence of $F^+$ centers and near-anionic vacancies. The ignition and extinction times of this luminescence are measured. The dependence of the change in luminescence intensity of $F^+$ centers and near-anionic vacancies under the action of the exciting light is established, and an explanation for the interrelationship between these centers is offered.

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## Influence of eddy currents on the time of magnetic-field establishment in band lines

### O.S. Kolotov, T.Sh. Musaev, V.A. Pogzhev

Moscow University Physics Bulletin 1983. 38. N 2. P. 87

The time for magnetic-field establishment in band lines under the action of eddy currents arising when a current difference is applied in a single band is investigated experimentally for the first time.

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## Method of experimental determination of three components of the instantaneous-velocity vector in a natural river flow

### O.N. Mel'nikova, V.P. Petrov, Yu.G. Pyrkin, V.A. Vinogradov

Moscow University Physics Bulletin 1983. 38. N 2. P. 90

A new simple method of experimental determination of the instantaneous-velocity vector using a thermohydrometer is proposed. Constant monitoring of the measuring-apparatus parameters allows measurements to be made in a natural waterway flow.

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## Creation of charmed particles in quark-gluon reactions

### M.N. Dubinin, D.A. Slavnov

Moscow University Physics Bulletin 1983. 38. N 2. P. 93

The role of the subprocess $2\to 3$ $qg\to \bar{c}cq$, when there are quarks and gluons in the initial state, in reactions of the hadronic creation of charmed particles is considered.

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## Laboratory model of a developing convective eddy

### S.B. Boboshina, A.A. Solov'ev

Moscow University Physics Bulletin 1983. 38. N 2. P. 96

The relation between the basic and meridional motion in a convective eddy is investigated. The velocity measurements are made by the method of laser anemometry. It is found that eddies of different kinds may be reduced to corresponding states.

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## Asymptote of retaining potentials and spectrum of the radial Schr$\stackrel{..}{o}$dinger equation. Quasiclassical approximation

### V.B. Gostev, A.R. Frenkin

Moscow University Physics Bulletin 1983. 38. N 2. P. 99

By means of a method based on the use of the quasiclassical quantization condition, the asymptotic formulas, $(r \to \infty)$ for the correction $\Delta V(r)$ to the reference potential $V(r)$ of retaining type - $(\lim_{r\to \infty} V(r) = \infty)$ - are obtained in the case of change in the number of states and shift of the energy levels in the spectrum of the radial Schr$\stackrel{..}{o}$dinger equation. In the proposed method, the correction $\Delta V(r)$ as $(r \to \infty)$ is determined from an integral equation of Abelian type, which differs significantly from the standard methods of the inverse problem of quantum mechanics associated with solving the Gel'fand-Levitan equations.

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## Radiational friction in the problem of the emission of an oscillator in the coherent state

### G.A. Chizhov, O.F. Dorofeev

Moscow University Physics Bulletin 1983. 38. N 2. P. 102

## Phase-transition theory

### I.P. Bazarov, P.N. Nikolaev

Moscow University Physics Bulletin 1983. 38. N 2. P. 105

On the basis of taking account of the asymptotic behavior of the free energy at small and large densities, phase transition in a system of solid spheres is described using series in terms of the density with improved convergence.

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## Sound emission by a turbulent boundary layer in critical flow conditions

### A.M. Gusev, Yu.K. Gulua

Moscow University Physics Bulletin 1983. 38. N 2. P. 108

A preliminary analysis is made of the acoustical quantities of emission in critical conditions of the flow of an air current around the surface of a marine wave. It is shown that the displacement of the air-flow breakaway point over the surface of the marine wave in critical flow conditions may be a source of intrasound waves in the atmosphere above the oceans.

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## Generalization of the Le Chatelier principle in the thermodynamics of irreversible processes

### E.V. Stupochenko

Moscow University Physics Bulletin 1983. 38. N 2. P. 112

The formulation of the properties of states with minimal entropy production such as to be an adequate generalization of the Le Chatelier principle is considered.

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## Magnetic properties in the alloy $Fe_{34}Cr_{41}Co_{25}$ after thermomagnetic treatment

### S.D. Antipov, L.A. Kondrashova, P.N. Stetsenko

Moscow University Physics Bulletin 1983. 38. N 2. P. 116

The magnetic states in the alloy $Fe_{34}Cr_{41}Co_{25}$ are investigated by the methods of M$\stackrel{..}{o}$ssbauer spectroscopy and thermomagnetic analysis. It is established that in the alloy, with various thermomagnetic treatments (at temperature of 610°C, H = 5000 Oe, and f = 70 Hz), stratification of the solid solution into antiferromagnetic, ferromagnetic and nonmagnetic phases occurs as a result of the separation of the intraphase segregations with the most probable configurations of the local atomic surroundings, the distribution of the relative proportions of which depends on the form of heat treatment.

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