R e g u l a r p a p e r s

Theoretical and mathematical physics

Moscow University Physics Bulletin 1997. **52**. N 6. P. 1

А notion of an integral over possibility conditional with respect to а prescribed σ-algebra, and analogous to that known in the probabllity theory has been considered.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 6

А model oflocal microwave hyperthermia is analyzed numerically. The fictitious sources method employed for the analysis allows significant savings of computer resources. Numerical modeling data are reported.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 11

An explicit solution of the Cauchy problem for the dynamo equation of mean fields has been constructed in the form of а Wiener integral over random paths. The solution obtained proves to bе much more complicated than the corresponding one for the induction equation. This solution is used to study the proem of constructing an effective upper estimate for the rate of growth of а mean magnetic field and the problem of the magnetic field evolution in the medium with fluctuating helicity.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 15

Analytical expression for the equation of state for the argon continuous phase at high densities and temperatures has been obtained using the asymptotic expansion method as the base. The expression is in satisfactory agreement with experimental data, as well as with calculations made bу means of the Monte Carlo method within their limits of accuracy.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 20

It has been demonstrated that the selection of the regularization parameter in Tikhonov's method "bу the L-curve techniques" introduces а nonremovable systematic error when solving any system of linear algebraic equations.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 24

Gauge transformation of an antisymmetric tensor field of second rank for the case of а space with torsion bу analogy with transformation of an electromagnetic field has been performed. The calculations made on а computer have yielded the expression for the correction of order one for the effective action of the antisymmetric tensor field in this space.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 30

An explicit solution has been set up for the boundary value problem of electric current running off from а periodic set of parallel electrodes soldered into а semiconductor film placed in а constant magnetic field. From the mathematical standpoint, а boundary value problem for harmonic functions with а skew derivative in the boundary condition has been studied. An explicit solution to this problem has been constructed bу reducing it to the Riemann-Hilbert problem for analytic functions followed bу the conformal mapping onto the canonical domain, in which the Riemann-Hilbert problem has а solution in the closed form.

Show AbstractAtomic and nuclear physics

Moscow University Physics Bulletin 1997. **52**. N 6. P. 37

Estimates have been made of the effective cross section of the electroinduced decay of а proton. An experiment is proposed on their basis on the observation of the decay of а proton inside а nucleus initiated bу intense flows of electrons and gamma-quanta from present-day accelerators.

Show AbstractRadiophysics

Moscow University Physics Bulletin 1997. **52**. N 6. P. 41

The preliminary results of testing an adaptive pulse accumulation algorithm in а gravitational wave experiment with the use of the experimental data of the Baksan long-baseline deformograph LD-1 have been presented as well as а catalog of gamma-events 3В BATSE. The detection characteristics were calculated using а family of Pearson curves.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 46

The physical model of а discharge in the surfatron may bе described as а plasma column along which а surface electromagnetic wave is propagating from the UHF generator. Part of the wave energy Wpl is consumed to contain the plasma with а high electron concentration and the remainder Wvac is emitted into the surrounding space. The relationship between Wpl and Wvac under various conditions is considered. The efficiency of the surfatron as а plasmatron and а plasma antenna is calculated.

Show AbstractOptics and spectroscopy

Moscow University Physics Bulletin 1997. **52**. N 6. P. 52

We present the results of а theoretical analysis of the influence of the noise of spontaneous Raman scattering on the parameters of optical solitons. On the basis of perturbation theory, integral representations have been received for the variance of the soliton amplitude and frequency fluctuations. Fluctuations growth with the distance has also been considered.

Show AbstractAcoustics and molecular physics

Moscow University Physics Bulletin 1997. **52**. N 6. P. 58

Enhancement of density turbulent fluctuations following the passage of а shock wave, turbulence scale, and also the correlation and spectral functions of fluctuations in the wake and ahead ofthe wave has been studied theoretically and experimentally in this paper. The calculations are based on the Euler equations, and turbulence is modeled bу а packet of velocity pulses. Experiments were conducted in а single-diaphragm shock tube, and turbulence was produced bу means ofa wire mesh. Jhe Mach number values were taken in the range ofl.1-3 in the shock-wave calculations and 1.35-1.6 in the experiments. The theoretical data are in good agreement with experimental results.

Show AbstractSolid state physics

Moscow University Physics Bulletin 1997. **52**. N 6. P. 63

It is shown that the stage character ofthe degassing process in the Pd-H system is due to the stage-by-stage development of the defective structure. For bulk samples the transition from one stage to another associated with origination of а new dislocation structure is accompanied bу the cessation of the β→∝ transformation.

Show AbstractMoscow University Physics Bulletin 1997. **52**. N 6. P. 68

The multiplication of dislocations under the effect of ultrasound and the evolution of dislocation loops generated bу the dislocation source have been studied bу the computer modeling technique. Conditions have been determined under which the generation of loops proceeds bу the classical and bу nontraditional mechanisms. Relationships have been estanblished between the ultrasonic frequency and the coefficient of dynamic viscosity on the one hand and the critical parameters, such as the dislocation source length, stress amplitude, and stress interval within wich the new mechanism is operative; on the other hand. Conditions have been determined under which the dislocations generated in the crystal bу the nontraditional mechanism are accumulated.

Show AbstractGeophysics

Moscow University Physics Bulletin 1997. **52**. N 6. P. 74

Deformation characteristics of the Caucasian seismically active region and of the adjacent areas of East Тurkey and West Iran are determined. Seismotectonic deformation rate tensors, deformation rate intensities, and orientation of the main axes of compression and extension deformations are calculated for the first time. Seismic risk zones are identified in the areas of minimum deformation rate intensities.

Show AbstractAstronomy

Moscow University Physics Bulletin 1997. **52**. N 6. P. 80

The motion of small bodies resulting in their collisions with the Moon on its reverse side is considered within the problem of two fixed centers. It is shown that collisions are possible if the body's Moon approach velocity is smaller than 3 km/s.

Show AbstractB r i e f r e p o r t s

Astronomy

Moscow University Physics Bulletin 1997. **52**. N 6. P. 85

New normal modes were demonstrated to appear in the Earth's rotation in space, when the atmosphere dynamics is taken into account. These modes are associated with the atmosphere rotation relative to the solid Earth and must bе taken into consideration when constructing the theory of nutation.

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