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

Theoretical and mathematical physics

Moscow University Physics Bulletin 2003. **58**. N 5. P. 1

We continue our study of the gravitational field in terms of Bogolyubov's group variables defined in paper [1]. The goal of the present article is to construct a regular perturbation theory and to obtain conditions for its validity.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 7

Examples of corrugated (asymptotically weakly irregular) waveguides with trapped modes at a given frequency are given. It is shown that fields existing in such waveguides can decrease in a power-like manner with any integer exponent.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 14

An integro-differential equation has been obtained to describe the weakly nonlinear dynamics of a flame with an arbitrary expansion coefficient of the gas in the gravitational field. It has been demonstrated that the presence of the gravitational field gives rise to specific stationary flame propagation conditions, for which the appropriate analytical solutions of the above equation have been found.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 19

The Konishi anomaly has been calculated in terms of component fields for N = 1 supersymmetric electrodynamics regularized by the method of higher derivatives. It has been established that the obtained result is consistent with the calculations performed in the supergraph formalism.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 24

The effect of a scalar charge on the trajectory of motion of massive particles in the case of a spherically symmetric model has been studied. The action of the gravitational field of a scalar star on the displacement of the trajectory pericenter of massive bodies has been demonstrated, as well as the agreement of the given theory with the predictions of the general relativity theory in the absence of a scalar source within the limits of the solar system.

Show AbstractOptics and spectroscopy

Moscow University Physics Bulletin 2003. **58**. N 5. P. 28

We have carried out numerical computation of the threshold gain increment and excitation time of a stimulated Brillouin scattering (SBS) mirror with a feedback loop for different parameters of the latter. The theoretical values obtained are compared with the experimental data available on a loop-type SBS mirror used as a cavity mirror of a solid-state laser.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 32

This work is devoted to studies on the effect of an external field providing for the drift of excitations on the luminescence yield and kinetics in conditions of near-surface quenching of luminescence. Based on the solution of a nonstationary equation for the concentration of excitations, relationships are found between the volume luminescence intensity and the near-surface recombination rate on the one hand and time and the external field strength on the other hand. Regions are revealed wherein the recombination rates decay in an essentially nonexponential manner.

Show AbstractAcoustics and molecular physics

Moscow University Physics Bulletin 2003. **58**. N 5. P. 38

Bovine serum albumin (BSA) solutions containing cadmium ions or europium chelate molecules in low concentrations have been studied by the polarized fluorescence technique. Luminescence spectra of the europium chelate in aqueous solutions differing in chelate concentration and pH value have been obtained, as well as luminescence spectra of europium chelate-containing bovine serum albumin (BSA) solutions differing in BSA concentration and the medium pH value. The rotational correlation time of particles in solutions containing, in addition to albumin, cadmium ions or europium chelate complexons is an order of magnitude longer than that of the albumin molecules proper. This result can be explained by the formation of protein clusters, which is also confirmed by the results obtained by means of the static light scattering technique.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 45

A new method has been suggested for calculating the level dissociation cross sections of diatomic molecules based on the solution of an improperly posed inverse problem. The method is used to calculate the dissociation rate constants of oxygen and nitrogen molecules in the temperature range from 300 to 40000 K.

Show AbstractSolid state physics

Moscow University Physics Bulletin 2003. **58**. N 5. P. 49

The authors have considered in a two-wave approximation of the diffraction theory specular and diffraction reflection of X-rays from a crystal film on the surface of a single-crystal (bicrystal) with different surface projections onto the vector surface of the film and substrate reciprocal lattice in conditions of noncoplanar grazing diffraction. It has been shown that the angular relationship of specular reflection intensity in the diffraction region is highly sensitive to the thickness, deformation and degree of amorphization of the surface layers.

Show AbstractMoscow University Physics Bulletin 2003. **58**. N 5. P. 55

Based on the Max Born theory, a new method has been proposed for calculating the intensity of thermal diffuse scattering by bcc and fee polycrystalline metals. In distinction to the hitherto much used Borie theory based on the Debye model, it has been suggested that real relationships between vibration frequencies and the wave vector be used. Phonon spectra were calculated both in the Born— Begbie approximation (with inclusion of elastic constants $c_{11},c_{12},c_{44}$) and by the model potential method with consideration for interactions in an arbitrary coordination sphere.

Show AbstractGeophysics

Moscow University Physics Bulletin 2003. **58**. N 5. P. 61

Acoustic remote sensing provides measurement of vertical profiles of the wind velocity vector in urban conditions up to an altitude of several hundred meters, where contact measurements involve difficulties. This article describes physical principles of a Doppler acoustic radar and presents characteristics of sonars (sodars) employed in the studies of a wind field over Moscow which are conducted jointly by the scientists of the Physics Faculty of Moscow University and the A. M. Obukhov Research Institute of Atmospheric Physics under RF Academy of Sciences. Preliminary results of sodar measurements of wind velocity at the center of Moscow have been presented.

Show AbstractAstronomy

Moscow University Physics Bulletin 2003. **58**. N 5. P. 67

This paper presents a complete analysis of classification of possible motion regions in L. Euler's problem of two fixed centers. It is shown that a final classification comprises 47 types of two-dimensional motion regions and 26 types of spatial motion regions.

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

Radiophysics

Moscow University Physics Bulletin 2003. **58**. N 5. P. 72

Dynamics of a spiral electron flux in the field of a circularly polarized traveling wave has been studied, and the interaction energy characteristics depending on the beam injection into different wave field phases have been calculated.

Show Abstract