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

Moscow University Physics Bulletin 1974. **29**. N 6. P. 1

Spatially periodic stationary solutions (dissipative structures) are considered for a model of a chemical reaction with diffusion; relationships are obtained between the amplitude of the dissipative structure and the wavelength, and the stability is also examined.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 6

Equations are derived to describe the behavior of communities of animals and plants in space and time; it is shown that the population density function takes the form of traveling waves in the linear approximation if the shifts in the environment are neglected and if there is a Yolterra interaction between species in the predator-prey system. A uniform distribution of the population densities in space is stable if there is a closed circulation of material.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 12

A percolation problem arises in calculating the jump conductivity of a disordered semiconductor, and this is considered as determination of the critical density of the bonds between centers ϑc. Exact limits are obtained for the critical mean bond density, and an approximation calculation is performed via the procedure that takes into account the energy dependence of the mean number of bonds for an individual center.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 16

Angular and energy relationships are examined for the part of the optical potential resulting from inelastic processes involving excitation of the lower collective states of the target; a comparison is made with the nonlocal Perey- Buck potential.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 21

A study is made of the basic parameters (including mass and radius) for equilibrium quark configurations having central densities from 10^{19} to 10^{32} g/C m^3; it is found that such objects should have large gravitational mass defects. It is assumed that quarks can recombine into hyperons, and it is shown that the number of recombined quarks is of the order of the total number of quarks in a star, the ratio of the number of free quarks to the recombined ones being 10^{-6}.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 25

Nonlinear representations are derived for the Lie algebra of the Lorentz group (nondegenerate series), and invariants of the representation are constructed; it is shown that the dimensions of the maximal irreducible representation are 6.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 33

The charged point particle moves in steady homogeneous parallel electric and magnetic fields; an analytic expression is derived for the total radiation energy incorporating polarization effects. A particular case is considered for motion in a steady and homogeneous electric field.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 38

Rigorous formulation of synthesis problems is considered; the synthesis problem is considered for a particular waveguide device. The results from a numerical experiment are presented and analyzed.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 47

Expressions are derived for the 4-velocity and path incorporating the radiation friction when an electron moves in mutually perpendicular electric and magnetic fields equal in magnitude. It is found that the solution differs from the exact one for the Lorentz-Dirac equation by a quantity less than the quantum corrections.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 51

The multiparticle interaction of atoms in a lattice corresponds to an approximation involving continuous energy loss by an atom moving through the lattice. The solution to the Lewis-Spencer equation gives the energy distribution of the atoms of generation m, and also the number of these atoms for the threshold formation energy for a radiation defect. The calculations agree well with results obtained by Vineyard's method.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 56

Matched filtration is considered for the electrical signals derived from the mechanical vibrations of high-Q tuned gravitational-radiation detectors. It is assumed that the gravitational perturbation is a pulse. The results are extended to pulses of finite duration.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 60

The parametric excitation mechanism is examined for even harmonics in a seriestuned circuit with a reactive nonlinearity having a characteristic of odd type. The calculated results are compared with experiment.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 66

Peynman's method of continual integration is applied to an electron in a random field; the ranges of application of the various approximations are elucidated. Green's functions and the state density are calculated with quantum corrections.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 73

A simple nontrivial example is considered for space-time with torsion, namely an isotropic and homogeneous universe. It is shown that the torsion effect is an effect of curvature type.

Show AbstractMoscow University Physics Bulletin 1974. **29**. N 6. P. 82

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B r i e f r e p o r t s

Moscow University Physics Bulletin 1974. **29**. N 6. P. 78