GRAVITATION, ASTROPHYSICS 
Particle collisions in an expanding universe

1

NUCLEI, PARTICLES, AND THEIR INTERACTION 
Phase transition in the rotational band of a nonaxial nucleus

5

On the depolarization of negative muons in hydrogen

13

ATOMS, SPECTRA, RADIATION 
Resonance transition radiation of relativistic charged particles in an ordered system of vacancion pores

20

Radiation of ultrarelativistic positrons moving in a single crystal near crystallographic planes

30

Critical phenomena in cooperative resonant fluorescence of a system of interacting atoms

38

Detection of forces acting on an oscillator by measuring the integral of its coordinate

43

Logarithmic perturbation theory and its application to the Stark effect in the hydrogen atom

46

Effect of resonant electromagnetic field on the autoionizing states of atoms

53

Spectralkinetic manifestations of nonadiabatic coupling of molecular states under conditions of fast vibrational relaxation

59

PLASMA, GASES 
Nonlinear Langmuir perturbations in an inhomogeneous plasma

64

Topological solitons in magnetohydrodynamics

69

Plasma turbulence and dissipation of a strong electromagnetic wave in the vicinity of the n_{c} / 4 resonance

74

Wave damping in a relativistic plasma

82

Rossby soliton in the laboratory

85

LIQUIDS 
Acoustooptical effect induced by an incident ultrasonic beam in a normally oriented nematic liquid crystal layer

96

Orientational effect of a light wave on a cholesteric mesophase

99

SOLIDS 
Magnetic channeling of neutrons in nonmagnetic crystals

105

Reversal of residual damping of longitudinal hypersound in dielectric crystals

108

Effect of impurities on superconductors with helical ordering of localized spins

115

Investigation of the static magnetic properties of antiferromagnetic CsMnF_{3} and FeCI_{2}

121

Statistical theory of the relaxation of a spinspin reservoir

126

Quasiacoustical and quasioptical oscillations of the domain structure of a uniaxial ferromagnet

132

Temperature dependence of the NMR shift and line width in Van Vleck paramagnets

135

Damping of thermomagnetic waves in bismuth

139

Model of a deep impurity center in a semiconductor twobandapproximation

143

Effect of mixing of the states of conduction electrons and of impurity d(f) ions on the electric conductivity

148

Phase transitions and highfrequency magnetic phenomena in semiconductors with point defects

152

Correlation functions of onedimensional systems

162

The thermal conductivity of perfect and plastically deformed ^{4}He crystals grown in a narrow bent capillary

166

Dopplerons and the GantmakherKaner effect in a compensatedmetal plate

175

Exponential contribution to the electric resistance of the superconducting compound Nb_{3}Al_{0.75}Ge_{0.25} and the anomalous temperature dependence of its crystallattice parameter
Exponential contribution to the electric resistance of the superconducting compound Nb_{3}Al_{0.75}Ge_{0.25} and the anomalous temperature dependence of its crystallattice parameter

185

Phase transition in a nuclear spin system in a semiconductor with optically oriented electrons

188
