SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25357 full-text translations 14926 English PDFs 22539 abstracts
Showing 50 of 2226 papers in Physics
This paper presents a method for estimating the spectral width of the infrared luminescence line associated with the iodine atom transition in a photodissociation optical quantum generator operating at 1.315 micrometers. The authors use a Fabry Perot etalon with a time swept interference pattern, re…
This paper studies the onset and post-critical development of cellular convection in an infinitely long horizontal gas layer heated from below, taking account of compressibility, the adiabatic temperature gradient, and gas properties beyond the Boussinesq approximation. The authors solve the two-dim…
This paper formulates the Einstein equations for spatially homogeneous gravitational fields in a comoving reference system, motivated by cosmological applications where the physical behavior of matter is most naturally described along the medium flow. Starting from metrics admitting a three-dimensio…
This paper reports ultrasonic measurements of longitudinal and transverse sound velocities in polycrystalline cesium chloride and sodium chloride under quasi-hydrostatic pressures up to about 100 kbar. Using a high-pressure chamber, corrected specimen-length measurements, and transit-time data refer…
This paper studies whether nonlinear curvature terms in the gravitational Lagrangian can remove cosmological singularities while preserving the usual Friedmann behavior at low curvature. Using field equations derived from an action of the form \(R + l^{-2}(l^2 R)^{4/3}\), the author constructs exact…
This paper develops a theoretical treatment of nuclear magnetic relaxation in molecular crystals arising from intramolecular dipole dipole interactions when molecules undergo hindered reorientation about a fixed axis. Using the distribution of molecular orientations for random rotational jumps in a …
The paper studies neutrino fields in general relativity governed by the Einstein-Dirac system, with attention to solutions invariant under three-dimensional motion groups acting on two-dimensional nonisotropic transitivity surfaces. By representing spinors through associated real tensor fields, it d…
This study examines the morphology of polymorphic transformations in potassium nitrate, with emphasis on the growth of the high-temperature beta phase from single-crystalline alpha-phase specimens. Using purified, well-faceted crystals and microscopic observation on a thermostated heating stage, the…
The paper develops a method for solving the Cauchy problem for the linearized Boltzmann equation and for computing space-time correlation functions of a classical one-component gas in the Boltzmann limit. Treating the collision term as an operator in a Hilbert space, it uses semiboundedness to invok…
This paper extends S. I. Vavilov’s theory of concentration depolarization of fluorescence by incorporating temperature and viscosity as variables affecting resonance migration of excitation energy in viscous solutions. Treating fluorescent molecules as Brownian particles, the authors derive collisio…
The paper addresses the difficulty of interpreting gas-dynamic interferograms in monochromatic light when fringe breaks, crowding, or discontinuities prevent direct fringe tracking, a problem often resolved by also recording achromatic fringes. It proposes a method for determining the integer optica…
This paper investigates antiferromagnetic resonance absorption in copper chloride dihydrate in an inclined magnetic field at low microwave frequencies between 0.65 and 5.2 GHz. Measurements of the resonance field as a function of the angle between the easy axis and the external field show frequency-…
The paper studies the low-energy and long-wavelength asymptotics of one-particle Green’s functions in a weakly nonideal Bose gas at low temperature. Using a projection method for decoupling equations of motion, the analysis extends the operator basis to include collective variables associated with q…
The paper studies nonlinear periodic waves governed by the Korteweg de Vries equation in a weakly inhomogeneous medium, focusing on exponentially small changes of wave quantities analogous to adiabatic invariants. By decomposing the Hamiltonian into a homogeneous part and a small inhomogeneous pertu…
This paper analyzes the radial stability of an infinite cylindrical incompressible conductor placed eccentrically inside a cylindrical surface carrying an azimuthal traveling-wave current. Using the quasi-stationary approximation, the Leontovich boundary condition, and Bessel-function expansions, it…
This paper reports an experimental observation of low-frequency ultrasonic modulation in the radiation intensity of solid-state traveling-medium lasers, in addition to previously noted high-frequency kinematic modulation. Oscillograms from ruby and neodymium-glass traveling-medium lasers show intens…
This paper proposes a small-angle X-ray scattering method for estimating distances between heavy atoms introduced into macromolecules in solution. The authors derive the scattering contributions from the macromolecule, the heavy atoms, and their interference, arguing that the heavy-atom term can pro…
This paper studies the unsteady magnetohydrodynamic flow of a supersonic electrically conducting ideal gas in a plane dielectric channel as it enters or exits a nonuniform transverse magnetic field. The authors formulate the coupled gas-dynamic and electrodynamic problem for finite magnetohydrodynam…
This paper examines nonstationary finite-amplitude wave propagation in nondispersive dissipative media, focusing on plane and cylindrically symmetric acoustic, and by analogy magnetoacoustic, disturbances. By applying self-similar substitutions, the governing nonlinear partial differential equations…
This paper formulates Petrov’s algebraic classification of gravitational fields in chronometrically invariant terms for a fixed reference system in general relativity. Using an orthonormal frame, it expresses the Weyl tensor through three-dimensional chronometrically invariant tensors and represents…
This note examines the gravitational collapse of a mass with small axial deviations from spherical symmetry, focusing on the behavior of nonspherical metric perturbations near the gravitational radius. Using a linear perturbation of the Schwarzschild metric, expansion in generalized spherical functi…
The paper applies a spin-dependent version of the factorizing quark model to high-energy production processes in which a pseudoscalar meson and proton produce a vector meson and a positive-parity baryon. It argues that, although quark spin-flip amplitudes are small relative to the main quark scatter…
This paper examines electron, phonon interaction in Nd3+ activated Y3Al5O12 crystals through temperature dependent induced emission spectroscopy. The authors analyze how generation energy, line width, wavelength shift, and saturation behavior vary with temperature, comparing experimental data with k…
This paper investigates the origin of hole conductivity in selenium and the role of oxygen impurities in determining carrier type. The authors measure electrical conductivity and thermoelectric emf in amorphous selenium with varying crystallinity and in single crystalline hexagonal selenium before a…
This paper examines thermo-optical properties of neodymium-activated laser glasses, motivated by thermal gradients in optically pumped glass rods that can distort resonator wavefronts despite high initial optical homogeneity. It presents a direct interferometric method for measuring the thermo-optic…
This paper investigates how amorphous boundary layers can preserve and transmit structural information from crystal surfaces, focusing on a proposed photoelectret mechanism in selenium films deposited on NaCl cleavage surfaces. Amorphous selenium layers were formed under controlled illumination cond…
This paper estimates electron positron pair production when intense focused laser radiation irradiates a dense, initially nonrelativistic plasma. The authors argue that, at attainable laser intensities, pair creation involving electron scattering by nuclei is far more probable than production by int…
This paper develops analytical expressions for the yield of characteristic X-ray photons emitted into one steradian per incident ionizing particle, as a parameter for comparing primary spectra excited by electrons and secondary spectra excited by X-ray photons. Using excitation-density models that i…
This paper proposes and analyzes a continuous-wave carbon dioxide laser in which the usual gas-discharge excitation is replaced by optical pumping from an alkali-metal resonance lamp. The authors describe an excitation chain in which resonant absorption by alkali-metal atoms transfers energy through…
This paper investigates whether a monoenergetic, well collimated proton beam can be used as a diagnostic of turbulent collective oscillations in a plasma. A 50 keV proton beam was passed through the turbulent plasma of a high voltage direct discharge, and time resolved beam broadening was recorded i…
This paper analyzes how the spatial distribution of standing-wave energy in a composite optical resonator with a moving dielectric affects stimulated radiation generation. Using a quasistationary treatment of longitudinal resonator modes, it distinguishes stationary and sliding modes, derives the po…
This paper analyzes thermal distortions in solid state laser resonators whose neodymium glass active element has the form of a thin rectangular plate rather than a circular rod. Using thermoelastic relations for a free plate with a symmetric temperature distribution through its thickness, the author…
The paper studies the entropy change produced by mixing two equal amounts of identical polarized gases whose internal spin states are described by arbitrary density matrices of spin s. Using the von Neumann entropy for mixed quantum ensembles, it derives a general expression for the entropy of mixin…
This paper analyzes energy absorption in pure KCl crystals using the concept of residual ionization potential, together with atomic ionization potentials, electron affinities, exciton levels, and virtual levels. The author calculates band and defect-related transition energies for neutral and ionize…
This paper reports experiments on capillary motion of mercury drops in hydrochloric acid under short-duration weightlessness produced by dropping a container. A flattened mercury drop was observed to contract after the onset of weightlessness, detach from the vessel bottom, and undergo damped oscill…
This paper examines coherent interactions of 60 GeV negative pions with emulsion nuclei, focusing on three-prong and five-prong events observed in BR-2 nuclear photoemulsion. The authors select candidate coherent events using angular, energy-balance, and four-momentum-transfer criteria, determine se…
The paper proposes a regional classification of the curvature tensor in four-dimensional Riemannian space using principal congruences and reference systems determined by timelike vector fields. It reformulates the Petrov classification through the splitting of the Weyl tensor into chronometrically i…
This paper reports the excitation and detection of hypersound in quartz in the millimeter radio range using conversion between a slow surface electromagnetic wave and acoustic waves in a piezoelectric crystal. The authors describe a slow-wave comb structure operated at liquid helium temperature and …
The paper studies a spherical wave associated with a scalar plankeon in the curved spacetime of the Einstein universe, using a scalar wave equation with curvature coupling. By separating variables in the metric, the author reduces the equation to a radial ordinary differential equation, gives its ge…
The paper derives an analogue of the Boltzmann kinetic equation for a classical system of many particles governed by quasicanonical equations that include non-Lagrangian forces, such as friction. Using Bogolyubov’s hierarchy for correlation functions, a virial expansion in inverse specific volume, e…
This paper examines the transverse stability of solitary wave solutions of the Korteweg-De Vries equation in weakly dispersive media when the soliton phase and amplitude vary slowly across the direction of propagation. Using a perturbative treatment for weak curvature and long transverse wavelengths…
This paper presents calculations of stellar opacity for astrophysical mixtures with photon absorption in spectral lines included alongside photoionization, bremsstrahlung absorption, and scattering. The authors use a Thomas-Fermi based self-consistent potential to compute electron states, occupation…
This paper reports an experimental observation of electric gyrotropy, the rotation of the polarization plane of light in a crystal under an external electric field, with attention to the role of spatial dispersion in the dielectric response. The author develops the phenomenological form of the relev…
This paper develops a theoretical description of gamma-magnetic resonance in a single-domain ferromagnetic absorber, extending earlier treatment of multidomain specimens where domain-wall nuclei dominated the effect. Using perturbation theory for a two-quantum process involving Mössbauer gamma absor…
A theory is developed for Stark broadening of hydrogen spectral lines in turbulent plasma, with attention to the use of Balmer line profiles for measuring the energy density of electrostatic oscillations. The analysis distinguishes quasistatic low-frequency ion-acoustic fields from nonadiabatic high…
This paper examines diffractive dissociation of 20.8 GeV/c protons on nuclear emulsion nuclei in the reaction producing a proton and two charged pions while the nucleus remains essentially unexcited. Using emulsion data taken in a strong magnetic field, the authors select clean three-particle events…
This paper derives a universal similarity law for turbulent heat and mass transfer from a smooth wall at large Reynolds and Peclet numbers, relating the Stanton and Nusselt numbers to the friction coefficient, Reynolds number, and Prandtl number. Using overlap arguments between the near-wall tempera…
This paper proposes and tests a spectroscopic method for measuring nonequilibrium electric fields in turbulent plasma using Stark broadening and splitting of hydrogen spectral lines. The authors apply high-speed electro-optical spectrochronography to collisionless magnetosonic shock waves in a theta…
The paper reports measurements of ferroelectric, dielectric, pyroelectric, piezoelectric, and electro-optic properties of natural stibiotantalite specimens from Mozambique. Using oriented cleaved crystals with fired silver electrodes, the authors measured temperature dependences of dielectric permit…
This paper analyzes stepwise ionization of atoms in discharge plasmas under conditions of large tube dimensions, high electron density, and electron temperatures small compared with the ionization energy. It derives scaling relations showing how the stepwise ionization constant depends on electron t…
