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 investigates the optical anisotropy and dichroism of metallic textures composed of oriented anisometric gold microcrystals embedded in high-polymer films. The authors produced such textures experimentally and interpreted their visible and near-infrared absorption using scattering calculat…
This paper examines the relation between molecular luminescence and absorption spectra, quantum yield, and luminescence duration, starting from Stepanov’s universal relation and its known conditions of validity. It derives a generalized expression that includes the number of excited molecules throug…
This paper investigates the optical constants of liquid water in the stretching-vibration band, where earlier infrared and reflection measurements gave incomplete or contradictory values for absorption and dispersion. The author applies frustrated total internal reflection measurements at several in…
This paper analyzes how an internal dielectric boundary between an active laser medium and an inactive region in a plane parallel resonator affects the spectral composition of induced radiation. Using a one dimensional axial mode model with continuity conditions at the boundary, it derives approxima…
This study examines the intrinsic luminescence of powdered europium orthotantalate and the luminescence of lanthanum orthotantalate containing trace europium impurity, motivated by interest in rare-earth compounds for laser applications. EuTaO4 and LaTaO4 were synthesized and investigated at 300 K u…
This paper investigates why the measured brightness temperature of strong shock-wave fronts in gases can be much lower than the calculated gas temperature behind the front. Using an explosive-driven shock apparatus and slit photochronography with red-light filtering, the authors measured shock-wave …
This paper develops a tensor representation of spinors in complex and pseudo-Euclidean spaces of arbitrary dimension using gamma matrices and spin representations of orthogonal groups. It first reviews the construction of covariant and conjugate spinors in even and odd dimensions, then shows that a …
This paper analyzes how a strong magnetic field affects recombination radiation in semiconductors for interband transitions. Using Landau quantization of carrier states, the authors derive an expression for the spontaneous emission intensity and show that the magnetic field enters primarily through …
This paper proposes a different-time decoupling scheme for correlation functions in a model electron-phonon Hamiltonian, motivated by cases where conventional equal-time decouplings give only exponential damping and fail to capture short-time dynamical behavior such as Gaussian dependence. The metho…
This paper investigates nonlinear transmission, or bleaching, in cobalt-activated zinc sulfide crystals under irradiation by giant pulses from a ruby optical quantum generator. It outlines criteria for observing bleaching in color-center systems and reports measurements of ZnS(Co) transmission at th…
This paper develops a quantum theoretical treatment of anisotropic ferromagnetism using a linearization of the Heisenberg equations of motion, extending methods previously applied to isotropic ferromagnets. For a lattice of spins with tensor exchange interaction and an external magnetic field, the m…
This study reports optical absorption spectra of neutral silver atoms stabilized at 77 K in frozen aqueous and alcoholic solutions of silver salts after x-ray irradiation. The authors compare spectra from different matrices, verify the presence of stabilized atoms by paramagnetic resonance and contr…
This paper investigates the drift mobility of heavy ions moving in a constant electric field through a gas of much lighter molecules, assuming dilute ions so that ion, ion collisions are negligible. Using the small width of the ion velocity distribution, the analysis derives relations between drift …
This paper examines the motion of charged particles in an acute-angle magnetic trap with opposing fields, described by a nonlinear system of equations in cylindrical coordinates. It identifies an exact particular solution, beyond the previously noted trivial cases, for trajectories passing through t…
The paper develops an asymptotic method in classical statistical mechanics for electrolyte systems whose particles interact through both Coulomb forces and a short-range repulsive potential. Using Bogolyubov’s distribution-function formalism and variational differentiation of a generating functional…
The paper studies the characteristic equation arising in the asymptotic description of radiation transfer in a thick plane layer, formulated as an eigenvalue problem for an integral scattering operator on the unit sphere. Under square integrability, nonnegativity, and normalization assumptions on th…
The paper examines rotational and electronic energy level splittings in slightly bent triatomic molecules in degenerate \(^{2}\Pi\) states, emphasizing how asymmetric-top effects can resemble or modify Renner and lambda-type doublings. It develops an argument that nuclear angular momentum in a sligh…
The absorption spectrum of gaseous sulfur hexafluoride was measured in the ultrasoft X-ray region near the sulfur LII and LIII absorption edges, over 170 to 300 eV, using gas absorption coefficient measurements at controlled pressure and instrumental resolutions down to 0.25 eV. The spectrum shows a…
The paper extends a previously developed method for obtaining hydrodynamic asymptotics of classical Green’s functions to quantum many-body systems. Starting from the quantum analogue of the Boltzmann equation with Bose or Fermi statistics, it reformulates the problem in terms of Green’s functions an…
The paper derives asymptotic expressions for equilibrium correlation functions of an interacting many-particle system in the hydrodynamic limit of small wave number and frequency. Using a second-quantized Hamiltonian coupled to scalar and transverse vector external fields, the author obtains lineari…
This paper investigates short range intermolecular forces in oxygen and nitrogen systems using elastic scattering of fast neutral molecular beams in oxygen, nitrogen, and argon. From the energy dependence of total effective scattering cross sections at 0.6 to 4 keV, the authors derive parameters for…
The study investigates damage produced by ordinary and giant laser pulses in transparent dielectrics, including alkali halide single crystals, polymethyl methacrylate, and glasses. Experiments varied pulse energy, focal position, temperature, and lens focal length, showing that damage morphology dep…
This paper derives Einstein’s gravitational equations from a flat space field-theoretic treatment of an interacting symmetric tensor field. Starting with a massive tensor field subject to a Hilbert-Lorentz type supplementary condition and then taking the massless limit, the authors require minimal i…
This paper examines how melting in a shock wave affects the shock adiabat of lead, a substance that expands on heating, and argues that the two-phase and liquid portions of the adiabat should deviate toward larger specific volume. The authors combine thermodynamic considerations with plane-impact ex…
This paper reports measurements of penetrating radiation made by the Luna-9 station during its flight to the Moon and after its soft landing in Oceanus Procellarum. Using an SBM-10 gas-discharge counter shielded by approximately 1 g/cm2 of aluminum, the authors compare counting rates in interplaneta…
This note analyzes pseudoscalar meson photoproduction on nucleons in a p state under absorption of magnetic dipole gamma quanta within SU(6) symmetry. Using SU(6) tensor methods for baryons, mesons, the photon operator, and an angular spurion, the authors count the invariant structures in the releva…
This note studies centrally symmetric self-similar motion of a relativistic gas in comoving coordinates, motivated by late-stage stellar collapse. Using Podurets’s reformulation of the Einstein equations in terms of the enclosed gas mass, the author reduces the field equations to ordinary differenti…
This paper examines the reconstruction of images of transparent and refracting objects using phase holograms, with attention to the improved brightness and contrast obtainable relative to amplitude phase holograms. The authors describe a transmission holography arrangement using a helium neon laser,…
This paper proposes a structural interpretation of electrooptic and thermooptic effects in triglycine sulfate type ferroelectric crystals, emphasizing the role of distorted sulfate or selenate tetrahedral ions in addition to nitrogen displacement in glycine groups. The authors argue that changes in …
The paper studies the energy spectrum and density of states of an electron in a one-dimensional periodic lattice containing randomly distributed delta-function defects, with particular attention to behavior near band edges where perturbation expansions fail. By reducing the phase recurrence for Bloc…
This paper analyzes how the absorption coefficient of the 1s band in single crystals depends on the polarization and orientation of x-ray radiation, using the quasi-atomic character of 1s states and crystal symmetry. General expressions are derived for polarized and unpolarized radiation, including …
The paper addresses the formulation of Dirac-type equations for spinor fields in a curved Riemannian space-time without relying on the Fock-Ivanenko tetrad formalism, whose tetrads are not uniquely fixed by the metric. Starting from the mass-shell relation in a gravitational field, the authors deriv…
This paper examines the relation between electrical energy release and hydrodynamic behavior in moderate current discharges in water, where magnetic forces and strongly supersonic channel expansion can be neglected. Using an approximate energy balance for the discharge channel, an acoustic treatment…
This paper analyzes the motion of a neutral Dirac fermion with an anomalous magnetic moment in a static electric field directed along the z axis. By using commuting momentum operators and a polarization tensor operator to classify spin states, the Dirac equation is reduced to coupled equations for t…
This paper develops an exact treatment for a class of nonstationary Schrödinger equations in which the time-dependent perturbation is a rank-one projection operator with a coefficient linear, or in a related case linear-fractional, in time. Using a Laplace-transform type contour integral representat…
The paper studies the first Born correction for the Helmholtz-type equation with an incident plane wave, focusing on its dependence on the potential and on the wave number as the latter tends to infinity. By rewriting the correction as a Fourier-type integral whose kernel is an integral of the poten…
The paper studies the construction of wave-field equations covariant under the n-dimensional real unimodular group, motivated by attempts to combine Lorentz and isotopic symmetries and by applications to SU(n) symmetry. It derives covariance conditions for first- and second-order matrix differential…
This paper examines recombination in CdS and argues that carrier capture at a single sensitizing recombination center can proceed through two parallel mechanisms rather than through distinct centers. Using kinetic measurements of infrared photocurrent quenching at 1.4 and 0.9 eV in CdS single crysta…
This paper analyzes the nonlinear quasiclassical equations describing the interaction of an electromagnetic field with a two-level medium, neglecting relaxation effects and avoiding preliminary linearization. Using conservation relations for probability and total matter-field energy, the authors red…
This paper studies the energy spectrum of stochastic gravity waves on the surface of an infinitely deep liquid in the weakly nonlinear equilibrium range. Starting from the hydrodynamic equations for the surface displacement and velocity potential, the authors transform to Fourier wave variables and …
This paper reports systematic optical measurements of excitation cross sections for lower helium levels produced by collisions with slow electrons. Using a stationarity relation between level populations, radiative transition probabilities, and measured spectral line intensities, the author derives …
This paper reports measurements of the angular distribution of fission fragments produced when Am-241 is fissioned by neutrons, motivated by comparison with the previously studied odd-odd compound nucleus Np-238. Using an electrostatic accelerator neutron source and glass fragment detectors position…
This paper analyzes positron beta decay in neutron-deficient nuclei as a basis for predicting delayed proton emission and identifying proton emitters. Using charge invariance, mirror-nucleus relations, Coulomb-energy estimates, and excitation energies of isobaric analogue states, it derives constrai…
The paper analyzes how the shape and propagation velocity of a light pulse change during nonlinear amplification in an active medium when the pulse duration exceeds the transverse relaxation time. Using rate equations for intensity, population inversion, and phase, the authors derive an expression f…
The study measures the total cross section of photoneutron reactions on the calcium-40 nucleus from the neutron-emission threshold at 15.62 MeV to 50 MeV. Photoneutron yields were obtained with bremsstrahlung radiation from a synchrotron using slowed-neutron counting with BF3 counters, and different…
This paper examines light absorption and dispersion associated with molecular exciton formation in three-dimensional molecular crystals, including the effects of both acoustic and optical phonons. Using temperature Green’s functions, the authors formulate the exciton mass operator and relate its rea…
This paper examines radiation transfer in plasma, emphasizing the difference between resonance line radiation and recombination or bremsstrahlung radiation under complete frequency redistribution. Using an integral formulation with a frequency-dependent emission profile and absorption coefficient, t…
This paper presents the design and testing of a gamma radiation quantometer intended to determine beam intensity by automatically integrating the depth dose, or transition, curve in an absorber. The authors argue that replacing Simpson-type integration used in earlier Wilson quantometers with a six-…
This paper develops a phenomenological symmetry method for determining the complete symmetry of stable ordered phases, focusing on ordinary superstructures whose translational periods do not vary within a single phase region. For binary substitutional solutions on Bravais lattices, the concentration…
The paper develops a variational formulation for a relativistic continuous medium in a four-dimensional Riemannian space whose state includes spinor and vector characteristics, with coupling to gravitational and electromagnetic fields. It first defines covariant differentiation and parallel transpor…
