Showing 50 of 25456 papers

On the Photoluminescence of Thallium Chloride

A. S. VYSOCHANSKII
1957 SovietRxiv: ru-195701.51496

This study examines the photoluminescence of thallium chloride in relation to its absorption, excitation, emission spectra, and temperature behavior. Using thin evaporated layers and several forms of TlCl phosphors, the work identifies absorption bands near 3520 and 3800 Å that increase after ultrav…

On a Difference Method for Solving a Nonlinear Goursat Problem

B. M. BUDAK and A. D. GORBUNOV
1957 SovietRxiv: ru-195701.51373

This note studies a finite difference method for the nonlinear Goursat problem \(u_{xy}=f(x,y,u,u_x,u_y)\) with prescribed data on the coordinate axes, allowing a general right hand side under continuity and Lipschitz assumptions. The authors construct a bilinear interpolating approximate solution f…

Adsorption of Vapors on the Surface of Gold

Unknown
1957 SovietRxiv: ru-195701.51222

This study investigates adsorption of water vapor on high purity gold foil using modified high sensitivity adsorption balances and pressure measurement systems designed for very small mass changes. After vacuum heat treatment of the gold, water vapor adsorption at 18°C showed an initial rapid uptake…

On the Preparation of Trivalent Neptunium

Unknown
1957 SovietRxiv: ru-195701.51200

This study examines a chemical method for preparing trivalent neptunium, a state that is difficult to obtain and preserve because of rapid oxidation in solution. Neptunium(IV) solutions in nitric and hydrochloric acid were treated with rongalite, and the resulting valence states were identified spec…

Reductive dimerization of derivatives of $\alpha$ , $\beta$-unsaturated acids

I. L. Knunyants and N. S. Vyazankin
1957 SovietRxiv: ru-195701.51142

This study examines the reductive dimerization of derivatives of alpha,beta-unsaturated acids using alkali metal and aluminum amalgams under comparable conditions. By reducing a range of esters, nitriles, amides, and related compounds, the authors assess how conjugation, steric effects, substituent …

Absorption of Light by CdS Crystals*

Unknown
1957 SovietRxiv: ru-195701.50946

The paper investigates narrow absorption bands near the absorption edge of hexagonal CdS single crystals at 20.4 K, using polarized-light microspectroscopy on crystals of different thickness, preparation, and local quality. The authors compare spectra from different specimens and from small regions …

Passage of Ions of Various Gases Through Thin Silver Foil

V. G. Tel’kovskii and V. I. Pistunovich
1957 SovietRxiv: ru-195701.50712

This paper investigates the transmission of intermediate energy ions through very thin silver foils, a range for which data beyond protons had been lacking. The authors describe a method for preparing homogeneous fine crystalline silver foils about 40 to 60 millimicrons thick, then measure energy an…

On the Influence of Features of Intermolecular Interaction on the Regularities of Deuterium Exchange

Unknown
1957 SovietRxiv: ru-195701.50699

This study examines how specific intermolecular interactions between solutes and solvents affect deuterium exchange in hydrocarbons, ketones, and methylated nitrogen heterocycles. Rate measurements in deuterated ethanol, liquid ammonia, and alcoholate solutions show that hydrocarbons and ketones exc…

STUDY OF THE MECHANICAL PROPERTIES OF THIN LIQUID LAYERS IN CONCENTRATED EMULSIONS BY THE FILTRATION METHOD

Unknown
1957 SovietRxiv: ru-195701.50632

This study investigates the mechanical properties of very thin aqueous layers separating droplets or solidified particles in highly concentrated benzene, water emulsions stabilized with saponin. Using the emulsion as a narrow-pore filtration viscometer, the authors estimate layer thickness from micr…

On Frommer's Method for Studying a Singular Point

Let us consider the differential equation
1957 SovietRxiv: ru-195701.50218

This paper develops Frommer’s method for studying characteristics of analytic differential equations near a singular point when possible real tangents occur. It defines the order and measure of curvature of characteristics entering the origin, introduces a polygonal diagram constructed from exponent…

REDUCTION OF AN EVOLUTIONARY SYSTEM OF LINEAR PARTIAL DIFFERENTIAL EQUATIONS WITH CONSTANT COEFFICIENTS TO ONE EQUATION

A system of differential equations in partial derivatives with constant coefficients of the form
1957 SovietRxiv: ru-195701.50142

The paper studies evolutionary systems of linear partial differential equations with constant coefficients and shows how such systems can be transformed into scalar equations or independently integrated subsystems. Using invariant factors and polynomial similarity transformations of the coefficient …

An asymptotic solution of equations for one-dimensional unsteady motion of ideal gas with cylindrical symmetry

G. M. SHEFTER
1957 SovietRxiv: ru-195701.49945

This paper derives an asymptotic solution for one-dimensional unsteady motion of an ideal gas with cylindrical symmetry, extending characteristic-variable methods previously applied to shock-wave attenuation. The solution represents direct and reflected waves, together with their interaction, as ser…

Natural contour of energy levels

Unknown
1957 SovietRxiv: ru-195701.49909

The paper examines the natural broadening of atomic energy levels associated with the interaction of an atom and the electromagnetic field, a question usually inferred from spectral line broadening rather than treated directly. Using the stationary Schrödinger equation for a two-level atom coupled t…

Study of explosive showers formed by high-energy cosmic particles

V. V. ALPERS, I. I. GUREVICH, V. M. KUTUKOVA, A. P. MISHAKOVA,
1957 SovietRxiv: ru-195701.49879

This paper reports preliminary observations of explosive showers produced by high energy cosmic particles using a nuclear emulsion chamber exposed for seven hours in the stratosphere at 27 km. From systematic examination of the emulsion, the authors identified 29 explosive showers, determined primar…

On Finding Time Correlation Functions for Statistical Systems with Long-Range Interactions at Times up to the Mean Free Time

V. V. TOLMACHEV
1957 SovietRxiv: ru-195701.49701

This paper develops a method for determining time correlation functions in statistical systems with long range interactions, focusing on a plasma in statistical equilibrium without external fields and on times shorter than the mean free time. Starting from a hierarchy of equations for symmetric dist…

On the possibility of catalytic dehydrogenation of silicon hydrocarbons

B. N. DOLGOV, G. V. GOLODNIKOV, and K. G. GOLODOVA
1957 SovietRxiv: ru-195701.49501

This paper examines whether silicon paraffins can undergo catalytic dehydrogenation, using trimethylbutylsilane as a test substrate after earlier work found no dehydrogenation of tetraethylsilane under selected conditions. Experiments over a selected stable catalyst at space velocity 30 showed forma…

Calculation of the Heat and Entropy of Adsorption from a Single Adsorption Isotherm

B. P. BERING and V. V. SERPINSKII
1957 SovietRxiv: ru-195701.49363

This paper examines conditions under which the differential heat and entropy of adsorption can be calculated from a single adsorption isotherm, rather than from calorimetry or temperature-dependent isosteres. Using Polanyi’s adsorption potential condition and thermodynamic relations including the Cl…

On Boundary Value Problems for Eigenvalues and Eigenfunctions for Ordinary Differential Equations Containing a Small Parameter in the Highest Derivative

Unknown
1957 SovietRxiv: ru-195701.49233

This note studies boundary value problems for eigenvalues and eigenfunctions of even order ordinary differential equations in which a small positive parameter multiplies the highest derivative. Using asymptotic representations of fundamental solutions, including boundary layer terms, it derives expa…

Catalytic Dehydrogenation of Isopentane

B. A. Kazanskii, M. N. Marushkin, O. D. Sterligov, and A. P. Belenkaya
1957 SovietRxiv: ru-195701.49013

This study examines catalytic dehydrogenation of isopentane to isoamylenes as a possible route toward isoprene production for synthetic rubber. Experiments were carried out in a flow apparatus using a potassium-promoted alumina, chromia catalyst, with variation of temperature, space velocity, contac…

ON THE SOLUTION OF THE BIHARMONIC PROBLEM

Unknown
1957 SovietRxiv: ru-195701.49010

The paper studies the biharmonic Dirichlet type problem in the unit disk with prescribed boundary values for the function and its radial derivative, relating Sobolev regularity of the solution to Nikol’skii type smoothness classes of the boundary data. Using Fourier expansions of biharmonic function…

Kinetics and Sequence of Hydrogenation of Bonds in Peroxide Compounds on a Nickel Catalyst

A. A. BALANDIN, N. V. NIKIFOROVA, and L. Kh. FREIDLIN
1957 SovietRxiv: ru-195701.48761

This study examines the kinetics and order of hydrogenation of peroxide compounds containing additional functional groups on a skeletal nickel catalyst. Using multiplet theory and bond energy calculations, the authors predict the relative ease of hydrogenation for nitro, peroxide, acetylenic, and et…

Dependence of relative heat resistance on composition in the $\mathrm{Cu}$ – $\mathrm{Ni}$ – $\mathrm{Si}$ system

Unknown
1957 SovietRxiv: ru-195701.48726

This study examines how relative high-temperature strength depends on composition in the Cu-Ni-Si ternary system, focusing on the role of phases coexisting with the copper-based solid solution. Binary Cu-Ni and Cu-Si alloys and ternary alloys along six radial sections were tested by long-time hardne…

Alkylation of Isopentane with Propylene and Isobutylene in the Presence of a Series of Phosphoric Acids Containing Fluorine and Boron Fluoride

A. V. TOPCHIEV and V. N. ANDRONOV
1957 SovietRxiv: ru-195701.48538

This study examines the catalytic alkylation of isopentane with propylene and isobutylene using monofluorophosphoric, difluorophosphoric, and orthophosphoric acids saturated with boron fluoride. Experiments compared catalyst operating life, alkylate yield, fractional composition, unsaturation, and p…

Surface phenomena in ternary metallic solutions $\mathrm{Hg}$ – $\mathrm{Cd}$ – $\mathrm{K}$, $\mathrm{Hg}$ – $\mathrm{Cd}$ – $\mathrm{Cs}$ at $22^\circ$

Unknown
1957 SovietRxiv: ru-195701.48519

This paper examines surface phenomena in ternary metallic solutions of Hg-Cd-K and Hg-Cd-Cs at 22 degrees, focusing on concentration buffering when cadmium and alkali-metal additives have opposite effects on mercury surface tension. Surface-tension measurements for 135 Hg-Cd-Cs solutions are compare…

Cross Section of Inelastic Proton-Proton Interaction at Proton Energies Above 7 BeV

K. I. ALEKSEEVA and N. L. GRIGOROV
1957 SovietRxiv: ru-195701.48413

This paper reports stratospheric measurements of the inelastic proton-proton interaction cross section for cosmic-ray protons with mean energy about 20 BeV. The experiment compared interactions in paraffin and graphite filters using counter telescopes and hodoscopic recording, applying two approache…