Showing 50 of 25456 papers

Photoproduction of $\pi^0$ mesons on complex nuclei

A. S. BELOUSOV, E. I. TAMM, and E. V. SHITOV
1957 SovietRxiv: ru-195701.43893

This paper investigates whether neutral pion photoproduction in complex nuclei occurs throughout the nuclear volume or primarily at the surface. Using bremsstrahlung from a synchrotron at maximum energies of 265 and 200 MeV, the authors measured the yield of decay gamma rays from neutral pions produ…

Entropy of Stochastic Processes

M. ROSENBLATT-ROT
1957 SovietRxiv: ru-195701.43882

This paper develops an entropy theory for stochastic processes with general, possibly nonstationary state spaces and densities relative to product measures. It defines time-dependent process entropy, relates its existence to Cesàro summability of conditional entropies, and gives conditions under whi…

Difference Schemes for Multidimensional Problems

K. A. Bagrinovskii and S. K. Godunov
1957 SovietRxiv: ru-195701.43571

This note proposes a method for constructing stable finite difference schemes for Cauchy problems for multidimensional hyperbolic systems by composing schemes for associated one-dimensional subsystems. The authors define a common weighted norm and show that if each one-dimensional scheme is locally …

INVESTIGATION OF THE HYDROGEN BOND BY SPECTROSCOPIC METHODS

V. I. Malyshev
1957 SovietRxiv: ru-195701.43506

This article aims to provide an overview of the principal works carried out by G. S. Landsberg, his students, and collaborators in the study of intermolecular interactions by spectroscopic methods, without, however, claiming to cover all the issues addressed comprehensively or to systematize the ent…

Reduction of Monoolefinic Hydrocarbons with Alkali Metals in Liquid Ammonia

I. V. GOSTUNSKAYA, M. I. ROZHKOVA, and B. A. KAZANSKII
1957 SovietRxiv: ru-195701.43133

This study examines the reduction of aliphatic monoolefins by alkali metals in liquid ammonia in the presence of alcohol proton donors, addressing whether isolated olefinic double bonds can be reduced under these conditions. Normal alpha olefins from pentene-1 to decene-1, as well as heptene-3 and o…

ON THE PROPERTIES OF SOME \(\delta s\)-OPERATIONS

Unknown
1957 SovietRxiv: ru-195701.43025

This note studies descriptive set theoretic properties of several derived delta s operations with rigid bases, focusing on points classified by the number and topological structure of chains in a reduced base that determine them. It defines first, second, third, and fourth type points, using uncount…

A Local Theorem for Lattice Distributions

V. V. PETROV
1957 SovietRxiv: ru-195701.42564

This note proves a refined local limit theorem for sums of independent, non-identically distributed integer-valued random variables. Assuming finite absolute moments of order 2 plus delta, a Lyapunov-type fraction, and an aperiodicity condition expressed through the lattice probabilities, it establi…

Cross Section for Inelastic Interactions of Protons with Kinetic Energies above 7 BeV with Carbon Nuclei

Unknown
1957 SovietRxiv: ru-195701.42204

This paper reports a stratospheric cosmic-ray measurement of the inelastic interaction cross section of protons with kinetic energies above about 7 BeV, with carbon nuclei. Using a counter telescope with graphite and lead absorbers, the authors determine the cross section by two approaches: attenuat…

Thermoelectric Properties of Chromium Silicides

Unknown
1957 SovietRxiv: ru-195701.42065

This study examines the electrical conductivity and thermoelectric behavior of chromium silicides and silicon-rich chromium alloys in order to assess their possible semiconductor properties. Alloys were prepared from refined chromium and silicon, annealed, and characterized by X-ray diffraction and …

Superequivalent Adsorption of Cations on a Negatively Charged Mercury Surface

A. N. FRUMKIN, B. B. DAMASKIN, and N. V. NIKOLAEVA-FEDOROVICH
1957 SovietRxiv: ru-195701.41872

This paper examines whether inorganic and organic cations can undergo specific, superequivalent adsorption on a negatively charged mercury surface, contrary to the usual electrocapillary assumption that only anions are specifically adsorbed. Differential capacitance measurements were made with a han…

ANODIC DISSOLUTION OF THORIUM IN SALT MELTS

Unknown
1957 SovietRxiv: ru-195701.41816

This study examines the anodic dissolution of metallic thorium in molten alkali-metal chlorides, a process relevant to the electrochemistry of molten salts. Polarization measurements were made for a thorium anode in an equimolar sodium chloride and potassium chloride melt at 710 and 815 degrees Cels…

ON THE THEORY OF THE PHOTOELECTRIC FLUXMETER

Unknown
1957 SovietRxiv: ru-195701.41815

This paper develops a unified control-theoretic account of photoelectric fluxmeters, treating them as closed-loop systems analogous to operational amplifiers with negative feedback through a differentiating element. Using operational calculus, it derives transfer functions for the galvanometer, phot…

Excitation of hypersonic-frequency oscillations in quartz

Unknown
1957 SovietRxiv: ru-195701.41764

A method is presented for exciting hypersonic oscillations in quartz by applying ultra-high-frequency resonance techniques rather than relying on very thin piezoelectric plates. Thick X-cut quartz plates were placed in coaxial lines or resonators driven by continuous generators tunable from 10^8 to …

On Conditions Necessary and Sufficient for the Complete Approximate Solvability of Equations of a Very General Nature

Unknown
1957 SovietRxiv: ru-195701.41746

This paper gives necessary and sufficient conditions for the complete approximative solvability of broad classes of equations when both operators and right hand sides are approximated. It shows that, for sequences of linear mappings converging uniformly, all solutions of a limiting equation can be a…

Production of xylenes by dealkylation and coupled alkylation of aromatic hydrocarbons in the presence of synthetic aluminosilicates

Unknown
1957 SovietRxiv: ru-195701.41477

This paper investigates the conversion of polyalkylaromatic coke-oven solvent, mixed with toluene, into xylenes and other low-molecular aromatic hydrocarbons over synthetic aluminosilicate catalysts. Experiments in flow reactors examined the effects of temperature, pressure, feed rate, and reaction …

ON A MEASURE OF HAUSDORFF TYPE

Unknown
1957 SovietRxiv: ru-195701.41443

This paper studies measures of Hausdorff type on metric spaces with a countable base, defined from countable Vitali covering systems with prescribed elementary measures. It proves that such measures have the F-property for analytic sets: finite-measure analytic sets contain closed subsets with measu…

Alkylation of $\alpha$- and $\beta$-naphthols with acetylene

V. L. VAISER
1957 SovietRxiv: ru-195701.41275

This study examines the alkylation of alpha and beta naphthols with acetylene in alcoholic solution using a phosphoric acid, boron trifluoride catalyst system with mercuric oxide. Experiments on beta naphthol varied catalyst concentration, temperature, solvent, acetylene flow, and reaction time, ide…

Kinetics of the Formation of Alcohol and Alkyl Acid in the Reaction of Propylene with Aqueous Sulfuric Acid

Unknown
1957 SovietRxiv: ru-195701.41234

The study examines the kinetics of propylene absorption by 67 percent aqueous sulfuric acid under conditions intended to minimize diffusion limitations. Experiments measured pressure decrease and product formation over a range of temperatures, with analyses of isopropyl alcohol and isopropyl hydroge…

ON FUNCTIONALS IN THE SPACES \(C_{s_1\ldots s_n}\) AND \(L^p_{s_1\ldots s_n}\), ANNIHILATING ON GENERALIZED POLYNOMIALS OF MANY VARIABLES

Unknown
1957 SovietRxiv: ru-195701.41213

This note studies linear functionals on the spaces of multivariable functions \(C_{s_1\ldots s_n}\) and \(L^p_{s_1\ldots s_n}\) that vanish on systems of generalized polynomials defined by prescribed one-variable function systems with nonzero Wronskians. It extends earlier representation results for…

On the Possibility of Complete X-ray Diffraction Dispersion Analysis of Graphite Powders and Colloidal Preparations

L. A. FEIGIN and V. N. ROZHANSKII
1957 SovietRxiv: ru-195701.41114

This paper examines whether complete particle size distribution analysis can be obtained from X-ray diffraction line profiles for highly dispersed graphite powders and colloidal preparations produced by vibratory grinding. Using harmonic analysis of diffraction line shapes, corrected by Stokes’ meth…

DEHYDROABIETIC AND PALUSTRIC ACIDS—CONSTITUENTS OF THE OLEORESIN OF NORWAY SPRUCE (*PICEA EXCELSA* LINK.)

Unknown
1957 SovietRxiv: ru-195701.40996

This study examines the acidic fraction of oleoresin from Norway spruce and reports the identification of dehydroabietic and palustric acids as additional constituents. Resin acids obtained from freshly tapped spruce oleoresin were separated through alkaline extraction, regeneration, reaction with m…

Inverse Theorems of the Constructive Theory of Functions Defined on a Finite Interval of the Real Axis

Unknown
1957 SovietRxiv: ru-195701.40967

This paper proves inverse theorems for polynomial approximation of functions on a finite interval, addressing the fact that classical Jackson type direct theorems do not have complete converses in this setting. Building on a strengthened Jackson estimate that improves approximation near the endpoint…

Kinetics of Hydrogen Peroxide Decomposition under Gamma Radiation

V. Ya. CHERNYKH, S. Ya. PSHEZHETSKII, and G. S. TYURIKOV
1957 SovietRxiv: ru-195701.40565

The study examines the kinetics of hydrogen peroxide decomposition in aqueous solutions over a broad concentration range, from 2 to 92 mole percent, under gamma irradiation, with comparison to thermal and ultraviolet initiated decomposition. Reaction rates were measured volumetrically by oxygen evol…

Direct Method in the Cauchy Problem for a Quasilinear Hyperbolic Equation in the Case of Two Independent Variables

G. GUSSI, V. POENARU, and K. FOIAȘ
1957 SovietRxiv: ru-195701.40412

This note studies the Cauchy problem for a quasilinear hyperbolic equation in two independent variables by replacing the classical wave operator with Böğel’s generalized hyperbolic operator. Using normal families and an analogue of Peano’s method, in the style of Montel’s treatment of the Goursat pr…

On Paleomagnetism as the Basis of a New Method for Correlation and Subdivision of Sedimentary Sequences

Unknown
1957 SovietRxiv: ru-195701.40407

This paper evaluates paleomagnetism as a method for correlating and subdividing sedimentary sequences, using oriented samples from Pliocene deposits in Western Turkmenia. Measurements of natural remanent magnetization and magnetic susceptibility in red-bed and related sections show stratigraphically…

Effect of Degree of Deformation on Ozone Cracking of Rubbers

Yu. S. ZUEV and S. I. PRAVEDNIKOVA
1957 SovietRxiv: ru-195701.40341

This study examines how the degree of deformation affects ozone cracking in vulcanized rubbers, addressing contradictory earlier reports on critical deformation. Using an objective method based on effective crack depth calculated from stress relaxation during ozonation, the authors compare natural r…

Synthesis of Some Carbon-Carbon Derivatives of Carbohydrates

Yu. A. ZHDANOV, G. N. DOROFEENKO, and L. E. ZHIVOGLAZOVA
1957 SovietRxiv: ru-195701.40127

This paper extends an organomagnesium approach to the synthesis of carbon to carbon derivatives of carbohydrates, using acetochloromonoses prepared from acetylated sugars as starting materials. The authors report preparations of new aryl and allyl acetylated derivatives of galactose, xylose, and ara…

Recrystallization Diagram of Molybdenum

Unknown
1957 SovietRxiv: ru-195701.40012

This study constructs a recrystallization diagram for first-grade molybdenum in order to relate grain size to cold deformation and annealing temperature, a relationship important for improving ductility through control of microstructure. Vacuum arc-cast, carbon-deoxidized molybdenum was forged, anne…

PROPAGATION OF A HEAT WAVE CLOSE TO SPHERICAL

Unknown
1957 SovietRxiv: ru-195701.39733

The paper analyzes the propagation of a heat wave whose shape is close to spherical in a medium with thermal conductivity depending as a power of temperature and with density differing slightly from a constant. Starting from the nonlinear heat equation in spherical coordinates and the known self-sim…

ON THE CONVERSION OF LEVOGLUCOSAN INTO AROMATIC COMPOUNDS

[Reaction scheme shown on the page.]
1957 SovietRxiv: ru-195701.39486

This study examines the conversion of trimethyllevoglucosan, prepared from levoglucosan obtained by vacuum dry distillation of starch, into aromatic products under the action of metallic sodium in liquid ammonia. By modifying reaction handling and product isolation, the authors increased the phenol …

On the Issue of Graphitization of Carbonaceous Substances

A. M. ZUBKO and E. Z. SPEKTOR
1957 SovietRxiv: ru-195701.39451

This paper examines narrow X-ray diffraction lines observed in cokes and other carbonaceous substances calcined at 1700 to 1800 degrees, lines that had sometimes been attributed to a special graphite modification or to the onset of graphitization. Comparing line positions with graphite spacings and …

Flow of Gas at the Speed of Sound Past Ellipses

Unknown
1957 SovietRxiv: ru-195701.39442

This paper applies Dorodnitsyn’s approximate numerical method for reducing two-dimensional nonlinear gas-dynamic problems to ordinary differential equations to the flow of a sonic gas stream past ellipses. The mixed potential motion upstream of the boundary characteristics is formulated in elliptic …