Showing 50 of 25357 papers

Transition from metal hydrides to $\pi$-allyl complexes and initiation of stereospecific butadiene polymerization

Unknown
1965 SovietRxiv: ru-196501.30490

This paper examines how nickel hydrides can initiate stereospecific polymerization of butadiene and proposes their conversion into soluble pi-allyl, specifically crotyl, nickel complexes as a key stage in active-center formation. Nickel hydrides prepared from anhydrous nickel chloride, ethylmagnesiu…

Study of Ambiguity in Determining Seismic Wave Propagation Velocity from the Hodograph

M. L. GERVER, V. M. MARKUSHEVICH
1965 SovietRxiv: ru-196501.30481

This paper studies the inverse problem of determining a depth-dependent seismic wave velocity from a travel-time hodograph, using an idealized geometrical optics model reduced from a spherical Earth to a planar ray problem. The authors analyze the functions describing ray depth, horizontal distance,…

Stability of the grid method for elliptic problems

Unknown
1965 SovietRxiv: ru-196501.30479

This paper studies the stability of grid, or net, methods for elliptic boundary value problems under small perturbations of the discrete operator, rather than only perturbations of the right-hand side. Using a variational construction of the discrete Dirichlet problem, Friedrichs extension, and Kant…

Autoignition in Systems with Unbranched Chain Reactions

Unknown
1965 SovietRxiv: ru-196501.30303

This paper examines self-ignition in systems where unbranched chain reactions proceed under nonisothermal, adiabatic conditions, focusing on chain-thermal explosions rather than purely thermal or isothermal chain ignition. Using model halogenation schemes for hydrogen, especially hydrogen chlorine a…

On the Phase Equilibrium and Reduction Mechanism of Solid Solutions of Manganese Ferrite and Chromite

T. D. Takenov, V. F. Balakirev,
1965 SovietRxiv: ru-196501.30282

This study examines the hydrogen reduction at 1000 degrees C of manganese ferrochromite, MnCr0.25Fe1.75O4, and the phase equilibria of related MnCrxFe2-xO4 spinel solid solutions. Samples prepared by ceramic synthesis were analyzed by X-ray diffraction, gas phase equilibrium measurements, weight los…

On the computation of heat conduction and gas dynamics equations by the sweep method in separate regions

V. L. ZAGUSKIN, V. E. KONDRASHOV
1965 SovietRxiv: ru-196501.30161

The paper proposes a domain-splitting variant of the sweep method for implicit finite-difference solution of one-dimensional heat-conduction and gas-dynamics problems when a full multidimensional time layer cannot conveniently be held in operative memory. The method transmits different interface dat…

On a Nonlinear Free Boundary Problem

Unknown
1965 SovietRxiv: ru-196501.30098

The paper studies a nonlinear free boundary problem for a harmonic function in a doubly connected domain inside the unit disk, with prescribed constant boundary values and prescribed gradient magnitude on the unknown inner boundary. Using conformal mapping to an annulus, the problem is reformulated …

High-Temperature Isomeric Transformations in Polyimides

A. P. RUDAKOV, M. I. BESSONOV, Corresponding Member of the Academy of Sciences of the USSR M. M. KOTON,
1965 SovietRxiv: ru-196501.30081

This paper examines high-temperature transformations in polyimide films prepared from several tetracarboxylic dianhydrides and diamines through polyamic acid intermediates. By monitoring weight loss, dielectric loss, infrared spectra, and mechanical properties during staged heat treatment, the autho…

STRUCTURE OF LIGNAN GLYCOSIDES FROM THE ROOTS OF ACANTHOPANAX

L. A. Elyakova, A. K. Dzizenko, G. B. Elyakov
1965 SovietRxiv: ru-196501.30055

This study investigates the structures of two aromatic glycosides, acanthosides B and D, isolated from the roots of Acanthopanax sessiliflorum, a physiologically active plant of the Araliaceae family. Using elemental analysis, acetylation, acid, alkaline, and enzymatic hydrolysis, methylation, chrom…

STUDY OF THE MECHANISM OF THE INTERACTION OF CERTAIN AROMATIC DINITRO DERIVATIVES WITH ALKALI BY THE E.P.R. METHOD

B. I. Shapiro, V. M. Kazakova, Ya. K. Syrkin
1965 SovietRxiv: ru-196501.29844

The interaction of 4,4′-dinitrodiphenylmethane, 4,4′-dinitrodibenzyl, and trans-4,4′-dinitrostilbene with tetra-n-butylammonium hydroxide in dimethylformamide and acetonitrile was studied by electron paramagnetic resonance. The spectra and supporting low-potential electrolysis experiments indicate t…

THE CAUCHY PROBLEM FOR THE LINEARIZED BOLTZMANN EQUATION

Unknown
1965 SovietRxiv: ru-196501.29797

The paper formulates the Cauchy problem for the linearized Boltzmann equation in an \(L_2\) framework, using the Fourier transform in spatial variables and treating the resulting equation as an abstract Cauchy problem with a dissipative collision operator. Under stated spectral, compactness, and reg…

Coefficient-Free Equations in Free Groups

A. A. LORENTS
1965 SovietRxiv: ru-196501.29788

This note studies coefficient-free equations in free groups, defined as equations in which each unknown or its inverse occurs and no coefficients from the ambient group are used. It proves that every solution of a normal coefficient-free equation in n unknowns over a free group of rank at least n is…

On Lower Bounds for Entire Functions of Finite Order and on the Convergence of Dirichlet Polynomials

I. F. Krasichkov
1965 SovietRxiv: ru-196501.29710

This paper studies lower estimates for entire functions of refined finite order whose zeros lie in an angle and approach the positive real axis. It gives a necessary and sufficient condition, expressed through an averaged local counting function for zeros, for the normalized lower limit of the logar…

On the Nature of Changes in the Vibrational Frequencies of $\mathrm{SCN}$ and $\mathrm{SeCN}$ Groups upon Coordination

M. A. Porai-Koshits
1965 SovietRxiv: ru-196501.29593

This paper examines why the stretching vibrational frequencies of thiocyanate and selenocyanate groups change when these ions form coordination bonds through nitrogen, through sulfur or selenium, or as bridging groups. Using approximate normal-coordinate calculations for linear and selected nonlinea…

INTEGRAL REPRESENTATION OF FUNCTIONS FORMING A MARKOV SYSTEM

M. A. Rutman
1965 SovietRxiv: ru-196501.29481

The paper studies finite and infinite Markov systems and their relation to Chebyshev systems, focusing on extension problems for such function systems and on continuation beyond an interval. It proves that, after suitable normalization and triangular linear transformation, every right-continuous Mar…

On the Solvability of General Mixed Problems in a Straight Cylinder for Analytic Hyperbolic Integro-Differential Equations

Z. O. MELNIK
1965 SovietRxiv: ru-196501.29465

The paper studies general mixed initial boundary value problems in a straight cylinder for multidimensional hyperbolic integro-differential equations of arbitrary order with analytic coefficients. It formulates a decomposition of the lateral boundary according to the signs of the characteristic root…

Application of Radioactive Sources of Characteristic Radiation for X-ray Structural Studies

S. I. Lobov, V. A. Tsukerman
1965 SovietRxiv: ru-196501.29463

This paper examines the use of radioactive isotopes emitting characteristic X-ray radiation, especially iron-55 and vanadium-49, as alternatives to conventional X-ray tubes in structural studies of crystals and polycrystalline materials. The authors estimate the source activity required for recordin…

Phragmén–Lindelöf Type Theorems for a Second-Order Linear Elliptic Equation

1°.** In this note we consider the uniformly elliptic linear equation of second order
1965 SovietRxiv: ru-196501.29109

This note studies Phragmen Lindelof type growth estimates and uniqueness classes for solutions of uniformly elliptic second order linear equations in unbounded domains, with zero boundary values. Replacing earlier volume based conditions by conditions expressed through capacity, it derives lower bou…

On Locally Finite Semigroups

The main result of the present note is the following.
1965 SovietRxiv: ru-196501.29087

This note proves that any bundle of locally finite semigroups is locally finite. The argument develops structural lemmas for commutative and matrix bundles, formulates closure conditions for abstract semigroup properties, and then verifies the needed conditions for local finiteness using results on …

SYNTHESIS OF HOMOLOGS OF 1,4-DIOXANE AND 1,4-DIOXENE

I. F. BEL’SKII, S. N. KHAR’KOV, Corresponding Member of the Academy of Sciences of the USSR N. I. SHUIKIN
1965 SovietRxiv: ru-196501.29024

This study examines catalytic routes to homologs of 1,4-dioxene and 1,4-dioxane, compounds for which earlier syntheses were limited or low yielding. Monofurfuryl ethers of 1,2-glycols were prepared and hydrogenated in the vapor phase over platinized carbon at 140, 180, and 220°C, with products ident…

ON A CLASS OF PARTITIONS OF LOBACHEVSKY SPACE

Unknown
1965 SovietRxiv: ru-196501.28920

The paper presents a geometric construction of infinitely many Fedorov groups in three-dimensional Lobachevsky space, avoiding the arithmetic methods commonly used for such examples. Starting from regular partitions of a Lobachevsky plane into regular n-gons with 3, 4, or 5 polygons at each vertex, …

On Lyapunov Theorems for Heat Potentials

Unknown
1965 SovietRxiv: ru-196501.28541

This note establishes Lyapunov type regularity theorems for heat potentials associated with time dependent surfaces in parabolic potential theory. It formulates anisotropic Hölder smoothness conditions on the boundary surface and on the density under which the heat potential of a simple layer, the h…

Conformal Mappings of a Multiply Connected Domain onto Multi-Sheeted Surfaces with Rectilinear Slits

Unknown
1965 SovietRxiv: ru-196501.28394

The paper studies extremal problems for conformal mappings of finitely connected planar domains onto multi-sheeted Riemann surfaces with rectilinear slits, allowing prescribed pole and logarithmic singularities. It constructs uniquely determined auxiliary functions satisfying mixed boundary conditio…

Asymptotic Behavior as $t\to\infty$ of the Solution of the Nonstationary Schrödinger Equation with a Non-Self-Adjoint Hamiltonian

I. V. STANKEVICH
1965 SovietRxiv: ru-196501.28356

The paper studies the large-time behavior of solutions to the nonstationary Schrödinger equation in a Hilbert space when the Hamiltonian is a non-self-adjoint perturbation of a self-adjoint operator. It introduces linear similarity to an unperturbed Hamiltonian and gives sufficient conditions, inclu…

Standard heats of formation of $\mathrm{ZrCl}_4$ and $\mathrm{HfCl}_4$

G. L. GAL’CHENKO, D. A. GËDAKYAN, B. I. TIMOFEEV, S. M. SKURATOV
1965 SovietRxiv: ru-196501.28310

This study determines standard heats of formation for crystalline zirconium tetrachloride and hafnium tetrachloride, thermodynamic quantities relevant to purification and separation of zirconium and hafnium metals. High purity iodide zirconium and hafnium samples were directly chlorinated at about 4…

Poincare Polynomials of Some Compact Homogeneous Spaces

Unknown
1965 SovietRxiv: ru-196501.28254

This paper studies Poincare polynomials of compact homogeneous spaces using invariant polynomial algebras of compact Lie groups and their Weyl groups. It first identifies generators for the invariant polynomial algebras of exceptional simple Lie algebras in terms of sums of powers of weights of the …

Corrections to the Article Keioside, a New Flavonoglycoside from the Far Eastern Lily of the Valley (Convallaria keiskei Miq.) (DAN, Vol. 158, No. 4, 1964)

Unknown
1965 SovietRxiv: ru-196501.28233

This paper concerns the evaluation of mexamine as a radioprotective agent within the field of biophysics. Based on the available translated text, the study is presented as an estimation of the compound’s protective efficiency against radiation, but no details of experimental design, measurements, or…

PHASE COMPOSITION OF AMORPHOUS FILMS OBTAINED BY VAPOR CONDENSATION DURING HEATING IN VACUUM OF A MIXTURE OF SILICON DIOXIDE AND SILICON

T. A. Fadeeva, Z. P. Pasheva
1965 SovietRxiv: ru-196501.28141

This study examines the phase composition of thin amorphous films formed by vacuum condensation of vapors produced from a heated mixture of silicon dioxide and silicon, materials commonly identified as silicon monoxide from their diffuse electron diffraction halo. Films 300 to 700 Å thick were prepa…

A New Route for the Synthesis of Furanosides. Synthesis of $3$ - $\mathrm{O}$ -( $\beta$ - $D$ -galactofuranosyl)- $D$ -mannitol

Corresponding Member of the Academy of Sciences of the USSR N. K. Kochetkov, A. Ya. Khorlin,
1965 SovietRxiv: ru-196501.28133

The paper addresses the limited availability of stereochemically defined O-furanosides and examines whether sugar orthoesters can serve as general glycosylating reagents for furanoside synthesis, as previously shown for pyranosides. As a test case, the authors prepare the previously unknown 3,5,6-tr…

On the Mechanism of Nitrogen Fixation in the Reacting System $(\mathrm{C}_5\mathrm{H}_5)_2\mathrm{TiCl}_2$ – $\mathrm{C}_2\mathrm{H}_5\mathrm{MgBr}$

Unknown
1965 SovietRxiv: ru-196501.28132

This study examines the mechanism of nitrogen fixation in the reacting system formed from biscyclopentadienyltitanium dichloride and ethylmagnesium bromide in ether. Using gas analysis, infrared spectroscopy, hydrolysis experiments, and deuterium labeling with deuterated ethylmagnesium bromide and e…

A Representation Theorem for a Class of Functions

Unknown
1965 SovietRxiv: ru-196501.28039

This paper introduces and studies a class of differentiable functions on n-dimensional Euclidean space whose generalized derivatives up to prescribed orders have finite mixed Lebesgue norms and whose higher derivatives satisfy mixed norm multiple Hölder conditions. It defines the space with a norm f…

On the Theory of the Current-Voltage Characteristic of a Thin-Film Field-Effect Triode

M. I. Elinson, V. B. Sandomirskiĭ
1965 SovietRxiv: ru-196501.28024

This paper develops a one-dimensional theory of the static current-voltage characteristic of a thin-film field-effect triode, emphasizing the role of deep, homogeneously distributed traps in the film. For an electron-enrichment regime with monoenergetic traps, the authors derive the carrier concentr…

Study of Free Radicals in Polyimides by EPR

A. G. Boldyrev, N. A. Adrova, M. I. Bessonov,
1965 SovietRxiv: ru-196501.27861

This study uses electron paramagnetic resonance to examine stable free radicals formed in polyimides during heating of polyamic acids and related model compounds. Three radical types are distinguished by their spectra, temperature ranges, concentrations, and stability: an initial broad singlet attri…

Mass Spectra of Some Monocyclopentadienyl Derivatives of Titanium

A. N. Nesmeyanov, V. A. Dubovitskii, O. V. Nogina, V. N. Bochkarev
1965 SovietRxiv: ru-196501.27825

This study examines the mass spectra of monocyclopentadienyl titanium derivatives of the series C5H5Ti(OC2H5)3-nCln, with n = 0, 1, 2, and 3, in relation to the character of the titanium to cyclopentadienyl bond. The spectra show molecular ions and characteristic fragment ions formed by loss of chlo…

Study of Beryllium Oxide Whisker Single Crystals Using an Ultrahigh-Voltage Electron Microscope

N. M. POPOV, D. B. SANDULOV
1965 SovietRxiv: ru-196501.27655

Filamentous single crystals of beryllium oxide were produced by high-temperature oxidation of metallic beryllium in argon and examined with a 400 kV ultra-high-voltage electron microscope. Electron diffraction confirmed BeO unit-cell parameters and showed that crystal diameters ranged from hundredth…

Protolysis of dibenzylmercury by the $S_E1$ mechanism

I. P. BELETSKAYA, L. A. FEDOROV, Academician O. A. REUTOV
1965 SovietRxiv: ru-196501.27524

This study examines the acid cleavage of dibenzylmercury by hydrogen chloride in several solvents as a possible example of electrophilic substitution at saturated carbon by a unimolecular mechanism. Kinetic measurements based on chloride ion consumption showed first-order behavior in dimethyl sulfox…

On the Absolute Convergence of Fourier Series

Unknown
1965 SovietRxiv: ru-196501.27402

This paper studies sufficient conditions for absolute convergence of Fourier series of periodic functions in terms of symmetric finite differences and related integral moduli of smoothness. It proves coefficient tail estimates for \(0<m\leq 2\), bounding sums of powers of Fourier coefficients by qua…