Recent Papers

Effect of $\gamma$ - and ultraviolet radiation on aqueous solutions of the triethylenediamine complex of cobalt(III)

This study examines the effects of gamma and ultraviolet irradiation on aqueous solutions of cobalt(III) tris(ethylenediamine) chloride and nitrate at several concentrations, doses, acidities, and gas saturation conditions. Changes were followed by absorption spectroscopy in the ultraviolet and visi…

On the Flow of a Nonequilibrium Gas

The paper examines gas flows with relaxation of low energy internal degrees of freedom or reactions, distinguishing weakly relaxing media from flows close to thermodynamic equilibrium. A small parameter expansion is formulated for weak relaxation and applied to vibrational relaxation, yielding first…

Study of the Structure of Polymeric Organotin Oxides $\mathrm{R}_2\mathrm{SnO}$ Using the Mössbauer Effect

Mössbauer spectra of a series of polymeric organotin oxides, R2SnO, were measured at liquid nitrogen temperature and compared with spectra of related organotin carboxylates, bis-alkyl-substituted tin oxides, and distannane derivatives. The observed chemical shifts and quadrupole splittings differ ma…

Effect of the Degree of Molecular Ordering of Crystallizing Polymers in the Melt on the Viscoelastic Properties of Melts

This study examines how secondary molecular ordering in crystallizing polymer melts affects viscoelastic behavior under high pressure, with emphasis on processes governed by chain mobility such as autohesion and crystallization. Polytetrafluoroethylene powders and granules were pressed at elevated t…

On Some Properties of the Discrete Spectrum of the Radial Schrödinger Equation

This paper studies the discrete spectrum of the radial Schrödinger equation with a Coulomb term and additional singular or integrable potentials. For a special rational power form of the potential, it derives an explicit representation of the coefficient function governing the asymptotics of the reg…

A New Spectroscopic Method for Studying the Anisotropy of Electronic Transitions in Polar Molecules

This paper proposes a spectroscopic method for determining the anisotropy and absolute polarization of electronic transitions in polar molecules without inducing optical anisotropy or performing polarization measurements. The approach relates solvent-dependent shifts in absorption and fluorescence s…

On the Question of Intramolecular Rearrangements

This paper develops a statistical vibrational treatment of intramolecular rearrangements, broadly defined as transformations of an isolated molecule into another molecule, isomer, conformation, or fragments. Assuming harmonic intramolecular vibrations in thermal equilibrium, it derives probability d…

Study of the extraction system $\mathrm{Th}(\mathrm{NO}_3)_4$ – $\mathrm{HNO}_3$ – $\mathrm{H}_2\mathrm{O}$ – $(\mathrm{C}_4\mathrm{H}_9\mathrm{O})_3\mathrm{PO}$ at $25^\circ$ C by the extraction ray method

The study examines the extraction system Th(NO3)4, HNO3, H2O, and tributyl phosphate at 25 °C using the method of extraction rays. Equilibrium aqueous and organic phase compositions, densities, solubility behavior, and distribution coefficients for thorium nitrate and nitric acid were measured acros…

Solvable Algebraic Groups

This paper studies solvable algebraic linear groups over fields of characteristic zero, with particular attention to the disconnected case where geometric methods are less effective. Using properties of unipotent algebraic groups, invariant unipotent subgroups, generalized tori, and conjugacy argume…

On the Role of the Triplet State of Aromatic Amines in the Photoreaction of Alcohol Dehydrogenation at $77^\circ$ K

This study examines the mechanism of ultraviolet photodehydrogenation of alcohols by aromatic amines at 77 K, using electron paramagnetic resonance to detect radicals formed in frozen methanol and ethanol solutions. Experiments with benzene and silica gel show evidence for hydrogen atoms abstracted …

Method for obtaining $\mathrm{N}$-substituted $\beta$-lactams

This paper examines whether the reaction previously observed between methacrylic acid derivatives and unsymmetrical dimethylhydrazine is general for anhydrides and acid chlorides of alpha,beta-unsaturated aliphatic acids. Reactions of acrylic and crotonic acid chlorides and crotonic anhydride with d…

Influence of Changes in the Parameters of Linear Gyroscopic Systems on Oscillation Frequencies and Damping Coefficients

This paper examines how changes in the parameters of linear gyroscopic systems affect characteristic roots, and hence oscillation frequencies and damping coefficients. Starting from the quadratic characteristic equation expressed through mass, damping, gyroscopic, stiffness, and nonconservative-forc…

Potentiometric Measurements in Various Media

The article addresses the difficulty of potentiometric measurements in poorly conducting or nonconducting media, especially during catalytic hydrogenation studies where conventional reference electrode arrangements require unstable electrolyte films or additives. It describes an electrode device con…

$(L_p,L_q)$-multipliers of Fourier integrals

The paper gives sufficient conditions for a function to be an \( (L_p,L_q) \)-multiplier of Fourier integrals in Euclidean space, extending earlier multiplier criteria of Marcinkiewicz and Mikhlin. The main theorem shows that if a multiplier candidate and its mixed first derivatives satisfy uniform …

Unified Methods of Information Transmission. General Case

This note extends uniform methods of information transmission to more general classes of sources and channels than the independent, discrete cases. It introduces systems of dependent message segments satisfying consistency and uniform strong mixing, and systems of channels without anticipation satis…

On Thermal Autoignition of a Homogeneous Gas Mixture in a Flow

This paper examines thermal self-ignition of a homogeneous combustible gas mixture in a laminar flow, with attention to gas-phase processes during combustion of condensed explosive systems. Using the assumptions of classical combustion theory, the authors formulate a stationary heat and reaction mod…

Kinetics of hydrolysis of $\delta$-valerolactam and the alkalinity function of aqueous solutions of $\mathrm{LiOH}$ , $\mathrm{NaOH}$ , $\mathrm{CsOH}$

This paper develops a kinetic approach to defining an alkalinity function for concentrated aqueous alkali solutions, where indicator methods are unsuitable. Using the alkaline hydrolysis of delta-valerolactam, the authors measured effective rate constants in LiOH, NaOH, and CsOH over specified conce…

Calculation of the Single-Stage Separation Factor for Some Chemical Exchange Reactions

This paper develops an approximate method for estimating single-stage isotope separation factors in chemical exchange reactions when full statistical calculations from spectroscopic data are impractical. Starting from the statistical thermodynamic expression for a simple exchange reaction, the autho…

Continuum as the Complete Limit Set of a Convergent Sequence of Analytic Functions

The paper studies boundary limit behavior of sequences of analytic functions in the unit disk, asking which plane continua can occur as complete limit sets. It proves that, for an arbitrary continuum satisfying the stated separation condition relative to a point w0, there exists a uniformly locally …

Effect of Mechanical Actions on the Crystallization Rate of Isotactic Polystyrene

This study examines how periodically applied mechanical forces affect crystallization and related thermomechanical properties in isotactic polystyrene. Amorphous pressed specimens were subjected either to thermal treatment or to sinusoidal vibrational compression at 100, 120, and 140°C, then analyze…

Free-radical isomerization of acetone diphenyl mercaptol

This paper investigates whether radicals in solution can undergo rearrangement with migration of an arylthio group, using acetone diphenylmercaptal as a substrate. Treatment of the mercaptal with tert-butyl peroxide in refluxing chlorobenzene produced 1,2-diphenylthiopropane, along with phenylisopro…

On a new criterion for the speciality of $\pi d$-groups with a prescribed number of classes of unattainable isoorder $\pi d$-subgroups

This paper studies finite pi d-groups in relation to the number r of classes of unattainable isoordinal pi d-subgroups and the number t of distinct prime pi-divisors of the group order. It gives simplified and strengthened proofs that such groups are solvable when r equals t minus 1, and also when r…

Finite-Amplitude Shear Waves in Polycrystals and Single Crystals of Metals

This paper reports experimental observations of nonlinear distortion in finite amplitude shear ultrasonic waves in polycrystalline metals and metal single crystals, detected through generation of a second harmonic. Using 5 MHz shear waves and resonant detection at 10 MHz, the authors examine magnesi…

In our paper (V. I. Arnold and Ya. G. Sinai, “On small perturbations of automorphisms of the torus”), published in *DAN*, vol. 144, no. 4, 1962, the smoothness of the curves considered in Theorem 1 is insufficient for applying Theorem 2 in the proof of Theorem 3. Theorem 3 itself, however, is valid, as follows from D. V. Anosov’s work “Roughness of geodesic flows on compact manifolds of negative curvature” (*DAN*, vol. 145, no. 4, 1962).

Correction to the article On One-Sided Boundary Value Problems in the Theory of Analytic Functions (DAN, Vol. 145, No. 2, 1962)

Dependence of the Intensity of Spectral Lines of Trace Elements in a Silicate System on Its Phase Diagram

This study examines how the intensity of spectral lines of trace elements in silicate matrices depends on the phase diagrams of binary oxide systems. Standards in the SiO2-Al2O3, SiO2-MgO, and Al2O3-MgO systems were prepared with added copper, silver, cobalt, and nickel, then evaporated from a carbo…

On the Refinement of the OIII Spectral Scheme Used in Calculating Its Recombination Spectrum in Stars and Nebulae

This note examines limitations of the assumption that all O III energy levels can be described by LS coupling in calculations of stellar and nebular recombination spectra. By analyzing observed intercombination lines, term overlaps, and alternative coupling schemes, the author argues that several le…

On the General Theory of Reduced Accelerations in Tangential Coordinates

This note develops a tangential-coordinate formulation for the general theory of reduced accelerations of arbitrary order in mechanisms undergoing spatial motion. Starting from vector equations for a moving plane and the locus of endpoints of higher-order acceleration vectors, the authors derive par…

Effect of Electron-Donor Additives on Chain Structure in the Stereospecific Polymerization of Butadiene

This study examines how electron donor additives affect the microstructure of polybutadiene formed by stereospecific polymerization of butadiene with a titanium tetraiodide and triisobutylaluminum catalytic system. Using dibutyl sulfide and triethylamine in benzene solution at 30°C, the authors comp…

Kinetic Stages of Ethylene Oxidation by Palladium Chloride in Aqueous Solutions

The paper examines the mechanism and kinetic stages of ethylene oxidation by palladium chloride in aqueous chloride solutions, with particular attention to the roles of chloride concentration, acidity, solvent isotope effects, and possible hydroxide participation. Kinetic measurements show first-ord…

Preparation of rhenium dichloromonoacetate and its derivatives with pyridine and thiourea

Rhenium dichloromonoacetate was prepared in crystalline form from reduced perrhenate solutions treated with glacial acetic acid and acetone, and its composition, oxidation state, water content, magnetic behavior, molecular weight, and thermal properties were examined. Analytical data, cryoscopic mol…

Paramagnetic component of the magnetic susceptibility of $\mathrm{A}^{\mathrm{III}}\mathrm{B}^{\mathrm{V}}$ semiconductor compounds according to X-ray diffraction analysis

This paper addresses the separation of paramagnetic and diamagnetic contributions to the magnetic susceptibility of sphalerite-type semiconducting AIIIBV compounds using X-ray diffraction data. The authors model the electron density of covalent sp3 bond bridges with a three-dimensional Gaussian func…

EPR study of the radical form of adsorption of molecular oxygen on reduced titanium dioxide

This study investigates the chemical nature of oxygen chemisorbed on partially reduced titanium dioxide using electron paramagnetic resonance. Anatase samples reduced by vacuum heating were exposed to oxygen at room temperature, and pressure dependent EPR spectra were compared with adsorption measur…

Study of Intermolecular Electron Transfer in Tetrapyrrole Pigments under Pulsed Illumination

This study examines primary photoreduction processes in tetrapyrrole pigments under powerful pulsed illumination, aiming to distinguish hydrogen atom transfer from intermolecular electron transfer. Using time-resolved absorption measurements on magnesium phthalocyanine and hematoporphyrin in several…

On the computation of the rotation of completely continuous vector fields associated with the problem of periodic solutions of differential equations

The paper studies the computation of the rotation of completely continuous vector fields arising from the search for periodic solutions of ordinary differential equations with periodic right-hand side. It relates the rotation of integral-operator fields in the space of continuous functions to the fi…

On the Participation of an Inhibitor in the Act of Degenerate Chain Branching

This study examines whether inhibitors can participate in degenerate chain branching during hydrocarbon oxidation, using isotactic polypropylene oxidized at 200° in the presence of alkylphenol inhibitors. A kinetic treatment relates the critical inhibitor concentration to the self-acceleration facto…

Extremal Problems for Surfaces of Bounded Gaussian Curvature

This paper studies extremal problems for closed convex hypersurfaces in Euclidean space under one-sided bounds on Gaussian curvature. Using Minkowski’s theorems for convex polyhedra, approximation by surface area measures, and Aleksandrov’s uniqueness theorem, it proves volume comparison results for…

Kinetics of Catalytic Deuterium Exchange Between Water Vapor and Hydrogen on Various Surfaces

The paper investigates the kinetics of catalytic deuterium exchange between water vapor and hydrogen for the reaction HDO with hydrogen forming HD and water. Experiments were conducted at atmospheric pressure in a flow circulation system on nickel, cobalt, palladium, copper, silver, and iron oxide c…

On a Problem in Value Distribution Theory

This paper addresses a problem in Nevanlinna value distribution theory concerning lower estimates for the ratio of the integrated counting functions of zeros and poles to the characteristic of a meromorphic function. Building on results of Nevanlinna and of Edrei and Fuchs, it proves that the lower …

On Instability Criteria for Shear Deformation Regimes in Viscoelastic Polymer Systems

The paper examines the onset of unstable shear deformation regimes in elastic-viscous polymer systems, particularly disturbances observed during polymer melt flow through capillaries. Using similarity theory applied first to Maxwell and related viscoelastic deformation models, the authors derive a s…

Hydrogenation of unsaturated compounds in buffer solutions

This study examines how buffer solution pH affects the liquid phase hydrogenation of several unsaturated compounds, including hexene-1, allyl and cinnamyl alcohols, dimethylethynylcarbinol, and phenylacetylene. Experiments were conducted on skeletal nickel, platinum black, and palladium on barium su…

Study of the Composition and Properties of Vanadyl Vanadates by Spectrophotometry

This study investigates the composition, stability, and charge of vanadylvanadate ions formed between tetravalent and pentavalent vanadium in aqueous solution over a range of pH values. Using spectrophotometry at constant ionic strength, supplemented by electromigration experiments, the authors meas…

Structure of Blood Group Substances. Proteolysis of Group Substance $\mathrm{A}$

This paper examines the structural organization of blood group substance A, with particular attention to the linkage between its carbohydrate and peptide components. The authors isolated a proteolytic enzyme from Asian influenza virus and used it to digest blood group substance A from pig stomach mu…

Wave Functions and Calculation of Matrix Elements for Longitudinally Polarized Vector Particles

The paper develops a covariant method for representing wave functions and calculating matrix elements for massive spin 1 vector particles, with particular attention to fixed longitudinal and transverse polarizations. Working in the 10 dimensional Duffin Kemmer beta formalism, it expresses spin proje…

$\mathrm{N}$-vinylthiopyrrolidone

The paper describes the synthesis and initial reactivity study of N-vinylthiopyrrolidone, a sulfur-containing analog of N-vinyllactams not previously described in the literature. N-vinylthiopyrrolidone was obtained in up to 60% yield by treating N-vinylpyrrolidone with phosphorus pentasulfide in xyl…

On refinement methods using higher-order differences and $h^2$-extrapolation

The paper develops and justifies higher-order difference refinement methods for numerical solutions of Poisson boundary-value problems in rectangles, including Dirichlet and mixed nonhomogeneous boundary conditions. It decomposes the solution into explicitly constructed singular and polynomial or ha…

EPR spectrum of the hydrated electron in irradiated frozen alkaline solutions

This study examines whether hydrated electrons can be detected by electron paramagnetic resonance in frozen alkaline aqueous solutions, where stabilization is expected to suppress conversion into atomic hydrogen. Frozen KOH and NaOH solutions in water and heavy water were irradiated at liquid nitrog…

On Autocatalysis in Polymerization Reactions

This paper proposes a kinetic interpretation of autocatalysis in polymerization reactions with linear chain termination, distinct from the conventional gel effect associated with radical recombination. It develops a simple scheme in which active centers formed in contact with existing polymer chains…

Anticholinesterase properties of some $\mathrm{O}$-ethyl $\mathrm{S}$-alkyl methylthiophosphinates

This study examines how the geometry of thioether radicals affects the anticholinesterase activity of organophosphorus inhibitors that lack heteroatoms in the thioether chain, addressing whether factors beyond positive charge contribute to cholinesterase binding. A series of O-ethyl-S-alkyl methylth…

Catalytic Synthesis of 7-Azaoctahydropyrrocolines

This paper extends catalytic intramolecular dehydration of furan and tetrahydrofuran amines to tetrahydrofuran diamines as a route to condensed pyrrolidine and piperazine systems. Furfural and methylfurfural derivatives were converted by reductive amination with ethylenediamine and subsequent hydrog…