In the present article we formulate results on estimates of double sums with a quadratic character.
The paper formulates estimates for double sums over arbitrary complex sequences weighted by quadratic characters, represented by Jacobi or Kronecker symbols. Its main theorem gives a decomposition into a possible main term from square arguments and an error bounded by the minimum of several expressi…
Yu. A. Kharitonov, È. A. Kuz'min, N. V. Belov
The paper reports a single-crystal X-ray determination of the structure of sodium dichromate dihydrate, Na2Cr2O7·2H2O, using three-dimensional Patterson and electron-density syntheses followed by least-squares refinement. The study revises the symmetry to the hemimorphic space group P21, locates 77 …
M. G. Gasymov
The paper studies the high energy distribution of eigenvalues for self-adjoint ordinary differential operators on the whole line generated by even order formally symmetric expressions with polynomially controlled coefficients. Under growth, regularity, and phase space integrability assumptions, it p…
R. G. Annaev, G. Myalikgulyev, L. S. Mel'nikova
This paper reports a study of the Hall effect and longitudinal and transverse galvanomagnetic effects in thin polycrystalline nickel copper alloy films at room temperature. The authors introduce a method for producing mechanically reliable, temperature resistant ohmic contacts by combining glued mul…
B. I. Rozenfel'd
The paper studies an extended category of locally trivial principal G-fiberings, in the sense of Gelfand and Fuks, after restricting bases to spaces satisfying the second axiom of countability. It constructs the corresponding universal fibering from nondegenerate n-frames in a countable product of l…
V. V. Pukhnachov
This paper studies the far-field behavior of stationary solutions to the three-dimensional Navier-Stokes flow-past problem for an exterior domain, focusing on the axisymmetric case with finite Dirichlet integral. It proves that every such axisymmetric solution satisfies Finn’s decay condition, by de…
O. N. Bondareva
The paper studies cooperative games whose core may be empty and seeks conditions under which a von Neumann, Morgenstern stable set nevertheless exists. It introduces auxiliary games on two parts of a partition of the player set, defines conjugate characteristic-function bounds for the two subgames, …
M. M. Popov
The paper studies high-frequency asymptotics for subsequences of eigenvalues of Dirichlet and Neumann boundary-value problems for the Helmholtz equation in a multidimensional bounded domain, focusing on eigenfunctions localized near stable one-dimensional extremal cycles. Using the ray method, the a…
D. P. Shashkin, M. A. Simonov, N. V. Belov
This study determines the crystal structure of uralborite, a hydrous calcium metaborate, using X-ray diffraction data from Weissenberg photographs and refinement by least squares in the monoclinic space group P21/n. The analysis confirms the composition Ca2[B4O4(OH)8], distinguishes hydroxyl groups …
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This note studies the asymptotic correcting capabilities of random binary linear codes of length n and dimension k equal to the integer part of nR, with fixed rate 0 < R < 1. Using a uniform probability measure on generator matrices, it analyzes the distribution of the minimum nonzero codeword weigh…
A. H. Gudiev
This paper studies Hölder continuity of generalized solutions in \(W_2^1(D)\) for a class of strictly elliptic divergence form equations whose lower order coefficients and free terms belong to mixed norm spaces. Since these spaces may include functions outside the integrability range covered by stan…
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This paper studies octupole excited states in deformed even-even nuclei with mass numbers 150 to 176 within the superfluid nuclear model using approximate second quantization. The calculations employ single-particle energies and wave functions from the Saxon-Woods potential, include pairing and octu…
V. A. Skoryupin
This paper reports measurements of high-frequency plasma noise during turbulent heating by a direct discharge current, motivated by theories that attribute anomalous plasma resistance to ion-acoustic current instability. Because the expected ion-acoustic wavelengths are too small for reliable Langmu…
A. D. Korshunov
This note studies the problem of recognizing the final state of a finite automaton treated as a black box, with particular attention to the length of the shortest homogeneous experiment. Building on earlier worst case bounds of Hibbard and on estimates involving the degree of distinguishability, it …
Yu. M. Ryabukhin
This paper studies nonassociative algebras over a fixed commutative associative ring with identity that contain no nilpotent elements, in the sense that x squared equals zero only for x equal to zero. It gives necessary and sufficient conditions, involving a conditional associativity type identity a…
G. G. Novitskii, A. N. Sevchenko, D. S. Umreiko
This study examines whether vibrational frequencies of ammonium cations can be identified in the fluorescence spectra of double uranyl salts through isotopic substitution. Infrared absorption and liquid nitrogen luminescence spectra were measured for ammonium uranyl chloride and ammonium uranyl sulf…
S. Sirota
This paper studies homogeneous subsets of absolutes and the possibility of obtaining new extremally disconnected topological groups from orbits of ultrafilters under groups of homeomorphisms. It proves that such orbits are homogeneous extremally disconnected subspaces of the absolute, gives decompos…
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The paper develops an energy equilibrium condition for crack growth in ideal elastic-plastic bodies when plastic deformation is concentrated in a narrow zone ahead of the crack tip. The plastic zone is replaced, in a linearized formulation, by an additional cut carrying stresses that represent the a…
M. A. Kolosov, A. V. Sokolov, L. V. Fedorova, R. A. Shirei
This study examines how the absolute attenuation coefficient of continuous laser radiation in aqueous fogs depends on droplet concentration and size. Experiments in an artificial fog chamber combined laser transmission measurements at wavelengths of 0.63, 1.15, and 3.39 micrometers with automated ph…
L. V. Kirenskii, N. M. Salanskii, V. I. Litvinchuk
This paper reports experiments on magnetostrictional instability in a parametron using a thin uniaxial magnetic film deposited on a glass substrate as the nonlinear element. Under rigid parametric excitation at an 11 MHz pump frequency, the authors varied the bias and pump fields and the film orient…
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This note introduces integral transforms associated with the first order differential operator in time that appears in a mixed boundary value problem for a second order elliptic operator with parameter. Motivated by the need to treat general time dependent boundary data in the contour integral metho…
HEAT ENGINEERING
This paper examines regularities of droplet carryover in bubbling and non-bubbling evaporating apparatuses, distinguishing entrainment by splashing from transported carryover of droplets that are not separated in the vapor space. A theoretical description is developed using droplet-size distribution…
A. I. Mal'tsev
This note develops a topological analogue of Słupecki’s theorem for continuous mappings on selected compact spaces. Using an Ostrand form of the Kolmogorov, Arnold superposition theorem, it proves a representation theorem for continuous maps from powers of a connected finite polyhedron into the circ…
E. M. Levich
This paper studies criteria for faithful matrix representations of solvable torsion-free groups over fields of characteristic zero, in relation to Mal’tsev’s theorem on solvable matrix groups. It introduces conditions using powered locally nilpotent groups, finite rank, and compatible inner automorp…
S. K. Abdullaev, A. A.-o. Babaev
This paper studies the Hilbert-type singular integral with summable density on a finite interval and estimates how its local \(L_p\) size and modulus of continuity depend on corresponding characteristics of the density. For \(1<p\leq\infty\), the authors prove integral inequalities relating \(\Omega…
L. N. Pyatnitskiĭ, G. P. Khaustovich, Vl. V. Korobkin
The paper addresses diagnostics of dense, low temperature plasma by analyzing the frequency shift and half width of satellites in the laser light scattering spectrum, where collective electron effects make integral intensity methods unsuitable. It develops a graphical procedure based on the full sca…
L. D. Bogomolova, V. N. Lazukin, N. V. Petrovykh
This study examines how cobalt affects the electron paramagnetic resonance signals of Cu2+, VO2+, Mn2+, and W5+ ions in borate, silicate, and phosphate oxide glasses at liquid nitrogen temperature. Measurements show that even small Co additions can strongly reduce the EPR intensity of these ions whe…
V. N. Lazukin, A. N. Terent'evskii
This paper investigates weak components of the electron paramagnetic resonance spectrum previously attributed to nitrogen-related centers in natural diamond, testing whether they arise from substitutional ions at tetrahedral carbon sites. By examining variety II diamond samples, the authors observe …
D. A. Raikov
V. K. Gavrikov, A. V. Kats, V. M. Kontorovich
This paper analyzes stimulated combination scattering of light by surface waves at the boundary between two media, including capillary, gravitational, and Rayleigh waves. Using electromagnetic boundary conditions and the linearized motion of an incompressible fluid surface, the authors derive scatte…
V. A. Molchanov, V. A. Snisar, V. M. Chicherov
This paper examines how the initial energy of incident ions affects the relative intensity of double-scattering peaks in energy distributions of ions scattered by crystal surfaces. Argon ions with energies from 10 to 20 keV were scattered from the (100) face of a copper crystal under different grazi…
Yu. K. Alekhin
This paper examines the generation of surface waves when an acoustic plane wave is scattered by a statistically rough interface between two liquid media. Using a perturbation approach modified to include attenuation of waves initially scattered in grazing directions, it derives effective boundary im…
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This paper develops a coordinate-free treatment of elastic wave propagation in piezoelectric crystals of arbitrary symmetry. Starting from the piezoelectric constitutive equations and the quasistatic electrodynamic approximation, it rewrites the Green-Christoffel equation as the ordinary elastic ten…
A. G. Ramm
The paper develops an iterative method for solving a class of integral equations in potential theory when the usual Neumann series is obstructed by a nearest eigenvalue. A general theorem is proved for completely continuous operators in a Hilbert space, showing convergence of an iteration on the ort…
G. N. Kovalev
This paper examines the thermal power of hydrothermal systems and active volcanoes in regions of modern volcanism, treating convective heat transfer as the dominant mechanism and relating heat flow to caldera and volcano-tectonic structures. Using published and calculated data from Kamchatka, the Ku…
A. N. Tikhonov, E. A. Lyubimova, V. K. Vlasov
This paper examines how melting zones in the Earth’s upper mantle evolve during the planet’s thermal history under heating by radioactive decay. The authors solve a spherically symmetric quasilinear heat-conduction problem by an implicit finite-difference method, allowing thermal parameters to chang…
V. P. Myasnikov
This paper analyzes binary collisions of solid spherical particles immersed in an ideal incompressible liquid, motivated by particle interactions in fluidized beds. Using Lagrange equations for a system of spheres coupled to the surrounding fluid, it derives jump conditions for velocities at the ins…
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The paper develops a parametrized form of perturbation theory for degenerate quantum levels whose unperturbed Hamiltonian is invariant under a simply reducible symmetry group. Using irreducible tensor operators, Clebsch-Gordan coefficients, and the Wigner-Eckart theorem, it rewrites the equivalent H…
A. M. Rubinov
The paper studies efficient trajectories in a positively homogeneous dynamic model of production, formulated through superlinear set-valued mappings between ordered cones and encompassing discrete variable-technology models and continuous convex programming problems. It establishes compactness and e…
A. V. Bitsadze, A. A. Samarskii
The paper proposes a generalization of linear elliptic boundary value problems in which prescribed boundary data on part of the boundary are supplemented by an equality condition linking values on another boundary portion to values on an interior diffeomorphic image. The authors examine the model ca…
V. D. Milman
The paper studies duality relations between beta and delta characteristics of Banach spaces, defined through extremal averages over families of subspaces. It introduces a convex function transformation related to the Legendre transform, establishes its inversion properties, and applies it to connect…
È. D. Rogacheva, A. A. Rosenblum, A. V. Belyustin
This paper examines avalanche-like crystallization of magnesium sulfate heptahydrate from supersaturated solution, focusing on the distribution of right- and left-handed crystals under conditions where crystal multiplication is significant. Experiments in closed vessels at different supersaturations…
A. Dzhuraev
The paper studies boundary value problems for a class of second order systems of composite type whose characteristic polynomial has one multiple family of real characteristics, focusing on a canonical system previously derived by the author. It formulates a boundary value problem with mixed conditio…
V. V. Fedorchuk
The paper studies continuous mappings under which covering dimension is constrained more sharply than in classical Hurewicz-type inequalities. It introduces the notion of a strongly closed mapping and proves that if such a mapping sends a normal space onto a paracompact space, with image dimension a…
L. M. Boyarshinov
This paper investigates the maximum energy and intensity of beta particles undergoing multiple backscattering from targets with different atomic numbers, motivated by applications in compositional analysis and coating-thickness measurement. Using a thallium-204 beta source, an end-window counter, an…

The paper proposes an experimental method for determining surface stresses in inelastic bodies under complex loading without relying on specific constitutive stress strain relations. The approach records the local deformation history, for example with photoelastic coatings, and reproduces it at the …
M. A. Gol'dman
This paper studies decompositions of a linear operator on a vector space over an arbitrary field, relative to the direct sum of generalized eigenspaces associated with a chosen subset of the field. It proves that, for any scalar outside this subset, an operator can be written as a sum of two operato…
A. A. Zykov
The paper constructs an algebraic framework for studying Hadwiger’s conjecture by assigning to each finite simple graph a polynomial in countably many variables, defined recursively through edge deletion and contraction and initialized on disjoint unions of complete graphs. It defines analogues of t…
V. E. Romanov, B. M. Yavorskii, R. S. Kozma
An approximate method is proposed for determining the wavelength-dependent refractive indices and absorption indices of dye molecules, quantities that are difficult to measure directly in dye films. The method treats dye molecules or aggregates as small spherical particles in a nonabsorbing solvent,…
G. S. Taras'ev
This paper develops a formulation of plane stress for thin plates undergoing finite elastic deformations, assuming negligible transverse stresses and weak variation through the thickness. Using principal stretches, rotation angles, Hencky strain invariants, and a stress function in complex coordinat…