Translated papers from the Chinese Preprint site, Chinaxiv
Showing 50 of 15540 papers
Generated abstract This paper studies the large-time behavior of the energy of solutions to a mixed initial-boundary value problem for the wave equation in an unbounded exterior-type domain in Euclidean space. Using scattering eigenfunctions for the corresponding exterior domain, the solution and its energy are repres…
Generated abstract This paper presents deep seismic sounding evidence for high-velocity layers in the upper mantle beneath the western Black Sea basin and the rift valley of the Arabian Indian Ridge. Using bottom seismograph records, travel-time curves, and comparisons between observed and theoretical amplitude graphs…
Generated abstract The paper formulates multidimensional analogues of the Darboux problem for a second-order hyperbolic equation in a three-dimensional domain bounded by characteristic conical surfaces and a plane, together with the corresponding formally adjoint problem. Using a weighted energy identity, suitable Hil…
Generated abstract This paper extends classical potential theory from Lyapunov surfaces to domains whose boundaries belong to the Lyapunov-Dini class, characterized by controlled variation of the surface normal. Using previously established uniqueness for the homogeneous Neumann problem and local geometric estimates f…
Generated abstract This paper reports measurements of the chemical composition of Venus’s atmosphere obtained during the parachute descents of the Venera 5 and Venera 6 automatic stations in 1969, extending and refining earlier Venera 4 results. Using onboard gas analyzers based on selective physicochemical reactions,…
Generated abstract This paper analyzes the reflection of unsteady long waves from a straight vertical wall in a homogeneous fluid of constant depth under rotation, with the Coriolis force included. Starting from the linear long wave equations, the authors formulate an initial value and boundary value problem for a loc…
Generated abstract A method is developed for solving Dirichlet and Neumann boundary-value problems for open surfaces, motivated by applications in diffraction, electrostatics, and analytic function theory. For the inhomogeneous Helmholtz equation, the construction introduces auxiliary closed surfaces and uses Green’s …
Generated abstract This paper examines the relationship between magnetic rotation dispersion and refractive index dispersion for the diamagnetic La3+ ion in aqueous lanthanum chloride solution, with particular attention to Becquerel’s formula and Serber’s coefficient. Refractive index dispersion was measured interfero…
Generated abstract The paper addresses the synthesis of large, strong polycrystalline formations of cubic boron nitride, a material valued for diamond-like hardness, high thermal stability, and chemical inertness toward iron. Motivated by earlier production of polycrystalline diamond aggregates, the authors sought pre…
Generated abstract This paper examines the structure of atmospheric aerosol under conditions of unusually high transparency near Leningrad, using spectral transparency measurements rather than direct particle sampling. Aerosol optical thickness was derived from Bouguer observations at several wavelengths, corrected fo…
Generated abstract The paper studies optimal prediction and filtering for functionals of random processes that solve nonlinear differential equations driven by Gaussian random functions, a setting that generally lies beyond the Markov diffusion case. It derives a conditional expectation formula by comparing the measur…
Generated abstract The paper analyzes propagation of the boundary between superconducting and normal phases in type-II superconducting thin films, where the film thickness is small compared with the magnetic-field penetration depth. Starting from the Maxwell-London equations, the authors introduce current functions fo…
Generated abstract The paper studies weak invariance of discrete dynamical systems with respect to external perturbations under a terminal quality criterion. Using a reference perturbation and the associated reference function, it derives necessary and sufficient conditions for invariance, including an equivalent form…
Generated abstract 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…
Generated abstract 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…
Generated abstract 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…
Generated abstract 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…
Generated abstract 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, …
Generated abstract This paper presents a qualitative method for analyzing second-order nonlinear dynamical systems by transforming the governing equations to a canonical form involving characteristic functions determined from a functional characteristic equation. The approach relates the real parts of these characteri…
Generated abstract This paper examines whether ion-induced amorphization of crystals can be used to assess the relative importance of cascade and focused-collision mechanisms in cathode sputtering. The authors argue that comparing sputtering from crystalline and amorphous phases of the same substance offers a relative…
Generated abstract This note addresses several questions on perfectly normal bicompact spaces, especially nonmetrizable examples and mapping properties. It constructs a nonmetrizable perfectly normal bicompact admitting an open countably multiple map onto the Cantor set, and, assuming the continuum hypothesis, a conne…
Generated abstract The note studies upper estimates for large inductive dimension and related inductive invariants of products of bicompact spaces using cofinal approximative dimension. It proves that for finite products of bicompacta, and under a paracompactness variant, the large inductive dimension is bounded by th…
Generated abstract This paper studies functional equivalence for finite control automata with a final state in Glushkov’s framework of interacting control and operational automata. It defines operators and conditions syntactically over variables, function symbols, and predicate symbols, interprets automata over arbitr…
Generated abstract The paper studies derivability in a formal arithmetical calculus with equality, order, successor, and symbols for all primitive recursive functions, focusing on formulas provable without induction or with induction applied only after logical inferences. It defines a hierarchy of classes according to…
Generated abstract This paper determines the continuous transformation groups of Pauli type that leave the Dirac equations invariant when the spinor and its conjugate are treated as an eight-component system. Using Lie group methods and imposing a reality condition on the transformation matrix, it derives the maximal …
Generated abstract The paper studies the multidimensional two-phase Stefan problem in a rectangular spatial domain, focusing on a regular classical solution with a moving phase-separation surface. For the two-dimensional case, with extension indicated to higher dimensions, the authors replace the Stefan condition by a…
Generated abstract This paper studies groups of generalized motions in Riemannian spaces using the notion of defect of invariance for manifolds under continuous transformation groups. It defines the defect of a Riemannian space relative to a group, proves a coordinate invariant rank formula analogous to the Killing eq…
Generated abstract The paper develops a generalized implicit function theorem for operators in Banach spaces under weakened differentiability assumptions, requiring only control of the deviation from the derivative at the origin and uniform boundedness of inverse linearizations. This result is applied to bounded solut…
Generated abstract This paper derives equations for the Brownian motion of aerosol particles in atmospheric flows when particle inertia cannot be neglected and the ordinary Smoluchowski approximation may fail. Starting from the Fokker-Planck equation, the authors assume local Maxwellian equilibrium of velocities after…
Generated abstract This study reports photoelectric Raman measurements for tetramethylsilane and a series of methylchlorosilanes, determining fundamental frequencies, peak and integral intensities, half-widths, depolarization degrees, corrected scattering coefficients, and polarizability-derivative tensor invariants. …
Generated abstract This paper proposes a variational formulation for quasi-brittle fracture that does not require the crack path to be prescribed in advance. Starting from an energy balance for a body with internal ruptures, it derives separate variational conditions for changes in crack trajectory and for motion of a…
Generated abstract The paper studies transitive subgroups of the finitary symmetric group on an infinite set, focusing on whether such groups can decompose as products of proper elementwise commuting normal subgroups. After establishing a lemma on the equivalence of the actions induced by an intransitive normal diviso…
Generated abstract This paper reports geothermal measurements across the Gakkel Ridge, an active mid-ocean ridge system in the Arctic Ocean, to assess whether heat flow is elevated in its rift zone relative to average oceanic values. Using a thermoprobe deployed from drifting ice, the authors measured geothermal gradi…
Generated abstract This note studies the boundary-layer equations for a stationary axisymmetric flow of a compressible fluid in the case of Prandtl number equal to one, using the corresponding relation between enthalpy and longitudinal velocity. By introducing variables based on the ratio of the velocity to the outer-…
Generated abstract This paper studies self-similar nonlinear waves in an ultrarelativistic ideal gas with equation of state energy density equal to three times the pressure, under spherical and cylindrical symmetry. The Cauchy problem is reduced to an ordinary differential equation for the dimensionless velocity, with…
Generated abstract This note studies an integral equation with a singular kernel arising in mixed elasticity problems, including crack problems and rigid punch loading of strips and wedges. Under analytic assumptions on the kernel, it establishes a large-parameter representation for the solution as the interval half-l…
Generated abstract This paper analyzes the asymptotic behavior of pair correlation functions near the critical point for a gas with short-range interactions, using the generating functional of correlation functions and the Ornstein-Zernike relation. It relates loss of uniqueness in the density equation to the spinodal…
Generated abstract This paper examines fine structure in the travel-time curve of longitudinal seismic waves by directly estimating its derivative with respect to epicentral distance. Using records from two regional seismic station networks in Siberia and Kirghizia for more than 200 earthquakes, mainly from the Pacifi…
Generated abstract This paper develops a broader generalized polyharmonic operator for Lebesgue integrable functions in domains of n-dimensional space. Starting from iterated differences between spherical surface means and ball means, it defines upper, lower, and limiting generalized polyharmonic operators of the seco…
Generated abstract The paper studies the limiting behavior, as noise tends to zero, of the unique invariant measure of a nondegenerate Markov diffusion that is a small perturbation of a dynamical system on a compact manifold. Using an action functional and the associated quantities V(x,y), the authors define equivalen…
Generated abstract This paper reports a search for long-lived distant transuranium elements in ferromanganese nodules from the southern Pacific Ocean, motivated by theoretical predictions of stable superheavy nuclei and earlier ambiguous observations of unexplained alpha activity and fission effects. The authors exami…
Generated abstract This paper examines electron heat transport in a high-temperature plasma confined by a toroidal magnetic field, focusing on drift-wave instability associated with trapped electrons in systems with small magnetic shear. Using a kinetic treatment for trapped electrons in a Tokamak-type geometry, the a…
Generated abstract This paper studies three-dimensional diffraction of elastic harmonic waves by an infinite periodic row of identical circular cylindrical cavities in an elastic body. Using longitudinal and transverse wave potentials in cylindrical coordinates, the authors exploit the phase periodicity of an incident…
Generated abstract This paper studies invariance of the terminal value of a functional for nonlinear dynamic systems subject to external disturbances, generalizing weak invariance in a variational framework. By analyzing large variations of the functional, it derives an exact integral formula for the change in the fun…
Generated abstract The paper develops a theory of elliptic problems of S. L. Sobolev type in which boundary conditions are imposed on submanifolds with finitely many conical point singularities rather than on the boundary of the ambient manifold. It introduces weighted functional spaces adapted to such singularities a…
Generated abstract The paper reports the synthesis and crystal-structure determination of the scandium sodium diorthosilicate Na3Sc[Si2O7], obtained as transparent rhombic single crystals in the Na2O, Sc2O3, SiO2, H2O system. X-ray diffraction, Patterson and electron-density syntheses, and least-squares refinement in …
Generated abstract This paper analyzes the hyperfine structure of Bragg maxima in Mössbauer diffraction and compares the information obtainable from diffraction peaks with that from conventional resonance absorption. It argues that, although the energy positions of hyperfine components are governed by the same nuclear…
