Translated papers from the Chinese Preprint site, Chinaxiv
Showing 50 of 15540 papers
Generated abstract The paper studies infinite nonabelian groups in which every infinite nonabelian subgroup is normal, viewed as a generalization of Schmidt groups and metahamiltonian groups. Under the assumption of local stepwise structure, it proves solvability, shows that nonperiodic examples are metahamiltonian wi…
Generated abstract This paper examines stable density stratification in the ocean using the Brunt-Väisälä frequency as a sensitive measure of vertical density gradients. Based on hydrographic data from 40 stations, mainly in the northern Pacific, the authors find that in interior layers between roughly 500 and 5000 m …
Generated abstract This note studies local conjugacy of smooth local diffeomorphisms of Euclidean space fixing the origin, revisiting results of Sternberg by replacing iterative constructions with a fixed-point approach. For infinitely differentiable diffeomorphisms, it proves that when the derivative at the fixed poi…
Generated abstract The paper derives a dispersion formula for the dynamic optical polarizability of the hydrogen atom in its ground state. Starting from the quantum mechanical sum over discrete and continuous spectra, it analyzes an integral representation based on Green functions and uses contour integration in the c…
Generated abstract The paper studies Green’s functions for Sturm-Liouville differential expressions with operator coefficients in a separable Hilbert space, extending earlier work from the case of identity leading coefficient to variable positive operator coefficients. Under stated boundedness, differentiability, meas…
Generated abstract This paper reports an electron paramagnetic resonance study of Dy2+ ions in CaF2 in the short wavelength submillimeter range near 0.34 mm at liquid helium temperature. Using a high resolution radiospectroscope, the authors measured resonance absorption lines for several orientations of the magnetic …
Generated abstract The paper studies a generalized class of convolution type integral equations on the real line with bounded measurable coefficients having generalized limits at infinity, in a range of Banach function spaces including Lebesgue, bounded measurable, and continuous function spaces. By decomposing the op…
Generated abstract This paper studies character sums over shifted primes, specifically sums of nonprincipal characters modulo a large prime q evaluated at p + k for primes p up to N. Combining I. M. Vinogradov’s method for estimating trigonometric sums with earlier ideas of the author, it proves an estimate that is no…
Generated abstract The paper constructs explicit analogues of the Cauchy kernel on the genus 2 hyperelliptic Riemann surface defined by a six branch point algebraic equation. It computes normalized Abelian differentials and period data, then develops several Cauchy-type kernels, including discontinuous and meromorphic…
Generated abstract The paper constructs a class of nonnegative Markov processes with gamma marginal distributions, defined through a bilinear expansion in normalized Laguerre polynomials. It proves that the proposed two-dimensional density satisfies the Markov equation, converges in mean, and is nonnegative by identif…
Generated abstract The paper develops second variation methods for extremal problems in the class of normalized univalent functions in the unit disk. Using Goluzin and Schiffer type variations generated by complex measures, it derives first variation formulas for Taylor coefficients, recovers the Schiffer equation as …
Generated abstract This paper develops a linear magnetohydrodynamic perturbation theory for axisymmetric cosmological solutions of the Einstein and Maxwell equations with a large-scale magnetic field. Using a synchronous comoving frame and assuming ideal conductivity, the perturbation equations are decomposed into vor…
Generated abstract This study examines the structural perfection of heavily tellurium-doped indium arsenide single crystals grown by the Czochralski method along the [111] direction. Using anomalous-transmission X-ray topography with MoK alpha radiation and {220} reflections, the authors analyze plate specimens of sev…
Generated abstract The paper studies observability for linear controlled systems when the observer knows the dynamics and the measured output but not the applied control. It defines ideal observability as unique reconstruction of the initial state from the output for all admissible controls, relates this notion to Kal…
Generated abstract This paper studies second order linear hyperbolic equations in four variables for which Huygens’ principle holds, focusing on the relation between this property and conformal invariance in pseudo-Riemannian spaces of signature three minus and one plus. Using the structure of spaces with nontrivial c…
Generated abstract This paper examines the spectral sensitivity and response speed of CdHgTe photoresistive radiation detectors intended for the 8 to 13 micrometer atmospheric window used by CO2 lasers. The authors synthesize and heat treat CdHgTe crystals, characterize carrier concentration and mobility by galvanomag…
Generated abstract This note studies sufficient conditions for the univalence of analytic and meromorphic functions arising in two inverse boundary-value problems, for functions regular in the unit disk and exterior disk. It derives criteria involving the logarithmic derivative, integral mean bounds, and Schwarzian de…
Generated abstract This note studies boundary value problems for higher order elliptic differential operators that degenerate on a hyperplane or on the boundary of a smooth bounded domain. It introduces and analyzes B-elliptic operators involving the singular Bessel operator in weighted spaces, proving a priori estima…
Generated abstract This paper studies selection problems for multivalued mappings in general topology, especially conditions under which lower or upper semicontinuous mappings admit continuous, sigma-continuous, or F-sigma-continuous sections. It establishes selection theorems for paracompact, perfectly normal, zero-d…
Generated abstract The paper studies differential reducibility of linear nonhomogeneous differential equations over a differential field of analytic functions, motivated by applications to algebraic independence results for values of special functions. It proves a reversible criterion: a nonhomogeneous equation is dif…
Generated abstract This paper develops a discrete analogue of coercive boundary conditions for elliptic difference operators on a half-space grid. It defines Sobolev-type spaces of grid functions, establishes a quasihomogeneous factorization theorem for elliptic symbols on the torus, and introduces a smoothness condit…
Generated abstract The paper studies the asymptotic behavior of functions in a quasianalytic class on the real line, using the limiting rate of decrease introduced by Korenblum. It constructs an associated function and narrowing infinite strip, then proves that each quasianalytic function can be decomposed, for any re…
Generated abstract A microwave delayed-coincidence method was applied to measure short lifetimes of excited nuclear states populated in the alpha decay of Ra-223 and Bi-211. The apparatus used phase-shifted microwave shutters for alpha particles and conversion electrons, with prompt-coincidence curves obtained by low-…
Generated abstract This study examines glasses in the RO, Al2O3, B2O3, SiO2 system, where RO is CaO, MgO, SrO, BaO, ZnO, CdO, or PbO, with attention to crystallization behavior and structural changes. Differential thermal analysis, forced crystallization, X-ray phase analysis, and infrared spectroscopy were used to co…
Generated abstract The paper introduces a formal notion of complex Markov chains by assigning complex amplitudes to events and paths, with ordinary probabilities recovered as squared moduli on true events. It defines homogeneous chains, their continuous limiting processes, and the associated Green function, then appli…
Generated abstract This note studies stabilization as time tends to infinity for the Cauchy problem for a parabolic equation with variable positive coefficient in the whole Euclidean space. Under boundedness, Hölder regularity, and an averaged convergence condition on the coefficient, the authors prove a necessary and…
Generated abstract The paper studies one-to-one mappings between affine spaces that send every translate of a fixed bounded set onto a translate of its image, and asks when such mappings must be affine. It introduces shifts preserving a generator and the associated class of quasicylinders, then proves that every conti…
Generated abstract The paper derives integral representations for solutions of the differential equations in the technical theory of shallow shells, focusing on the case with constant curvature parameters after transformation to complex variables. The governing coupled shell equations are reduced to a fourth order equ…
Generated abstract This note establishes Phragmén-Lindelöf type alternatives for solutions of general linear uniformly elliptic equations of arbitrary order with variable coefficients, under Hörmander’s condition excluding multiple characteristics. For cylindrical domains, it proves that bounded Cauchy data on the lat…
Generated abstract This paper examines the hydraulic resistance of granular porous media during colmatation caused by filtration of dilute suspensions, a problem relevant to water treatment and other filtration technologies. The authors describe experiments in which dynamic porosity was measured without disturbing dep…
Generated abstract This paper studies cooperative games in reduced 0-1 form and the relation between the core and stable solutions under continuous changes of the characteristic function. It considers a family of games in which coalition values are nondecreasing continuous functions of a parameter, defines a set forme…
Generated abstract This study examines the internal growth structure of sphalerite-type boron nitride crystals produced by phase transformation from hexagonal boron nitride. The authors used chemical etching in molten KOH followed by micromorphological analysis of the etched crystal faces to reveal defect distribution…
Generated abstract This paper examines stability of convergent iterative algorithms for solving finite-dimensional, generally nonselfadjoint difference equations when computations are affected by roundoff errors. It introduces a criterion based on the number of additional guard digits required to keep the limiting err…
Generated abstract This paper studies a class of linear nonstationary automatic control systems composed of a stationary element with a rational transfer function and a feedback gain inversely proportional to a linear function of time. Using Laplace transform representations and convolution formulas for the system wei…
Generated abstract This paper estimates the structure of the outer solar corona from visible-light brightness measurements obtained during the 15 February 1961 solar eclipse by a rocket-borne electrophotometer at about 100 km altitude. The authors formulate the correction of the observed brightness distribution as an …
Generated abstract The paper studies limiting distributions of additive functionals of a finite semi-Markov process restricted to a set of states up to the first exit from that set. Under a group condition for the state set and attraction assumptions on the one-step functional increments, it derives weak limits for su…
Generated abstract The paper studies how extreme order statistics contribute to large deviations of sums of independent identically distributed random variables with mean zero and finite variance. It derives conditional limiting distributions for the maximum, second maximum, and in some cases the minimum, under condit…
Generated abstract This paper studies observability for a class of nonlinear differential equations in a Hilbert space with a Lipschitz nonlinear term and a possibly noninvertible observation operator. It introduces exact, finite time approximate, and asymptotic approximate observability, then constructs an auxiliary …
Generated abstract This study examines the nature of dislocation loops formed near interblock boundaries in strengthened polycrystalline aluminum after a sharp temperature decrease during creep. Using transmission electron microscopy, diffraction contrast analysis, foil tilting, and bright-field and dark-field imaging…
Generated abstract This paper analyzes the stability of an inhomogeneous high-pressure plasma in a homogeneous magnetic field under the condition of very large beta and initially vanishing pressure gradient. Using a local dispersion relation for low-frequency, long-transverse-wavelength perturbations in a collisionles…
Generated abstract This paper develops basic structures of matrix space motivated by a covariant formulation of spinor fields in general relativity. It defines matrix tensors built from position-dependent Dirac matrices, analyzes the subgroup of similarity transformations that preserves algebraic relations involving c…
Generated abstract The paper studies best approximation of functions on the real axis by entire functions of finite degree in \(L_p\) metrics, with emphasis on determining sharp or improved constants in Jackson-type estimates for \(L_2\). Using Fourier transform methods and Plancherel’s theorem, it identifies the best…
Generated abstract This paper studies approximation of functions in Sobolev type classes by splines of order m on an interval and on the real line, allowing both fixed and adaptively chosen knots. It establishes error estimates in Lp and Lq metrics for functions with kth derivative in Lp, including bounds for derivati…
Generated abstract This paper reports shipboard radiometric measurements of the integral water vapor content of the atmosphere over the Atlantic Ocean between 47 degrees N and 23 degrees S during the 1969 cruise of the research vessel Akademik Kurchatov. The method derives vertical radio-wave absorption by atmospheric…
Generated abstract The paper constructs compact Hausdorff spaces whose small and large inductive dimensions do not coincide, refining earlier examples by obtaining spaces of cardinality continuum and, in one version, satisfying the first axiom of countability. The construction uses a general gluing procedure applied t…
Generated abstract The paper studies reflection of a plane acoustic wave by a periodically corrugated surface whose boundary combines rigid convex arcs with straight segments satisfying an impedance condition. Using the Maliuzhinets formulation, the diffraction problem for the Helmholtz equation with quasiperiodicity …
Generated abstract This note studies linear isometries defined on subspaces of complex and real \(L^p\) spaces, with emphasis on the case \(p \ne 2\). It proves distributional lemmas showing that, except for even integer cases requiring an additional algebraic condition, an \(L^p\)-norm preserving operator on a subspa…
Generated abstract This note studies uniqueness for the Cauchy problem for second-order parabolic equations with complex parameter and variable coefficients, allowing unbounded lower-order terms and solutions on a finite time interval. The argument reduces the variable-coefficient problem to a uniqueness question for …
Generated abstract This paper analyzes ray oscillations in a two-dimensional open resonator formed by a circular mirror and a plane mirror. A finite-difference mapping for successive reflected rays is derived and linearized near the axial solution, then numerical calculations are used to identify nonresonant zones ass…
Generated abstract This paper introduces and studies auto-reducibility for mass problems, formalized as membership problems for sets of natural numbers, using oracle machines that compute each value without querying that value itself. It relates non-auto-reducibility to Kolmogorov and Loveland selection-based randomne…
