Search

Abstract: The paper considers \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n \times n$$\end{document}systems of ordinary differential equations of the form \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$y'-By-C(\cdot, \lambda)y=\lambda Ay, \qquad y=y(x), \quad x \in [0, 1],$$\end{document}where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$A=\operatorname{diag}\{a_1(x), \dots, a_n(x)\}$$\end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$B=\{b_{jk}(x)\}_{j, k=1}^n$$\end{document}, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C= \{c_{jk}(x, \lambda)\}_{j, k=1}^n$$\end{document}. All functions in these matrices are complex-valued and integrable over \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$x \in [0, 1]$$\end{document}, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\|c_{jk}(\cdot, \lambda)\|_{L_1} \to 0$$\end{document}as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lambda \to \infty$$\end{document}. The theorems proved in the paper generalize the results of the classical Birkhoff–Tamarkin–Langer theory concerning asymptotic representations of fundamental solutions in sectors and half-strips of the complex plane as \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lambda \to \infty$$\end{document}. The focus is on the minimality of the smoothness requirements on the coefficients.

Abstract—The effect of thermal treatment on the microstructure, phase composition, and microhardness of Ni + B4C composite coatings is studied. The coatings are deposited onto the surface of an austenitic steel by cold gas-dynamic spraying. The initial coating is shown to be a nickel matrix containing distributed B4C particles. Thermal treatment causes diffusion processes in the coating, which results in the formation of Ni3B and Ni2B compounds. The average microhardness of the initial coating is 3.4 GPa, and heat treatment results in an increase in the coating microhardness due to the formation of hard nickel borides.

This article consolidates and organizes modern methods for calibrating relative gravimeters, aiming to streamline the selection and implementation of effective calibration systems, particularly in Kazakhstan. The concept of the calibration function and various methods for its determination are presented. Practical implementations of laboratory methods relevant to modern high-precision relative gravimeters are discussed, including the tilt, moving mass, artificial acceleration, and line calibration methods. Data processing through least squares adjustment at the calibration line and an overview of existing software packages for gravity observation equalization are explored. The article also covers existing horizontal and vertical calibration systems in different countries, detailing their main characteristics and schematics. Finally, an estimation of scale factors for five years of measurements with Scintrex CG-5 gravimeters at the Zhetygen calibration line in Kazakhstan is provided.

Abstract: We consider a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2 \times 2$$\end{document}system of ordinary differential equations \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$y'-By=\lambda Ay, \qquad y=y(x), \quad x \in [0, 1],$$\end{document}where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$A=\operatorname{diag}\{a_1(x), a_2(x)\}$$\end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$B=\{b_{kj}(x)\}_{k, j=1}$$\end{document}, and all functions occurring in the matrices are complex-valued and integrable. In the case \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$a_1,a_2, b_{21},b_{12} \in W^n_1[0,1], \qquad b_{11}, b_{22} \in W^{n-1}_1[0,1],$$\end{document}we obtain \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n+1$$\end{document}terms of the asymptotic expansion in powers of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lambda^{-1}$$\end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lambda \to \infty$$\end{document}, of the fundamental matrix of solutions of this equation. These asymptotic expansions are valid in the half-planes \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Pi_{\kappa}=\{\lambda \in \mathbb{C} \mid \operatorname{Re}{\lambda} \ge -\kappa \}$$\end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\kappa \in \mathbb{R}$$\end{document}, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-\Pi_{\kappa}$$\end{document}if \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$a_1(x)-a_2(x) > 0$$\end{document}. They hold in the sectors \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$S=\{\lambda \in \mathbb{C} \mid \lvert\operatorname{arg}\lambda\rvert \le \pi/2-\phi-\varepsilon\}$$\end{document}, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varepsilon > 0$$\end{document}, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-S$$\end{document}under the condition that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lvert\operatorname{arg}\{a_1(x)-a_2(x)\}\rvert<\phi<\pi /2$$\end{document}. The main novelty of the work is that we assume minimal conditions for the smoothness of the functions and in addition we obtain explicit formulae for matrices involved in asymptotic expansions. The results are also new for the Dirac system.

Abstract: Synthesis of proton-conducting materials based on track-etched membranes from polyvinylidene fluoride and sulfonated cross-linked polystyrene is described. The synthesis has been carried out by filling the pores of the original or gamma-irradiated track-etched membrane by copolymerization of styrene/divinylbenzene followed by sulfonation of polystyrene with chlorosulfonic acid. The resulting membranes have been studied by scanning electron microscopy and ATR IR spectroscopy. Membrane ionic conductivity, hydrogen gas permeability, ion-exchange capacity, and water absorption were measured. The ionic conductivity at 30°C reaches 51.7 mS/cm, which is almost three times higher than for Nafion®212 membranes; however, the gas permeability of the obtained materials also increases simultaneously.

Abstract: This paper provides information on the chemical composition of intrusive diorites the gold–porphyry deposit of Bolshoi Karan, located in the northern part of the Voznesensk–Prisakmar structural zone (Main Ural Fault), in the north of the Uchaly ore district. Additional information is given on 1) primary magmatic, 2) accessory, 3) hydrothermal—metasomatic, and 4) ore minerals. Special attention is paid to the geochemical features of accessory minerals from the ore-bearing zone diorites. According to the Nb/Yb and Th/Yb ratios in gabbroids, taking into account other materials, geodynamic reconstructions were carried out, as a result of which groups were identified of gabbrodiorites formed in the Voznesensk–Prisakmar zone in areas with oceanic, island-arc, and subcontinental types of crust smelted from depleted and enriched mantle sources. The Bolshekaran–Voznesensk–Karagaikul ore-bearing zone is confined to an area with a thick crust of island-arc or subcontinental type.

The kinetics of barium photoplasma upon absorption of laser radiation by atoms in the resonant transition at λ=553.5nm is studied by numerical simulation. At resonance transition saturation, seed electrons are generated. They gain energy through the superelastic processes and cause avalanche ionization of the gas. The brightening of the medium begins. After the metastable levels of barium are quenched by electrons, the brightening changes to darkening. The numerical results explain the experiment from [J. Appl. Phys.57, 4968 (1985)JAPIAU0021-897910.1063/1.335271], where the darkening effect of barium vapor was first obtained. The second probe laser affected the barium resonance ion line at λ=493.41nm and induced fluorescence. The limits of applicability of the optically thin medium model for diagnosing photoplasma are discussed.

This paper presents the results of a study of the effect of preliminary heat treatment and ball milling of aluminum powder on the cold spraying process and the properties of the obtained coatings (porosity and microhardness). The ball milling of aluminum powder leads to an increase in specific surface area, a decrease in apparent density and a decrease in the value of the crystallite size, which indicates a decrease in grain size. It is shown that coatings deposited from ball milled powders have slightly higher coatings hardness averagely. The profilometry of aluminum coatings obtained under the same conditions from the initial and processed powders did not reveal significant changes in the form of coatings and their typical dimensions (width, thickness), which indicates the absence of significant changes in the deposition coefficient of the initial and processed aluminum powders. Ball milled powders on average correspond to slightly higher hardnesses of coatings.

Influence of the rate at which energy is applied to aluminum powder during its ball milling is investigated. Rolling granulation is a main process due to which treated particles achieve their unique morphology and microstructure. Drastic temperature rise at rapid ball milling leads to increase in plasticity and local melting of treated powder particles that result in their adherence to the surfaces of milling balls and mill cylinder walls. Mass of aluminum powder adhered to the ball surface is proportional to the total surface area of all balls loaded in mill.

The European XFEL is a hard X-ray free-electron laser (FEL) based on a high-electron-energy superconducting linear accelerator. The superconducting technology allows for the acceleration of many electron bunches within one radio-frequency pulse of the accelerating voltage and, in turn, for the generation of a large number of hard X-ray pulses. We report on the performance of the European XFEL accelerator with up to 5,000 electron bunches per second and demonstrating a full energy of 17.5 GeV. Feedback mechanisms enable stabilization of the electron beam delivery at the FEL undulator in space and time. The measured FEL gain curve at 9.3 keV is in good agreement with predictions for saturated FEL radiation. Hard X-ray lasing was achieved between 7 keV and 14 keV with pulse energies of up to 2.0 mJ. Using the high repetition rate, an FEL beam with 6 W average power was created.

The authors have performed a comparative paleovolcanic and metallogenic analysis of two massive sulfide-bearing regions: the Southern Urals and Rudny Altai, which are located in different parts of the Ural-Mongolian fold belt. Comparison of the geodynamic evolution of these areas, the formation and facies composition of the ore-hosting strata and types of massive sulfide deposits has made it possible to conclude that the regions are similar only in the most general terms. Fundamental differences in the structure and composition of the Earth’s crust in these regions resulted in differences in the profile of island-arc magmatism: basaltoid in the Southern Urals and rhyolitoid in Rudny Altai. This in turn determined the predominant composition of massive sulfide mineralization: copper-zinc in the former region and polymetallic in the latter. They are also characterized by opposite trends in the evolution of volcanism: homodromous in the Southern Urals and antidromous in Rudny Altai, which resulted in different positions of the types of massive sulfide deposits in the strata of ore districts: from bottom to top, copper-massive sulfide deposits are replaced by polymetallic deposits in the Southern Urals, and barite-polymetallic deposits, by massive sulfide-polymetallic and copper-massive sulfide deposits in Rudny Altai. There are also substantial differences in the regularities of lateral ore localization: more starkly manifested control of mineralization by central-type paleovolcanic edifices in the Southern Urals and the frequent position of mineralization in intermediate and remote volcanic facies in Rudny Altai, which is expressed in the predominance of volcanic rock in Ural ore-bearing sequences and a significantly larger fraction of relict rocks (20–80%) in strata hosting mineralization in Rudny Altai.

At present, information on deflections of the vertical (DOV) is obtained by means of modern global geopotential models. The authors have derived DOV model values in the Western Siberia region. The results of the comparison of the DOV model values calculated with the use of the global geopotential model EIGEN-6C4 and the astrogeodetic measurements taken in the Western Siberia region are analyzed. The study has shown that in plains, standard deviations of DOV model values from the terrestrial data obtained by traditional astrogeodetic method do not exceed 1 arcsec.

The paper pioneers the complex experimental investigation of the metal-ceramic coating made by the additive technologies, the combination of the cold gas-dynamic spraying (CS) and following layered laser processing. The coating is made of ceramic powders WC and B4C, the concentration in the initial mixture of 10-70 wt.%, and metal powders based on Ti+Al, the ratio 94:6 wt.%, and Ni. The result is the strategy of the production of the heterogeneous material without pores and cracks by the consequent deposition of the powder by the CS method followed by the laser action; the thickness of the coating is 4 mm.

The paper considers a complex technology of navigation and geodetic support for airborne geophysical surveys by the example of an airborne electromagnetic survey that makes use of an outboard platform connected to the helicopter with a cable. The technology is based on satellite and photogrammetric methods. The innovation methods used to determine navigation and geodetic parameters are protected by the Russian patents and have been tested in practice. The paper presents the results of the authors’ long-term experience in this field of research.

The zoned composition changes of the massive sulfide deposits in the major massive sulfide zone of the Southern Urals such as the Magnitogorsk Megasynclinorium are considered. The zoning is expressed as the trend of Ni–Co–Cu → Zn–Cu → Cu–Zn → Au–Ba–Pb–Cu–Zn. This trend is related to two basic factors: (1) the subduction process with the slab’s eastward subsidence preconditioned the formation (from the west to the east) of the following massive sulfide zones: accretionary prism, frontal island arc, developed island arc, inter-arc spreading zone, split back arc, and back-arc spreading; (2) the longitudinal zoning of the massive sulfide paleovolcanic belts related to changes in the thickness of the crust’s basaltic layer and an inclination of the subducting plate in transverse blocks of the belt. The first factor affects the general paleovolcanic and metallogenic latitudinal zoning of the studied region, while the second factor defines the local meridional zoning. The composition of ore-bearing solutions is dependent on the formation depth of the subduction fluids, magma differentiation type, and the ratio of deep fluids to solutions of near-surface convective cells. The combination of the geodynamic factors expressed in the composition of ore-bearing volcanic complexes and the specific geological settings defines the massive sulfide mineralization composition and productivity criteria. The most productive structures include the frontal island-arc and inter-arc spreading zones and within them, the central-type volcanic edifices whose basalts are referred to as the island-arc tholeiite series and are characterized by the minimum TiO2and Zr content and low La/Yb ratios.

Regularizing properties of stabilizing factors are studied to improve the accuracy of the Fourier series summation by spherical functions, used to describe the Earth’s gravitational field. The efficiency of the tested methods is estimated using the nonregularized global gravity field model ITSG-Grace2014s available on the ICGEM website [8].