Vol 484, No 5 (2019)
- Year: 2019
- Articles: 28
- URL: https://journals.eco-vector.com/0869-5652/issue/view/758
- DOI: https://doi.org/10.31857/S0869-56524845
Mathematics
A construction of reflecting Lévy processes
Abstract
For some classes of Lévy Processes, the notion of reflection from an interval boundary is introduced. It is shown that trajectories of a reflecting process define random operator that map functions defined on the interval boundaries into elements of L2 on the whole interval.
Local metric properties of level surfaces on Carnot–Caratheodory spaces
Abstract
For level sets of -mappings of Carnot manifolds to Carnot–Caratheodory spaces, we introduce an adequate local metric characteristic. Moreover, for mappings defined on Carnot groups, we construct a special adapted basis in the preimage such that it assigns a suitable local sub-Riemannian structure on a complement of a kernel of a sub-Riemannian differential to the initial sub-Riemannian structure in the image.
Mathematical physics
On the formation of structures in nonlinear problems of physical kinetics
Abstract
A number of phenomena associated with the formation of macroscopic structures due to the high interaction intensity of elements of spatially homogeneous systems and due to linear spatial transport in spatially inhomogeneous systems are addressed. A characteristic feature of the considered class of problems is the violation of the continuity of the operators describing the evolution of a system in natural norms determined by local conservation relations.
Control theory
Inversion of hyperoutput time-delay systems
Abstract
An inversion problem for LTI hyperoutput time-delay system is considered. For such systems canonical form with isolated zero dynamics is obtained, system invariant zeros and their relation to spectral observability of zero dynamics subsystem are investigated. Using this results, inversion algorithm is suggested for time-delay systems.
Mechanics
Large deformations of a cylindrical tube with prestressed coatings
Abstract
The problem of large deformations in a combined nonlinear elastic hollow cylinder under internal and external pressures, loaded with a longitudinal force and torque at the end faces, is under consideration. The combined cylinder is a tube with the internal and external coatings in the form of prestressed hollow circular cylinders. An exact solution to the problem is found, which is valid for any model of isotropic incompressible elastic materials.
Large deformations of a cylindrical tube with prestressed coatings
Abstract
General theoretical relations for calculating the redistribution of the preliminary irreversible strain field during unloading or elastic loading of a medium are obtained for the nonlinear multiplicative gradient model of large elastic-plastic deformations. It is shown that the dynamics of elastic shock waves does not depend directly on the previously accumulated plastic strains. A formula for the plastic-strain rotation tensor is obtained. It is shown that rigid rotation of plastic strains under elastic shock waves can be jump-like. All results are obtained for the general case of model relations of isotropic media and are valid for both compressible and incompressible materials.
MHD effects in continuous spin detonation
Abstract
Conversion possibility of the chemical energy of combustion products of a hydrogen–oxygen mixture into electrical energy with the use of continuous spin detonation has been demonstrated for the first time in an MHD system. The specific conductivity of detonation products in the region of rotation of the detonation front was measured to be ~3 · 10–2 Ω–1 m–1. The structure of transverse detonation waves was examined, their velocity was measured (2220 ± 50 m/s), and the flow in their vicinity was studied.
Chemistry
New approach at x-ray investigation of microstructure of supersaturated films of CdxPb1-xS solid substitutional solutions
Abstract
The films of supersaturated CdxPb1-xS solid substitutional solutions (0 < x < 0,25) with thickness 0.6–1.0 μm were synthesized by chemical bath deposition. The dependences of dislocation density, crystallite sizes and texture coefficient versus the cadmium content in the films were determined by analyzing X-ray diffraction spectra with the use of modified method of Williamson—Hall (MWH).
Thermodynamic analysis of the interaction of components in the Si–C–O system in the carbothermic synthesis of silicon carbide
Abstract
Phase equilibria in the Si–C–O system at temperatures of 1400–1700°C were modeled to theoretically determine the optimal conditions for implementing our proposed method of carbothermic synthesis of silicon carbide in reactors with an autonomous protective atmosphere. It was found that, depending on the ratio between the initial components and the synthesis temperature, the equilibrium products of the synthesis can be various combinations of silicon carbide, a gas phase, residual amounts of silicon oxide and carbon, andan oxide melt formed at high temperatures.
Magnetic resonance imaging of water absorption by highly porous ceramic materials
Abstract
By using the magnetic resonance imaging method the nontrivial character of water absorption was demonstrated for the first time in highly porous ceramic materials. The effect of hygroscopic memory was found out which is that the preferable concentration of absorbed water in certain areas within the sample persists regardless the subsequent sample wetting history. Coating the oxide fibres with fluorine-containing hydrocarbons in supercritical CO2 in order to hydrophobize the material has been shown to affect substantially the water transport within the sample that can be referred to as an effective approach to protect the porous materials from humid environment. The results obtained demonstrate the advantages of the magnetic resonance imaging in studying the water absorption processes and visualization of water pathways in highly porous ceramic materials.
The redox properties and antiradical activity of terpenophenols
Abstract
The redox properties and antiradical activity of terpenophenols (2,6-diisobornyl-4-methylphenol and 3-isocamphyl-2-naphthol) in comparison with BHT (butylhydroxytoluol, 2,6-di-tret-butyl-4-methylphenol) have been studied. The terpenophenols have been shown to react more readily in electron transfer processes as compared with BHT, and they have been found to react with electrochemically generated superoxide radical anion (О2•–). The effect of the compounds on the rate of generation upon adrenaline oxidation in an alkaline medium and the ability of biopreparations based on Russian sturgeon liver and gonad homogenates to deactivate have been studied. Adrenaline oxidation inhibition and the increase in superoxide dismutation activity of the biopreparations in the presence of terpenophenols have been shown, and this fact can indicate the ability of these compounds to decrease the probability of oxidative stress enlargement. A correlation has been established between the redox properties and antioxidant activity of terpenophenols in the model system of adrenaline oxidation in the presence of the biopreparations.
Chemical Technology
The distribution of Nb and Ce betweet two immiscible melts in the system CePO4–SiO2–NaF–Fe2O3–Nb2O5
Abstract
The CePO4 – SiO2 – NaF – Fe2O3–Nb2O5 system is characterized by a wide area of two immiscible melts. As the temperature in the system increases, the region of incompressibility of melts increases. Mutual solubility of immiscible melts is low and is 3–5% by weight. The decrease in the melting point of the components is due to chemical reactions between SiO2 and NaF and between cerium orthophosphate and sodium fluoride. New previously unknown phases were established in the system: double salt of cerium and sodium, fluoride phosphate of cerium and sodium and phase with high content of niobium. Niobium oxide is distributed between the silicate melt, silicate balls, which is part of the phosphate fluoride melt and a phase with a high content of niobium. Cerium is concentrated in the phosphate-salt melt, where it is found in the double salt of cerium and sodium and the fluoride phosphate of cerium and sodium.
Geology
Kumystin granosyenites complex of the late Cryogenian in Bolshoi Karatau (South Kazakhstan), age substantiation
Abstract
The results of U–Pb geochronological studies of quartz syenites of the Kumystin complex of the Bolshoi Karatau ridge in southern Kazakhstan are presented and their late Neoproterozoic (717 ± 4 Ma) age is substantiated. Kumystin syenites complex together with rhyolites and basalts of the Kainar Formation are the youngest formations taking part in the basement of Karatau-Dzhebagly precambrian massif and formed in the second half of Cryogenian. The data set about the ages of the youngest complexes taking part in the basement of precambrian massifs of the Western part of the Central Asian belt indicates that the ending of magmatic activity within various massifs occurred asynchronously during the Neoproterozoic.
Early Jurassic magmatism of the Kobyuminsky system of grabens (Verkhoyansk frame of the Siberian platform) and its geodynamic nature
Abstract
The Kobyuminsky system of grabens was formed in the Early Jurassic within the Verkhoyansk passive margin of the Siberian platform. The volcanic complex of grabens is represented by basalts with elevated TiO2 contents (> 1.8 wt%). According to geochemical characteristics, the rocks of the volcanic series occupy an intermediate position between the basalts of the oceanic islands (OIB) and the basalt-rich mid-oceanic ridges (E-MORB). The data obtained led to the conclusion that the Kobuminsky system of grabens within the passive margin of the Siberian continent arose in connection with the activity of a small mantle plume.
Two genetic types of pseudotachylytes
Abstract
The study of two varieties of pseudotachylytes (PST) in granitoids of the Riphean complex on the Barents Sea coast of the Kola Peninsula (Rybachii and Srednii peninsulas) and in metapsammite of the Paleoproterozoic complex in the Northern Ladoga region by a few independent analytical methods has made it possible to establish that they belong to different genetic forms, such as mechanically crushed rocks and melting products, respectively. As for the melting differences, we have given a detailed description of the mineral and material transformations of the original rock into the PST glass matrix and obtained evidence for the initial melting out of the micaceous eutectics with its subsequent shift to the granite type. The conclusion has been made on the most likely formation of molten PST due to frictional rock melting under rapid rise of its blocks from a depth of 12–15 km to the crustal surface (less than 3 km) along the faults of presumably seismogenic nature. It is suggested that crushing and frictional melting can be complementary, rather than mutually exclusive processes, and the formation of molten PST is commonly preceded by the mechanical rock crushing stage.
Geochemistry
Interphase distribution of rare and rare earth elements in silicate-fluorine systems at T = 800–1200˚C AND P = 1–2 kbar (experimental investigation)
Abstract
The melting in the system of aluminosilicate (granite) melt — fluoride salt melt at T = 800–1200˚C and P = 1–2 kbar was experimentally investigated. The data on the phase composition of silicate-salt systems and the character of the interphase distribution of ore components are presented. The partition coefficients of rare-earth elements between the granite melt and fluoride phase at 900–1200˚C, P = 1–2 kbar were obtained. It is shown that REE enrich the fluoride phase with respect to the silicate melt. Elements of the (V, Nb, Ta), (Ti, Zr, Hf) groups almost always prefer a silicate melt relative to fluoride.
Origin of hydrocarbons in suspended matter and bottom sediments near the Crimean peninsula
Abstract
It was established that the content of hydrocarbons in the surface waters of the Feodosia Gulf fluctuated were varied a wide range (11–179 μg/l), and exceeded the MPC values for petroleum hydrocarbons in individual samples. The highest concentrations were observed in 2016. The composition of alkanes suggested their mixed (autochthonous and allochthonous) origin. The weathered petroleum hydrocarbons have been identified only in a few cases. In bottom sediments, the concentrations of hydrocarbons depended on their grain size distribution, and terrigenous alkanes were dominated in their composition. The oil and pyrogenic hydrocarbons’ pollution were established based on the composition of polycyclic aromatic hydrocarbons. In the open part of the Black Sea, southward the Crimean peninsula, the hydrocarbon content in surface waters and bottom sediments were at the level of background concentrations, and homologs of terrigenous origin dominated in their composition.
The physical nature of heterogeneity of the composition of river water
Abstract
Experimental data are presented to show that the spatial and temporal variability of the composition of river waters cannot be explained solely by the influence of sources and effluents of the substances and that there are additional significant factors that support or even initiate the dispersion of the concentration of pollutants here. This variation is reflected in the resources and the economic characteristics of the rivers; so identification of its reason is important. Thus, the hydrodynamic structure of the water flow is studied by analyzing the complete system of equations of fluid motion mechanics. The completed work allowed us to show that the elements of this structure are waves, vortices, and highly gradient layers (ligaments), presumably creating the described dispersion effect. Further investigation of the relationship of the precise hydrodynamic and hydrochemical structures of river waters will contribute to better understanding of the water-environmental processes, ensuring the perfection of water management methods.
Geophysics
Infrasound signals from earthquakes of December 5, 2014 in the water area of lake Hovsgol, Northern Mongolia
Abstract
A comprehensive analysis of waveforms of seismic and infrasonic vibrations from the earthquake that occurred on December 5, 2014, in the water area of Lake Hovsgol was performed. The analysis showed that the infrasonic signal recorded at the Tory station (Geophysical Observatory of the Institute of Solar-Terrestrial Physics, Russian Academy of Sciences) was formed by the sources of three generation types: local, secondary, and epicentral. The obtained results allow us to propose the model of epicentral infrasonic signal generation by flexural waves from an elastic ice membrane on the surface of Lake Hovsgol.
Geography
Large-scale atmospheric–oceanic interaction regimes in the Norwegian and Barents seas
Abstract
Large-scale atmosphere–ocean interaction in the Atlantic sector of the Arctic Ocean is analized. New studies demonstrate that the variability of Atlantic water inflow into Nordic seas is driven largely by the leading mode of year-to-year variations in the ocean – atmosphere system–the North Atlantic Oscillation (NAO). A new vision of the effect of the NAO on the hydrophysical characteristics of the Norwegian and Barents seas is offered.
Oceanology
Picophytoplankton of the Laptev sea in the autumn
Abstract
The abundance and biomass of picophytoplankton, the total concentration of chlorophyll “a”, and the contribution of the picofraction to chlorophyll “a” were studied in the Laptev Sea in 2017. These were the first data for the western sea area. An increase in picophytoplankton abundance in the eastern part of the sea in comparison with that in 1991 was not revealed. The contribution of the picofraction to chlorophyll “a” was the highest (to 56%) in areas with a low total concentration of chlorophyll “a”.
Biochemistry, biophysics, molecular biology
Personalized approach to assessing mRNA expression of histidine-rich glycoprotein and immunohistochemical markers in diseases of the breast
Abstract
Biopsy material of patients with malignant and benign breast diseases was examined. HRG mRNA expression was detected in 70% of cases in biopsy material obtained from patients with nonspecific invasive carcinoma and in 66.7% of cases in biopsy material of patients with benign breast diseases. Immunohistochemical analysis revealed expression of collagen II, the beta-1 integrin, and E-cadherin – markers of epithelial–mesenchymal transition. The use of RT-qPCR combined with immunohistochemical study made it possible to identify atypical cells, which can be regarded as precancerous changes, in individual patients.
Sigma-1 receptor antagonists haloperidol and chlorpromazine modulate the effect of glutoxim on NA+ transport in frog skin
Abstract
Using voltage-clamp technique, the involvement of sigma-1 receptors in immunomodulatory drug glutoxim regulation of Na+ transport in frog skin was investigated. We have shown for the first time that preincubation of the frog skin with sigma-1 receptor antagonists – haloperidol or chlorpromazine – attenuates the stimulatory effect of glutoxim on Na+ transport. The results suggest the possible involvement of the sigma-1 receptors in glutoxim effect on Na+transport in frog skin epithelium.
Oncogene c-MYC controls the expression of PHF10 subunit of PBAF chromatin remodeling complex in SW620 cell line
Abstract
The PBAF(SWI/SNF) multiprotein complex, which changes the chromatin structure, is widely involved in the regulation of eukaryotic gene expression. A specific component of this complex is the PHF10 protein, which is involved in recruiting this complex to chromatin. We showed that the PHF10 expression in cells of different lines is activated by the c-MYC oncogene. Since PHF10 stimulates cell proliferation, its c-MYC-dependent activation in cancer cells should lead to an increase in their proliferation rate.
Development of an immunosorbent for solid-phase NMR-based assay
Abstract
The conditions for constructing an immunosorbent reagent for solid-phase NMR analysis were optimized. For this purpose, we increased the area of the sensitized portion of the membrane to fit the relaxometer coil size and added the agent sorption buffer. This provided the penetration of the anti-ligand molecules into the membrane thickness and their uniform distribution.
Regulation of recombinase RAG-1 expression by female sex steroids in Treg and Th17 lymphocytes. role of oncostatin M
Abstract
The effect of estradiol (E2), progesterone (P4), and oncostatin M (OSM) on the differentiation of CD4+ T cells to T regulatory (Treg) lymphocytes and T helpers 17 (Th17) was investigated. The possibility of revision of the T cell receptor in these subpopulations by evaluating the expression of RAG-1 recombinase was also studied. E2 at concentrations characteristic of pregnancy trimester I, but no P4 or OSM, increased the Treg level. Combination of sex steroids with OSM increased the percent of CD4+FOXP4+ cells and enhanced RAG-1 expression in these cells, thus promoting the development of immune tolerance during pregnancy. In the study of Th17 such effect of the hormones and OSM was not detected.
Physiology
Endothelium-dependent hyperpolarization-mediated relaxation pathway in bovine mesenteric lymph nodes
Abstract
In vitro, endothelium-dependent relaxation mechanisms of smooth muscle cells of the bovine mesenteric lymph node capsule have been studied. The addition of L-NAME and indomethacin to physiological saline inhibited the production of endothelium NO and prostacyclin. In this solution, tetraethylammonium chloride and TRAM-34 increased the tone of the precontracted lymph nodes. Thus, in bovine mesenteric lymph nodes there is an relaxation mechanism mediated by endothelial hyperpolarization, realized by activating Ca2+-dependent K+-channels of large- and intermediate conductance.