Vol 484, No 6 (2019)

Mathematics
Detailed description of the evolution mechanism for singularities in the system of pressureless gas dynamics
Aptekarev A.I., Rykov Y.G.
Abstract

The system of pressureless gas dynamics is a hydrodynamically justified generalization of the system consisting of the Burgers vector equation in the limit of vanishing viscosity and the mass conservation law. The latter system of equations was intensively used, in particular, in astrophysics to describe the large scale structure of the Universe. The solutions of the vector Burgers equation involve interesting dynamics of singularities, which can describe concentration processes. However, this dynamics does not satisfy the law of momentum conservation, which prevents us from treating it as dynamics of material objects. In this paper, momentum-conserving dynamics of singularities is investigated on the basis of the pressureless gas dynamics system. Such dynamics turns out to be more diverse and complex, but it is also possible to formulate a variational approach, for which the basic principles and relations are obtained in the work.

Доклады Академии наук. 2019;484(6):655-658
views
Molecular dynamics of water clusters and interaction potentials
Belega E.D., Trubnikov D.N.
Abstract

The molecular dynamics method was used to analyze the dynamic characteristics of water clusters in the solid and liquid phase. A criterion is proposed for choosing the interaction potential, which is based on the distributions of the potential energy of cluster molecules in different phases. The connection of the obtained distributions with the dynamics and structure of the hydrogen bonds’ net of the cluster is shown.

Доклады Академии наук. 2019;484(6):659-662
views
On classical solutions to the first mixed problem for the Vlasov-Poisson system in an infinite cylinder
Belyaeva Y.O., Skubachevskii A.L.
Abstract

The first mixed problem for the Vlasov-Poisson system in an infinite cylinder is considered. This problem describes the kinetics of charged particles in a high-temperature two-component plasma under an external magnetic field. For an arbitrary electric field potential and a sufficiently strong external magnetic field, it is shown that the characteristics of the Vlasov equations do not reach the boundary of the cylinder. It is proved that the Vlasov-Poisson system with ion and electron distribution density functions supported at some distance from the cylinder boundary has a unique classical solution.

Доклады Академии наук. 2019;484(6):663-666
views
Reachability of optimal convergence rate estimates for high-order numerical convex optimization methods
Gasnikov A.V., Gorbunov E.A., Kovalev D.A., Mokhammed A., Chernousova E.A.
Abstract

The Monteiro-Svaiter accelerated hybrid proximal extragradient method (2013) with one step of Newton’s method used at every iteration for the approximate solution of an auxiliary problem is considered. The Monteiro-Svaiter method is optimal (with respect to the number of gradient and Hessian evaluations for the optimized function) for sufficiently smooth convex optimization problems in the class of methods using only the gradient and Hessian of the optimized function. An optimal tensor method involving higher derivatives is proposed by replacing Newton’s step with a step of Yu.E. Nesterov’s recently proposed tensor method (2018) and by using a special generalization of the step size selection condition in the outer accelerated proximal extragradient method. This tensor method with derivatives up to the third order inclusive is found fairly practical, since the complexity of its iteration is comparable with that of Newton’s one. Thus, a constructive solution is obtained for Nesterov’s problem (2018) of closing the gap between tight lower and overstated upper bounds for the convergence rate of existing tensor methods of order p ≥ 3.

Доклады Академии наук. 2019;484(6):667-671
views
Informatics
Reconstruction of three-dimensional maps based on closed-form solutions of the variational problem of multisensor data registration
Vokhmintcev A.V., Melnikov A.V., Mironov K.V., Burlutskiy V.V.
Abstract

A closed-form solution is proposed for the problem of minimizing a functional consisting of two terms measuring mean-square distances for visually associated characteristic points on an image and meansquare distances for point clouds in terms of a point-to-plane metric. An accurate method for reconstructing three-dimensional dynamic environment is presented, and the properties of closed-form solutions are described. The proposed approach improves the accuracy and convergence of reconstruction methods for complex and large-scale scenes.

Доклады Академии наук. 2019;484(6):672-677
views
Physics
11B NMR STUDY OF AMORPHOUS ALLOYS Fe85-xCrxB15 (x = 0-20)
Pokatilov V.S., Sigov A.S., Makarova A.O., Pevtsov E.F.
Abstract

Amorphous alloys Fe85-xCrxB15 (x = 0-20), prepared by rapid quenching of the melt, have been studied by pulsed nuclear magnetic resonance (NMR) on nuclei 11B at a temperature of 4,2 K. The amorphous alloys consist of nanoclusters with short-range order of the tetragonal t-(Fe, Cr)3B and α-(Fe, Cr) phases which contain chromium atoms in the nearest surroundings of boron atoms. The average magnetic moments of magnetic atoms in the nearest sphere of boron atoms in nanoclusters and their dependence on the chromium content in alloys are estimated.

Доклады Академии наук. 2019;484(6):678-681
views
Technical Physics
Variations in the strain parameters of titanium nickelide during martensitic transformation cycling
Erofeev V.Y., Kabanov M.V.
Abstract

The results of analyzing the long-term variations in the strain rate of a TiNi element during martensitic transformation cycling have been reported. It is shown that the factors involved in the formation of the state of the environment lead to unstable operation of functional technical elements similar to those based on titanium nickelide.

Доклады Академии наук. 2019;484(6):682-685
views
Astronomy, Astrophysics, Cosmology
Features of the fossil tidal bulge formation for the early moon
Voropaev S.A., Dnestrovskii A.Y., Marov M.Y.
Abstract

The limitations imposed on the orbit and the distribution of the density of the early Moon by present-day measurements of its fossil tidal bulge are studied. A semi-analytical method has been developed for calculating gravitational potentials, which makes it possible to investigate the equi-potential surfaces of a self gravitating inhomogeneous mass in an external field. Universal expressions are obtained for the two-layer mantle-crust model of the early Moon, which makes it possible to make general estimates of the density of the upper crust and semiaxes of its orbit in the case of tidal capture by the Earth.

Доклады Академии наук. 2019;484(6):686-690
views
Chemistry
Dynamics of dissolved inorganic carbon and co2 fluxes between water and atmosphere in the main channel of the ob river
Pipko I.I., Pugach S.P., Savichev O.G., Repina I.A., Shakhova N.E., Moiseeva Y.A., Barskov K.V., Sergienko V.I., Semiletov I.P.
Abstract

The results of investigation of the carbonate system parameters dynamics in the middle and lower reaches of the Ob River in July 2016 were analyzed. The distributions of the carbonate characteristics of the river waters were found to follow a steady latitudinal trend determined by the landscape-geochemical conditions of the drainage basin and by the permafrost distribution. The first field data on the magnitude and direction of the CO2 fluxes in the river water-atmosphere system in this region were presented. It was shown that the waters in the middle and lower reaches of the river are multiply supersaturated with CO2 with respect to its atmospheric content, and the daily average evasion reaches 625,9 mmol m-2 day-1 at an average value of 102,1 mmol m-2 day-1. It was determined that the waters of the Ob River in the studied reaches are a significant CO2 source to the atmosphere; according to conservative estimates, the total flux in July was 2 ⋅ 1011 g of carbon in the form of CO2.

Доклады Академии наук. 2019;484(6):691-697
views
New photochromic salt spiropyrans of indoline series
Pugachev A.D., Lukyanova M.B., Tkachev V.V., Lukyanov B.S., Makarova N.I., Shilov G.V., Rostovtseva I.A., Lapshina L.S., Minkin V.I., Aldoshin S.M.
Abstract

The synthesis and study of the structure and photochromic properties of the new salt spiropyrans of the indoline series containing chlorine and bromine atoms as a substituent at the 6' position in 2H-chromene moiety are presented. The structure of the obtained compounds was confirmed by NMR 1H spectroscopy and X-ray diffraction analysis. The compounds are photochromic; the long-wavelength maximum of the absorption band of their open photoinduced form has a significant hypsochromic shift, and the lifetime substantially increases in comparison with the fluorine analog.

Доклады Академии наук. 2019;484(6):698-702
views
Chemical Technology
Electrospray preparation of biocompatible lactide–glycolide copolymer capsules with incorporation of interferon
Khlusov I.A., Kibler E.V., Kudryavtseva V.L., Tverdokhlebov S.I., Bolbasov E.N., Botvin V.V., Latypov A.D., Gazatova N.D., Litvinova L.S., Buznik V.M., Choynzonov E.L.
Abstract

The electrospray method was used for the first time to prepare polymeric capsules from bioresorbable dl-lactide and glycolide copolymer loaded with biological molecules from the cell secretome and, in particular, human interferon a-2b (IFN a-2b). The obtained nearly spherical submicron capsules were studied by scanning electron and confocal laser microscopy. The capsules retain the structural integrity and the cytotoxic activity of IFN a-2b towards tumor cells. The electrospray method is distinguished by high adaptability and environmental safety and is suitable for manufacture of a broad range of materials with different composition and morphology promising for the targeted delivery of drugs and biological molecules.

Доклады Академии наук. 2019;484(6):703-708
views
Production of hollow ceramic rods by SHS extrusion
Chizhikov А.P., Stolin A.M., Bazhin P.M., Alymov M.I.
Abstract

The possibility of producing hollow ceramic rods from an Al2O3-based material by SHS extrusion was first shown. A mechanism of formation of such rods by die swell was proposed. It was demonstrated that, at high temperatures, the material can have viscoelastic properties. The studies were performed in the system 2B2O3-6Al-2Cr2O3, in which a ceramic material based on aluminum and chromium oxides with strengthening chromium boride particles forms by self-propagating high temperature synthesis and redox reactions.

Доклады Академии наук. 2019;484(6):709-711
views
Physical chemistry
Nanostructured ZrO2-Y2O3-based systems for perovskite solar cells
Vildanova M.F., Nikolskaia A.B., Kozlov S.S., Karyagina O.K., Larina L.L., Shevaleevskiy O.I., Almjasheva O.V., Gusarov V.V.
Abstract

ZrO2–Y2O3 nanostructured systems with different yttria content (Y2O3 = 0, 3 and 10 mol.%) were synthesized under hydrothermal conditions and their structural, optical and electronic properties were investigated. Using ZrO2–Y2O3 systems the electron-conductive thin-film photoelectrodes were fabricated and used to develop the perovskite solar cells (PSCs) with the device configuration glass/FTO/ZrO2-Y2O3/CH3NH3PbI3/spiro-MeOTAD/ Au. The comparative studies of the PSCs photovoltaic parameters revealed that under 1000 W/m2 (AM1.5G) illumination solar cells with ZrO2–Y2O3 photoelectrodes demonstrated considerably higher power conversion efficiency in comparison with PSCs based on the undoped ZrO2 photoelectrodes.

Доклады Академии наук. 2019;484(6):712-715
views
Geology
Mineralogical-geochemical types and 190Pt-4He age of ferroan platinum of placers of the Anabar River basin, northeastern part of the Siberian Platform
Okrugin A.V., Yakubovich O.V., Gedz A.M., Zemnukhov A.L., Ivanov P.O.
Abstract

Typical features of platinum group minerals (PGMs) and the results of 190Pt–4He dating of the Fe–Pt solid solutions are presented for complex gold–platinum–diamond placers with unidentified sources of the Anabar River basin. For the first time, the 190Pt–4He isotopic system is used for determination of the possible age of the primary source of a PGM placer from the example of ferroan platinum with a disordered structure along with isoferro- platinum. The PGMs of these placers mostly include ferroan platinum and isoferroplatinum and rare Ru–Ir–Os alloys. The calculated bulk composition of the silicate inclusion of Ir platinum corresponds to the rocks of the ijolite–melteigite series. The 190Pt–4He age of the Fe–Pt solid solution grains is 261 ± 13 Ma. Thus, our data indicate the relation between placer PGMs of the Anabar River basin and Permian-Triassic complexes of alkaline-ultramafic rocks.

Доклады Академии наук. 2019;484(6):716-720
views
Rare Th-Sc minerals in picrites of the Southern Urals and their genetic value
Kovalev S.G., Puchkov V.N., Kovalev S.S., Vysotsky S.I.
Abstract

The first data on the discovery of Th-Sc mineralization in the pyritic complexes of the Southern Urals are presented. The minerals of Th (thorite) and Sc-containing thorium minerals are described. The conclusion is made that the Th-Sc mineralization formed due to crystallization of a residual melt in the local volume.

Доклады Академии наук. 2019;484(6):721-724
views
Paleoproterozoic age of carbonates and trondhjemites of the central azov group: Sr-isotope chemostratigraphy and U-Pb geochronology
Kuznetsov A.B., Lobach-Zhuchenko S.B., Kaulina T.V., Konstantinova G.V.
Abstract

The Sr-isotope composition of the Central Azov Group carbonates (0.70322-0.70352) and Nd model age of silicate sediments (2.34-2.31 Ga) has been reported. The U-Pb age of trondhjemite (2052+5 Ma) cutting the carbonates has been determined. According to the obtained data, the marine sedimentary cover of the Azov block making up the Early Precambrian Sarmatia Continent emplaced in the Early Paleoproterozoic at 2.23-2.34 Ga.

Доклады Академии наук. 2019;484(6):725-728
views
The relationship between global volcanic activity and variations in the velocity of Earth's rotation
Levin B.W., Sasorova E.V., Gurianov V.B., Yarmolyuk V.V.
Abstract

Analysis of observations of the Earth's rotational velocity and volcanic activity of the planet from 1720 until 2015 suggests that higher volcanic activity temporally coincided with periods of decreased angular velocity of Earth's rotation (deceleration), and, vice versa, lower volcanic activity coincided with the periods of increased velocity of the Earth's rotation (acceleration). Our analysis employed the data from the catalog by the Smithsonian Institute, United States, in which each volcanic explosion had its own determined value of the Volcanic Explosivity Index (VEI). The total number of selected intensive eruptions with VEI > 4 was 160, including 25 eruptions with VEI > 5. At present (beginning from 2006), the Earth was entry in a deceleration phase and series of catastrophic eruptions reveals the tendency toward intensifying volcanic activity.

Доклады Академии наук. 2019;484(6):729-733
views
The exotic inim block of the argun continental superterrane of the central asian fold belt: results of U-Th-pb geochronological (LA-ICP-MS) and Sm-Nd isotopic-geochemical studies
Ovchinnikov R.O., Sorokin A.A., Kotov A.B., Sal'nikova E.B., Kovach V.P., Sorokin A.P.
Abstract

The results of studies indicate that the age of the protoliths of garnet-bearing biotite–sericite–muscovite schists of the Inim Block is <991 Ma, and they are derived from rocks of the Neo-, Meso-, and Paleoproterozoic (as well as Archean) crust. This suggests that the Inim Block is exotic relatively to the Argun Superterrane due to the formation of the protolith of its metasedimentary rocks largely from erosion products of the Early Precambrian continental crust, the presence of which within the Argun Superterrane is not proven. It is not excluded that the Inim Block is a fragment of the Dzhugdzhur–Stanovoi Superterrane implanted in the structure of the Argun Superterrane as a result of Mesozoic tectonic events.

Доклады Академии наук. 2019;484(6):734-738
views
Geochemistry
First data on the nature and age of the protolith of high-pressure tectonites of Yenisei ridge: a link to the early stage of formation of the Paleoasian Ocean
Likhanov I.I., Savko K.A.
Abstract

The petrogeochemical characteristics of high-pressure mafic tectonites from the Yenisei suture zone of Yenisei Ridge indicate that N-MORB and E-MORB with an age of 701.6 ± 8.4 Ma were their protolith. The formation of N-MORB with the more primitive chemical composition occurred at the initial stages of spreading, when the upper horizons of the depleted mantle were molten. The high-Ti basalt was formed as the product of melting of the enriched mantle substrate at the later stages of spreading. These events are related to the early stage in the evolution of the Paleo-Asian Ocean on the western margin of the Siberian Craton.

Доклады Академии наук. 2019;484(6):739-744
views
Geophysics
Comparison of borehole geoacoustic and electromagnetic data with data of earthquake focal mechanisms
Gavrilov V.A., Lander A.V., Morozova Y.V.
Abstract

The results of comparing the data of two methods of geophysical monitoring of the stress-strain state of a borehole of the geoenvironment in the zone of Petropavlovsk-Kamchatsky geodynamic testing site to the data on the focal mechanisms of earthquakes that occurred in this zone on the same time interval are presented.

Доклады Академии наук. 2019;484(6):745-749
views
Geography
New possibilities of remote spectrometry of surface water bodies
Sukhorukov B.L., Nikanorov A.M.
Abstract

Article presents a new approach to the analysis of spectrometric data obtained by modern spectrometers in the visible range of wavelengths for surveys of surface water bodies. The efficiency of the new approach in the interpretation of spectrometric data in the visible range is shown with the use, proposed by us, of the space of optical images (SOI) formed by a combination of experimental and model ranges of the remote sensing reflectance (RS). The RS ranges calculated parallel to measuring the absorbance indexes in particular hydrological seasons with a known structural composition of phytoplankton permit us to gradate the SOI with respect to the structural composition of phytoplankton. The curve of the status of the ecosystem of the Don River constructed by the data of remote spectrometry shows changes in the structure of phytoplankton during the observation period.

Доклады Академии наук. 2019;484(6):750-754
views
Oceanology
Features of vortical suppression of tsunami waves underwater barriers
Boshenyatov B.V., Zhiltsov K.N.
Abstract

The features of vortical suppression of tsunami waves by an impermeable underwater barrier have been studied. The height of the barrier is close to the optimum corresponding to the maximum effect of vortical suppression of the wave energy. It is shown that the energy of suppressing tsunami waves by such a barrier depends on the wave height and can vary from zero to 80% of the incident wave energy.

Доклады Академии наук. 2019;484(6):755-759
views
Biochemistry, biophysics, molecular biology
The steroidogenic effect of a low-molecular agonist of luteinizing hormone receptor in the course of its administration to male rats
Bakhtyukov A.A., Derkach K.V., Dar'in D.V., Shpakov A.O.
Abstract

The thienopyrimidine derivative TP03 (a low molecular weight agonist of the luteinizing hormone receptor, LHR), when administered to male Wistar rats, stimulated the production of testosterone (“T”), elevated level of which was maintained for 7 days, and increased the expression of the LHR gene. At the same time, the steroidogenic effect of human chorionic gonadotropin (hCG), which significantly increased the “T” level on the first day of treatment, was further weakened, which was accompanied by a decrease in the expression of the LHR gene in the testes, indicating the development of resistance of Leydig cells to hCG. In the testes, the hCG treatment induced a compensatory increase in the expression of genes of the steroidogenic enzymes, such as the cytochrome P450scc and the dehydrogenase 3P-HSD. In the case of TP03 treatment this effect was absent.

Доклады Академии наук. 2019;484(6):760-763
views
Quality assessment of decellularization and recellularization of tissue-engineering constructions by the chemiluminescence method
Gubareva E.A., Kuevda E.V., Kade A.K., Bykov I.M., Pavlyuchenko I.I., Gaivoronskaya T.V., Sidorenko A.N., Tsymbalov O.V., Ovsyannikov V.G., Myasnikova V.V., Shashkov D.I., Dzhimak S.S.
Abstract

It has been established that indicators of the intensity of chemiluminescence in the native and muscle cellized tissues of rat muscular organs, as well as in their decellularized matrices, can serve as one of the express criteria that allows, along with ultrastructural analysis, to quantify the viability of cell structures in biological samples of the diaphragm.

Доклады Академии наук. 2019;484(6):764-767
views
Magnetic fields and magnetic isotope 25Mg effects on biofilms formation by bacteria E. coli
Letuta U.G., Tikhonova T.A.
Abstract

The biofilm formation by bacteria E. coli is a magnetosensitive process. The combined effects of a magnetic magnesium isotope 25Mg and a static magnetic field in the range of 20-35 mT stimulate biofilm formation by bacteria E. coli compared to non-magnetic magnesium isotopes 24,26Mg. Magnetic field effects in the range of 2-10 mT, registered for all bacteria regardless of magnesium-isotope enrichment of nutrient medium, indicate the sensitivity of intracellular processes to weak magnetic fields.

Доклады Академии наук. 2019;484(6):768-771
views
Functional analysis of coilin in virus resistance and stress tolerance of potato Solanum tuberosum USING CRISPR/Cas9 editing
Makhotenko A.V., Khromov A.V., Snigir E.A., Makarova S.S., Makarov V.V., Suprunova T.P., Kalinina N.O., Taliansky M.E.
Abstract

The role of the nuclear protein coilin in the mechanisms of resistance of potato Solanum tuberosum cultivar Chicago to biotic and abiotic stresses was studied using the CRISPR/Cas9 technology. For the coilin gene editing, a complex consisting of the Cas9 endonuclease and a short guide RNA was immobilized on gold or chitosan microparticles and delivered into apical meristem cells by bioballistics or vacuum infiltration methods, respectively. Editing at least one allele of the coilin gene considerably increased the resistance of the edited lines to infection with the potato virus Y and their tolerance to salt and osmotic stress.

Доклады Академии наук. 2019;484(6):772-776
views
Innate immune protein Tag7 stimulates the appearance of cytotoxic NK cells after incubation with lymphocytes
Sharapova T.N., Romanova E.A., Sashchenko L.P., Gnuchev N.V., Yashin D.V.
Abstract

Tag7 (PGRP-S) is an innate immune protein that is involved in the antibacterial and antitumor defense and stimulates the maturation of cytotoxic lymphocyte subpopulations. It was found that the incubation of lymphocytes with Tag7 for 3 days promotes the appearance of cytotoxic NK cells that are active against a number of tumor cell lines.

Доклады Академии наук. 2019;484(6):777-780
views
General biology
To the analysis of weak two-locus viability selection and quasi linkage equilibrium
Pasekov V.P.
Abstract

A model of weak viability selection at two multi-allele loci with standardization of approaches through the use of perturbation theory is examined. The estimate of the quasi-equilibrium value for the linkage disequilibrium coefficient D is analyzed, and results in terms of average effects in quantitative genetics and in terms of the theory of singular perturbations in mathematics are obtained. The approximation of a discrete-time model of a random mating population with non-overlapping generations under weak selection by ordinary differential equations is considered. Weak selection is considered as a perturbation of the model without selection. The resulting model is singularly perturbed; that is, fast (D) and slow (allele frequencies) variables can be distinguished. The first approximation equation for quasi-equilibrium of D is obtained using the first terms of the Taylor series expansion of the model functions. It coincides with the corresponding part of the system of the first approximation of the asymptotic series for solving singularly perturbed equations.

Доклады Академии наук. 2019;484(6):781-785
views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies