Vol 488, No 4 (2019)

Mathematics
Universal computational algorithms and their justification for the approximate solution of differential equations
Betelin V.B., Galkin V.A.
Abstract

The paper is devoted to the problem that determines the typical characteristics of computing equipment associated with the amount of work needed to obtain a result at a given point in the computation domain. The use of grid methods is associated with the need for continuous processing and storage of data arrays determined by the number of grid elements, which is directly proportional to the performance of the systems used. We consider alternative approaches for the construction and justification of computational methods that are not focused on the grid structure of the approximations. The substantiation of the convergence of kinetic approximations to the solution of the Cauchy problem is obtained.

Доклады Академии наук. 2019;488(4):351-357
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Inferences on parametric estimation of distribution tails
Rodionov I.V.
Abstract

We propose a general method of parameter estimation of a distribution tail that does not depend on the fulfillment of the conditions of Gnedenko theorem. We prove the consistency of the proposed estimator and its asymptotic normality under the stronger conditions imposed on the parametric family of distribution tails. Additionally, the adaptation of the proposed method to Weibull and log-Weibull tail indices estimation is provided.

Доклады Академии наук. 2019;488(4):358-361
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Mathematical physics
Infinite Kirchhoff plate on a compact elastic foundation may have arbitrary small eigenvalue
Nazarov S.A.
Abstract

An inhomogeneous Kirhhoff plate composed from semi-infinite strip-waveguide and a compaсt resonator which is in contact with the Winkler foundation of small compliance, is considered. It is shown that for any ε > 0, it is possible to find the compliance coefficient O(ε 2) such that the described plate possesses the eigenvalue ε 4 embedded into continuous spectrum. This result is quite surprising because in an acoustic waveguide (the spectral Neumann problem for the Laplace operator) a small eigenvalue does not exist for any unsubstantial perturbation. A reason of this dissension is explained as well.

Доклады Академии наук. 2019;488(4):362-366
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An inverse phaseless problem for electrodynamic equations in an anisotropic medium
Romanov V.G.
Abstract

For the system of equations of electrodynamics which has the anisotropy of the permittivity, an inverse problem of determining the permittivity is studied. It is supposed that the permittivity is characterized by the diagonal matrix ∈ = diag (ε1(x), ε1(x), ε2(x)) and ε1 and ε2 are positive constants anywhere outside of a bounded domain Ω0 ⊂ ℜ3. Periodic in time solutions of the system of Maxwell’s equations related to two modes of plane waves falled down from infinity on the local non-homogeneity located in Ω0 is considered. For determining functions ε1(x) and ε2(x) some information on the module of the vector of the electric strength of two interfered waves is given. It is demonstrated that this information reduces the original problem to two inverse kinematic problems with incomplete data about travel times of the electromagnetic waves. An investigation of the linearized statement for these problems is given. It is shown that in the linear approximation the problem of the determining ε1(x) and ε2(x) is reduced to two X-ray tomography problems.

Доклады Академии наук. 2019;488(4):367-371
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Technical Physics
The influence of the heating scheme of a heterogeneous drop on the characteristics of micro-explosion fragmentation
Antonov D.V., Rebrov A.K., Strizhak P.A.
Abstract

According to the experimental results, a comparison of sizes of child-droplets after micro-explosion of drop based on water and diesel has been made. Convective, conductive, or radiative heat exchange has been dominated. The temperature of the medium and the relative volume concentration of the flammable liquid have been varied in ranges: 100-450 °С, 10-90 vol. %. The ratios of the sizes of the formed drops to the initial ones have been established. The conditions, which make it possible to increase the total evaporation surface area of a liquid by tens of times, are shown.

Доклады Академии наук. 2019;488(4):372-376
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Mechanics
Modelling the attitude dynamics of small spacecraft with a magnetic attitude control system in three-axis stabilization mode
Kulkov V.M., Egorov Y.G., Firsyuk S.O., Terentyev V.V., Shemyakov A.O.
Abstract

The problem of modeling the attitude-control modes of small spacecraft with the use of electromagnetic systems, interacting with the Earth’s magnetic field is considered. A small spacecraft angular motion mathematical model is developed. A control law for magnetic attitude control system of small spacecraft is formulated. Results of satellite with magnetic attitude control system movement numerical modelling are presented.

Доклады Академии наук. 2019;488(4):377-382
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Chemistry
Polymers with regular alternation of 1,7-bis[(dimethyl)silylmethylene]-m-carborane and diorganosiloxane units
Izmaylov B.A., Vasnev V.A., Markova G.D.
Abstract

New high-thermostable carboranylmethyl-containing diorganosiloxane polymers have been obtained by polycondensation of equimolar amounts of 1.7-bis[hydroxy(dimethyl)silylmethylene]-m-carborane with bis(dimethylamino)diorganosilanes. It was shown, that in the case of replacement of 24 to 33 mol. % of dimethylsiloxane units with methylphenylsiloxane or diphenylsiloxane units with bulk phenyl groups, only amorphous polymers are formed. The polymers are highly soluble in organic solvents and have high thermostability.

Доклады Академии наук. 2019;488(4):383-385
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Physical chemistry
Effect of Fe nanopowder sample density on ignition parameters at heating in the air
Alymov M.I., Vadchenko S.G., Suvorova E.V., Zelensky V.A., Ankudinov A.B.
Abstract

Ignition of Fe nanopowders of bulk density and its samples compacted to relative density of 0,3-0,5 was studied while they were heated in the air. The ignition temperature of the compacted samples does not depend on the heating rate and comprises 100-115 °C. The oxidation process includes the stages of inert heating, ignition, surface and filtration modes of the reaction and afterburning. The time of the active stages, i.e. ignition and filtration mode, depends on the sample density at the same heating terms. It allows one to develop storage methods of Fe nanopowders as compacts.

Доклады Академии наук. 2019;488(4):386-390
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The interaction effect of bacterial cellulose with gold nanoparticles obtained by metal-vapor synthesis
Rubina M.S., Pigaleva M.A., Butenko I.E., Budnikov A.V., Naumkin A.V., Gromovykh T.I., Lutsenko S.V., Vasil’kov A.Y.
Abstract

In the present work, a promising method was proposed for the formation of new functional nanocomposite materials based on bacterial cellulose and Au nanoparticles obtained by a biocompatible and environmentally friendly metal vapor synthesis. The structure and composition of the composite films surface were studied by XPS, SEM, and IR spectroscopy. It was determined that Au nanoparticles effectively chemisorb the bacterial cellulose nanofibrils forming nanoparticles with a size of about 25 nm with a “metal core-hydrocarbon shell” structure.

Доклады Академии наук. 2019;488(4):391-396
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Geology
New minimal 87SR/86SR values in biogenic carbonates of the Permian of the Omolon massif (North-Eastern Asia)
Biakov A.S., Brynko I.V., Bond D.P., Harvey J., Goryachev N.A., Vedernikov I.L., Filimonova T.V.
Abstract

For the first time very low values (up to 0,706707) of the ratio 87Sr/86Sr were recorded in the biogenic carbonates of the Omolon massif (Northeast Asia) of the Capitanian age. These results are in good agreement with previously obtained data on limestones in Japan (Kani et al., 2013; 2018). In general, the strontium ratio curve constructed by us repeats the well-known world trend, differing by its somewhat underestimated (by an average of 0,000-0,0008) its values. The Capitanian strontium minimum can be associated with the entry into the ocean of significant amounts of lightweight femic strontium due to a sharp increase in paleospreading. The maximum values of the strontium ratio, obtained from the middle part of the Intomodesma evenicum bivalve Subzone are 0,706986, which corresponds to the upper part of the Wuchiapingian stage.

Доклады Академии наук. 2019;488(4):397-402
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Geochemical environments of the Archean-Proterozoic
Kuznetsov V.G.
Abstract

In the Precambrian section, there is a change of Archean calcite carbonate rocks to magnesia and ferrous in the Proterozoic. This is correlated with the massive development of cyanobacteria, the absorption of which carbon dioxide and the generation of oxygen, led to a change in the acidic reduction conditions of Archaean alkaline oxidizing in the Proterozoic.

Доклады Академии наук. 2019;488(4):403-407
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Active faults of the Kerch’s Peninsula: new results
Ovsyuchenko А.N., Vakarchuk R.N., Korzhenkov A.M., Larkov A.S., Sysolin А.I., Rogozhin E.A., Marahanov A.V.
Abstract

In the paper there are results of a recent study of the active faults in the Kerch’ Peninsula. There was compiled a Map of Active Faults - sources of the strong earthquakes occurred in Late Holocene. The map is a regional seismotectonic model of strong earthquake sources - detailed basis for a spatial prognosis of the seismic hazard. Results of the study show that the Kerch’ Peninsula demonstrates signs of the classical morphostructures, and a morphology of the modern peninsula contours is caused by the large active fault zones.

Доклады Академии наук. 2019;488(4):408-412
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Geochemistry
The sources of zircons in clastic rocks of the Riphean deposits of the Urals
Krasnobaev A.A., Puchkov V.N., Sergeeva N.D., Busharina S.V.
Abstract

New age determinations of detrital zircons of sandstones augmented the possibilities of interpretation of their provenance. This interpretation is often restricted by a formal comparison of age-and-composition characteristics of detrital crystals with any very distant model objects. A different situation arises when the role of a source of a detritus is claimed by local objects. The analysis of SHRIMP and TIMS - datеs of zircons and U and Th concentrations in them, and also a comparison of histograms of primary zircons from Riphean volcanics and rocks of the Taratash complex on one hand and the detrital zircons from the sandstones of Vendian (Asha series) and Lower Riphean (Ai Formation) on the other, have shown that the age variations of sources and clastics are comparable in many aspects. It means that the age characteristics of primary zircons from the Riphean volcanics and rocks of the Taratash complex as sources of zircon clastics for the Riphean and Vendian sandstones in the Southern Urals are regulated by processes of resedimentation, though the influence of distant sources is not excluded.

Доклады Академии наук. 2019;488(4):413-419
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Modeling method for obtaining kinetic parameters of metamorphic reactions in texture-homogeneous rocks
Likhanov I.I.
Abstract

A new approach for deriving kinetic parameters of diffusion-controlled metamorphic reactions is described. It is based on comparison of models of temperature field evolution near a cylindrical intrusion and observable chemical changes in minerals at the contact aureole of the Kharlovo massif. The calculations yielded estimates of the effective rates of metamorphic reactions (~10-12 s-1) and the effective diffusion coefficient (5.29 ·10-16 cm2s-1 at T = 475 °С). These values are consistent with experimentally and theoretically derived estimates of solid-state diffusion, including grain-boundary diffusion in mineral aggregates and segregations for the respective PT-parameters.

Доклады Академии наук. 2019;488(4):420-424
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Microscopic fungi sorption of chemical elements from multicomponent solution
Pavlova L.M., Shumilova L.P., Radomskaya V.I., Sorokin A.P., Ivanov V.V.
Abstract

The data of micromycetes’ species and strain specificity in the process of toxic elements extracting from multicomponent solutions were obtained as results of modal experiments. The results also indicate the capability of biogenic mineral formation in organic strata.

Доклады Академии наук. 2019;488(4):425-428
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Geophysics
Seismic attributes of basement in Podvodnikov Basin
Butsenko V.V., Poselov V.A., Zholondz S.M., Smirnov O.E.
Abstract

The seismic attributes of the basement in the Podvodnikov Basin (primarily its P-wave velocities (5.9-6.2 km/s), the VP /VS ratio (1.71), the characteristic diffraction features of reflections from the basement) indicate the continental origin of the basin and suggest that its tectonic evolution began at the pre-oceanic stage of geological history of the Arctic.

Доклады Академии наук. 2019;488(4):429-433
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On shear wave velocity in the top of the Earth’s inner core
Krasnoshchekov D.N., Ovtchinnikov V.M., Usoltseva O.A.
Abstract

Analysis of PKIIKP waves reflected off the inner surface of the solid core boundary and recorded close to the antipode indicates the shear wave velocity in its top can be by 10-60% below 3.5 km/s envisaged by standard models of the Earth.

Доклады Академии наук. 2019;488(4):434-438
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Geography
Regularities of the variability of large-scale sea ice drift structures in the Arctic Ocean (based on satellite data 1978-2017)
Volkov V.A., Mushta A.V., Demchev D.M.
Abstract

Based on the 39-year satellite observation data series (1978-2017), three main types of large-scale sea-ice drift field in the Arctic Ocean (AO), characteristic of the winter season, were identified. The types of atmospheric circulation that form the structure of the drift fields are identified, the mechanism of the effect of changes in the drift fields on the interannual variations in the ice cover of the AO is described.

Доклады Академии наук. 2019;488(4):439-442
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Biochemistry, biophysics, molecular biology
The novel element in the mechanism of endogenous regulation of depressive-like states
Garibova T.L., Gudasheva T.A., Seredenin S.B.
Abstract

It was shown previously that cyclo-prolylglycine, an endogenous neuropeptide, is a positive AMPA receptor modulator and is able to increase the content of BDNF in neurons. In the present work it was shown that cyclo-prolylglycine at a dose of 1 mg/kg with subchronic intraperitoneal administration reduces the time of animal immobility to passive control, from 167.6 to 83.6 s on the 12th day of the experiment using the model of learned helplessness in rats. That indicates the presence of antidepressant-like activity. The results of the study allow us to consider that cyclo-prolylglycine is a link in the physiological regulation of a depressive-like state.

Доклады Академии наук. 2019;488(4):443-445
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Expression of P-type ATPases of marine green microalga Dunaliella maritima under hyperosmotic salt shock
Khramov D.E., Matalin D.A., Karpichev I.V., Balnokin Y.V., Popova L.G.
Abstract

Partial sequences of P-type ATPases were cloned from the marine microalgae Dunaliella maritima: two presumably H+-ATPases (DmHA1 and DmHA2) and two putative Ca2+-ATPases (DmCA1 and DmCA2). The functions of cloned proteins were estimated on the bases of their primary structure similarity with the proteins whose functions have been already characterized. The transcriptional response of cloned ATPase genes to a sharp increase in the NaCl concentration in the culture medium (from 100 to 500 mM) was investigated by quantitative RT-PCR. Hyperosmotic salt shock led to a significant increase in DmHA2 expression and to a slight increase in DmCA2 expression, while the expression of two other ATPases, DmHA1 and DmCA1, was repressed. The obtained data indicate that DmHA2 is involved in maintenance of ion homeostasis in D. maritima cells under hyperosmotic salt shock.

Доклады Академии наук. 2019;488(4):446-451
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Cell biology
Immunoistochemical and morphological study of periodont tissues when predicting the results of dental implantation in patients with chronic parodontitis
Kulakov A.A., Kogan E.A., Brailovskaya T.V., Vedyaeva A.P., Zharkov N.V.
Abstract

A morphological and immunohistochemical study of 24 gums biopsies was conducted in 19 patients aged 35-60 years with a diagnosis of partial secondary edentulous, chronic generalized periodontitis of moderate and severe degree (14 patients), and also without pathological changes in the periodontal disease (5 patients), who underwent dental implantation. Immunohistochemical reactions with antibodies to Ki-67, VEGF, SMA were performed on serial paraffin sections. It has been established that chronic periodontitis is characterized by a higher proliferative activity of the epithelium, which reflects its hyperplastic changes, as well as a lower content of SMA positive cells and the practical absence of the formation of privascular couplings from SMA-positive cells that are associated in tissues with “growth zones”, which indirectly indicates reduced tissue regenerative capacity. Therefore, in the case of the operation of dental implantation requires additional treatment aimed at anti-inflammatory and pro-regenerative effects.

Доклады Академии наук. 2019;488(4):452-456
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General biology
Personality influences risk of parasitism in fish
Mikheev V.N., Pasternak A.F., Taskinen J.
Abstract

Influence of fish personality on infection rate is almost not studied. In the experiments on the young-of-the-year Oncorhynchus mykiss and cercariae of a trematode Diplostomum pseudospathaceum we tested the hypothesis that infection rate differs between more and less active (“bold” and “shy”) fish. Will individual differences in infection persist upon re-infection? Fish serve as a second intermediate host for this trematode. A positive correlation was found between the results of consecutive infections. Accumulation of parasites with successive infections leads to an aggregated distribution of D. pseudospathaceum among the hosts, affecting individual fitness and polymorphism in fish populations. Persistent individual differences in parasite burden among fish and, as a result, vulnerability for predators confirms the role of parasites as an important factor of natural selection.

Доклады Академии наук. 2019;488(4):457-460
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