Vol 486, No 5 (2019)

Mathematics
Optimal feedback control for alpha-Leray model and for alpha-Navier-Stokes model
Zvyagin А.V.
Abstract

The existence of optimal feedback control for the alpha-Leray model and for the alpha-Navier-Stokes model are proved. The existence of an optimal solution yielding the minimum of a specified bounded lower semicontinuous quality functional is obtained. To establish the existence of an optimal solution, the topological approximation method for studying problems of hydrodynamics is used.

Доклады Академии наук. 2019;486(5):527-530
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Operator cosine-functions and boundary value problems
Kostin V.A., Kostin A.V., Kostin D.V.
Abstract

For the first time, the theory of strongly continuous operator cosines of functions (COF) is applied to the study of the correct solvability of boundary value problems for second-order linear differential equations in Banach space (elliptic case). Usually in COF terms the correct solvability of the Cauchy problem (hyperbolic case) is formulated. The note specifies the conditions on the order of COF growth under which the Dirichlet boundary value problem is correct on the finite interval. The integral representation of the solution and its exact estimation are given.

Доклады Академии наук. 2019;486(5):531-536
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Hydrodynamic instabilities and nonequilibrium phase transitions
Radkevich E.V., Lukashev E.A., Vasil’eva O.A.
Abstract

For laminar-turbulent transition model is built reconstruction of the initial stage of instability as a nonequilibrium phase transition, the mechanism of which is diffusion stratification. It is shown that the Gibbs free energy deviations from the homogeneous state (relative to the instability under consideration) is an analogue Ginzburg-Landau potentials. Numerical experiments were performed. Self-excitation of a homogeneous state by edge control condition of increasing speed. Under external influence (increase in speed at the input), there is a transition to chaos through bifurcations of period doubling, when the internal control parameter (analogue of the Reynolds number) changes, like the Feigenbaum period doubling cascade.

Доклады Академии наук. 2019;486(5):537-542
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Physics
The results of the competitiveness analysis of photovoltaic microgeneration systems in the Russian Federation
Gabderakhmanova T.S., Popel O.S.
Abstract

The results of the economic feasibility assessment of photovoltaic (PV) microgeneration systems by the criterion of the cost of energy are presented. The assessment is based on dynamic modelling of three different configurations of grid-connected PV systems - without energy storage, with electrical energy storage and with thermal energy storage - performed for weather and electricity tariff conditions of several prospective Russian regions. Government support measures and regulatory standards currently developing in Russia for microgeneration technologies are taken into account. It is shown that under certain conditions PV microgeneration technologies could be economically feasible in some energy isolated areas and non-pricing zones of the wholesale electricity and capacity market of Russia, particularly in the Sakha Republic, whereas in pricing zones - couldn’t for any of the considered system configurations.

Доклады Академии наук. 2019;486(5):543-546
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Mechanics
On subharmonic motions of a pendulum in a movable platform
Markeev A.P.
Abstract

The motion of a pendulum on a rotating platform is investigated in the presence of disturbances caused by its vertical harmonic oscillations of small amplitude. The parameters of the unperturbed system are considered close to the values, upon passing through which the number of relative equilibria of the pendulum and the nature of their stability change. The non-linear problem of the existence and stability of periodic motions of the pendulum relative to the platform with a period multiple to the period of its vertical oscillations is solved. The question of the splitting of separatrices of the unperturbed system is also considered.

Доклады Академии наук. 2019;486(5):547-553
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Physical chemistry
On the mechanism of the process of digestive ripening
Irzhak T.F., Irzhak V.I.
Abstract

The literature describes a relatively new method of regulating the size distribution function of nanoparticles - the process of digestive ripening, which, unlike Ostwald ripening, consists in dissolving large nanoparticles and forming small ones. However, a reasonable explanation of this phenomenon is still missing. The work substantiates the mechanism of the process, based on taking into account the dependence of the critical radius of the nanoparticle on the concentration of monomeric units and the size of the ligand layer.

Доклады Академии наук. 2019;486(5):554-557
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Improving the strength properties of aluminum powder materials by the addition of magnesium oxide nanoparticles
Mironov V.V., Agureev L.E., Eremeeva Z.V., Kostikov V.I.
Abstract

New data were obtained on the effect of small additions of magnesium oxide nanoparticles on the mechanical properties of aluminum. For the preparation of samples of composites, cold pressing and sintering of powdered aluminum, including those with copper, were used in the forvacuum. As a result, a significant increase in the strength properties of materials modified with magnesium oxide nanoparticles was found: tensile strength, compression, bending strength, and yield strength.

Доклады Академии наук. 2019;486(5):558-561
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Geology
New data concerning the ferromanganese crusts of the Mendeleev rise (Arctic Ocean)
Bazilevskaya E.S., Skolotnev S.G.
Abstract

The results of study of Fe-Mn crusts from the Mendeleev Rise in the Arctic Ocean in 2016 sampled with manipulators from a submarine are presented. Concentrations of Fe, Mn, Co, Ni, Zn, Cu, Cr and Pb are measured in collected Fe-Mn crusts. The variations in the content of these elements are determined by the chemical properties of the elements, the height of the underwater topography, the composition of the underlying substrate and the presence of bottom silt.

Доклады Академии наук. 2019;486(5):562-566
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The first U-Pb (SHRIMP-II) evidence of the Franklin tectonic event at the western margin of the Siberian craton
Likhanov I.I., Reverdatto V.V.
Abstract

Geochemical and isotope-geochronological evidence of the manifestation of Late Riphean intraplate magmatism within the Chernorechensky massif at the western margin of the Siberian craton were obtained. These rocks crystallized from high-temperature and anhydrous (water unsaturated) magmas with high concentrations of alkalis, iron, and, mostly incompatible elements, which is typical for anorogenic A-type granites in intraplate extension setting. Their U-Pb zircon age 723 ± 6 Ma can be correlated with the Franklin rift event widely manifested in the north of Laurentia, associated with the breakup of Rodinia. The synchronous successions and similar style of magmatic activity and concomitant rifting, as well as a similar sequence of tectonic-thermal events along the Arctic margin of Rodinia support the spatial proximity of Siberia and the North Atlantic cratons at this time as proposed for the paleogeographic reconstructions.

Доклады Академии наук. 2019;486(5):567-571
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The Lower Precambrian in the structure of paleozoic in the Subpolar Urals
Pystina Y.I., Pystin A.M., Hubanov V.B.
Abstract

In many polymetamorphic complexes of the Urals, rocks with Early Precambrian age marks have been established. But only with respect to the two polymetamorphic complexes located on the western slope of the Southern Urals: the Taratash and Aleksandrov, their indisputable belonging to the Archean-Paleoproterozoic section is recognized. They are framed by weakly metamorphosed Lower Riphean sediments and reliable geochronological data are obtained from them, which unambiguously indicate the Early Precambrian age of rock metamorphism. The available Early Precambrian age datings for other Ural polymetamorphic complexes (with the prevailing number of Late Precambrian and Paleozoic age values) are interpreted differently. Therefore, their attitude to the Lower Precambrian section has been disputed by many researchers. In the article, for the first time, based on the results of mass U-Pb dating of metamorphic zircons from the gneiss of the Nyrtin polymetamorphic complex of the Subpolar Urals, taking into account the available data, the Paleoproterozoic age of the earliest stage of rocks metamorphism (2127 ± 31 Ma) is substantiated. This gives grounds to assert that the complex under consideration, as well as the Taratash and Alexandrov complexes of the Southern Urals, belongs to the Lower Precambrian formations involved in the structure of Uralides.

Доклады Академии наук. 2019;486(5):572-576
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Conditions of formation of Paleozoic picrite basalt complexes of the basement of the Western Siberian Plate
Simonov V.A., Kontorovich V.A., Stupakov S.I., Filippov Y.F., Saraev S.V., Kotlyarov A.V.
Abstract

The carried out researches with the help of 40Ar/39Ar analysis have shown a coincidence of formation (about 490 million years) of Paleozoic picrite and basalt complexes of the basement of the Western Siberian Plate. The data on petrochemistry, geochemistry of rare and rare-earth elements, and also on compositions of clinopyroxenes, testifies to formation of picrites of borehole № 11 (Chkalovsky area) as a result of action of intra plate magmatic systems of oceanic islands - OIB. Calculations on the basis of clinopyroxene compositions speak about considerable parameters of crystallization of picrite porphyrite minerals: 1215-1275 °C, 4.5-8 kbar. As a whole, it is established that considered picrite basalt complexes were formed with the assistance of enriched plume magmatic systems in intra plate conditions of ancient ocean near to its active margin.

Доклады Академии наук. 2019;486(5):577-582
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Geochemistry
Geochemistry of garnet megacrysts from the Mir kimberlite pipe (Yakutia) and the nature of prothokimberlite melt
Agashev A.M.
Abstract

The paper presents the results of major and trace elements composition study of garnet megacrysts from Mir kimberlite pipe. On the major elements composition those garnets classified as low Cr and high Ti pyropes. Concentrations of TiO2 show a negative correlation with MgO и Cr2O3 contents in megacrysts composition. Fractional crystallization modeling indicates that the most appropriate melt to reproduce the garnet trace elements signatures is the melt of picritic composition. Composition of garnets crystallized from kimberlite melt do not correspond to observed natural garnets composition. Kimberlites contain less of Ti, Zr, Y and heavy REE (rare earth elements) but more of very incompatible elements such as light REE, Th, U, Nb, Ba then the model melt composition that necessary for garnet crystallization.

Доклады Академии наук. 2019;486(5):583-587
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Hafnium isotope composition of zircon from the Kondyor clinopyroxenite-dunite massif (Khabarovsk territory, Russia)
Badanina I.Y., Belousova E.A., Malitch K.N.
Abstract

This study evaluates for the first time Hf-isotope characteristics of zircon from dunite of the Kondyor massif, which is closely related to an economic platinum placer deposit. The significant range in εHf(t) values (from -8.4 ± 0.8 to 10.5 ± 1.3) in Mesozoic zircons indicates the interaction of a ‘juvenile’ mantle source with distinct magma sources, equivalent to a subcontinental lithospheric mantle and/or a continental crust. The peculiarities of the Hf-isotopic composition of Precambrian zircons (εHf(t) from -2.3 to +0.3) is consistent with their xenogenic origin and inheritance from basement rocks of the Siberian Craton.

Доклады Академии наук. 2019;486(5):588-592
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A new model of sulfur isotopes behavior in the modern submarine hydrothermal systems
Dubinina E.O., Bortnikov N.S.
Abstract

A model of sulfur isotope distribution at modern submarine hydrothermal systems is proposed. It is assumed that thermogenic sulfate reduction at the water-rock interaction zone takes place under closed system conditions respectively to fluid phase. As a result, the Rayleigh exhaustion with respect to the 32S isotope arises in the fluid. The model also takes into account the simultaneous extraction of reduced sulfur from surrounding rocks. The calculated fraction of extracted sulfur at the total content of reduced sulfur in the fluid varies from 0.15 to 0.06 for submarine systems associated with tholeiitic basalts and peridotites, respectively. The model application to published data can explain the well-known contradictions that have arisen during the study of the sulfur isotope composition of sulfides from world Ocean deep-sea edifices.

Доклады Академии наук. 2019;486(5):593-597
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U-Pb (SHRIMP) age of zircons from granitoid pebbles of Kukkarauk conglomerates of Vendian asha series in the Alatau anticlinorium (Southern Urals)
Krasnobaev A.A., Puchkov V.N., Sergeeva N.D., Busharina S.V.
Abstract

The absence of reliable radiometric data in Vendian deposits of the Uralian and other regions resulted in uncertainty of the ideas of the age of the lower boundary of Vendian. According to the decision of the Interdepartment Stratigraphic Committee, it is located at 600 ±10 Ma. Analysing zircons of granitoid pebbles from Kukkarauk Formation of the standard sections of Vendian in the Alatau anticlinorium, the authors obtained a concordant SHRIMP date - 713.6 ± 6.1 Ma; practically, it is up to now the only reliable date that can be used as a reference for the rocks in the provenance area of the Vendian basin in the Southern Urals which witness for a Vendian erosion of granites which are alike the granites of the Mazara and Barangulovo massifs, situated in the northern part of the Uraltau zone of the Southern Urals, to the east of the area of Vendian sedimentation.

Доклады Академии наук. 2019;486(5):598-602
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Sedimentary-migration of the magmatic hypothesis for the formation of oil
Skvortsov V.A.
Abstract

As a result of physical and chemical modeling of hydrocarbon formation conditions at the Ereminsko-Chonsky oil cluster (Leno-Tungusskoy oil and gas province), it was found that at the stage of sedimentogenesis at (T = 35 °C, P = 0.1 MPa) methane and organic matter accumulate at the bottom of the reservoir. With diagenesis (T = 60 °C and P = 5-10 MPa) at a depth of 60-100 m, films and oil droplets are observed in the formation of source formations in rocks, pentane C5H12 appears from liquid hydrocarbons. At the stage of catagenesis at a depth of 250 C6H14 hexene is formed, and at 2000 m - C7H16 heptene, at 3100 m - octane C8H12 and at 3800 m (at T = 90 °C and P = 110 MPa) - nonane C9H20. During the period of apocatagenesis and metamorphism (at T = 105 °C and P = 450 MPa), C10H22 dodecane is formed at a depth of 13-15 km, and C11H24 undecane is formed at T - 200 °C. When the temperature rises to 250 °C and the pressure reaches 490 MPa, at a depth of about 15 km, a large group of liquid hydrocarbons from dodecane C12H26 to pentadecan C15H32 and solids from hexadecan C16H34 to octadecane C18H38, as well as other groups, form in the basement rocks. When the pressure becomes 850 MPa, isoprenoids are observed at a depth of 25 km: from C19H40 to nonadecane to C24H50 to tetracosane, etc. Based on the simulation, it becomes obvious that it is not possible to explain the conditions for the formation of hydrocarbons in the range up to 25 km using only one of the hypotheses biogenic or abiogenic and a new sedimentary-migration-magmatic hypothesis of oil formation is proposed. Its essence is as follows: to a depth of 3800-4000 m, the source of hydrocarbons is methane, which accumulates at the bottom of water bodies, and organic matter of rocks, and at a depth of 13-15 and 25 km - mantle deep methane.

Доклады Академии наук. 2019;486(5):603-606
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Geophysics
Paleomagnetism of Middle Paleozoic bazites Southeast board of the Vilyui paleorift
Konstantinov K.M., Tomshin M.D., Konstantinov I.K., Yakovlev A.A.
Abstract

Formation of eastern frontier of the Siberian craton is bound to the riftogenny processes, which split the continent at the end of the Middle Paleozoic. The paleomagnetic data obtained on middle Paleozoic kimberlites and bazites from a zone of dynamic influence of the Vilyui paleorift indicate a turn of the Aldan terreyn rather Angaro-Anabar clockwise in the post-late Devonian time. The corner of a turn of terreyn gradually increases in east direction and reaches 22° for east flank of the Charo-Sinsk dyke belt.

Доклады Академии наук. 2019;486(5):607-612
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Geography
Metals composition of the surface waters of the Southern Baikal region and its connection with landscape and geological conditions
Semenov M.Y., Snytko V.A., Semenov Y.M., Silaev A.V., Semenova L.N.
Abstract

The metal composition of water and bottom sediments of southern Lake Baikal tributaries was studied and the water migration coefficients for micro- and trace elements were calculated. The map showing the study area divided into zones according to their ability to provide the certain water quality was drawn. The significant differences in mineralization, macro- and trace element composition between Lake Baikal water and tributary waters were found out. It was shown that values of water migration coefficients calculated for macro elements are similar in southern and main tributaries whereas coefficient values calculated for trace elements are quite different. This is due to dissolved matter sources such as rocks and deep ground waters which chemical composition is not typical for landscapes of Lake Baikal basin. The contribution of southern tributaries to macro element composition of lake water is between 7 and 15%, whereas tributaries contribution to trace element composition can hardly be evaluated because of higher element concentrations in riverine waters. The lower trace element concentrations in lake water with respect to riverine one is due to trace element migration in the form of complex organic compounds: long water residence time in lake favors to organic compounds decay by means of microbial- and photo-degradation followed by metal precipitation.

Доклады Академии наук. 2019;486(5):613-619
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Biochemistry, biophysics, molecular biology
Lipid fatty acid from the pericarp Cydonia oblonga Mill. and Mespilus germanica L. involved in plant adaptation to altitudinal zonality
Ivanova T.V., Voronkov A.S., Kuznetsova E.I., Kumakhova T.K., Zhirov V.K., Tsydendambaev V.D.
Abstract

The composition of fatty acids of total lipids of the outer and parenchymal part of the pericarp in Cydonia oblonga Mill and Mespilus germanica L. Maloideae (ROSACEAE), growing in the Northern Caucasian mountains at altitudes of 300, 500, 700, and 1200 m above sea level in various natural zones from experimental sites, was studied for the first time. It is established that the altitude of plant growth is largely correlated with the changes in the FA composition of the outer, but not the parenchymal, part of the pericarp. The nature of this variability suggests that the adaptation of plants to the conditions of significant temperature differences in the mountains is associated with the regulation of cell membrane fluidity, based on the interaction of opposite processes of synthesis of polyunsaturated and very-long-chain fatty acids.

Доклады Академии наук. 2019;486(5):620-625
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The spatial metabolic heterogeneity of solid type of Ehrlich carcinoma
Inzhevatkin E.V., Savchenko A.A.
Abstract

The NAD(P)-dependent dehydrogenase activity was studied in different fields of solid form of Ehrlich carcinoma. It was shown that there is a metabolic distinction between different fields of the solid tumor. In this way there is a significant difference between ascites and solid type of Ehrlich carcinoma.

Доклады Академии наук. 2019;486(5):626-630
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Physiology
Hypothermia induces postrepolarization refractoriness in the atrial myocardium of the hibernating and active ground squirrel Citellus undulatus
Kuzmin V.S., Abramov A.A., Egorov J.V., Rosenshtraukh L.V.
Abstract

The heart of the hibernating mammals demonstrates tolerance to the cold-induced arrhythmias and the electrophysiological mechanisms that underlie this phenomenon expecially in the atrial myocardium is still not elucidated. This study is aimed to the investigation of the hypothermia-induced changes of the atrial action potentials (AP) and refractoriness of the hibernating ground squirrel Citellus undulatus. APs were recorded with usage of standard sharp-electrode technique in the isolated, perfused multicellular continuously paced atrial myocardium preparations obtained from hibernating (HS) and summer active (SAS) squirrels. Action potentials duration (APD) and refractoriness duration (RD) were estimated at 37-17 °С and at various pacing cycle length (200-500 ms). It has been demonstrated that hypothermia causes prolongation of both APD and RD similarly in HS and SAS animals. However, the duration of the refractoriness in the atrial myocardium significantly exceeds the duration of the APs during hypothermia (27-17 °C). Revealed phenomenon may be considered as postrepolarization refractoriness (PRR). Proposed hypothermia-induced PRR probably substantially contributes to the insusceptibility of the hibernators to the cold induced arrhythmias by preventing the afterdepolarizations.

Доклады Академии наук. 2019;486(5):631-637
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General biology
Dental microwear and mesovear of Microtus voles before and after experimental feeding of owls
Kropacheva Y.E., Zykov S.V., Smirnov N.G., Salimov R.M.
Abstract

Form of expressions of dental microwear and mesovear of small mammals depends on abrasiveness, hardness and a number of other characteristics of the feed. Analysis of micro- and mesorelief is used on paleontological materials for the reconstruction of some parameters of the animals diet. Small mammals move a hard way from objects of biocenoses to fossils. Bone remains are modified in the process of accumulation and fossilization. In particular, bone remains from ornithogenous deposits were influenced to the substances of the digestive system of birds. In this work, an experimental estimation was made of the degree of changes in a number of characteristics of narrow-headed vole molars (Microtus gregalis) from the pellets of two species of owls. On the same samples before and after exposure to substances of the digestive system of a Polar Owl (Nyctea scandiaca) and Eagle Owl (Bubo bubo), it was shown that the microrelief of the tooth enamel undergoes serious changes and haven't information about the in vivo diet of the voles. A different degree of preservation of the mesoreliefs characteristic was shown. An assessment of their applicability for paleoreconstructions depending on this was given.

Доклады Академии наук. 2019;486(5):638-642
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Hypolagus brachygnathus (Lagomorpha, Leporidae) from the Lower Pleistocene of the Taurida Cave in Crimea
Lopatin A.V.
Abstract

The remains of Leporidae from the Lower Pleistocene deposits of the Taurida karstic cave discovered in 2018 in the central Crimea (Belogorsk district, Zuya village) are referred to Hypolagus brachygnathus (Kormos, 1930). This species is characteristic of the interval from the beginning of the Pleistocene (Late Villainian, MN17) to the Middle Pleistocene (latest Biharian, Q2) of Europe. It has not been previously observed in Crimea.

Доклады Академии наук. 2019;486(5):643-646
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