Vol 487, No 6 (2019)

Mathematics
On orbits of action of 5-dimensional non-solvable Lie algebras in three-dimensional complex space
Atanov A.V., Kossovskiy I.G., Loboda A.V.

Abstract

After the description by E. Cartan in 1932 holomorphically homogeneous real hypersurfaces of two-dimensional complex spaces, a similar study in the 3-dimensional case remains incomplete. In a series of works performed by several international teams of authors, the problem is reduced to describing homogeneous surfaces that are non-degenerate in Levi sense and have exactly 5-dimensional Lie algebras of holomorphic vector fields. In this paper, precisely such homogeneous surfaces are investigated. At the same time, a significant part of the extensive list of abstract 5-dimensional Lie algebras does not provide new examples of homogeneity. A complete description of the orbits of 5-dimensional non-solvable Lie algebras in a three-dimensional complex space, given in the paper, includes examples of new homogeneous hypersurfaces. The presented results bring to finish a large-scale scientific study of interest to various branches of mathematics.

Доклады Академии наук. 2019;487(6):607-610
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Finite-dimensional maps describing the dynamics of a logistic equation with delay
Glyzin S.D., Kashchenko S.A.

Abstract

This article discusses a family of maps that are used in the numerical simulation of a logistic equation with delay. This equation and presented maps are widely used in problems of mathematical ecology as models of the dynamics of populations. The paper compares the dynamic properties of the trajectories of these mappings and the original equation with delay. It is shown that the behavior of the solutions of maps can be quite complicated, while the logistic equation with delay has only a stable equilibrium state or cycle.

Доклады Академии наук. 2019;487(6):611-616
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Grothendieck-Serre duality and theta-invariants on arithmetic surfaces
Osipov D.V.

Abstract

In the paper, a description of the Grothendieck-Serre duality on an arithmetic surface by means of fixing a horizontal divisor is given and this description is applied to the generalization of theta-invariants.

Доклады Академии наук. 2019;487(6):617-621
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Physics
Caused by the giant magnetoresistive effect changes of microwave refractive index
Rinkevich A.B., Perov D.V., Kuznetsov E.A., Milyaev M.A.

Abstract

Studies of the interaction of electromagnetic microwaves with [Co88Fe12/Cu]n, nanostructures, in which the giant magnetoresistive effect (GMR) shows itself, have been carried out. It is established that the GMR effect contributes to changes in the microwave complex refraction coefficient, including the refractive index.

Доклады Академии наук. 2019;487(6):622-625
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Chemistry
New ferrocense containing tiophene derivatives
Rodlovskaya E.N., Vasnev V.A.

Abstract

A new 2-amino-4-ferrocenyl-thiophene-3-carbonitrile was synthesized by the Gevald reaction and Schiff bases, precursors for new optoelectronic and magnetic materials, were obtained on its basis. The structures of the synthesized compounds were determined by elemental analysis, IR and 1H NMR spectroscopy.

Доклады Академии наук. 2019;487(6):626-629
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Chemical Technology
Pyrolysis of derivatives of technical mixtures of polychlorinated biphenyls
Kulikova T.V., Maiorova A.V., Safronov A.P., Gorbunova T.I., Pervova M.G., Shunyaev K.Y., Leontiev L.I.

Abstract

Thermal stability and gas phase composition of the most common technical mixtures of polychlorinated biphenyls “Sovol” and “Trichlorobiphenyl” were studied by simultaneous thermal analysis and mass spectrometry compared to their derivatives synthesized by the interaction of these mixtures with sodium methoxide in dimethyl sulfoxide and methanol. For the first time it was established that derivatives of polychlorinated biphenyls are less thermostable compounds as compared with the initial products and under pyrolysis they undergo not only evaporation stages, but also decomposition processes to the simplest volatile substances. Thermal destruction of derivatives is characterized by a decrease in the level of emission of hazardous compounds and requires less energy.

Доклады Академии наук. 2019;487(6):630-635
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External friction in the process of SHS-compaction
Stolin A.M., Stelmakh L.S., Karpov S.V., Alymov M.I.

Abstract

On the basis of previously developed rheodynamic models of high-temperature SHS‑compaction, a theoretical analysis of the process of backward pressing with the active action of external friction force was carried out. It is shown that in this version of extrusion external friction is a useful technological effect, which allows to obtain a uniform distribution of density over the volume of the pressing material. Analytical relationships have been obtained for calculating the characteristic pressing time and stress distribution.

Доклады Академии наук. 2019;487(6):636-639
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Physical chemistry
Heat capacity and thermodynamic properties of SmFeGe2O7 in the range 350-1000 K
Denisova L.T., Izotov A.D., Kargin Y.F., Irtugo L.A., Beletskiy V.V., Belousova N.V., Denisov V.M.

Abstract

SmFeGe2O7 germanate was obtained by solid-state reactions from stoichiometric mixtures of starting oxides with multistage firing within 1273-1473 K. The effect of temperature on the heat capacity of the compound was studied using differential scanning calorimetry. Based on the dependence Cp = f(T), its thermodynamic properties are calculated.

Доклады Академии наук. 2019;487(6):640-643
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Geology
New data on the age of metamorphic rocks from the granite-greenstone ruker terrane (the southern Prince Charles Mountains, East Antarctica)
Alexeev N.L., Maslov V.A., Kaminsky V.D., Semenov V.S., Bogomolov E.S., Kapitonov I.N., Gonzhurov N.A., Melnik A.Y., Yegorov M.S.

Abstract

Paper presents results of isotope studies of primary igneous and sedimentary rocks of Mawson and Menzies series from the southern Prince Charles Mountains, East Antarctica. Obtained data show that igneous protholith crystallization of Mawson orthogneiss occurred at 3164,2±9,2-3163,2±7,8 Ma ago. The Mawson orthogneiss were a basement for Menzies series sediment. The maximum time of sediment deposition is estimated to be in the range of 3,0-3,1 Ga. Sediment protholith involves an admixture of Paleoarchean material.

Доклады Академии наук. 2019;487(6):644-649
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Finding the refractory inclusions in the meteorite Severny Kolchim (H3)
Berzin S.V., Ivanov K.S., Burlakov E.V.

Abstract

For the first time refractory forsterite rich objects were installed in meteorites in the meteorite Severny Kolchim (H3). Refractory forsterite rich objects are found mainly in carbonaceous chondrites, their finds in ordinary chondrites are wery rare. These inclusions are considered by most researchers as one of the earliest formations in the Solar System. The inclusions in the Severny Kolchim meteorite consist of high-magnesian forsterite (FeO 0,4-2%), CaO 0,5-1%, Al2O3 up to 0,4% and depleted by MnO. Some forsterite are intergrown with high-magnesian enstatite (FeO 0,5-2,5%), CaO up to 0,5%, Al2O3 up to 1,5% and depleted by MnO. A characteristic feature of forsterite-rich inclusions is that, unlike chondras, they are mostly represented by acute-angled fragments, which is probably due to their relatively frequent collisions.

Доклады Академии наук. 2019;487(6):650-652
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New U-Pb geochronological data on the age of volcanic-plutonic assemblage of Oloy belt, Alazey-Oloy fold system (West Chukotka)
Kara T.V., Luchitskaya M.V., Katkov S.M., Belousova E.A.

Abstract

New U-Pb (SIMS and LA-ICP-MS) geochronological data for rocks of Egdygkych complex of hypabyssal intrusions, Nichan and Vukney plutons, and felsic volcanic rocks and tuffs from host strata of Oloy volcanic belt of Alasey-Oloy fold system are obtained. Concordant ages of Egdygkych complex rocks correspond to Early Cretaceous (Berriasian-Valanginian), those for host strata, to the end of Late Jurassic (Tithonian) - beginning of Early Cretaceous (Berriasian). New U-Pb geochronological data allow confidently to distinguish uniform volcanic-plutonic assemblage of Late Jurassic (Tithonian) - Early Cretaceous (Berriasian-Valanginian) age of Oloy volcanic belt. Obtained data more definitely determine age limits of Au-Mo-Cu mineralization, associated with contacts between rocks of Egdydkych complex and host volcanic-sedimentary rocks or contacts of separated intrusive phases.

Доклады Академии наук. 2019;487(6):653-658
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Geochemistry
REE geochemistry and mineralogy of ores from the Talgan Cu-Zn massive sulfide deposit, South Urals
Ayupova N.R., Maslennikov V.V., Filippova K.A.

Abstract

The high REE contents (57,23-561,2 ppm) of thin-layered sulfide ores of the Talgan Cu-Zn massive sulfide deposit (South Urals) are related to the presence of REE minerals: galgenbergite, parisite, bastnesite, synchysite and xenotime, which were found for the first time in massive sulfide deposits of the Urals. These minerals occur in quartz-carbonate-chlorite matrix of sulfide layers, as well as pyrite nodules and sub- and euderal crystals. The chondrite-normalized REE patterns are enriched in LREEs relatively to HREEs and the presence of weak negative cerium and positive europium anomalies. The LREE contents decrease by an order of magnitude and the LREE and HREE contents become similar with decreasing amount of hyaloclastic material in sulfide layers. The REEs for the formation of REE minerals are derived from mixed carbonate-hyaloclastic and ore material during the formation of layered sulfide ores.

Доклады Академии наук. 2019;487(6):659-662
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First data on molybdenite and its primary orebody in Pay-Khoy (Nenets autonomous district): mineralogy, geochemistry, raman spectroscopy
Shaybekov R.I., Isaenko S.I., Tropnikov E.M.

Abstract

The first data on five primary molybdenite sources within the gabbro-dolerite complex of Pay-Khoy (Pay-Khoy Ridge, Yugra Peninsula, Russia) are presented. The mineral is extended areally in Devonian ore-bearing gabbro-dolerites, contact rocks, and quartz veins. This paper considers the mineralogical-geochemical features of molybdenite, its occurrence, the composition of host rocks, and spectroscopic studies.

Доклады Академии наук. 2019;487(6):663-668
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Geophysics
NOx-limiting regime of ozone generation in a weakly polluted boundary layer over Central Siberia as derived from O3 and Nox observations at Zotto tall tower observatory in 2007-2015
Moiseenko K.B., Berezina E.V., Vasileva A.V., Shtabkin Y.A., Skorokhod A.I., Elanskii N.F., Belikov I.B.

Abstract

Quantitative estimates on the ozone production efficiency (OPE) per a molecular of NOx (=NO+NO2), ΔP, and ozone production rate, PQ, are derived for the region of Central Siberia based on near surface observations of O3, NO, and NO2) at Zotino Tall Tower Observatory in 2007-2015. Experimental data follow are a power law dependencies on NOx abundance: PQ χ [NOx]-n+1, ΔP χ [NOx]-n, n = 0,82±0,06 (coefficient of determination R2 = 0,66), with the power law exponent corresponding to a NOx-limiting regime of ozone production in a weakly polluted air mass. During summer, the value of ΔP ranges from 30,0-43,7 [mol.O3/mol.NOx] which agrees well with the corresponding estimate of 39,8 [mol.O3/mol.NOx] derived from GEOS‑chem CTM model simulations. The derived estimates provide an observation based conclusion on the important role of regional anthropogenic emissions of NOx in summertime ozone photochemistry in the remote areas of Siberia.

Доклады Академии наук. 2019;487(6):669-673
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Geography
High resolution stable oxygen deuterium diagrams of ice wedges of Batagay yedoma, north of Central Yakutia
Vasil’chuk Y.K., Vasil’chuk J.Y., Budantseva N.A., Vasil’chuk A.C., Trishin A.Y.

Abstract

The main aim of the study is to determine stable oxygen and hydrogen isotope composition of Late Pleistocene syngenetic ice wedges of Batagay yedoma and to obtain the detailed isotope diagrams. Reconstructed mean January palaeotemperature is lower than -51 °С than completely confirmed validity of earlier created palaeotemperature maps for the period 30-25 thousand years ago where Batagay section is located within isotherm of -48 °С.

Доклады Академии наук. 2019;487(6):674-678
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Runoff over Siberian river basins as an integrate proxy of permafrost state
Melnikov V.P., Pikinerov P.V., Gennadinik V.B., Babushkin A.G., Moskovchenko D.V.

Abstract

A new phenomenon has been investigated - an increase in the winter and early spring streamflow of northern rivers. Assuming that the increased discharge may be due to permafrost degradation in river basins, the thaw rate was estimated by modeling. A mathematical model that takes into account the typification of the four permafrost categories, reflecting the dependence of the runoff on the cryological conditions of the watershed areas, showed a rapid degradation of sporadic permafrost and expansion of discontinuous permafrost at the account of continuous one.

Доклады Академии наук. 2019;487(6):679-683
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Climatology and annual displacement of the upper-level frontal zones in the middle troposphere of the Northern Hemisphere
Razorenova O.A., Shabanov P.A.

Abstract

An updated climatology of upper level frontal zones (UFZ) of the Northern Hemisphere is presented, based on a numerical analysis of geopotential gradients and the allocation of maximum gradient zones. Differences in the position of the UFZ during the development of meridional and zonal processes are revealed. Based on the analysis of years with the predominance of various forms of circulation, it is shown that the position of high-altitude frontal zones is an objective diagnostic tool for studying modern climate variability.

Доклады Академии наук. 2019;487(6):684-690
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Oceanology
Features of sound propagation in the presence of bubble clouds in the perturbed surface layer of the ocean
Bulanov V.A., Bugaeva L.K.

Abstract

There are contradictory views on the contribution of the near-surface layer of bubbles to the attenuation of low-frequency sound in the ocean. Taking into account the new experimental data on the distribution of bubbles in sea water, it is shown that the influence of the near-surface layer of bubbles on the structure of the spatial decay in the propagation of sound can be significant at fairly typical concentrations of bubbles in the near-surface layers of the ocean. A possible explanation for the contradictions is the spatial restructuring of the field structure, in which the main effect of the bubbles is concentrated at the near distance, at the same time not affecting the sound attenuation at the far distance.

Доклады Академии наук. 2019;487(6):691-695
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Primary production and associated environmental conditions in the East Siberian Sea in autumn
Demidov A.B., Gagarin V.I.

Abstract

Spatial variability of primary production (PP) was study on vast area of East Siberian Sea in autumn 2017. Water column PP (IPP) value was equal to 28±13 mgC m-2 day-1 on average that testify ultraoligotrophic conditions. IPP was limited by low incident and underwater photosynthetically available radiation and nitrate concentration. Ammonium concentration partly compensates lack of dissolved nitrogen.

Доклады Академии наук. 2019;487(6):696-700
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Biochemistry, biophysics, molecular biology
LH2 complexes (B800-850 AND B800-830) are assembled in the cells of sulfur bacterium Thiorhodospira sibirica, strain Kir 3, without any carotenoids
Bolshakov M.A., Ashikhmin A.A., Makhneva Z.K., Moskalenko A.A.

Abstract

It has been studied the result of assembling the light-harvesting complexes in the cells of purple sulfuric bacterium Thiorhodospira (T.) sibirica, strain Kir‑3, while suppressing biosynthesis of carotenoids by diphenylamine (DPA). LH2 complexes (B800-850 and B800-830) with different carotenoids’ composition were isolated from the cells obtained. Maximal inhibition of carotenoid biosynthesis (~90% of the control) was achieved at the inhibitor concentration of 53,25 mM (9 mg/l). It has been established that changes in qualitative and quantitative composition of carotenoids do not affect the assembling of B800-830 and B800-850 complexes. It is assumed that in the population of DPA-LH2 complexes from T. sibirica, strain Kir‑3, both carotenoidless complexes and the complexes, containing one or two carotenoid molecules, can be assembled. These results support a hypothesis that carotenoids are not required for assembling B800-850 and B800-830 complexes.

Доклады Академии наук. 2019;487(6):701-705
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General biology
Sexual accent and biphonation in the ground squirrels’ sound signal (Mammalia, Rodentia)
Nikol’skii A.A.

Abstract

The spectral structure of the alarm call of ground squirrels was studied. A sexual accent was found in the signal of a small ground squirrel (Spermophilus pygmaeus): in the signal of males, the high-frequency component has a higher peak and maximum frequency than in the signal of females. In the signal of four species of ground squirrels (Sp. pygmaeus, Sp. musicus, Sp. xanthoprymnus, Sp. alaschanicus) biphonation was detected. It is suggested that in the signal of these species of ground squirrels low and high frequency components generate different sources of the vocal tract. Material collected in the field.

Доклады Академии наук. 2019;487(6):706-710
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Electrogenesis in two african upside-down catfishes, Synodontis sorex and S. batensoda (Mochokidae, Siluriformes)
Orlov A.A., Baron V.D., Golubtsov A.S.

Abstract

Weak electric discharges generated by the two species of African upside-down catfishes, Synodontis sorex and S. batensoda, are described. In both species two types of discharges were recorded in the course of aggressive-defense interactions in the pairs of individuals: short simple biphasic and longer (duration > 20 ms) discharges with more complex waveform. The discharges of the latter type seem to result from a temporal summation (with various latency) of simple discharges. It is suggested that formation of the long quasimonopolar discharges enhances the coincidence of frequency spectrum of the catfish discharges with maximum sensitivity range of their ampullary electroreceptors.

Доклады Академии наук. 2019;487(6):711-714
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