Vol 486, No 1 (2019)


On the classification of stably reflective hyperbolic Z[√2]-lattices of rank 4

Bogachev N.V.


In this paper we prove that the fundamental polyhedron of a 2-arithmetic reflection group in the three-dimensional Lobachevsky space contains an edge such that the distance between its framing faces is small enough. Using this fact we obtain a classification of stably reflective hyperbolic 2-lattices of rank 4.

Доклады Академии наук. 2019;486(1):7-11
pages 7-11 views

Homogenization limit for the Diffusion Equation in a domain Perforated along (n - 1)-Dimensional Manifold with Dynamic Conditions on the Boundary of the Perforations: Critical Case

Zubova M.N., Shaposhnikova T.A.


The problem of homogenization the diffusion equation in a domain perforated along an (n - 1)-dimensional manifold with dynamic boundary conditions on the boundary of the perforations is studied. A homogenization model is constructed that is a transmission problem for the diffusion equation with the transmission conditions containing a term with memory. A theorem on the convergence of solutions of the original problem to the solution of the homogenized one is proved.

Доклады Академии наук. 2019;486(1):12-19
pages 12-19 views

Perron stability and its study at the first approximation

Sergeev I.N.


Natural concepts of Perron stability, asymptotic stability, and complete instability of the trivial solution to a differential system are introduced. Their features and relationships with Perron exponents and similar Lyapunov ones are indicated. An absolute and unique coincidence of research opportunities for Perron and Lyapunov stability and asymptotic stability at the first approximation is found.

Доклады Академии наук. 2019;486(1):20-23
pages 20-23 views

Some properties of ultrafilters of widely understood measurable spaces

Chentsov A.G.


Filters and ultrafilters (maximal filters) on the π-system with “zero” and “unit” are considered (here, π-system is a nonempty family of sets closed with respect to finite intersections); so, our π-system contains including and empty sets. Characteristic properties of ultrafilters obtained from special representations for bases of two typical topologies connected with construction of Wallman extension and Stone compactums are investigated. The topology of Wallman type on the ultrafilters set of arbitrary π-system with “zero” and “unit” is defined. In addition, initial set is transformed in a compact T1-space with points in the form of ultrafilters of above-mentioned π-system. Under equipment of the resulting ultrafilter set with two topologies (by sense, Stone and Wallman topologies), bitopological space with comparable topologies is obtained; for this space, the degeneracy (in the sense of coincidence for above-mentioned topologies) and nondegeneracy conditions are indicated. The initial set is immersed in above-mentioned bitopological space as everywhere dense subset. Resulting construction is oriented on application in extensions of abstract attainability problems with constraints of asymptotic character (we keep in mind the possible application of ultrafilters as generalized elements).

Доклады Академии наук. 2019;486(1):24-29
pages 24-29 views


Wave mixing in a system of moving coaxial cylinders

Ganiev R.F., Reviznikov D.L., Sukharev T.Y., Ukrainskii L.E.


The results of computer simulation of mixing in a system of moving coaxial cylinders are presented. Detailed spatial-temporal pictures of the processes occurring were obtained and the main structures in the flow field were determined. Based on the analysis of the singular points of the vector velocity field of the liquid, a method for profiling the rotor is proposed. Introduced dimensionless quantities, the use of which allows the transition from laboratory bench installations to real production devices.

Доклады Академии наук. 2019;486(1):30-33
pages 30-33 views

Transverse deformation and nonlinearity of force interactional interaction of solids

Sanditov D.S.


At this stage, it is necessary to allow the dependence of the Poisson coefficient (parameter of elasticity theory) on the nonlinearity of the interatomic interaction force and the anharmonicity of lattice vibrations (Gruneisen parameter). This dependence follows from the experimental data and finds justification in the framework of the existing theoretical developments, primarily the BRB model (Berlin-Rothenburg-Baserst). The relationship between the linear (harmonic) and nonlinear (anharmonic) properties of solids is discussed using the example of the unambiguous connection of the Poisson coefficient μ with the Gruneisen parameter.

Доклады Академии наук. 2019;486(1):34-38
pages 34-38 views

Technical Physics

The fractal model of reinforcement of nanocomposites polymer/carbon nanotubes with ultrasmall concentrations of nanofiller

Kozlov G.V., Dolbin I.V., Koifman O.I.


The structural aspects, defining reinforcement degree (enhancement of elasticity modulus) of nanocomposites polymer/carbon nanotubes with ultrasmall concentrations of nanofiller, were considered. It has been shown that the indicated parameter is controlled by two factors, namely, structure of nanocomposite and type of reinforcing component. Introduction of nanofiller in matrix polymer changes its structure in virtue of formation of interfacial regions. Hence, the efficiency of nanofiller as reinforcing element is defined by its ability to generate interfacial regions.

Доклады Академии наук. 2019;486(1):39-43
pages 39-43 views

Analysis of the crystallogeometry of tetragonal martensite in indium-cadmium alloys by the method of electron back scattering diffractions

Schastlivtsev V.M., Khlebnikova Y.V., Rodionov D.P., Egorova L.Y.


It was shown in the work using electron back scattering diffractions analysis that when cooling lower than temperature of the martensitic fcc-hct transformation in the alloy In - 4.5 wt% Cd a packet structure is formed consisting of colonies of tetragonal lamella plates. At the next packages there are always three grades of the plates of a tetragonal martensite which are in twinning situation and differing with the direction of the tetragonality axis. Each martensitic plate consists in turn of a set of more shallow submicrotwinning plates alternating in the direction of an axis of tetragonality. On the basis of the obtained data it is possible to conclude that the structure of the package consisting of twinning plates and the structure of the separate martensitic plate consisting, in turn, of submicro-twins submits to the general regularities. At each structural level in group of the neighboring areas the building blocks of three grades differing with the direction of a tetragonality axis are found.

Доклады Академии наук. 2019;486(1):44-48
pages 44-48 views


A new approach to obtaining carboranylmethylsiloxanes

Izmaylov B.A., Vasnev V.V., Markova G.D.


The efficient method for the synthesis of o(m)-carboranylmethylsiloxanesby the Grignard reaction based on 1,2 (7)-bis(bromomagnesiummethyl)-o(m)-carboranes and 1-chloro-1,1,3,3,3-pentamethyldisiloxane was developed. As a result, 1-(1,1,3,3,3-pentamethyldisiloxanylmethyl)-2(7)-methyl-o(m)-carboranes, 1,2(7)-bis(1,1,3.3,3-pentamethyldisiloxanylmethyl)-o(m)-carboranes, exocyclic 1,2-(o-carborano)-4,6-bis(dimethylsilyl)-5-oxa-cycloheptane, 1,7-bis(chloro-1,1,3,3-tetramethyldisiloxanylmethyl)-m-carborane and the oligomer containing two 1,7-bis(dimethylsilylmethyl)-m-carborane units were obtained.

Доклады Академии наук. 2019;486(1):49-52
pages 49-52 views

Sources of paleomagnetic signal in iron-bearing marine sedimentary deposits

Rudmin M.A., Mazurov A.K., Sergienko V.I., Savichev O.G., Semiletov I.P.


This paper presents the results of interpreting the change in the magnetic signal of ferruginous marine sedimentary rocks using the example of the Cretaceous-Paleogene Bakchar deposit (Western Siberia). Anomalous magnetic susceptibility (MS) values are determined by two factors: (a) a diagenetic process accompanied by the formation of pyrrhotite, greigite and siderite in ironstones, (b) an increase detrital input with deposition of magnetite and ilmenite in the siltstones on the background of climate moistening and intense weathering. It is shown that increased MS values in iron-bearing marine sedimentary deposits can be associated with the formation of ferrimagnetic sulfides, which indicates to the methane emission through ancient marine bottom sediments.

Доклады Академии наук. 2019;486(1):53-56
pages 53-56 views

Chemical Technology

The influence of sodium niobate addition on sintering and properties of zirconia ceramics

Smirnov V.V., Smirnov S.V., Obolkina T.O., Goldberg M.A., Antonova O.S., Barinov S.M.


The study of sintering, microstructure and phase composition of zirconia ceramics containing the additive - sodium niobate. It is shown that the use of an additive helps to reduce the sintering temperature to 1,400 ° C. The obtained materials are characterized by a high content of the tetragonal phase, a fine-crystalline structure and high strength up to 440 MPa during bending. The developed low-temperature materials can be used in dentistry as ceramic crowns.

Доклады Академии наук. 2019;486(1):57-60
pages 57-60 views

Physical chemistry

Voltammetric analysis in blood serum in patients with severe combined trauma

Tsivadze А.Y., Petrikov S.S., Goroncharovskaya I.V., Evseev А.K., Shabanov A.K., Batishchev O.V., Andreev V.N., Goldin M.M.


Voltammetric analysis of antioxidant activity of blood serum in patients with severe combined trauma showed differences in favorable and adverse outcome groups. Based on the experimental data a criterion for assessing risk of adverse outcome in critically ill patients is proposed.

Доклады Академии наук. 2019;486(1):61-64
pages 61-64 views


Influence of asphaltenes on wettability of gas and oil saturated reservoir rock

Mikhailov N.N., Ermilov O.M., Sechina L.S.


The wettability of terrigenous and carbonate rock cores of oil and gas condensate fields extracted with n-hexane and chloroform by asphaltenes was studied. The obtained values of core wettability with asphaltenes show their contribution to the change of wettability of different rocks.

Доклады Академии наук. 2019;486(1):65-68
pages 65-68 views

Specific features of supercontinent cycles in the metallogeny of tantalum

Tkachev A.V., Rundqvist D.V., Vishnevskaya N.A.


The metallogeny of tantalum through the geological history has been analyzed. A representative sampling contains mineral deposits of five types: pegmatitic, granitic, alkaligranitic, foidic, and carbonatitic ones. They were formed with a variable intensity during the time range from the Late Mesoarchean to Cenozoic. The most notable resources of tantalum are known in the deposits of the Rodinian cycle, as well as the Pangean and Colombian ones. All these cycles stand out against other ones by a leading role of the deposits associated with alkaline magmas of mantle origin. However, the concentrates of the highest quality to extract tantalum are obtained from the deposits in rare-metal pegmatites and lithium-fluorine granites produced by crustal magmas. Only the pegmatitic deposits are known for the Kenoran cycle in tantalum metallogeny. They contain a maximum amount of such high-quality resources.

Доклады Академии наук. 2019;486(1):69-73
pages 69-73 views

Geodynamic position of large and super large precious metal and uranium ore districts and nodes in the East Asia

Khomich V.G., Boriskina N.G.


The analysis results of the geophysical, seismic tomography and mineragenic data are presented, revealing the prerequisites for the regular of the location large and unique precious metals and uranium ore nodes of Southeast Russia, East Mongolia and Northern China. Shown that probable causes localization of the world-class ore clusters and districts above a stagnant oceanic slab perimeter are predetermined by concentration of the lower mantle fluid-heat fluxes at the frontal part of the slab and on its flanks, which are represented by sublatitudinal paleotransformal faults.

Доклады Академии наук. 2019;486(1):74-77
pages 74-77 views

Deep xenolith of platinum-bearing websterite from paleoproterozoic Volchetundra gabbro-anorthosite massif in the Kola region

Chashchin V.V., Savchenko Y.E., Lyulko M.S.


The results of studies of the deep platinum-bearing xenolith found in the Volchetundra gabbro-anorthosite massif of the Kola region are presented. It is shown that xenolith with a size of 8.5 × 4 m is composed of websterite in the central part and plagiowebsterite in the marginal. The chemical and mineral composition of xenolith rocks was studied. Information is given on the contents of noble and chalcophile elements in them, as well as the composition of platinum group minerals.

Доклады Академии наук. 2019;486(1):78-82
pages 78-82 views


New data on fiedlerite-1A from ancient slags of Lavrion, Greece: crystal structure and H-bonding

Zubkova N.V., Chukanov N.V., Pekov I.V., Pushcharovsky D.Y., Katerinopoulos A., Voudouris P., Magganas A.


The crystal structure (R = 0.0750) of fiedlerite-1A Pb3Cl4F(OH) H2O from ancient slags of Lavrion (Greece) was studied on a single crystal. The mineral is triclinic, a = 8.5741(7), b = 8.0480(5), с = 7.2695(4) Å, (a = 90.087(5), (b = 102.126(6), (g = 103.424(6)) V = 476.37(6) Å3, Z = 2. Pb2+ cations centre bicapped trigonal prisms Pb(1)F(H2O)Cl6, Pb(2)(OH)2FCl5 and Pb(3)(OH)F2Cl5. Additional Pb′site with 10% occupancy was revealed in the structure. There are two basic structure fragments alternating along the a axis: (100) layers formed by Pb(2)- and Pb(3)-centred polyhedra and elongated along the b axis zig-zag chains formed by Pb(1)-centred polyhedra sharing common edges. IR spectrum of fiedlerite-1A is given.

Доклады Академии наук. 2019;486(1):83-87
pages 83-87 views

Cell biology

The adhesion of human dermal fibroblasts on anodized nanotube-layered titanium, modified for implantology application

Fadeyev F.A., Khrunyk Y.Y., Belikov S.V., Lugovets D.V., Gubaeva O.V., Karabanalov M.S., Leontyev S.L., Popov А.А.


Anodization of titanium implants is accompanied by the formation of titanium oxide nanotubes improving osseointegration. An excessive fibroblast adhesion on the surface might lead to the formation of fibrous capsule resulting in implant rejection. In our research, we demonstrated that the adhesion activity of human dermal fibroblasts on anodized surface was not elevated, which is promising for the use of titanium with nanotube-layered surface for implantology.

Доклады Академии наук. 2019;486(1):123-126
pages 123-126 views

General biology

Siboglinids (Annelida, Siboglinidae) as possible indicators of carbohydrates on the case of the Sea of Okhotsk

Karaseva N.P., Gantsevich M.M., Obzhirov A.I., Shakirov R.B., Starovoytov A.V., Smirnov R.V., Malakhov V.V.


Siboglinids (Annelida, Siboglinidae) as possible indicators of carbohydrates on the case of the Sea of Okhotsk Geographical and bathymetric distribution of siboglinides in the sea of Okhotsk was studied. More than 75% of all siboglinides were found at a depth of 400 m. These findings were mainly concentrated in the North-Western part of the shelf. A comparison of the distribution of siboglinides in the Sea of Okhotsk and generalized geological data on the distribution of hydrocarbons showed that siboglinides in the sea of Okhotsk were mostly found in the areas of hydrocarbon manifestations and were absent in the central regions, where in the bottom sediments and in the near-surface layer of water we have registered minimal methane and hydrocarbon concentrations.

Доклады Академии наук. 2019;486(1):127-130
pages 127-130 views

The provisional dermal folds in the mouth apparatus of the American paddlefish Polyodon spathula Walbaum, 1858 (Acipenseriformes, Polyodontidae)

Tsessarsky A.A.


The transitory dermal infoldings are described for the first time in front and behind the upper jaw in the larvae and postlarvae of the American paddlefish, Polyodonspathula Walbaum, 1858. In sturgeons these infoldings are necessary for the jaw protraction. In the paddlefishes, they, probably recapitulate the ancestral state. At the same time, the presence of these folds at the larval stages might indicate that the paddlefish larvae possess the protractive jaws. Further developmental studies of the jaw kinematics in Polyodonspathula are needed to test both hypotheses.

Доклады Академии наук. 2019;486(1):131-134
pages 131-134 views

This website uses cookies

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

About Cookies