Source: http://nasb.gov.by/eng/publications/dan/dan51_1.php
Timestamp: 2019-04-19 22:22:17+00:00

Document:
Summary: Lyapunov's bases of infinite vector subspaces are considered. The property of the non-exstensibility of these bases is investigated. Some applications to the theory of asymptotic expansions in the sense of Poincare are considered.
Summary: A new heuristic algorithm for Boolean functions decomposition is suggested. The problem is reduced to the random search for a suitable simplest partition on the set of arguments and its successive expansion.
Summary: A new form of Kantorovich's iterations theorem is proved. New sufficient conditions are obtained for convergence of nonstationary iteration methods for solution of operator equations.
Summary: Differential equations with the discontinuous and generalized right-hand side are investigated. It is shown that the associated solutions of the corresponding differential equations in the algebra of mnemofunctions coincide with those of equations under consideration that are understood in the sense of differential inclusions.
Summary: For systems of differential-difference equations of neutral type the parametric criteria for complete constructive iden-tifiability and complete controllability are proved, when the system solution is understood as a continuous function.
Legchekova H. V., Skiba A. N., Titov O. V.
Summary: Let G be a finite group, H be a subgroup of G. Then we say that H is weakly quasinormal in G if G has a quasinormal subgroup T such that HT = G and TÇH is quasinormal in G. In this article we use the weak quasinormality to obtain new characterizations for some classes of finite soluble groups.
Shirko A. V., Kamluka A. N., Nemtsov V. B.
Summary: The change in the form of a DNA macromolecule and the redistribution of bend and twist energies depending on an external force are investigated.
Summary: A correct description of building-up charge gratings excited by standing light in a photorefractive crystal in the presence of an external electric field is given. It is shown that the process is set forth by the fourth-order equation. The particular solutions of the obtaind equation are found, and a general solution satisfying the given initial condition is built.
Summary: The reduction of the biquaternionic Dirac equation in R2.1 was done. The developed algebraic formalism gives the possibility to embed the solutions of the (2 + l)-dimensional of Dirac equation into the physical space -- time.
Kouznetsova T. F., Agabekov V. E., Ratko A. L., Karpinchik E. V., Eremenko S. I.
Summary: The properties of stable silica nanosol prepared using the ion-exchange method including the particle growth and concentration are described. A specific surface area was determined by means of hydroxide ion adsorption at the SiO2/ water interface. Sol obtained had a specific surface area of 230 m2/g, a particle diameter of 11.9 nm, a SiO2 mass concentration of 30.0% and a pH value of 9.3. It is shown that the stability of silicanano sol stabilized by an aluminum silicate ion increased with decreasing pH value.
Mozheiko F. F., Korshuk E. F., Potkina T. N., Goncharik I. I.
Summary: Different-kind compositions based on phosphorite flour and salt solutions have been prepared. It has been shown that their properties depend on an initial blend composition, a solid particle size, viscosity, density, a sedimentation degree of the solid phase, a pH value, fluidity.
Yegorova O. M., Zlenkovsky V. M., Soldatov V. S.
Summary: The processes bringing to the formation of composite iron-bearing sorbent FIBAN-As were studied. The optimal conditions of its preparation were determined. The computer analysis of Fe (III) salt solutions composition was carried out. The structures forming in the polymer matrix of an amidoamine ion exchanger after Fe2(SO4)3 adding were calculated using the simulation package GAMESS.
Potkin V. I., Maier N. A., Rudakov D. A., Zalesskaya E. G., Shirokii V. L.
Summary: The chlorination of monoanion [5,6-Br2-7,8-C2B9H10]- by N-chlorosuccinimide and the iodination by elementary iodine are found to lead to the corresponding B(9) substituted derivatives [9-X-5,6-Br2-7,8-C2B9H9]- (X = Cl, I). The bromination of anion by N-bromosuccinimide proceeds with the introduction of two bromine atoms in the B(9, 11) sites and ends with the formation of tetrabromo substituted compound [5,6,9,11-Br4-7,8-C2B9H8]-.
Galkovskaya G. A., Vezhnovets V. V., Vlasov B. P., Majsak N. N., Molotko D. V.
Summary: The species richness and the ratio between the taxonomic groups of a higher rank (genus, family) in the total density of littoral zooplankton were studied in connection with the geomorphological features of the littoral zone. Essential differences in the species similarity indices and the dominance structure peculiarities in Rotifera and Crustacea taxonomic groups were revealed by comparing the sampling stations. The formation of subcommunities in the littoral plankton community was substantiated by the geomorphological specificity of the littoral zone of the lakes considered.
Semenchenko V. P., Razlutskij V. I.
Summary: A new multimetric index (MI) based on the data of the pelagic cladocerans community structure and species composition is proposed. MI is an average value of the sum of species decimal, Margalef index and quantitative similarity of the Sorensen index between investigated and reference lakes. A strong relation (R2 = 0.727) was obtained between MI and trophic states (Carlson Index) of 21 lakes from the same region. Additional data on 25 water bodies (lake, reservoirs, pounds) confirmed such a relation (R2 = 0.641). Thus, MI can be used for determining the trophic status and the ecological water quality of lentic waters.
Kulahava T. A., Semenkova G. N., Kvacheva Z. B., Mikhadzionak M. N., Koran S. V., Cherenkevich S. N.
Summary: To establish the mechanisms of oxygen-activated menadione action on C6 glioma cells in a monolayer, the investigation of diverse reactive oxygen species and NO-generating enzymes contribution to this process was realized using the lucigenin-enhanced chemiluminescence method. It was shown that superoxide basically and, to a certain extent, hydrogen peroxide, nitric oxide and singlet oxygen make a contribution to menadione-induced chemiluminescence of astroglial cells. It was determined for the first time that NO-syntheses and mainly neuronal isoform of this enzyme participate in the reactive oxygen species formation in C6 glioma cells under the menadione action. The ability of nNOS to generate O2.- depends on the enzyme conformation which is regulated by substratum L-arginine concentration.
Kushniarevich A. I., Sivitskaya L. N., Danilenko N. G., Tsybovsky I. S., Davydenka A. G., Villems R.
Summary: Sequencing of the first hypervariable segment of mitochondrial DNA in combination with the RFLP-analysis of a coding region was performed on 292 samples of the belorassians from six different geographic regions of Belarus. Haplogroups H, J, K, Nl, T, U4, U5, V, X, W (European type) are around 90% of the mitochondrial pool of the ethnic Belarusians. Analysis of the haplogroup distribution among Belarusian subpopulations has shown the intrapopulation heterogenety according to frequencies of haplogroups J, U, V, T.
Veretennikov N. V., Laptsevich A. G.
Summary: The results of investigation and petrographic diagnosis of volcanic rocks from the section of the borehole 772 drilled within the Luchin group of the Zhlobin diatreme field are presented. For the first time in Belarus this borehole has exposed carbonatites that are represented by their chromium-rich (up to 1,000 g/t) tetraferriphlogopite-calcic variety and are associated with pyroxene-free olivine melilitites and their tuffs. These rocks form a volcanic pipe or infill the cratervent part of a small Late-Devonian palaeovolcano.
Summary: It is was established that as a result of low heat flow and temperature, the deposits of Orsha and Podlesse-Brest depressions did not generate oil and gas and do not have oil and gas pools.
Summary: The analysis of the dynamics of spatiotemporal migration of the annual zone positioning of earthquake foci in the north-western part of the Pripjat yield has been conducted. Group mechanisms of earthquake foci have been constructed. The key elements of the focal earthquake mechanisms have been estimated and the types of their seismic dislocation have been defined. The data on spatial orientation of the compression axis and the axis of stretching taken from the solutions of focal mechanisms of earthquake foci have been used to characterize the stress field. The major axis of tension has been determined, and a summary diagram of focal earthquake mechanisms has been plotted.
Shapovalov V. M., Bochkaryov D. I., Pleskachevsky Yu. M.
Summary: The efficiency of application of different-nature modifying additives in a composite bitumen-mineral material system, which provide a temperature displacement of basic phase transformations of bitumen to a higher-temperature area and the expansion of the temperature range of its plastic condition, is established. All this taken together enables one to purposefully control technological and service properties of composite mixtures based on the best system.
Summary: Numerical results on the modeling of interaction between a turbulent jet and a co-flow of liquid in the cylindrical channel of round cross-section are presented. The standard k -- e turbulence model has been adopted for computations. Two flow regimes: with a recirculation zone developed near the channel walls and without it are considered. The standard k -- e turbulence model is verified by the available experimental data. The use of different sets of constants of the above model known from free turbulent j et studies has shown that the modification of constants Cµ =0.06, Ce2 = 1.87 had given the best results as compared to the experimental data on the considered flow regimes.
Summary: The present article is concerned with numerical results on heat transfer enhancement of a circular cylinder by means of installing guide elements - plates. Computations have been made for the case of laminar crossflow past a heated cylinder in an inhomogeneous viscous medium when its thermal and physical properties depend essentially on temperature. In our case, turbine oil MS-20 has served as an inhomogeneous medium. Numerical results on local heat transfer, thermohydrodynamic efficiency and total Nusselt number are presented as a function of length of the installed plates. The data obtained are compared with the identical results for a single cylinder.
Ilyuschenko A. Ph., Akimov A. I., Fedotova J. A., Letsko A. I., Bonnet G., Dubois S., Talako T. L., Belyaev A. V.
Summary: The effect of the initial microstructure of Fe3Al samples sintered by high isostatic pressing on the kinetics of the alumina formation during high-temperature oxidation in the controlled atmosphere at 900°C, 1000°C and 1100°C has been studied. It has been observed that the formation of a surface oxide layer started with the island-like growth of transition aluminium oxides and finished with the precipitation of fine-structure stable >a-Al2O3. The lamellar structure and inhomogeneous chemical composition of lamellars of the initial mechanoactivated Fe-Al mixture were the dominating factors influencing the kinetics of Fe3Al high-temperature oxidation.

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