Doklady of the National Academy of Sciences of Belarus, 2009, Vol.53, No.2
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Doklady of the National Academy of Sciences of Belarus, 2009, Vol.53, No.2
||DOKLADY OF THE NATIONAL ACADEMY OF SCIENCES OF BELARUS|
(Doklady Natsionalnoi Akademii Nauk Belarusi)
Published by The Belaruskaya Navuka Publishing House, Minsk, Republic of Belarus
Volume 53, Number 2; March-April, 2009
Alehno A. G.
Gilbert boundary-value problem with an infinite index of logarithmic order. pp. 5--10
Summary: The conditions of solvability are obtained and under such conditions the general solution of the Gilbert problem for the half-plane plane is built.
Bedziuk N. V., Yablonski A. L.
Differential equations with generalized coefficients in algebra of mnemofunctions. pp. 11--15
E-mail: nbedyuk(at)gmail.com, Yablonski_oleg(at)rambler.ru
Summary: Differential equations with generalized coefficients using algebra of mnemofunctions are investigated. Under such an approach solutions of differential equations are mnemofanctions. In the article, necessary and sufficient conditions that show when solutions can be interpreted as ordinary functions are presented.
Maksimovich A. V., Tyshkevich R. I.
Normal form of domishold graphs. pp. 16--18
E-mail: aleh.maksimovich(at)gmail.com, tyshkevich(at)bsu.by
Summary: We introduce a new type of domishold graph decomposition and call it the normal form of a domishold graph. The uniqueness of the normal form is proved. A linear algorithm for computing the normal form of a domishold graph is proposed on this basis. It is also proved that domishold graphs with the same vertex degrees are isomorphic.
Knyazhishche L. B.
Lyapunov functionals with a semi-definite derivative in the uniform ultimate boundedness conditions for in delayed equations. pp. 19--23
Summary: Lyapunov functionals with a semi-definite derivative based uniform ultimate boundedness conditions for in delayed equations are proposed.
Gabasov R., Kirillova F. M., Poyasok E. I.
Optimal closable output feedback. pp. 24--28
Summary: In the class of discrete control actions an optimal control problem for linear dynamical systems under uncertainty is considered. A concept of optimal clo sable (discrete) output feedback is introduced. A method for calculating in real time current values of the optimal closable feedback is justified.
Orlovich Yu. L., Gordon V. S., De Werra D.
Hardness of approximating the independent dominating set problem in 2P3-free perfect graphs. pp. 29--33
E-mail: orlovich(at)bsu.by, gordon(at)newman.bas-net.by
Summary: A subset of vertices of a graph is dominating if every vertex outside it has a neighbor in this subset. A subset of vertices is independent if no two vertices in this subset are adjacent. An independent dominating set is a vertex subset that is both independent and dominating. The independent dominating set problem asks for a minimum independent dominating set in a given graph. We show that for any e > 0 the independent dominating set problem for 2P3-free perfect graphs of order n cannot be
approximated within a factor of n1 - e in polynomial time, unless P = NP . The result holds even if the graph in question is restricted to be weakly chordal.
Zabreiko P. P., Tanyhina A N.
Hicks theorem and the LeChatelier--Samuelson principle for the open Leontiev--Ford model in ideal spaces. pp. 34--40
E-mail: zabreiko(at)mail.ru, anast-minsk(at)yandex.ru
Summary: The analogs of the Hicks theorem and the LeChatelier--Samuelson principle for the open Leontiev--Ford model in ideal spaces are given. Two cases are separated: the case, when r(A) < 1 for the technological operator A of the model, and the case, when r(A) > 1. In particular, the criterion of diminishing residual damages in the environment is stated.
Zakrevskij A. D.
Vector method of minimizing Boolean functions of many variables. pp. 41--44
Summary: A new method of minimization of Boolean functions of many variables is offered, which is based on using parallel operations above neighbor units in the Boolean space M and including the build-up of a Boolean matrix of the neighborhood in the characteristic set M1.
Bogush A. A., Red'kov V. M., Krylov G. G.
Quantum particle in a uniform magnetic field on the background of the Lobachevsky space. pp. 45--51
E-mail: redkov(at)dragon.bas-net.by, krylov(at)bsu.by
Summary: Schrodinger equation in the 3-dimensional Lobachevsky space has been solved in the presence of an external magnetic field, being an analogue of a uniform magnetic field in the flat space. Generalized Landau levels have been found, modified by the presence of the space curvature. The feature of the spectrum is that the number of bound states is finite and determined by three parameters: a magnitude of the magnetic field B, the curvature radius r and the magnetic quantum number m.
Novikau A. G., Ratkevich S. V., Gaiduk P. I., Komarov F. F.
Oxidation induced Ge segregation in SiGe alloys. pp. 52--56
Summary: Oxidation of SiGe is under intensive investigation. The present study deals with Ge segregation in polycrystalline SiGe alloy layers during thermal oxidation. It can be concluded from the experimental RBS and TEM results, that during thermal oxidation, Ge is completely rejected from the oxide and piles up at the oxide/SiGe interface, forming a Ge-rich layer. There is no visible loss of Ge on dry oxidation and considerable Ge loss during wet oxidation. The oxidation at high temperatures (> 1000 ° C) assists Ge diffusion into the Si substrate even through barrier SiO2. Obtained after dry and wet temperature oxidation in furnace SiO2/SiGe/SiO2/Si-sub structures are very promising in formation of memory structures, also with very thin layers of tunnel SiO2.
Kudina E. F., Pleskachevsky Yu. M.
Effect of microwave heating on the properties of alkali-silicate solution. pp. 57--64
E-mail: kudina_mpri(at)tut.by, pleskym(at)mail.ru
Summary: Comparative investigations have been undertaken to study the influence of microwave heating and thermal treatment upon physico-chemical properties and sol-gel transition processes in alkali-silicate solutions. Microwave heating was found to result in significant activation of the solution, acceleration of cross-linking processes and intensification of interactions between molecules. It is shown that the type of thermal treatment defines the kinetics, structurization mechanism, and morphology of the resultant xerogels.
Morgulets E. N., Prokopchuk N. R., Goncharova I. A.
Influence of pigments and water-dispersing binders on the bio stability of coatings. pp. 65--68
Summary: The study is devoted to the investigation of the influence of pigments and water-dispersing binders on the biostability of coatings. Compositions based on Mowilith DM 760, Primal AC 261K with titanium dioxide and zinc oxide have shown the best fungitoxicity. Zinc sulphide has stimulated the sporulation in all cases.
Kashevsky B. E., Goranov A. V., Zholud A. M., Prohorov A. V.
Magnetic sorting of b-cells. pp. 69--71
Summary: The motion is investigated of a intended for transplantation cellular suspension of fetal rabbit pancreas under the action of a high-gradient magnetic field. It is found that single cells, cell islets and pieces of debris demonstrate the contrasting magnetic behavior in the nutrient medium 199 (diamagnetic, non-magnetic and paramagnetic, respectively). This suggests the possibility to magnetically enrich the suspension with the most valuable component (islets) and purified it from debris appeared at various stages of the conventional technique.
Potapovich M. I., Nikolaichik Y. A., Prokulevich V. A.
Cloning and expression of chicken interferon alpha gene in Escherichia coli cells. pp. 72--75
Summary: Recent outbreaks of avian flu and the impact on the poultry industry and farming, together with implications of viral diseases of avian origin such as SARS (severe acute respiratory syndrome) and influenza on human health have rekindled interest in avian interferons. Chicken interferon alpha gene was isolated from the whole-blood DNA, sequenced and cloned into expression vector pET24b(+), and recombinant plasmid was transformed into Escherichia coli strain BL21 (gDE3). Induction with IPTG or lactose results in high-level accumulation of the protein having the same molecular weight as chicken interferon alpha.
Bulai P. M., Denisov A. A., Molchanov P. G., Pitlik T. N., Cherenkevich S. N.
Extracellular electric signals of neurons at the cell-surface contact. pp. 76--79
Summary: Investigation explored the influence of cellular adhesion during cultivation to a surface on an amplitude and form of extracellular signals. Study was carried out with a culture of dissociated neurons of snail Lymnaea stagnalis on the planar electrode array. It was shown that the amplitude as well as the form of extracellular signals depends on electric and geometric parameters of the cell-surface contact: seal resistance, cleft height and conductivity of the cleft.
Pozdnyakova A. S., Astrovko A. P.
TB epidemiological juxtaposition in children, teenagers and adults in the Republic of Belarus. pp. 80--84
Summary: The article analyses the epidemiological situation in Belarus and establishes the interconnection of epidemiological tendencies in adult population, exerting an influence on the epidemiological situation among teenagers and children. The article also examines the causes of TB problems in teenagers and children.
Nosova E. S., Titov L. P.
Molecular analysis of ESBL genes of SHV type in enteropathogenic Klebsiella spp. Strains. pp. 85--90
E-mail: nosova2002(at)mail.ru, leonidtitov(at)tut.by
Summary: A WaSHV gene product was detected in 90% K. pneumoniae and 40% K. oxytoca. With the use of RFLP we detect strains with mutations gene SHV which are associated with increasing resistance level to b-lactams in order to differentiate earlier b-lac-tamase SHV-1 from its derivatives. 60%) strains contain mutation at position 35, 238 H 240 (according to Ambler's numbering scheme) of blaSHV genes in combination or alone. Nucleotide sequence analysis of SHV-specific PCR products revealed that isolates carried the genes non-ESBL (55%) and ESBL (45%). SHV-1 (40%), SHV-11 (15%), SHV-2 (10%), SHV-5 (15%), SHV-31 (20%) were the most frequent beta-lactamases. Substitutions at position 35,238 or 240 are most common and associated with the resistance to ceftazidime, cefotaxime and aztreonam. Mutation 238 alone had a rather low to moderate impact on resistance. Combination of mutation at position G238S and E240K yielded higher resistance than G238S alone. Together with E240K it does improve interaction of the enzyme with the carboxylic acid group of CAZ and AZT. The effect is stronger in SHV-5 than in SHV-2. SHV-5 containing the substitution of G238S and E240K. Effect of those substitutions -- highest levels of resistance, significantly higher than SHV-2. Concerning non-active-site substitution (position 35) -- the effect is generally much smaller. L35Q (SHV-11) substitution does not give MIC evaluation (MIC CAZ, CTX, AZT 0.125--2.0 µ g/ml).
Konoplya N. E.
New approach to the treatment of medulloblastoma in children. pp. 91--94
Summary: We estimated the efficacy of the developed treatment method in children with medulloblastoma using induction chemotherapy (77 children) and high dose chemotherapy with peripheral stem cell transplantation (31 children). It was demonstrated that high dose chemotherapy with peripheral stem cell transplantation allowed reaching a 6-year relapse-free survival rate of 77% in the group of patients with a high risk of relapse. The use of induction chemotherapy provided a 7-year relapse-free survival rate of 84% in the standard risk group of patients.
Konischev V. S.
Structural-genetic classification of coal deposits and coal shows of Belarus. pp. 95--100
Summary: It is shown that principal factors of coal beds formation were tectonic, galokinetic and karst processes, and the classification of coal deposits is proposed.
Bibikova E. V., Aizberg R. E., Naidenkov I. V., Gribik Ja. G.
Tectonic position of granitoides of the Surazh borehole (Orsha depression). pp. 101--106
Summary: The Surazh 1 borehole was drilled in the far north-eastern Belarus within the Orsha Depression. It penetrated into the crystalline basement represented by granodiorites. Its radiologic age of 1986.9 ± 5.8 m. y. was derived from the analysis of circons. This dating is close to the time of the granite massifs formation of the volcanic-plutonic belt, which is perspective for rare and non-ferrous metals.
Pinchuk L. S., Korotkiy M. V., Goncharova E. P., Sytsko V. E., Goldade V. A.
Bioelectrical mechanism of immobilizing microorganisms on polymer electret films. pp. 107--110
Summary: The method of electret-thermal analysis developed in the physics of dielectrics has been applied for monitoring bioelectric phenomena that accompany immobilization of microorganisms on electret substrates. A spectrum of thermally stimulated currents (TSC) has been obtained for the first time for biofilms consisting of immobilized cells of Saccharomyces. The spectrum is represented as a halo in the region of 30 ¸ 90 °C. Immobilization of cells on the electret polyethylene films was found to result in their depolarization that is recorded on TSC spectra as a reduction of the current peak corresponding to the polyethylene melting point. A hypothesis has been put forward that interprets the named phenomenon as the absorption of electric energy of polarized substrates by the cells for sustaining metabolic reactions.
Khudoley A. L., Klimenko S. E., Sosnovsky I. A.
Change of the load capacity of sliding bearings by design. pp. 111--114
Summary: Constructive solutions that allow to reduce the contact pressure for the most loaded areas of friction bearing are considered. A new design of friction bearings is proposed for improving the resistance of shaft misalignment.
Rupasova Zh. A., Pirogovskaja G. V., Autko A. A., Vasilevskaja T. I., Autko An. A., Poznyak O. V.
Effect of edaphic and meteorological factors on the yield and biochemical composition of production of vegetables under the conditions of Belarus. pp. 115--123
Summary: The article presents the results of a comparative research on the degree of transformation of the biochemical composition of carrot, table beet and cabbage production against the background of application of unilateral mixtures and different types and doses of conventional fertilizers and new complex chlorine-containing and non-chlorine mineral fertilizers developed by RUE 'Institute of Edaphology and Agrochemistry' which were supplemented with chemical agents and biologically active compounds. The research was conducted in a triennial cycle of observations within the frames of similar field experiments, using a 10-alternative pattern, on sod-podzol sandy loam soil under the conditions of Belarus. The types of fertilizers and the schedules for their application capable of ensuring the maximum yield of useful matters to vegetable production have been established.
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