# Доклады Национальной академии наук Беларуси, 1998, Том 42, No.4

/ Издания академии / Научные журналы

Доклады Национальной академии наук Беларуси, 1998, Том 42, No.4

## СОДЕРЖАНИЕ

**МАТЕМАТИКА**

*Guletskii V. I., Yanchevskii V. I.*
**Torsion of Bauer groups of the curves defined over multidimensional local fields.** pp. 5--8

*Summary:* Explicit estimates of the length of the cyclic algebra representation of primary torsion in Bauer groups of the curves defined over multidimensional local fields under the condition of rationality of the corresponding torsion in the Jacobian manifold were found in the article

*Vasyuk G. B.*

**On 2-torsion part of Brauer groups elliptic curves with bad reduction in reducible case defined over the field of 2-adic numbers.** pp. 9--12

*Summary:* Let *E* be an elliptic curve defined over the field of 2-adic numbers *Q*_{2} and *E*(*Q*_{2}) be its subgroup of *Q*_{2}-rational points. The presentation of the group _{2}Br*E* by unramified central simple algebras over the function field *Q*_{2}(*E*) of curve *E* having a bad reduction is obtained for reducible case

*Rovba E. A.*

**On the approximation of functions of a limited variation by the Freyer and Jackson rational operators.** pp. 13--17

*Summary:* Estimates of approximations of the functions, having a limited variation over the section and satisfying Lipshits' condition of the order of a, 0 < a < 1, are obtained by means of Freyer's and Jackson's operators

*Lazakovich N. V., Yablonskii O. L.*

**Stochastic q-differentials in the algebra of generalized random processes.** pp. 18--22

*Summary:* Approximations of stochastic q-integrals in the algebra of generalized random processes are considered in this article

*Alekhno A. G.*

**The homogeneous Riemann boundary-value problem with an infinite index in the space of functions with quite regular growth.** pp. 23--28

*Summary:* A general solution of the Riemann boundary-value problem with an infinite index is considered in the case of multilateral vorticity

*Minyuk S. A.*

**On the problem of a quadratic regulator for linear discrete systems.** pp. 29--32

*Summary:* A solution of the square-law regulator problem is given for linear discrete systems

*Kilbas A. A., Glaeske H.-J.*

**Bessel type integral transforms on weighted ***L*_{p}-spaces. pp. 33--39

*Summary:* Two integral transforms of the form (*Kf*)(*x*) = ò_{0}^{¥} *K*(*xt*) *f*(*t*)*dt* (*x* > 0)
with the kernels *K*(*x*) generalizing the modified Bessel function of the third kind *K*_{g}(*x*), are studied in the spaces *L*_{v, r} of functions *f* with
ò_{0}^{¥} | *t*^{n} f(t) |^{r} (*dt/t*) < ¥ (1 £ *r* < ¥, n Î **R**).
On the basis of the theory of **H**-transforms the boundedness conditions, different integral representations and characterization of the ranges for the considered transforms are given

*Orlovich Yu. L.*

**On Hamilton cycles in ***e*-locally connected graphs. pp. 40--44

*Summary:* In recent years a number of results dealing with graphs which contain no *K*_{1, 3} as an induced subgraph has been obtained. It is proved in this paper that *K*_{1, 3}-free connected *e*-locally connected graphs have some stronger properties than Hamiltonianity. The main results are stated in terms of cycle extensions

*Zyl A. N., Matus P. P.*

**Efficient difference schemes for multi-dimensional parabolic equations on irregular grids.** pp. 45--50

*Summary:* New efficient and unconditionally stable computational methods for the parabolic equation of the second order of approximation on irregular rectangular grids are constructed and investigated. A priori estimates of the solution in the norm *C* are obtained in the new principle of maximum for the derivatives

*Bernik V. I., Dickenson H., Dodson M.*

**Approximation of real numbers by integer polynomials.** pp. 51--54

*Summary:* We proved the inhomogeneous case of A. Baker's conjecture: for any *d* Î **R** the inequality |*P*(*x*) + d | < *H*(*P*)^{-n+1} Y (*H*(*P*)) has only a finite number of solutions in integer polynomials of a degree £*n* for the monotoneously decreasing function Y(*x*) satisfying the condition å_{H = 1}^{¥} Y (*H*) < ¥

**ФИЗИКА**

*Sirota N. N.*
**A method for calculating phonon spectra of solids.** pp. 55--60

*Summary:* New simple interpolation method of determination of phonon spectra for quasi-isotropic solids is regarded using the values of elastic moduli: bulk modulus *B*, Young's modulus *E* and shear modulus *G*. The phonon spectra calculated with this method are in good agreement with those determined by the Born--Karman method

*Vyshatko N. P., Olekhnovich N. M., Salak A. N.*

**The structure and dielectric properties of stable and metastable phases of PbCu**_{1/3}Nb_{2/3}O_{3}. pp. 61--64

*Summary:* PbCu_{1/3}Nb_{2/3}O_{3} at high pressure and temperature is found to exhibit the phase transition from pyrohlore structure to perovskite one. Results of the weak-field dielectric response investigations are given. The temperature phase transition is shown to be due to change of character of dipole ordering for both structure modifications. For perovskite modification it corresponds to relaxor ferroelectric type

*Zaporozhchenko V. A., Katarkevich V. M., Rubinov A. N., Ryzhechkin S. A., Efendiev T. Sh.*

**A picosecond DFB dye laser with stable parameters of generation.** pp. 65--69

*Summary:* A picosecond light source with improved energy and wavelength stability including a holographic DFB dye laser pumped with an actively mode-locked YAG: Nd laser is reported. Such a laser system provides generation of ~10 ps pulses at a repetition rate of 12.5 Hz with energy stability of 5 % and temperature wavelength sensitivity of 0.08 nm/degree

*Korshunov F. P., Mudryi A. V., Patuk A. I., Shakin I. A.*

**Luminescence of heteroepitaxial silicon films on sapphire.** pp. 70--73

*Summary:* Low-temperature (4.2 K) photoluminescence of silicon on sapphire films with different thicknesses has been investigated. The experiments show that the common form of luminescence spectra in the energy range from 0.7 to 1.15 eV (the number of wide bands in the spectra, their shape, the energy position, the intensity) is strongly dependent on the thickness of the films. Some of these bands can be definitely assigned to radiative recombination at dislocations. It is found that in the luminescence spectra of silicon on sapphire films impurity-bound emission, bands are shifted relative to their position in single-crystal bulk silicon. The residual compressive stress in silicon on sapphire films is estimated, using the photoluminescence method

**ХИМИЯ**

*Vorobyova S. A., Sobal N. S., Lesnikovich A. I.*
**Colloidal silver produced by two-phase reduction.** pp. 74--78

*Summary:* A colloidal silver solution in the organic phase was synthesized by chemical reduction in a two-phase system (decane--water) without special stabilizers. Dispersity and phase composition of the disperse phase of the colloidal solution were analysed with the methods of chemical and X-ray analyses, electron microscopy. UV and visible spectroscopy. It is shown that the disperse phase of the colloidal solution contains spherical crystal silver particles with the size 20--110 nm (*d*_{max} = 26 nm, s = 0.67)

**БИОЛОГИЯ**

*Sholukh A. M., Artamonov I. D., Baranova L. A., Volotovsky I. D.*
**Localization of tyrosine kinase activity in bovine rod outer segments.** pp. 79--82

*Summary:* Localization of the tyrosine kinase activity in bovine rod outer segments is studied. The activity is found in discs, plasma membrane and cytosol. The target protein of tyrosine kinas has a molecular weight of about 70 kDa

*Melnikova A. M., Matus V. K., Skorinko E. V., Baranets N. L., Martynova M. A., Titok V. V., Plenina L. V., Khlyustov S. V., Konev S. V.*

**A pool of low-molecular metabolites based on yeast biomass produced under ozone-induced stress.** pp. 83--88

*Summary:* The composition of the pool of low-molecular compounds accumulated in the medium during ozone treatment was studied, using yeasts Candida utilis and Saccharomyces carisbergensis. Significant amounts of nucleotides and nucleosides (mainly, adenine-containing), vitamins **B**_{1} and **B**_{2} as well as a complete set of amino acids characteristic of the yeast cells have been found. This ozone-induced accumulation of low-molecular products is shown to result from the damage of cell membrane permeability barriers followed by efflux of the pool of free metabolites rather than from ozone-catalyzed destruction of the cell biopolymers

*Pisarchik A. V., Kartel N. A.*

**The effect of insertions of simple sequences into the 35S CaMV promoter on its activity in the case of transient transformation of tobacco protoplasts.** pp. 89--93

*Summary:* A possible role of simple sequences in regulation of transcription is studied. For this purpose there were developed constructions, containing AC and AT repeals of various length in distal and proximal to TATA-box regions of 35S CaMV promoter. Promoter activity was modified to a greater extent when simple sequences were inserted in proximal to TATA-box region, than in a distal one. (AC)_{n} insertions in proximal region led to decrease and (AT)_{n} to increase of promoter strength

*Pyzhova N. S., Nikandrov V. N.*

**The role of redox reactions in activation of plasminogen by subcellular particles of brain and liver.** pp. 94--99

*Summary:* A plasminogen-activating ability of mouse brain and liver "nuclear", "mitochondrial" and "heavy membranes" fractions is modified by metabolic poisons (0.001 M). 2,6-dichlorophenolindophenol, NADH (0.007 M) and active oxygen species scavengers. NADH presence changes the character of above mentioned compounds influence. It has been concluded, that one of the causes of the indicated ability is redox-reactions, which produce an active oxygen species

*Aleshchenkova Z. M.*

**Preparatory metabolism of tetraphthalate esters in ***Rhodococcus* bacteria. pp. 100--103

*Summary:* Strains of *Rhodococcus erythropolis, R. ruber, R. luteus, R. maris*, utilizing dimethylterephthalate, diethylterephthalate, dibutylterephthalate, diallylterephthalate as the sole source of carbon have the common route of initial metabolism of these compounds: diester -- monoester --terephthalate -- benzoate -- *p*-hydroxybenzoate -- protocatechuate -- 3-ketoadipinate. Benzoate may also be transformed via catehol into 3-ketoadipinate

*Giginyak Yu. G.*

**Ecological determination of biogeographic ranges of the distribution of hydrobionts.** pp. 104--108

*Summary:* In the article the possibility of a theoretical approach to determination of biogeographical ranges of distribution of hydrobionts is considered, proceeding from the biological ability to reproduce within a certain temperature range. It is shown that, knowing the species area, it is possible to calculate the temperature range most favorable for the reproduction of a species or to determine its biogeographical ranges from the temperature range in which the species is able to reproduce

*Potapnev M. P., Kuzmenok O. I., Potapova S. M., Smolnikova V. V., Myslitskii V. F., Rzheutskii V. A., Vasilevskaya T. A., Vasyukhina L. V.*

**Functional disorders of T-cell immunity in persons engaged in Chernobyl emergency operations -- 10 years after the accident.** pp. 109--113

*Summary:* The results evaluating T-cell immunity of 148 persons affected by consequences of Chernobyl accident are presented in this work. We demonstrated that 10 years after the accident immunophenotyping of peripheral blood lymphocytes did not reveal marked disturbance in lymphocyte subpopulation content in exposed group as compared with healthy control. Determination of cell proliferation in vitro indicated the decrease in DNA synthesis of T-lymphocytes stimulated with optimal and particularly suboptimal concentrations of polyclonal T-cell activators. Based on individual deviation of results of T-lymphocyte proliferation the groups with high and low level of response were sorted out for further examination

**НАУКИ О ЗЕМЛЕ**

*Rylova T. B.*
**Biostratification of Belovezhian and Alexandrian interglacial Pleistocene horizons in Belarus.** pp. 114--117

*Summary:* Biostratigraphic subdivision of the Belovezhian and Alexandrian interglacial deposits of the Belarus Pleistocene into regional pollen assemblage zones is given in the paper

**ТЕХНИЧЕСКИЕ НАУКИ**

*Lynkov L. M., Petrov N. P.*
**Structural characteristics of zirconium oxide films produced by rapid thermal annealing.** pp. 118--120

*Summary:* Results of a study of structural and barrier properties of thin zirconia films on Si substrates are presented. The influence of rapid thermal annealing on these properties was investigated. *X*-ray diffractometry, AEM, TEM and SIMS methods were used in these experiments. Thin ZrO_{2} films were obtained by thermal oxidation of thin Zr films. Varying characteristics of rapid thermal annealing (temperature and duration of annealing), both quality dense and destructive thin ZrO_{2} films can be formed on Si substrates. These thin ZrO_{2} coatings can be used as a high temperature dielectric and as a material for lift--off lithography purposes in microelectronics

/ Издания академии / Научные журналы / К началу страницы

Разработана и поддерживается Николаем Н. Костюковичем. Последнее обновление: *6 сентября 2008 г.*

Создана при участии Игнатия И. Корсака

Копирайт © 1998-2008 Национальная академия наук Беларуси

Копирайт © 1998 Издательство "Беларуская навука"