of National Academy of Sciences
of Tajikistan

News of the National Academy of Sciences of Tajikistan.
Department of physical, mathematical, chemical, geological and technical sciences

Известия Академии наук Республики Таджикистан. Отделение физико-математических, химических, геологических и технических наук, №3, 2017 г.

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Jurakhonov O.A.
Approximation some classes functions of two variables the triangular sums Fourier-Hermite and the values of the widths some classes of functions
The exact inequalities of Jackson-Stechkin type are received on sets in which the values of the best polynomial approximations are estimated from above by K -functional and exact values of the various n -width some classes of functions are found through continuity modules of order m -th.

Ключевые слова: наилучшие приближения; модуль непрерывности; ряд Фурье-Эрмита; неравенство типа Джексона-Стечкина; K-функционал; N-поперечники; best approximation; modulus of continuity; sums fourier-ermita; K-functional; inequalities of Jackson-Stechkin type; n-width.

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Madimarova F.M.
On the best approximation in the mean with Chebyshev weight of certain clasess of differentiable functions of two variables
In this paper the upper bounds of the best approximation by "nodes" of algebraic polynomials for classes of differentiable functions of two variables in the metric of the space with Chebyshev weight are found.

Ключевые слова: верхние грани; гильбертово пространство; единичный оператор; тензорное произведение; квазипоперечник; upper bounds; Hilbert space; unit operator; tensor product; quasiwidth.

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Kurbanshoev S.Z.
Contruction and properties of nonlinear projections of differential equation system with divergent argument
The article is dealt with the concept of resolving operator for named systems. The assessment to the solution of nonlinear equation in cone is given, as well as the concept linear and nonlinear Green operators. Some properties of integral manifold are studied, determined with nonlinear projections.

Ключевые слова: банахово пространство; оператор Грина; экспоненциальная дихотомия; интегральное многообразие; проекторы; a Banach space; Green operator; exponentially dichotomies; integral manifold; nonlinear projections.

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Majidzoda F.A., Muminov Kh.Kh.
Simulation of nanostructured single-junction solar cells based on ZnSnN
A thin-film single-junction solar cell based on ZnSnN is proposed. The results of numerical simulation show that the maximum efficiency of the proposed design of thin-film solar cells with thickness of the p-ZnSnN layer at 1100 nm and thickness of the n-ZnSnN layer at 1320 nm could reach 24.56%, while the open circuit voltage V=1.69 V, and the short-circuit current density J =36.4 mA / cm.

Ключевые слова: тонкоплёночные солнечные элементы; фотогенерация; рекомбинация; электронно-дырочная проводимость; уравнение Пуассона; thin-film solar cells; photogeneration; recombination; electron-hole conductivity; Poisson equation.

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Muminov Kh.Kh., Muhamedova Sh.F., Asghari-Larimi M.
Numerical modeling of evolution of the two-solitonic solution of the scalar nonlinear Shroedinger equation with the potential of attraction
We study two-solitonic solutions to the nonlinear Schrödinger equation with potential of attraction under condensate boundary conditions, which have been constructed by finite-zone method. Numerical simulations demonstrate stability of the above mentioned solutions under different vacua on the left and right boundaries. The solitonic solutions shows Akhmediev breather - like behavior during its motion, freezing under vanishing velocities.

Ключевые слова: бризер; конденсатные граничные условия; скалярное нелинейное уравнение Шредингера; breather; condensate boundary conditions; scalar nonlinear Schrödinger equation.

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Sattarov M.A.
Derivation of Saint-Venant equations from Reynolds equations
In this paper, a closed system of Navier-Stokes-Reynolds (NSR) equations of motion with new differential terms of first and second order with corresponding coefficients of effective Boussinesq viscosity and Taylor vorticity transport is obtained. New axial and plane Saint Venant models derived from this system are proposed for solving problems of flood wave motion in the beds of large rivers and river-type water reservoirs.

Ключевые слова: водные ресурсы; моделирование; прогноз; паводки; наводнения; экология; методы расчёта; water resources; simulation; prediction; high water; flood; ecology; calculation methods.

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Davlatnazarova M.D., Isobaev M.D., Abdullaev T.Kh.
The properties of technical adsorbents from coal and waste of processing agricultural crops
Sorption properties with respect to lead char semi-coke, obtained from coal of Tajik deposits, walnut shells and sunflower basket, were investigated. The adsorption capacity of semi-coke depends on the content of mineral substances (ash content), sorbent particle size and solution concentration. The semi coke from the sunflower basket shows less activity than the semi-coke from the walnut shell. The optimal particle size of the adsorbent is 0.025mm.

Ключевые слова: угли месторождений Таджикистана; полукокс; технические адсорбенты из скорлупы грецкого ореха и корзинки подсолнечника; сорбция солей свинца; Coal from Tajik deposits; semi-coke; walnut shells; sunflower basket; adsorption of lead ions.

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Rahimov F.A., Ganiev I.N., Obidov Z.R., Umarova T.M., Abulhaev V.J.
Influence of molybdenum on corrosion-electrochemical properties of Zn5Al alloy, in the neutral medium
In paper results of potentiodynamical researches of influence of additives of molybdenum on corrosion-electrochemical properties of Zn5Al alloy, in the of NaCl electrolyte medium are presented. It has been shown, that introduction of molybdenum in alloy zinc-aluminium promotes reduction of corrosion rate at 1.5-2 times.

Ключевые слова: сплав Zn5Al; молибден; потенциостатический метод; электролит NaCl; потенциал коррозии; скорость коррозии; Zn5Al alloy; molybdenum; potentiostatically method; NaCl electrolyte ; corrosion potential; corrosion rate.

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Boboev Kh.B., Nazarov Sh.B., Ibrohimov S.Z.
Investigation of the effect of humidity and the mass share of the organic and inorganic part of solid domestic wastes on the temperature mode of its processing
The results of a study of the effect of moisture and the mass fraction of organic and inorganic parts of solid domestic waste on the temperature regime of thermal processing, which do not require the preliminary preparation of solid waste and the attraction of an additional source of energy for their thermal decomposition, are presented. The range of humidity at which thermal destruction of solid waste is possible is determined.

Ключевые слова: твердые бытовые отходы; термическая переработка; температурный режим; влажность; solid household waste; thermal processing; temperature regime; humidity.

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Finaev A.F., Kobuliev Z.V., Shaymuradov F.I., Rakhimov I.M., Majidov T.S., Finaeva E.A.
Use of isotope techniques to assess sources of water supply in Dushanbe, Tajikistan
The article represents result of chemical and isotope study of waters in the Kafirnigan river basin in conditions of mountain subtropical climate of Tajikistan. The study area is one of water supply sources for the capital Dushanbe city. Admixture of chemical elements in water does not exceed maximum permissible concentration (MPC). However, excessive contents of particular chemical elements in several sites were revealed. Assessment of stable isotopes δO and δH was done which helped to distinguish two water groups of various origins. Combined study of chemical composition and natural isotopes can be useful for hydrological and hydrogeological investigations of other river basins in Central Asia.

Ключевые слова: природные изотопы; тритий; гидрология; качество воды; бассейн реки Кафирниган; водоснабжение; environmental isotopes; tritium; hydrology; water quality; Kafirnigan river basin; water supply.

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Juraev R.U.
The use of macroseismic data in assessing the seismic vulnerability of the urbanized territories on the example of Dushanbe
The importance of macroseismic data in assessing seismic safety of the urbanized territories on the example of Dushanbe has been shown. Based on their analysis of the theoretical model maps of isoseists and scenarios for earthquakes of different focal zones, representing the danger to Dushanbe is composed.

Ключевые слова: эпицентр землетрясения; магнитуда; интенсивность; землетрясения; изосейста; сейсмограмма; макросеймика; очаговая зона; earthquakes epicenter; magnitude; intensity of earthquake; isoseist; macroseismic; focal area.

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Najibullohi R., Rakhmonov A.D.
Research on physical and mechanical properties of composite armature depending on the manufacturing method
Results of research of physical and mechanical properties of composite armature and methods of manufacturing of non-metallic composite constructions are presented.

Ключевые слова: композитная арматура; температура; физико-механические свойства; composite armature; temperature; physical and mechanical properties.

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