Известия Академии наук Республики Таджикистан. Отделение физико-математических, химических, геологических и технических наук, №2, 2017 г. |
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Скачать | Saidusaynov M.S. | 7-17 | K-functional and the values of -widths in Bergman space |
In this paper the problem of mean-square approximation of complex variables functions which are regular in bounded domain of complex plane by the orthogonal in the domain of system of functions Fourier series is considered. When the domain is a unit disk, accurate estimates of convergence rate of Fourier series by orthogonal system { z } ( k= 0,1,2,…) on class of functions given by K-functional of derivatives by defined order were obtained. An exact values of some widths for specified class of functions were calculated. |
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Ключевые слова: обобщенный модуль непрерывности; неравенство Джексона-Стечкина; K-функционал; n-поперечники; generalized module of continuity; Jackson-Stechkin inequality; K-functional; n-widths. | |
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Скачать | Tukhliev K., Murodov K.N. | 18-31 | An exact upper bounds of the best approximation by Fourier-Bessel sum in the space and the values of -widths of some classes of functions |
In Hilbert space with the weight the exact inequalities in the mean of Jackson-Stechkin which colligate the best approximation of functions by partial sum of Fourier-Bessel series with positive average weight of generalized modulus continuity where is a differential operator of second order, are received. For some classes of functions defined by smoothness characteristic the values of -widths are calculated in space. |
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Ключевые слова: обобщенный модуль непрерывности; наилучшее приближение; ряд Фурье-Бесселя; n-поперечники; generalized modulus of continuity; the best approximation; Fourier-Bessel series; n-widths. | |
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Скачать | Azizov M., Muhlis A. | 32-41 | Information complexity of approximate solution of integral Fredholms equations with harmonic coefficients |
The eхat logarithmic order is found of the minimal radius of information for the second kind with periodic and harmonic kernels. The result shows that information complexity of the Fredholm problem of the second kind with harmonic kernels has more high order in comparison with complexity of the corresponding problem of approximation. |
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Ключевые слова: минимальный радиус; интегральное уравнение; гармоническое ядро; информационная сложность; число Гельфанда; minimal radius; integral equations; harmonic kernels; information complexity; Gelfand number. | |
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Скачать | Usmanov Z.D., Dovudov G.M. | 42-48 | On a statistical portrait of tajik sentences |
On the basis of a statistical processing of the text collection, the frequency of sentences to different lengths, their PoS averaged structure, PoS frequency of the first and last word in a sentence, the frequency distribution of PoS in sentences with one, two, ... and ten words are established. |
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Ключевые слова: таджикский язык; предложение; часть речи; частотность; Tajik language; sentence; part of speech (PoS); frequency. | |
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Скачать | Ashurova Sh.N., Kosimov A.A. | 49-54 | Efficiency evaluation of using words unigramm for a text identification |
By this work the possibilities of N.V.Smirnov’s homogeneity criterion and its modifier for text identification by frequencies of word unigrams were explored. |
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Ключевые слова: таджикский язык; униграмма; частотность; статистика; эффективность; Tajik language; unigram; frequency; statistics; efficiency. | |
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Скачать | Kokhirova G.I., Abdulloev S.Kh., Khamroev U.Kh. | 55-61 | Potentially hazardous asteroid (357439) 2004BL86 during close approach to the Earth on january 27, 2015 |
The results of observations of asteroid (357439) 2004BL86 denoted as potentially hazardous asteroid during its close approach to the Earth on January 27, 2015 are given. The coordinates and light curve were obtained, and the rotation period of asteroid was estimated. |
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Ключевые слова: астероид; астрометрия; фотометрия; координаты; кривая блеска; период вращения; asteroid; astrometry; photometry; coordinates; light curve; period of rotation. | |
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Скачать | Muminov Kh.Kh., Maksudov A.T., Toshov T.A. | 62-73 | To the theory of magnetoelectric interactions in ferromagnetics with high values of spintaking into account exchange anisotropy |
Studies of a non-Heisenberg ferromagnet with a spin S = 1 with exchange anisotropy in the presence of phonon modulation of spin-quadrupole waves by the method of generalized coherent states of the SU (3) group are carried out. It is shown that the presence of a mechanism of magnetoelastic interactions can lead to an exchange of energy between the phonon and spin-quadrupole subsystems. |
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Ключевые слова: негейзенберговский ферромагнетик; спин-фононное взаимодействие; магнитоупругие волны; спин-квадрупольные волны; non-Heisenberg ferromagnet; spin-phonon interaction; magnetoelastic waves; spin-quadrupole waves. | |
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Скачать | Salikhov T.Kh., Mahmalatif A., Khodjaev Yu.P. | 74-87 | Features of generation of the fundamental harmonic of nonlinear photoacoustic response in optically inhomogeneous two-layer samples |
A theory of fundamental harmonic generation of a nonlinear photoacoustic signal in optically inhomogeneous two-layer samples is proposed. For the most interesting cases, the dependencies of the amplitudes and phases of this signal on the frequency of modulation of the incident beam and the thermal coefficients of thermophysical and optical parameters, including the optical absorption coefficient, are established. |
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Ключевые слова: фотоакустика; нелинейный фотоакустический отклик; двухслойные системы; тепловая нелинейность; основная гармоника; оптическая неоднородность; photoacoustic; thermal nonlinearity; two layers systems; nonlinear photoacoustic response; fundamental harmonic; optical inhomogeneous. | |
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Скачать | Korzun K.A., Kovalevsky A.A., Kotov D.A., Granko S.V. | 88-94 | Composition and electrophysical parameters of graphene-like material produced under coal transformations |
Results of study of the material obtained by converting coal into multilayer graphene structure as a result of mechanical activation are given in the work. The research was conducted by use of scanning and transmission electron microscopy, Raman spectroscopy, Auger, IR and X-ray photoelectron spectroscopy. The mechanism of formation of multilayer graphene nanocoals is proposed by on the basis of experimental studies morphology, chemical composition and structure of the obtained material. |
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Ключевые слова: уголь; наночастицы; многослойный графен; спектр комбинационного рассеяния; дифрактограмма; coal; nanoparticles; multilayer graphene; Raman spectrum; diffractogram. | |
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Скачать | Nazarov Sh.B., Barotov A.M., Kurbonov A.S., Misratov Zh.A., Mirsaidov U. | 95-100 | Study of the basis of decomposition of boronand aluminum silicate ores by sintering with CaCl |
The results of decomposition of boron- and aluminum silicate ores by sintering with CaCl are presented. The optimal parameters for the sintering process are defined. The comparative assessment of the decomposition basis of boron ore and nepheline syenites with CaCl is stated as well. |
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Ключевые слова: спекание; нефелиновые сиениты; боросиликатная руда; хлористый кальций; sintering; nepheline syenites; boron silicate ore; chloride calcium. | |
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Скачать | Fozilov Dj.N., Alidodov B.A. | 101-110 | Elements of the impurities in coal coalfield background Yagnob |
Angles of coalfield background Yagnob are characterized by increased concentrations of accompanying small elements like zinc, barium, phosphorus, vanadium, chromium, nickel, manganese, tin, silver (CC-10-55). With few exceptions, their content is increased in coal ash as well (100-760 g/t). These data may be of interest for the complex use of coal deposits. |
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Ключевые слова: галлий; фосфор; ртуть; цинк; барий; ванадий; хром; никель; марганец; коэффициенты; концентрации; Gallium; phosphorous; mercury; zinc; barium; vanadium; chromium; nickel; manganese; ratios; concentrations. | |
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Скачать | Mahmadaliev A.T., Fayziev A.R. | 111-118 | Geological and mineralogical features of the Baljuan strateform deposit (Afgan-Tajik depression) |
The article provides information on the geological structure, mineralogy and ore-bearing rocks of the stratiform deposit of Baljuan. |
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Ключевые слова: месторождение; Бальджуан; галенит; сфалерит; кальцит; ярус; deposit; Baljuan; galena; sphalerite; calcite; tier. | |
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Скачать | Sabirov A.A. | 119-127 | The boundaries and biostratigraphy of the famennian stage by foraminifers in Tajikistan |
On the basis of study of foraminifers in carbonate sections of Tajikistan the boundaries’ location and scope of the famennian stage in this region have been ascertained and its biostratigraphical sequence has been carried out. Within this stage limit 7 foraminiferal zones are sorted out, which were compared with the zones of other regions. |
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Ключевые слова: фораминиферы; фаменский ярус; биостратиграфия; Таджикистан; foraminifers; famennian stage; biostratigraphy; Tajikistan. | |
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Скачать | , | 128-130 | M.N.Maksumov (1937-2013) |
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Ключевые слова: . | |
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Скачать | , , , | 131-134 | F.Kh.Khakimova (1937-2017) |
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Ключевые слова: . | |
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