Известия Национальной академии наук Таджикистана. Отделение физико-математических, химических, геологических и технических наук, №1(186), 2022 г. |
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Скачать | M.Sh.Shabozov , A.S.Quraishi | 7-22 | Exact upper bounds of root mean square approximations some classes of periodic differentiable functions
in space L |
In the article, the exact values of the upper bounds of the best mean non-quadratic approximations of some classes of periodic of rendered functions by trigonometric polynomials, characterizing generalized modulus of continuity generated by a specific generalized shift operator in the space are found. Sharp Jackson-Stechkin-type inequalities are obtained for both better joint approximation of functions and for -functionals on the classes . |
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Ключевые слова: best root mean square approximation functions; upper bounds; generalized modulus of continuity; generalization operator displacement; Petre -functional. | |
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Скачать | E.Kh.Safarzoda | 23-32 | On the absolute convergence of the double Fourier series of almost periodic functions |
In this paper, we investigate sufficient conditions for the absolute convergence of double Fourier series of almost periodic functions in the sense of Bezikovich. Depending on the behavior of the Fourier exponents, the higher order continuity modulus and the averaging modulus of order are used as structural properties of the functions under consideration. |
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Ключевые слова: almost periodic functions of Bezikovich; double Fourier series; Fourier exponents; modulus of continuity; averaging module; absolute convergence; range of functions. | |
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Скачать | K.E.Khaknazarov | 33-39 | Variational Dirichlet problem for non-divergence form elliptic operators with uncoordinated degeneracy |
The paper has a proof of a theorem on solvability of the variational Dirichlet problem for non-divergence form elliptic operators in a bounded domain of n-dimensional Euclidean space with uncoordinated power degeneracy along the entire boundary of the domain. The solution of the problem under study is sought in a weighted Sobolev-type space, which is the closure of the class of infinitely differentiable finite functions. The concept of higher forms is introduced, and only the degrees of degeneracy of the coefficients of the higher forms are involved in the definition of the solutions space. |
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Ключевые слова: variational Dirichlet problem; non-divergence form elliptic operator; uncoordinated power degeneracy; bounded domain. | |
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Скачать | G.I.Kokhirova , P.B.Babadzhano , M.N.Latipov , A.I.Jonmuhammadi , U.H.Khamroev | 40-61 | New near-earth objects in the Taurid complex |
The Taurid meteoroid stream, comet 2P/Encke being the parent of the stream and more than 30 near-Earths asteroids which are in fact extinct fragments of the parent comet have form the Taurid comet-asteroid-meteoroid complex. The Taurid stream produces the meteor showers and sub-showers observable on the Earth annually during October-November and May-June. We carried out a new search for asteroids belonging to the Taurid complex. On the base of calculation of orbital evolution of a sample of NEAs discovered in 2004-2015 and determination of theoretical features of related showers a search for observable active showers close to theoretically predicted ones was performed. As a result, predicted showers of 16 NEAs were identified with the showers produced by the Taurid meteoroid stream. Revealed association points to their common cometary origin. New near-Earths objects alongside with already established ones are moving within the Taurid stream and are very likely extinct fragments of comet 2P/Encke - parent of the Taurid complex or remnants of a larger comet-progenitor that was disintegrated 20-30 thousand years ago. |
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Ключевые слова: comet; asteroid; extinct comet; meteoroid stream; meteor shower; orbit; radiant; evolution. | |
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Скачать | F.Sh.Shokirov | 62-70 | Majorana representation for quantum spin systems |
The description of the states of a quantum system with a high spin value in a multidimensional Hilbert space is associated with the complexity of an intuitive understanding of the geometric interpretation of the processes under study. In this paper, using Majorana's method of representing pure spin systems based on the basic states with spin S=1/2, a system of Majorana polynomials for the general case is determined. |
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Ключевые слова: Majorana representation; Bloch sphere; Hilbert space; mathematical modeling. | |
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Скачать | Sh.Kh.Khalifaeva | 71-77 | Heavy metals in soils of south and central parts of Tajikistan |
Statistical characteristics of heavy metals (HM) in soil samples of the south and central parts of the country are given. The interannual variation of some heavy metals (zinc, arsenic, lead) is considered. |
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Ключевые слова: heavy metals; soil; pollution; environment. | |
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Скачать | F.A.Khamidov , M.Yu.Akramov , J.N.Eshov , D.T.Isozoda , A.Badalov | 78-87 | System analysis of thermochemical properties of binary hydrides of s-elements, lanthanides (II) and modeling of their change regularities |
The known and/or specified values of thermodynamic properties of binary hydrides of s-elements, lanthanides (II) have been summarized. The system analysis of thermodynamic characteristics of binary hydrides of mentioned elements have been carried out by means of semiempirical and computational methods. The regularities of their change in the range of IА, IIА groups and lanthanides (II), as well as periods have been defined. A clear deviation of hydrides properties of typical elements of IА and IIА periods from subsequent typical analogs has been shown.
It has been defined that change of thermodynamic characteristics of lanthanide hydrides depending on their nature has complicated character with appearance of tetrad-effect.
The mathematical models of defined regularities have been drawn up. |
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Ключевые слова: system analysis; thermodynamic properties; binary hydrides; lanthanides; regularity; modeling. | |
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Скачать | К.О.Boboev , М.D.Boboyorov , J.N.Eshov , B.B.Barotov , U.М.Mirsaidov | 88-92 | Thermodynamic analysis of processing processes
in decomposition of uranium-containing ore
with sulfuric acid |
The article presents the results of a thermodynamic calculation of the decomposition of uranium-containing ores from the Oktyabrsky deposit with sulfuric acid, the thermodynamic characteristics of the minerals that make up the raw materials and the calculation of the Gibbs energy for each reaction are also determined. |
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Ключевые слова: uranium ore; enthalpy; entropy; Gibbs energy; decomposition; sulfuric acid. | |
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Скачать | U.R.Jobirov , I.N.Ganiev , M.Ch.Shirinov , Z.R.Obidov | 93-97 | Influence of additives of erbium on anode behaviour Zn0.5Al zinc alloy in alkaline environment |
In paper results of potentiostatical researches influence of additives of erbium on anode behaviour of Zn0.5Al zinc alloy, in the alkaline environment are presented. Showed, that speed of corrosion of Zn0.5Al zinc alloy decreases at the additives in it 0.01-1.0 wt.% Cr. |
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Ключевые слова: Zn0.5Al alloy; erbium; potentiostatically method; HCl electrolyte; corrosion potential; corrosion rate. | |
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Скачать | M.M.Mamadvafoev , D.A.Davlatshoev | 98-109 | Carbon in the rocks of the intrusive complexes in Kafandara ore field (Eastern Gissar) |
The article examines the distribution function of carbon, its abundance, dependence on petrochemical characteristics and correlations with petrogenic elements of intrusive complexes of the Southern Tien Shan in the position of the Kafandara ore field. |
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Ключевые слова: carbon; distribution function; occurrence; correlational relation; Kafandara ore field. | |
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Скачать | S.Kh.Negmatullaev , R.U.Juraev , T.R.Ulubiev | 110-122 | The manifestation of strong earthquakes on the territory of Tajikistan in 2020 |
The data on Tajikistan's strong earthquakes are presented that occurred in the year 2020. The description and analysis of the distribution of their epicenters in the territory of Tajikistan is given. Isoseist maps of surveyed seismic events had be used on April 24 and July 4, the nature of manifestation on the surface and their confinement to geological structures are given. Some information about the vulnerability of local buildings in the epicentral zones of earthquakes is presented. |
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Ключевые слова: earthquake epicenter; magnitude; earthquake intensity; isoseist; macroseismic; aftershock. | |
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Скачать | Sh.A.Yoqubov , A.R.Ischuk | 123-132 | Hazardous exogenous geological processes and seismic hazard of the Surkhob river basin |
The article assesses the susceptibility of the mountain slopes of the Surkhob river valley to the formation of mass displacements on the slopes under seismic impacts. Using modern GIS technologies, it is shown that almost the entire populated and developed territory of the Surkhob river basin is at risk of landslides, mudflows and strong earthquakes. Based on the results of the assessment, a map of the susceptibility of slopes to landslides was constructed, on which the susceptibility varies from medium to high, with the dominance of zones with high susceptibility. Based on the assessment, the necessity of taking measures to reduce the risk of earthquakes and secondary exogenous phenomena is shown. |
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Ключевые слова: Surkhob river; hazard; landslide; mudflow; earthquake; geological processes; seismic hazard; sustainability. | |
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Скачать | I.M.Azizxonov , B.L.Talgamer | 133-144 | Assessment of the feasibility of involving the ancient ephels and dumps of the Tereklikan section of the Kandzhol deposit into operation |
The expediency of involving technogenic deposits formed during the extraction of non-ferrous metals in operation is justified. The description of ancient efels and dumps of the Tereklikan section of the Kanjol deposit is given. The method and results of furrow testing are presented and its reliability is evaluated. An underestimation of the silver content was found in the manual method of furrow testing performed by the predecessors. The industrial value of these deposits for silver mining has been established. A basic technology for extracting valuable components is proposed. |
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Ключевые слова: technogenic deposits; furrow testing; control testing; material analysis; development technology. | |
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Скачать | M.A.Mirakov , F.Sh.Iskandarov , Y.N.Nurulloev | 145-152 | First find of hessite at Sangvor golden deposit
(North-Western Darvaz) |
The article provides a detailed description of silver telluride - hessite from the gold - placer Sangvor deposit with its chemical composition, X-ray data and other physical and optical properties. |
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Ключевые слова: hessite; concentrate; placer; silver minerals; tellurium minerals; Sangvor deposit; gold admixture; microhardness; Darvaz; Tajikistan. | |
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Скачать | G.N.Petrov , S.Rasulov , M.Ilolov , Kh.Akhmedov , M.G.Khulmi | 153-160 | Economic efficiency of construction of a small hydroelectric power station in the protected area of the Karatag river basin |
The issues of assessing the absolute and comparative economic efficiency of electricity supply to consumers in the protected area of the Karatag River are considered. The only two possible options are the construction of a 100 kW SHPP and the connection to a centralized power supply by constructing a 35 kV transmission line with a length of 31 km. |
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Ключевые слова: project life cycle; discount rate; payback; electricity losses; present value; efficiency radius; electricity tariff; electricity transit; financial flows; net present value. | |
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Скачать | | 161-163 | |
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Ключевые слова: . | |
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Скачать | | 164-168 | |
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Ключевые слова: . | |
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