Известия Академии наук Республики Таджикистан. Отделение физико-математических, химических, геологических и технических наук, №3(180), 2020 г.
|Article title and abstract||Pages|
|M.Ilolov , S.Rasuli , J.Sh.Rahmatov |
Fractional-order evolution equations with delay and with almost sectorial operators
In this article, we establish some conditions for the existence and uniqueness of solutions of one class of fractional evolution equations with delay and with almost sectorial operators.
Ключевые слова: fractional Gerasimov-Kaputo derivative; almost sectorial operator; resolving families of operators; system with delay.
|N.Rajabov , N.Sh.Karimova |
To theory one class of degenerate loaded second order differential equation with integral conditions
In this works for one class of second order degenerate differential equation with integral conditions, depend from the roots of characteristic equation, integral representation manifold solution is found. Invers formula is found, that is arbitrary constants by valued unknoun function in singular point is found. In basis obtained integral representation, invers formulas and its property ascertained correct stand Coushy tape boundary value problems, when condition is given in singular point. The solution this problem is found in clearly form.
Ключевые слова: degenerate differential equation; integral conditions; cans by problems; integral representation; loaded differential equation.
|Z.D.Usmanov , A.A.Kosimov |
About the influence of the digital text portrait on the recognition of the author of the works
By the example of a model collection, the quantitative descriptions of the works of which are based on various variants of ordering alphabetic n-grams (n = 1,2,3) with spaces, features of the use of the γ-classifier in recognizing the author of the text are revealed.
Ключевые слова: text; n-gram; -classifier.
|G.I.Kokhirova , P.B.Babadzhanov , U.H.Khamroev , A.I.Zhonmuhammadi , I.V.Kulaev |
Beta-Librid asteroid-meteoroid complex
The β-Librid meteoroid stream produces the meteor showers and sub-showers active annually during April-May and November-December. A certain parent comet is not found. To establish the parent comet we performed a new search for NEAs belonging to the β-Librid asteroid-meteoroid complex. On the base of calculation of orbital evolution of a sample of NEAs and determination of theoretical features of related showers a search for observable active showers close to theoretically predicted ones was carried out. As a result, predicted showers of 7 asteroids were identified with the showers and subshowers produced by the β-Librid meteoroid stream. Revealed association points to a cometary nature of the asteroids that are moving within the β-Librid stream and may be considered as extinct fragments of a larger comet-progenitor of the β-Librid asteroid-meteoroid complex.
Ключевые слова: comet; asteroid; extinct comet; meteoroid stream; meteor shower; orbit; radiant.
|Kh.Kh.Muminov , Sh.F.Muhamedova |
Pulsation generation of dissipative solitons of the vector nonlinear schrödinger equation with self-consistent
Using a numerical simulation method, pulsation was generated with one and two pulsations of dissipative solitons of the nonlinear Schrödinger vector equation (a system of two equations) with a self-consistent potential in the presence of swapping and a non-zero velocity. An analysis of numerical experiments of multisoliton solutions shows that in the presence of dissipation and pumping and the speed of the soliton, long-lived dissipative solitons of limited cycle are formed.
Ключевые слова: soliton solution; pumping; dissipation; vector nonlinear Schrödinger equation; dissipative soliton; pulsation; bifurcation.
|Kh.Kh.Muminov , Sh.F.Muhamedova |
Dissipative solitons of the scalar nonlinear Schrödinger equation
Using numerical simulation methods, we analyze the evolution of a dissipative soliton solution of the scalar nonlinear Schrödinger equation with decreasing boundary conditions, taking into account attenuation and swapping by external boundary conditions and a nonzero velocity. The formation of a stable breather solution, i.e., a pulsating soliton with double pulsations, is observed.
Ключевые слова: breather; scalar nonlinear Schrödinger equation; bifurcation; dissipative soliton; decreasing boundary conditions.
|Sh.Sh.Shodiev , S.F.Abdullaev , V.A.Maslov , B.I.Nazarov , U.Madvaliev |
Satellite monitoring of greenhouse gases
on the territory of Tajikistan
The article presents the results of satellite measurements of greenhouse gas concentrations, evaluates their impact on climate change. Greenhouse gases in the atmosphere of Tajikistan were monitored in the fall of 2019 for six zones of different climate systems: in the Ayvadzh desert, in the urban city of Dushanbe, on the Bobobo, Zarafshan, Medvezhy, and Grumm-Grzhimailo glaciers. To monitoring greenhouse gases in the atmosphere, satellite data from the ECMWF site were used.
Ключевые слова: greenhouse gases; ozone; carbon dioxide; nitric oxide; carbon monoxide; water vapor.
|L.Soliev , M.T.Jumaev |
Structure of the diagram of the phase complex of the system Na,Ca||SO,CO,НСО-HO at 50°С
Using the translation method, the phase equilibria of the Na,Ca||SO,CO,НСО-HO system at 50°С were studied. It has been established that the system under study at 50°С is characterized by the presence of 8 invariant points, 16 monovariant curves, and 25 divariant fields. Based on the data obtained, her diagram at a given temperature was first constructed.
Ключевые слова: diagram; phase complex; invariant points; monovariant curves; divariant fields.
|J.Kh.Juraev , A.S.Kurbonov , R.J.Akramzoda , U.M.Mirsaidov |
Kinetics of the phosphoric acid decomposition process of sintered borosilicate ore concentrate
The results of studies on the kinetics of the phosphoric acid decomposition of sintered borosilicate ore concentrate of the Tajikistan Ak-Arkhar deposit are presented in the article. The mechanisms of the reactions and the technological parameters affecting the decomposition process have been determined.
Ключевые слова: borosilicate ore; leaching; phosphoric acid; decomposition; extraction; kinetics; activation energy.
|M.Mamadvafoev , D.A.Davlatshoev |
The iron in the intrusive rock complexes of the Kafandara skarn-magnetite ore field (Eastern Hissar)
This article is the first presenting data on the abundance, distribution, degree (coefficient) of iron oxidation in rocks of intrusive complexes and the partial pressure of oxygen in a magmatic melt during crystallization of iron-containing minerals. It also addresses the issue of the source of iron in ore-forming solutions.
Ключевые слова: East Gissar; Kafandara skarn-magnetite ore field; rocks of intrusive complexes; abundance and distribution of iron; iron oxidation coefficient (degree); source of iron in ore-forming solutions; partial pressure of oxygen in magma.
|A.R.Fayziev , B.N.Sharipov |
Peculiarities of the mineral composition of alkaline pegmatites Darai-Piez (Central Tajikistan)
The article presents data on the features of the mineral composition of pegmatites of the alkaline massif Darai-Piez. In some pegmatite bodies, biotite acts as a dark-colored mineral, in others - tourmaline. It is assumed that tourmaline is of auto-metasomatic nature and could be formed as a result of the reaction of biotite with a boron-containing melt solution. Another feature of pegmatites is that the quartz in them, both in biotite and tourmaline differences, has a pink color.
Ключевые слова: pegmatite; biotite; tourmaline; quartz; feldspar; alkaline massif; Darai-Piez.
|J.Niyazov , S.Saidov |
Evaluation and prevention of dangerous mudflow and landslide processes in the territory of Lakhsh district
The paper discusses issues of early detection and prevention of dangerous mudflows and landslide processes in the Lakhsh region of Tajikistan and raising awareness, knowledge and potential for effective response, self-defense of the population living in difficult high altitude conditions.
Ключевые слова: risk assessment; natural disasters; elevation topography; mudflows; landslides; processes; natural environment; slope; ravine; earthquakes.
|G.N.Petrov , H.M.Akhmedov , M.Ilolov , S.Rasulov , A.S.Kodirov , J.Sh.Rahmatov |
Scheme of energy development of water resources
of the Karatag river
The analysis of the efficiency of the use of river hydropower resources through the construction of cascades of hydropower plants shows that the most economically viable (cheap) option is the construction of a diversion cascade of hydropower plants. From an environmental point of view, derivation hydropower plants and small hydropower plants with low-pressure dams have the least negative impact on the environment (flooding and flooding of the territory, change of shores). Given that in today's conditions the main task of socio-economic development of Tajikistan is not the large-scale utilization of all river water resources, but in the near future the full and reliable provision of consumers at the lowest cost and minimal negative impact on the environment, more efficient development of water resources successive construction of derivation hydropower plants.
Ключевые слова: renewable energy sources; hydropower; hydroelectric power plants with dams; derivation hydroelectric power plants; cascades of hydroelectric power plants; efficiency criteria; technical efficiency criterion; clean energy; economic efficiency criterion; environmental efficiency criterion.
|D.N.Nizamov , Ahmad Farhad |
Numerical solution of dynamic fixed supported plate
problems by sequential approximation method
Dynamic behavior of plates with fixed supported boundary conditions, under the action of an instantaneous impulsive and harmonic dynamic load are investigated. The numerical solution of dynamic plate problems named Sequential Approximation method (SAM) are used. An iterative method is used to solve the differential equation. The developed algorithm and a computer program in C ++ are implemented using the example of a square plate. The reliability of the results is confirmed by their comparison with data obtained by other methods.
Ключевые слова: sequential approximation method; dynamic; numerical; boundary condition; square plate.
|G.Q.Hakimov , S.S.Ziyavodinov , A.Madaliev , Z.V.Kobuliev |
Selection of the construction diagram of the drying unit of the induction type
In the paper the design features of some dryers for drying fruits, vegetables and plant materials are described. The factors effecting the design features of dryers are substantiated. The authors of the paper, based on the exploratory research and development work, presented the developed designs of induction-type drying plants in two versions.
Ключевые слова: drying devices; energy supply; energy-saving technologies; electrical technology; mini-technical; drying of fruits and plants.
|D.Kh.Mirzoev , Sh.O.Azamov , N.M.Jamolov , U.M.Mirsaidov |
Thermodynamic assessment of decomposition of green clays of the Tajikistan Chashma-Sang deposit
with hydrochloric acid
The results of thermodynamic assessment of the decomposition of green clay minerals from the Tajikistan Chashma-Sang deposit at various temperatures during decomposition with hydrochloric acid are presented. The changes in Gibbs energy as a function of temperature and the occurrence probability of processes during the interaction of green clay minerals with the indicated acid are shown.
Ключевые слова: green clay; thermodynamic assessment; hydrochloric acid; Gibbs energy.
Ключевые слова: .