Production technology and optical absorption characteristics of CuIn<Subscript>0.95</Subscript>Ga<Subscript>0.05</Subscript>Se<Subscript>2</Subscript> semiconductor solid solution films

A production technology of thin CuIn_0.95Ga_0.05Se₂ films has been developed based on the method of two-stage selenization of CuIn_0.95Ga_0.05 precursor by a reactive component (selenium) in a carrier gas (nitrogen) flow. The morphology and structure of obtained films were studied by electron microscopy and X-ray diffraction techniques. The spectral dependence of the optical absorption coefficient was measured.     

The Thermophysical Properties of Solid Solutions of CaLa2S4-La2S3 System

The thermal conductivity coefficient in the temperature range from 275 to 450 K and the coefficient of thermal expansion in the range from 300 to 900 K are experimentally determined for solid solutions of the CaLa₂S₄-La₂S₃ system. The mechanisms of heat transfer in CaLa₂S₄- La₂S₃ samples in the investigated temperature range are discussed, as well as the factors which define the complex concentration dependence of thermal conductivity coefficient. The correlation is treated between the value and temperature dependence of the coefficient of thermal expansion and the variation of the interatomic bond force in the case of variation of the concentration of cation vacancies in the investigated crystals.     

Radiothermoluminescence of γ-irradiated composites of polypropilene and dispersed oxides

The peculiarities of stabilization of the excess charges in composites based on PP and dispersed metal oxides are investigated using the method of radiothermoluminescence (RTL). It is shown that introduction of fillers such as BeO and ZrO₂ into PP leads to change in the intensity and temperature of realization of the β₁, β, α, and α₁ peaks on the RTL curves, and this can be used to predict the electroactive, dielectric and physical mechanical properties of the composites based on them.     

Stability of Infinite-Dimensional Systems

A new class of Lyapunov–Krasovskii functionals for studying the stability of a wide class of systems with an infinite number of degrees of freedom is introduced.     

Preparation of Single-Crystal TlSe Films

Single-crystal TlSe films with a tetragonal structure (a= 8.52 Å, c= 12.68 Å) were prepared on NaCl substrates.     

Algorithms for constructing optimal controllers for gaslift operation

We consider the optimal stabilization problem for delivered gas and gaslift operation debit for oil wells. Under certain natural assumptions, the general problem reduces to a linear-quadratic control problem that lets us find program controls and trajectories on which we further construct the optimal controller with respect to all phase coordinates and a (debit) part of them in both continuous and discrete case. For a special case, numerical results are illustrated with graphs that let us use this method in oilfield practice.