Uchenye Zapiski Zabaikalskogo Gosudarstvennogo Universiteta. Seriya Fizika, Matematika, Tehnika

11-16

Authors: Fedor A. Kovalev

A Cauchy problem for an unbounded rod consisting of two parts with different weight and thermal parameters is considered. An explicit solution of the problem in one-time quadratures is constructed. For instant heat source the solution of the problem is obtained in the final form. Temperature function graphs with a certain time step for different composite rods are constructed.

24-32

Authors: Vladimir A. Tolpayev, Kurban S. Akhmedov, Aleksandr M. Kravtsov, Musheg T. Petrosyants

The article proposes a simplified dynamic statement of the linear filtration problem with the replacement of the classical static condition at the bottom of the well with the dynamic boundary conditions of the steady-state regime of harmonic pressure pulsations. The estimation of the oscillation correction to the static solution for pressure and flow rate is obtained. Analytical dependencies for well flow rates allow us to describe more accurately the filtration processes in the reservoir system, taking into account the dynamic character of the processes at the bottom of the well.

42-50

Authors: Svyatoslav Ye. Kholodovskii, Pavel A. Chuhrii

A Cauchy problem for an unbounded string consisting of two homogeneous parts with different density is considered. We give the linear formulation of the problem. The solution of the problem in explicit form in single quadratures is obtained. String graphs with a certain time step for different combinations of composite string densities are constructed.

56-68

Authors: Oleg N. Shablovsky, Dmitry G. Kroll, Ivan A. Kontsevoy

The growth of a dendrite in a unicomponent overcooled melt is studied. The phase boundary is considered as a strong rupture surface complying the conditions of dynamical compatibility subjected to the integral conservation laws. We studied the class of movements with the phase boundary velocity depending on the angle between the normal and the growth line. The time evolution of the two-dimensional contour of the phase boundary was studied both analytically and numerically. The shape of the growth line, its curvature, velocity and heat flux in the solid phase were studied as well. With respect to the problem of the vibration effect on the crystallization process, the influence of phase boundary velocity fluctuations on the heat transfer intensification is considered. The calculations showed strong sensitivity of the heat flux to changes in the vibration amplitude. The uniform (with account to the special time coordinate) growth of a two-dimensional axially symmetric contour of dendrite is considered. The case when the original line suffers a perturbation localized at a final distance from the vertex is analyzed. It is established that the perturbation of the growth line curvature (a protrusion or a dent) induces a harbinger of a side branches of an axon. Its geometrical image is the point of intersection of the time-evolving the contour line. The applied aspects of the report refer to the methods of high-speed solidification of melts and obtaining new functional materials.

110-117

Authors: Sergei D. Krylov

The possibility of using microwave measurement technique to study the processes taking place in ice and porous media containing water during cooling and heating was investigated. Two methods were considered: waveguide and radiometric. The basis of these methods is the following: there is a significant difference in the absorption coefficient of electromagnetic waves for water and ice, and it is not difficult to study the water – ice phase transitions. It is also possible to study media in a different state in a confined space, in a waveguide and in free space by a radiometric method. Two examples of the application of these techniques are presented. As follows from the results of the experiments carried out, there are differences in the nature of the eutectic processes that can occur due to the stressed state of the sample when ice forms in the closed space and free space.

127-132

Authors: Nikolay P. Stepanov

In semiconductor materials Bi2Te3