Vol 3, No 23 (2015)
- Year: 2015
- Published: 25.12.2015
- Articles: 10
- URL: https://ogarev-online.ru/2311-2468/issue/view/19204
Full Issue
Ultimate boundedness of generalized velocities of mechanical systems with low inertia characteristics
Abstract
The article deals with the problem of ultimate boundedness of generalized velocities of mechanical systems with the complete set of forces and low inertia characteristics. The problem is reduced to the study of the Lagrange equations of the second order with a large positive parameter. The estimations of ultimate boundedness area and transient time have been obtained.
On the problem of perturbation of periodical solutions to differential equations with degenerate operator before the derivative
Abstract
By the methods of bifurcation theory, the authors investigate the perturbation problem for n-multiple pair of pure imaginary eigenvalues at the presence of generalized Jordan chains. The resolving system in the form of a homogeneous system of linear algebraic equations is obtained. A reduction of the problem to the perturbed operator matrix problem is carried out.
Application of discontinuous Galerkin method for solving one-phase filtration problem in anisotropic media
Abstract
The article considers the application of discontinuous Galerkin method for one- phase filtration problem in anisotropic media. For the numerical experiment the initial-boundary problem for two-dimensional one-phase filtration is chosen. Calculations of the modeling problems demonstrate a high degree accuracy of the offered method.
A study of structural changes of silver-contaning paste during sintering
Abstract
The authors study the changes of the mean size of coherent scattering regions (CSR) and the values of microdeformations conductivity layers of silver pastes of two brands sintered at the pressure of 10 psi and the temperature of 250°C (0.42 Tm). It is demonstrated that the electrical conductivity of the sintered layers increases with the size CSR. The possible reasons for these changes are the decrease in concentration of defects and the increase of interparticle contact areas, occurring at return and primary recrystallization.
The solution of gas dynamics equations using CUDA technology
Abstract
The article presents a numerical algorithm for solving the equations of gas dynamics. The stages of implementation of the algorithm in the language of CUDA C are described. The two-dimensional Sod’s Riemann problem was chosen for the numerical experiment. The results of the test problem solution demonstrate the parallelization quality and the capability of parallel version.
The use of SEM to study the structure and adhesive properties of silver-containing paste sintered layers
Abstract
The article presents the results of a study of the microstructure and adhesive properties of silver paste sintered layers (SP) used in power semiconductor devices for low- temperature electrically active silicon structure (CS) containing pn-junctions with molybdenum temperature compensator (MT). The microstructure of the boundaries between the sintered layer and the metallized surfaces of the COP and the MT as well as the border between the sintered layer and the surface of mechanically peel test strip was investigated by analyzing the SEM images obtained by SEM Quanta 200i 3D FEI.