# Physics

## About the Definition of a Nonlinear Inductance in Static and Dynamic Regimes

The integral relations and integral-differential equations that take into account the influence of the magnetic shields (magnetic) inductance have been obtained. The non-linear magnetic materials with hysteresis and without it, and approximation of nonlinear materials and inductors have been considered. It is shown that for hysteresis we should use the nonlinear equation for the magnetization. The establishment of oscillations in a chain with the simplest approximation of a nonlinear inductance are reviewed.

## Calculation of Field Amplitude Distribution of Ultrasonic Wave Beam in Moving Media

The results of acoustical (ultrasonical) wave beam amplitude distribution modeling in free space and in application of moving media are presented. The propagation of ultrasonical wave has been considered in x-y coordinate plane for infinitive plate radiator restricted on x – axis. The shift of ultrasonical beam field for different distributions of moving media velocity projections in the plane of wave propagation is considered.

## Application of Thin Film Structures Based on Amorphous Silicon for pH Measurements in Solutions

Formation possibility of pH-sensor based on amorphous silicon thin films is shown. The principle of sensor operation is similar to the ionselective field effect transistor. Change of the investigated solution pH leads to change of depletion width and conductivity of amorphous silicon thin film structure.

## Recovery of Models of Time-delay Systems from Short Experimental Time Series

Time-delay systems reconstructed from short and noisy time series is conducted by the specialized method based on utilizing of driven system with the structure similar to the structure of the studied object. To show the efficiency of this approach, parameters were reconstructed for radiophysical chaotic generator and for the model of biological system.

## The Influence of Monogaloidosubstitution on the Structure and Dynamics of Sixmember Cyclic Compounds

The structure and vibrational states of monosubstituted cyclic compounds (monogaloidosubstituted of benzene, benzoquinone, gammapyrone and tiopiron) by density functional DFT / b3LYP 6-311G ** and 6-311+** are simulated. Vibrational states are interpreted.

## Low-density Approximation in the Theory of Creation the Electron-positron Plasma from Vacuum in Strong Laser Fields

Kinetic description of the vacuum creation of the electron-positron plasma under action of the strong electromagnetic fields is considered in two simplest approximations. The results are compared with the numerical solution of the relevant kinetic equation. It allows to select the regions of effectiveness of the introduced methods and to analyse some features of the obtained analytical solutions.