Izvestiya of Saratov University.
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)


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.

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.

Contemporary problems in modeling from time series

Mathematical modeling from discrete sequences of experimental data (time series) is an actively developing field in mathematical statistics and nonlinear dynamics. It started from approximation of a set of data points on a plane with a smooth curve, while currently such empiric models take the form of sophisticated differential and difference equations and are capable of describing even nonlinear oscillatory and wave phenomena. Practical applications of the empiric models are various ranging from future forecasts to technical and medical diagnostics.