Search articles

VIBRONIC SPECTRA AND STRUCTURE OF EXITED STATES OF POLYATOMIC MOLECULES

The methods of determination of molecular model parameters in exited electronic states are considered. Structural-dynamic models polyatomic molecules are developed using a semi-empirical method of hybridized atomic orbitals. It is shown that the electronic-vibrational spectra make it possible to identify the tautomeric forms in different phases states, taking into account the intermolecular interaction.

РАДИОТЕХНИЧЕСКИЕ МЕТОДЫ АНАЛИЗА МНОГОЧАСТОТНЫХ РЕЖИМОВ РАБОТЫ ЛУЧЕВЫХ ПРИБОРОВ С ПРОДОЛЬНЫМ ВЗАИМОДЕЙСТВИЕМ

Проведен обзор радиотехнических методов анализа нелинейных усилителей. Предложено представление нелинейного усилителя в виде типового радиотехнического звена, состоящего из входного и выходного фильтров и безынерционного нелинейного элемента. Описаны методы идентификации элементов радиотехнического звена. Обсуждается проблема учета амплитудно-фазовой конверсии. Продемонстрирована возможность успешного описания с помощью предложенной модели многочастотных режимов работы СВЧ усилителей.

RADIOTECHNICAL METHODS FOR THE ANALYSIS OF THE MULTIFREQUENCY WORKIING REGIMES OF THE BEAM DEVICES WITH LONGITUDINAL INTERACTION

The survey of the radiotechnical methods for the nonlinear amplifiers analysis is conducted. The presentation of the nonlinear amplifier as typical radiotechnical link, consisting of input and output filters and inertionless nonlinear amplifier, is proposed. The methods of the identification of the radiotechnical link elements are described. The problem of registration of amplitude-to-phase conversion is discussed. The possibility of the successful description of the multifrequency working regimes of the microwave amplifiers using the proposed model is demonstrated.

CLUSTER SYNCHRONIZATION DESTRUCTION AND CHAOS IN AN INHOMOCENEOUS ACTIVE MEDIUM

Authors: Anishchenko V. S., Vadivasova T. Е., Strelkova G. I.

We show that in an inhomogeneous self-sustained oscillatory medium the destruction of perfect clusters of partial synchronization, that is induced both by varying the control parameter and by noise, leads to the onset of chaotic behavior. We study the mechanisms of chaos formation in both cases. It is demonstrated that as parameters change, the transition to chaos in the deterministic medium can result from a hard (subcritical) period-doubling bifurcation and can be accompanied by intermittency.

UNARY FUNCTION OF HARD SPHERE DISTRIBUTION NEAR IDEAL WALL

Hard sphere system upon ideal wall was analyzed using equilibrium statistic physics methods. The integration equation for oneparticle distribution function of coordinate region is received. Resolve of
obtaining equation we analyzed. Numerical results illustrating particles local relative density depending of distance to the wall are showed.

Nanostructured Porous Silicon Layers Formation at Low Doses of γ-Radiation

Authors: Bilobrova O. Y., Galushka V. V., Karagaychev A. L., Zharkova E. A., Polyanskaya V. P., Sidorov V. I., Therin D. V., Mantsurov A. A.

We present results of experimental study of nanoporous Si (SiNР) structure formation by using the method of metal-stimulated chemical etching upon irradiation with small doses of γ-radiation directly in the process of production (in situ). It is shown that the radiation leads to an increase of the crystallization of SiNP structures obtained on previously irradiated substrates. Apparently, this can be explained by a decrease in the initial defectiveness of the silicon substrate due to irradiation with small doses of γ-radiation.