ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)

Прикладные задачи нелинейной теории колебаний и волн

Effect of low-frequency vibrations on nonlinear dissipative forces

The paper examines the impact of the slow movements to e?ective values of dissipative forces in the equations of fast motion of oscillatory system. It was previously shown that the dissipative characteristics obtained experimentally under harmonic oscillations can change signi?cantly with polyharmonic excitation. In this paper the problem is considered in more detail in relation to the determination of the resonance amplitudes and threshold conditions for parametric and subharmonic resonances.

Study of chaotic regimes of collective electron dynamics in semiconductor superlattice in external resonator

The paper deals the external resonator e?ect on collective electron dynamics in the semiconductor superlattice. Numerical simulations have shown that semiconductor superlattice which is characterized by only the regular oscillations in autonomous regime demonstrates chaotic microwave oscillations in the case of interaction with the external electrodynamical system. This phenomena gives a strong potential for novel applications of semiconductor superlattice requiring microwave chaotic signals.

Synchronization of reactively coupled phase oscillators driven by external force

Synchronization of two reactively coupled van der Pol oscillators with external force is investigated in this paper. We consider and compare quasi-periodic motion of oscillators with frequency-locked mode. The paper includes maps of Lyapunov’s exponents, two-parametric bifurcation diagrams and phase portraits. Possible types of motion in driven system are discussed.

Relationship of generalized and phase synchronization in two unidirectionally coupled chaotic oscillators

The behavior of the boundary of generalized synchronization in two unidirectionally coupled chaotic oscillators depending on the value of the control parameter mismatch between interacting systems has been studied. Peculiarities in its behavior in the ?eld of the relatively large values of the control parameter mistuning have been found. The character of this behavior and physical mechanisms resulting in the generalized synchronization regime onset in such systems have been explained by the analysis of the spectral compound of signal from response system.

Method for calculation of lyapunov exponents spectrum from data series

The new method for the calculating of the spectrum of the Lyapunov exponents from data series is proposed. The already known methods of the same thematic are investigated. The Roessler system is given as an example for describing the proposed method. The results of numerical modeling are presented.

Spectral components’ behavior in coupled pierce diodes near the phase synchronization boundary

In this article we study the dynamics of two unidirectionally coupled Pierce diodes near the phase synchronization boundary in terms of synchronization of spectral components. We show that systems under consideration demonstrate self-similar behavior with any value of coupling strength within the region of our study. The results correlate with the data of the similar research for R ?ossler systems and circle map.

Coherent resonance in klystron oscillators on self-excitation threshold

This work presents experimental results of synchronization of coherent resonance phenomena in cascade klystron oscillator with delayed feedback on self-excitation threshold. Degree of coherence, signal-to-noise ratio and synchronization wideband for single and cascade klystron oscillators were compared.

The investigation of subterahertz gyrotron for dnp spectroscopy in the iap ras

The paper presents the results of research is carried out in the Institute of Applied Physics and is aimed at creating a CW submillimeter gyrotrons with an output power of several tens of watts. Results of experiments on the 258 GHz gyrotron at the second harmonic of the gyrofrequency are presented. In the course of experiments maximum output power of 200 W and the relative stability of the output frequency at 5 · 10?6 for the hours-long continuous operation of the gyrotron were achieved.

The studies of the arising of oscillations in the quasi­harmonic model of the self­sustained oscillatory medium under multiplicative noise excitation

The multiplicative noise influence on the self­sustained oscillatory medium near the oscillation threshold is studied. The chain of the identical quasi­harmonic self­sustained oscillators with the periodic boundary conditions is taken as a simplest model of the oscillatory medium. The parameters of the oscillators are modulated with the white Gaussian noise. The stochastic bifurcations are analyzed for the cases of homogenous and spatially­nonhomogenous noise.

Destruction of the coherent mode in system of two oscillators at the strong resonant mutual couplings

The hypothesis about destruction of a coherent mode in system of two mutual couplings microwave oscillators is examine, each of which in a stand­alone mode generates stable unifrequent oscillations. It is experimentally shown, that at strong resonant couplings synchronous oscillations are unstable, therefore the system go over in in a mode of dynamic chaos.