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1.
The effect of the electron transverse and longitudinal velocity spread at the entrance to the interaction space on wide-band chaotic oscillations in intense multiple-velocity beams is studied theoretically and numerically under the conditions of formation of a virtual cathode. It is found that an increase in the electron velocity spread causes chaotization of virtual cathode oscillations. An insight into physical processes taking place in a virtual-cathode multiple-velocity beam is gained by numerical simulation. The chaotization of the oscillations is shown to be associated with additional electron structures, which were separated out by constructing charged particle distribution functions. 相似文献
2.
Summary Optically pure (+)-beta-eudesmol is a possible starting material for the synthesis of several termite defense compounds. A
two step procedure for the isolation of gram quantities of (+)-beta-eudesmol from commercially availableAmyris balsamifera oil (syn. West Indian sandalwood oil), containing 8% beta-eudesmol, was developed. Step one consisted of an efficient vacuum
distillation of the total oil. Step two was a medium pressure LC separation with an AgNO3 impregnated silica gel stationary phase. Several other separation procedures failed due to the presence of many closely related
sesquiterpene alcohols (75% of the oil). 相似文献
3.
V. V. Grubov E. Yu. Sitnikova A. A. Koronovskii A. N. Pavlov A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(12):1361-1364
The time-frequency structure and dynamics of oscillatory patterns in electroencephalograms of rats is studied by means of continuous wavelet transform and the decomposition of the signal by empirical modes. A method for the automatic selection of patterns using the empirical modes is developed. The method is applied to the study of sleep spindles, and it is shown that their dynamics depends on the regularities of on-off intermittency. 相似文献
4.
Chaotic synchronization of two electron-wave media with interacting counterpropagating waves and cubic phase nonlinearity
(transverse-field backward-wave oscillators) is studied. Analysis is based on considering a continuous set of the phases of
a chaotic signal. The parameters of chaotic synchronization in a system of unidirectionally coupled backward-wave oscillators
are found, and the complex dynamics of establishing the chaotic synchronization conditions in an active medium is investigated. 相似文献
5.
M. O. Zhuravlev A. A. Koronovskii O. I. Moskalenko A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2018,82(1):87-89
The noise-induced intermittent behavior of multistable systems is studied using the example of a reference system (a Chua generator). It is shown that upon exposing the Chua generator to external noise, a noise-induced intermittency is observed at certain values of the control parameters. The statistical characteristics obtained for this type of behavior are compared to the appropriate theoretical formulas. 相似文献
6.
Kulminskiy D. D. Ponomarenko V. I. Prokhorov M. D. Hramov A. E. 《Nonlinear dynamics》2019,98(1):735-748
Nonlinear Dynamics - We study both numerically and experimentally the synchronization in an ensemble of nonidentical neuronlike oscillators described by the FitzHugh–Nagumo equations. The... 相似文献
7.
Wideband chaotic microwave oscillation in a ring self-oscillatory system is studied. The system includes a solid-state power amplifier and a wideband nonlinear transmission line with a ferromagnetic film in which magnetostatic waves of different types are excited. It is found that the eigenmodes of the self-oscillatory system excited in the passband of the transmission line on magnetostatic waves become noisy because of spin wave parametric excitation due to the magnetostatic wave and nonlinearity of the power amplifier. A continuous spectrum of modes observed in the wideband chaotic signal is associated with the presence of a descending portion in the dynamic characteristic of the nonlinear transmission line, which arises when a magnetostatic surface wave is excited. 相似文献
8.
The time-scale synchronization of chaotic oscillations in two dissipatively coupled radiofrequency chaotic oscillators has
been experimentally studied. The effect of noise on the efficiency of chaotic synchronization diagnostics is analyzed and
a high stability of time-scale synchronization to noise in the coupling channel between the oscillators is shown. 相似文献
9.
A universal mechanism underlying generalized synchronization conditions in unidirectionally coupled stochastic oscillators is considered. The consideration is carried out in the framework of a modified system with additional dissipation. The approach developed is illustrated with model examples. The conclusion is reached that two types of the behavior of nonlinear dynamic systems known as generalized synchronization and noise-induced synchronization, which are viewed as different phenomena, actually represent a unique type of the synchronous behavior of stochastic oscillators and are caused by the same mechanism. 相似文献
10.
A new type of intermittent behavior is described to occur near the boundary of the phase synchronization regime of coupled chaotic oscillators. This mechanism, called ring intermittency, arises for sufficiently high initial mismatches in the frequencies of the two coupled systems. The laws for both the distribution and the mean length of the laminar phases versus the coupling strength are analytically deduced. Very good agreement between the theoretical results and the numerically calculated data is shown. We discuss how this mechanism is expected to take place in other relevant physical circumstances. 相似文献