General decay asymptotic stability of neutral stochastic differential delayed equations with Markov switching

The p-th moment and almost sure stability with general decay rate of the exact solutions of neutral stochastic differential delayed equations with Markov switching are investigated under given conditions. Two examples are provided to support the conclusions.     

Synchronization for stochastic hybrid coupled controlled systems with Lévy noise

In this paper, synchronization for stochastic hybrid-delayed coupled systems with Lévy noise on a network (SHDCLN) is investigated via aperiodically intermittent control. Here time delays, Markovian switching and Lévy noise are considered on a network simultaneously for the first time. After that, by means of Lyapunov method, graph theory, and some techniques of inequality, some sufficient conditions are derived to guarantee the synchronization for SHDCLN. In addition, the designed range of aperiodically intermittent controller parameters is shown. Meanwhile, the coupling strength and the perturbed intensity of noise have a great impact on the intensity of control. Then, we investigate synchronization for stochastic hybrid delayed Chua's circuits with Lévy noise on a network as a practical application of our theoretical results. Finally, a numerical example is given to illustrate the effectiveness of the theoretical results.     

Controlling chaos in RCL-shunted Josephson junction by delayed linear feedback

The resistively--capacitively--inductively-shunted (RCL-shunted) Josephson junction (RCLSJJ) shows chaotic behaviour under some parameter conditions. Here a scheme for controlling chaos in the RCLSJJ is presented based on the linear feedback theory. Numerical simulations show that this scheme can be effectively used to control chaotic states in this junction into stable periodic states. Moreover, the different stable period states with different period numbers can be obtained by appropriately adjusting the feedback intensity and delay time without any pre-knowledge of this system required.     

Time-delay feedback control in a delayed dynamical chaos system and its applications

The feedback control of a delayed dynamical system, which also includes various chaotic systems with time delays, is investigated. On the basis of stability analysis of a nonautonomous system with delays, some simple yet less conservative criteria are obtained for feedback control in a delayed dynamical system. Finally, the theoretical result is applied to a typical class of chaotic Lorenz system and Chua circuit with delays. Numerical simulations are also given to verify the theoretical results.     

牵制控制含噪声的多延迟超网络的结构识别

本文研究了含噪声的多延迟超网络的结构识别问题,利用随机微分时滞方程的LaSalle不变原理和Lyapunov稳定性理论,获得了通过牵制控制进行超网络结构辨识的理论.通过数值仿真验证了理论结果的有效性.以三层网络为例,仅控制一个节点就可以成功识别出该网络的未知拓扑结构,同时,驱动网络和响应网络达到了同步.     

时滞反馈控制扭转振动系统的振动

研究了采用时滞反馈来控制扭转振动系统的振动问题.在一个带有非线性动力吸振器的扭转振动系统中,采用时滞反馈来控制主系统的振动.研究了反馈增益系数和时滞对主系统振动的影响.研究结果表明,对某一固定的反馈增益系数,存在时滞的某段调节区间,可以通过调节时滞来抑制主系统的振动.在时滞的调节区间内存在一个最佳点,主系统的振动被抑制到最小值.可以同时调节反馈增益系数和时滞两参数,当反馈增益系数和时滞都调节到最佳值时,主系统振动的振幅由0.24减小到0.03,取得了很好的减振效果. 关键词： 时滞反馈 扭转振动 减振     

具有修理延迟的两不同部件冷贮备系统的可靠性分析

研究了有修理延迟的两个不同部件和两个修理工组成的冷贮备系统.假定部件的工作寿命服从一般分布,故障后的延迟修理时间和修理时间均服从指数分布.利用马尔可夫更新过程、拉普拉斯变换和拉普拉斯-司梯阶变换工具,得到了系统的首次故障前时间、可用度和平均故障次数等可靠性指标.     

Global dissipativity of mixed time-varying delayed neural networks with discontinuous activations

In this paper, the problems of global dissipativity are investigated for neural networks with mixed time-varying delays and discontinuous activations. Some new criteria for checking the global dissipativity of the addressed neural networks are established by constructing appropriate Lyapunov functionals and employing the theory of Filippov systems and M-matrix properties. Finally, two numerical examples with simulations are presented to demonstrate the effectiveness of the theoretical results.     

Theoretical insights into the absorption and emission properties of blue luminescent copper(I) complexes based on the pyrazolyl‐pyridine ligands

The ground geometrical and electronic structures, charge transfer (CT) behaviors, absorption, and emission properties of the three copper(I) complexes [Cu(pypz)(POP)]⁺ (1) , [Cu(pympz)(POP)]⁺ (2) , and [Cu(pytfmpz)(POP)]⁺ (3) (pypz=1‐(2‐pyridyl)pyrazole, pympz=3‐methyl‐1‐(2‐pyridyl)pyrazole, and pytfmpz=3‐trifluoromethyl‐1‐(2‐pyridyl)pyrazole), have been investigated using density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT). The vertical absorption energies of the all copper(I) complexes are well reproduced by TD‐DFT calculations based on the CT amount calculations. The triplet emission properties of the all copper(I) complexes were correctly evaluated at BMK/LANL2DZ/6‐31G* level of theory. In addition, the thermally activated delayed fluorescence properties of 1–3 were discussed in detail based on the spatial separation of the HOMO and LUMO and vertical excited energies. These theoretical insights should be expected to provide some guides for the design and synthesis of efficient luminescent copper(I) complexes. © 2014 Wiley Periodicals, Inc.     

同时带有强迫项和有限时滞的Lienard方程周期解的存在性

利用Mawhin延拓定理证明了一类具有强迫项的有限时滞Lienard方程x″(t)+f_1(x)x′(t)+f_2(x)(x′(t))~2+g(x(t-τ))=e(t)存在周期解的充分条件.