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511.
一类非线性时滞系统概周期解的存在唯一性 总被引:2,自引:0,他引:2
应用Liapunov,泛函,研究了一类时滞系统概周期解的存在唯一性,得到了保证系统存在唯一概周期解的一组充分条件. 相似文献
512.
Theoretical verification of intermolecular hydrogen bond induced thermally activated delayed fluorescence in SOBF-Ome 下载免费PDF全文
Mu-Zhen Li 《中国物理 B》2021,30(12):123302-123302
Thermally activated delayed fluorescence (TADF) molecules have attracted great attention as high efficient luminescent materials. Most of TADF molecules possess small energy gap between the first singlet excited state (S1) and the first triplet excited state (T1) to favor the up-conversion from T1 to S1. In this paper, a new TADF generation mechanism is revealed based on theoretical simulation. By systematic study of the light-emitting properties of SOBF-OMe in both toluene and in aggregation state, we find that the single SOBF-OMe could not realize TADF emission due to large energy gap as well as small up-conversion rates between S1 and T1. Through analysis of dimers, we find that dimers with intermolecular hydrogen bond (H-bond) are responsible for the generation of TADF, since smaller energy gap between S1 and T1 is found and the emission wavelength is in good agreement with experimental counterpart. The emission properties of SOBF-H are also studied for comparison, which reflect the important role of H-bond. Our theoretical results agree ith experimental results well and confirm the mechanism of H-bond induced TADF. 相似文献
513.
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. 相似文献
514.
关于B值随机元随机指标和的矩的讨论 总被引:1,自引:0,他引:1
在本文中,我们研究停止时间N的矩、B值随机元X_n的矩以及{X_n,n≥1}的随机指标和S_N的矩之间的关系。特别,在赋予Banach空间以某些特定的几何性质,例如假设B为p-阶光滑空间、q-凸空间及Hilbert空间的情形下,讨论了上述各种矩之间的关系。 相似文献
515.
Minimum Renyi’s pseudodistance estimators (MRPEs) enjoy good robustness properties without a significant loss of efficiency in general statistical models, and, in particular, for linear regression models (LRMs). In this line, Castilla et al. considered robust Wald-type test statistics in LRMs based on these MRPEs. In this paper, we extend the theory of MRPEs to Generalized Linear Models (GLMs) using independent and nonidentically distributed observations (INIDO). We derive asymptotic properties of the proposed estimators and analyze their influence function to asses their robustness properties. Additionally, we define robust Wald-type test statistics for testing linear hypothesis and theoretically study their asymptotic distribution, as well as their influence function. The performance of the proposed MRPEs and Wald-type test statistics are empirically examined for the Poisson Regression models through a simulation study, focusing on their robustness properties. We finally test the proposed methods in a real dataset related to the treatment of epilepsy, illustrating the superior performance of the robust MRPEs as well as Wald-type tests. 相似文献
516.
The anomalous diffraction theory (ADT) that is originally introduced by van de Hulst (Light scattering by small particles, Wiley, New York, 1957), is often highly simplified so that the extinction and absorption efficiencies of randomly oriented particles are determined by the ratio of particle volume to the projected area. In this work, we compare the simplified ADT and the original one for randomly oriented particles with different shapes. Significant differences are found in both extinction and absorption efficiencies. 相似文献
517.
In this paper, we propose a memory state feedback model predictive control (MPC) law for a discrete-time uncertain state delayed system with input constraints. The model uncertainty is assumed to be polytopic, and the delay is assumed to be unknown, but with a known upper bound. We derive a sufficient condition for cost monotonicity in terms of LMI, which can be easily solved by an efficient convex optimization algorithm. A delayed state dependent quadratic function with an estimated delay index is considered for incorporating MPC problem formulation. The MPC problem is formulated to minimize the upper bound of infinite horizon cost that satisfies the sufficient conditions. Therefore, a less conservative sufficient conditions in terms of linear matrix inequality (LMI) can be derived to design a more robust MPC algorithm. A numerical example is included to illustrate the effectiveness of the proposed method. 相似文献
518.
本文通过积分检验, 刻画了不同分布的$\varphi$-混合序列后置和的极限结果,并由此导出了它们的Chover型重对数律,推广和改进了已有的结果. 相似文献
519.
Various first-order and second-order sufficient conditions of optimality for nonlinear optimal control problems with delayed argument are formulated. The functions involved are not required to be convex. Second-order sufficient conditions are shown to be related to the existence of solutions of a Riccati-type matrix differential inequality. Their relation with the second variation is discussed.The authors are indebted to an anonymous referee for valuable suggestions that lead to various improvements in the paper. 相似文献
520.
田德生 《数学的实践与认识》2008,38(11):163-167
应用锥不动点定理研究了一类时滞微分方程周期解的存在性问题,建立了该系统具有至少一个正周期解的充分条件. 相似文献