Frequency Resonance in Stochastic Systems

The phenomenon of frequency resonance,which is usually related to deterministic systems.is investigated in stochastic systems.We show that for those autonomous systems driven only by white noise,if the output power spectrum exhibits a nonzero peak frequency,then applying a periodic signal just on this noise-induced central frequency can also induce a resonance phenomenon,which we call the frequency stochastic resonance.The effect of such a resonance in a coupled stochastic system is shown to be much better than that in a single-oscillator system.     

Stochastic Resonance and Ratchets： Two Closely Related Phenomena in Brownian Motors

Ratchet effect as well as the phenomenon of stochastic resonance (SR) is investigated in a simple flashing ratchet model. Numerical simulations show that both the power spectrum amplitude and the mean mobility of the system vary non-monotonically in similar manners with increasing the noise intensity and both reach their highest point nearly at the same noise level. We point out that the consistency of these two phenomena are just due to the existence of circular flux in non-equilibrium state.     

广义Toda链的τ-函数解与表示论

本文由Semenov-Tian-Shansky 约化定理所给出的完全可积Hamilton 系统的求解框架出发,利用Lie群、Lie代数表示论的方法;求得了广义Toda链的τ-函数解.     

主丛上的扩散过程与配丛截面空间的微分算子

本文研究扩散过程在主丛上的提升及微分算子在配丛截面空间上的提升。我们证明了提升得到的扩散过程的生成元可作为配丛截面空间上的二阶微分算子,它就是原扩散过程的无穷小生成元的提升。由此我们给出了协变的Feynman-Kac公式,这是文献[4]结论在非平凡主丛上的推广。应用这些结果,我们给出了Riemann流形上Girsanov-Cameron-Martin定理的几何形式的证明。     

TWO-GATE FORMULA

The two gate formula for a diffusion X_t in R~n is considered.The formula gives an expressionof the density function of X_t in terms of the path integral of the Brownian bridge starting from xand ending on y at time t.     

鞍点分界线圈的稳定性及其分支出极限环的条件

<正> 考虑系统(?)=p_0(x,y)+εP_1(x,y,ε),(?)=Q_0(x,y)+εQ_1(x,y,ε).其中 P_0,Q_0对 x,y、P_1,Q_1对 x,y,ε具有我们所需要的任何程度的光滑性.例如,可设它们是 C~2类的或解析的等等.     

L_2 SCATTERING THEORY AND STATIONARY STATE SCATTERING WAVE FUNCTION

There exist two approaches to the theory of quantum scattering, the stationary and the time dependent approaches. In the stationary formalism, for the calculation of the scattering cross section, the standard method is to solve the Schrdinger equation     

COHERENT STATES, INVERSE MAPPING FORMULA FOR WEYL TRANSFORMATIONS AND APPLICATION TO EQUATIONS OF KdV TYPE

In this paper, we consider the trace of generalized operators and inverse Weyl transformation.First of all we repeat the definition of test operators and generalized operators given in [18],denoting L~2(R) by H.     

Dynamical Behavior in Behavior in Simple and Coupled Systems of Continuous Josephson－Junctions

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非自治系统的不变圈(解流形)分支

<正> 在文献[1]中已对自治系统证明,古典的Hopf分支条件可以减弱:即当奇点由渐近稳定变为不稳定的同时,一定分支出极限环.本文对非自治系统分支出不变圈的问题证明类似的结论(定理2),但如要得到与自治系统完全平行的结果,则还有待进一步的研究.然而由本文的结果可以看出,用来处理稳定性的方法,是解决分支问题的有力工具,一系列临界情况的分支现象都有可能用这个方法加以讨论.