Could one single dichotomous noise cause resonant activation for exit time over potential barrier？

This paper studies the mean first passage time （or exit time, or escape time） over the non-fluctuating potential harrier for a system driven only by a dichotomous noise. It finds that the dichotomous noise can make the particles escape over the potential barrier, in some circumstances; but in other circumstances, it can not. In the case that the particles escape over the potential harrier, a resonant activation phenomenon for the mean first passage time over the potential barrier is obtained.     

PHASE TRANSITION FOR A NOISE-DRIVEN MODEL COUPLED BY A MEAN FIELD

We report a new model for infinite interacting noise driven subsystems which are coupled by a mean field and study its nonequilibrium phase transitions. In this model, under some circumstances the phase transition is between the state with zero mean field and the state with non zero mean field, and has a breaking of symmetry, which is similar to that reported by Van den Broeck, Parrondo, Toral, and Armcro [Phys. Rev. Lett.,73(1994),3395; Phys. Rev., E49(1994),2639], by Pikovsky, Rateitschak, and Kurths [Z.Phys.,B95(1994),541], and by other authors. We style this nonequi librium phase transition the symmetry breaking mean field. However, under other circumstances, the nonequilibrium phase transition of our model is not of the symme try breaking mean field type, which is a new phenomenon that has not been reported before.     

SUPERCONDUCTING JUNCTIONS IN THE CASE OF CORRELATED SYMMETRIC NOISES

We study two models for Josephson junctions, i.e.,a Gaussian white noise model and a symmetric dichotomous noises model. In this study we find that the correlated symmetric noises can produce a net voltage. This phenomenon is due to the correlation between the additive and the multiplicative noises. We show some characteristic features for this phenomenon: the net voltage is always negative and has a peak value when the strength of the additive noises varies for the former model(or when the strengths of the noises vary for the latter model). The results provide a theoretical foundation for reducing the net voltage caused by the correlated symmetric noises.     

岩板顺层斜坡和直坡演化过程中的随机共振及混沌

对岩板顺层倾斜边坡和直立边坡变形弯曲的演化过程进行了研究.发现岩板顺层斜坡和直坡在其演化过程中有随机共振和混沌现象.当随机共振发生时，即使较小的随机因素也可引起坡体较大的变形弯曲.随机混沌是由于环境因素的周期性变化，特别是每天和每年的周期性变化所致，混沌的出现使得对滑坡的预测和预报变得较为困难. 关键词：     

Escape for System with Non-Fluctuating Potential Barrier Only Driven by Three-State Noise

We study the escape for the mean first passage time （MFPT） over a potential barrier for a system with non- fluctuating potential barrier and only driven by a three-state noise. It is shown that in some circumstances, the three-state noise can induce the resonant activation for the MFPT over the potential barrier; but in other circumstances, it can not. There are three resonant activations for the MFPT over the potential barrier, which are respectively as the functions of the transition rates of the three-state noise.     

System Driven by Correlated Gaussian Noises Related with Disorder

A system driven by correlated Gaussian noises related with disorder is investigated. The Fokker-Planck equation （FPE） for the system is derived. Using the FPE derived, some systems driven by correlated Gaussian noises related with disorder can be investigated for Brownian motors, nonequilibrium transition, resonant activation, stochastic resonance, and so on. We only give one example： i.e., using the FPE derived, we study the resonant activation for a single motor protein model with correlated noises related to disorder. Since the correlated noise related to disorder usually exists with the friction, for the temperature, and so on, our results have generic physical meanings for physics, chemistry, biology and other sciences.     

粘弹性模型在木材蠕变中的应用

本文是根据短时间的木材弯曲蠕变实验曲线来确定粘弹性模型元件数和元件常数的探讨.通过核桃楸试件三点弯曲蠕变的实验研究表明:实测蠕变曲线与模型的计算曲线有较高的拟合度.因此我们认为在木材物性研究上或在工程应用上可以采用粘弹性模型元件常数.而且在各树种和环境条件下,一旦确定了适合其蠕变的元件数和元件常数,就将和力学性质中的常数一样,来表示蠕变度量,这将给木材的蠕变研究和木材的应用带来很大方便.     

Drift coefficients of motor proteins moving along sidesteps

In the paper, we investigate two motor proteins moving along the sidesteps： a motor protein moving along a two- dimensional sidestep and another protein moving along a three-dimensional sidestep. The drift coefficients （or stationary average velocities） of these two motor proteins are calculated. We believe that our investigation of the motor proteins moving along the sidesteps in the present paper can benefit the investigation of the transport of the motor proteins to some extent.     

Effect of Asymmetry of Dichotomous Noise on Transport of Particles

In this paper, an additive dichotomous noise model and a multiplicative dichotomous noise model are investigated for the effect of the asymmetry of the additive and multiplicative dichotomous noises on the transport of the particles, in the presence of spatial symmetry and asymmetry, respectively. It is shown that, in the presence of spatial asymmetry, the asymmetry of the dichotomous noise can weaken or enhance the transport of the particles; while in the absence of spatial asymmetry, the nonzero current induced by the noise＇s asymmetry is ＂symmetric＂ around the zero current. In addition, a current reversal can be produced by controlling the noise＇s asymmetry parameter; and we find that, for some values of the noise＇s asymmetry parameter, the multiplicative dichotomous noise can more easily induce the transport of the particles than the additive dichotomous noise.     

Noise composed of multiplication of two dichotomous noises

In this paper, we introduce a noise which is composed of multiplication of two dichotomous noises, and derive the probability density and the statistical properties of this noise. The obtained results can help study the resonant activation phenomenon, the phenomenon of stochastic resonance, the transport of particles, and the nonequilibrium （phase） transition for the systems driven by this noise.