布朗马达的非均匀高斯跃迁模型

提出了布朗马达的非均匀高斯跃迁理论，用布朗粒子在多态之间的跃迁模型描述分子马达的定向运动.假定跃迁速率与位置有关，且在跃迁点附近具有高斯函数形式，将布朗粒子在x处的概率密度Pm(x,t)在跃迁点附近展开，可以进行任意阶的近似计算.这一理论涵盖了以往的定点跃迁模型和均匀跃迁模型.作为具体例子，研究了系统在两态之间的跃迁问题.假定在一个周期内有两个跃迁点，讨论了布朗粒子定向运动产生的概率流随温度、跃迁速率和跃迁宽度的变化关系.关键词：布朗马达高斯跃迁概率流

A nonuniform ratchet model with Gauss-transition rates for Brownian motor

A nonuniform ratchet model with Gauss-transition rates is proposed to discuss the directional motion of Brownian particles in an asymmetrical periodic potential. It is assumed that the particles experience several internal states in a single mechanical-chemical circle. In this model, the transition rates between different states are position-dependent, which have the form of Gaussian function. For any internal states, the probability distribution as a function of time and position may be expanded near the transition points to any rank if necessary. Finally, the focus of our study is concentrated on a two-state model, in which we choose (M, K)=(2, 2) and calculate the average current as a function of the transition width, temperature and transition rate. It is revealed that the transition width influences the current greatly.