摘要
研究具有幂律记忆性的细胞液中双头分子马达的定向输运现象,选取幂函数作为广义Langevin方程的阻尼核函数,建立了分数阶过阻尼耦合Brown马达模型,讨论了阶数及耦合系数对双头分子马达定向输运速度的影响.仿真结果表明,分数阶过阻尼双头分子马达也会产生定向输运现象,并且在某些阶数下会产生整数阶情形所不具有的反向定向流.当噪声强度固定时,输运速度随着阶数以及耦合系数的变化均会出现广义随机共振现象.特别地,研究发现双头分子马达在记忆闪烁棘轮势中具有某些单头分子马达所不具备的运动特性,定向流的大小和方向由噪声与双头间作用力相互耦合控制.
Focusing on the directed transport phenomena of the two-headed molecular motor, we adopt power function as the damping kernel function of general Langevin equation due to the power-law memory characteristics of cytosol in biological cells and present the model of fractional coupling Brownian motor in overdamped condition in this paper. We also discuss the influences of fractional order and coupling factor on the transport speed. From the simulation results there are found the directed transport phenomena and the inverse transport which is not seen in the conventional Brownian motor, in the overdamped fractional coupling Brownian motor. When the noise density is fixed, the generalized stochastic resonance appears when transport speed varies with the fractional order and coupling factor. In particular, the results reveal that the magnitude and direction of the directional flow are controlled by coupling the noise with the interaction force between the two heads, which is the movement characteristic of the two-headed molecular motor in the memory ratchet, rather than of the single-headed motor.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第24期7-13,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11171238)资助的课题~~
关键词
分数阶双头分子马达
欠扩散
定向输运
广义随机共振
fractional two-headed molecular motor
sub-diffusion
directed transport
stochastic resonance in a broad sense
