Effective Diffusivity for Transport with Fluctuating Drift Velocity.
Effective Diffusivity for Transport with Fluctuating Drift Velocity.
复制标题
波动漂移速度传输的有效扩散率。
DOI：
10.1021/acs.jpcb.1c01856
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Szabo,Attila
中科院分区：
文献类型：
--
作者：
Berezhkovskii,AlexanderM;Szabo,Attila
Consider a particle whose drift velocity fluctuates due to transitions among discrete states or due to diffusion in a confined moving fluid. At long times, the dynamics of the particle in the direction of transport can be described in terms of the average drift velocity and an effective diffusivity. For both types of fluctuations, we show that the effective diffusivity is the sum of the average intrinsic diffusivity and the time integral of the velocity correlation function of the deviation of the fluctuating velocity from its mean value. For nearest-neighbor interstate transitions and for one-dimensional diffusion in a perpendicular direction, the time integral can be found in closed form. Our analytical expressions for the effective diffusivity recover the classic results for Taylor dispersion in the laminar flow of viscous fluid and for cargo transport along microtubules by molecular motors.
