空间非均匀摩擦棘轮的输运性能  

Transport performance of spatial non-uniform friction ratchets

作　　者：曹佳慧 刘艳艳 艾保全[2] 黄仁忠[1] 高天附[1] Cao Jia-Hui;Liu Yan-Yan;Ai Bao-Quan;Huang Ren-Zhong;Gao Tian-Fu(College of Physical Science and Technology,Shenyang Normal University,Shenyang 110034,China;School of Physics and Telecommunication Engineering,South China Normal University,Guangzhou 510006,China)

机构地区：[1]沈阳师范大学物理科学与技术学院,沈阳110034 [2]华南师范大学物理与电信工程学院,广州510006

出　　处：《物理学报》2021年第23期4-12,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11347003);沈阳师范大学高层次人才支持计划资助的课题.

摘　　要：本文研究了耦合布朗粒子在空间非均匀摩擦环境下的定向输运问题,并进一步讨论了摩擦系数振幅、空间相位差等因素对耦合粒子质心平均速度及能量转化效率的影响.研究发现,耦合粒子的质心平均速度和能量转化效率随摩擦系数振幅的变化都能呈现多峰结构.这一结果表明摩擦阻尼并不总是阻碍布朗粒子的定向运动,一定条件下合适的摩擦环境还能多次增强耦合布朗棘轮的输运性能.此外,在小摩擦系数振幅条件下通过改变外力振幅、外势不对称度、空间相位差还能诱导摩擦棘轮流反转的产生.本文所得结论不仅有助于理解摩擦环境中耦合布朗粒子的输运性能,还可为微观纳米机器的设计与粒子的筛选分离技术提供理论指导.Biomolecular motor is a kind of protein macromolecule widely existing in cells.It can convert the chemical energy contained in ATP molecules into mechanical motion,and then continuously provide power for the material transport process.In order to further study the directional transport of molecular motors,the Brownian ratchet model is established based on Brownian motion theory.However,most of the considerations in previous studies are devoted to the motion of Brownian particles under the condition of unit friction damping.In order to further study the influence of medium damping on the directional motion of Brownian particles,our group further study the directional transport of Brownian ratchets in different damping environments,and find that the suitable friction damping coefficient ratio can increase the center-of-mass mean velocity of the coupled Brownian particle.It should be pointed out that the above studies of Brownian ratchets consider the motion of Brownian particles under the condition of uniform spatial friction.In fact,the cell environment in organism is very complex,and the concentration and impurities in the cell change all the time.The medium damping of molecular motor is not always fixed,so choosing the space non-uniform friction condition to study the directional motion of coupled Brownian particles under different damping environments can better understand the directional transport characteristics of friction ratchets.In addition,other point of interest in the research of biomolecular motors is the high efficiency of energy conversion.Experimental results show that the energy conversion efficiencies of most molecular motors are more than 70%,and the efficiencies of some motors are even close to 100%.However,by comparing the experimental results with the theoreticalstudies,it can be found that the efficiency calculated by ratchet model is much lower than that measured in experiment.Therefore,in this paper,the directional motion of coupled Brownian particles in the space non-uniform friction envi

关 键 词：摩擦棘轮 质心平均速度 能量转化效率 摩擦系数振幅 

分 类 号：TB383.1[一般工业技术—材料科学与工程]