Directional Transport Of Overdamped Brownian Particles Under Complex External Forces

In recent years,biomolecular motors have attracted much attention.The biomolecular motor is a biological macromolecule that converts chemical energy into mechanical energy.Its size is only a few nanometers or tens of nanometers,and it is a biological nanomachine that human beings have long dreamed of.Studies have shown that all the basic processes in living organisms are involved in molecular motors,such as gene replication,transcription,translation,division and synthesis are inseparable from the directional movement of molecular motors.Many known proteases,such as RNA polymerase,have been found to be molecular motors in nature.In living organisms,molecular motors use the energy released by the hydrolysis of ATP to achieve their own directional motion.In the cell movement,muscle contraction,cytoplasmic movement and signal transduction are motor proteins along the filaments to complete the directional movement.Because they operate in small Spaces and are flexible enough to make directional movements in blood plasma,the goal of eliminating tumors in the body without surgery can be achieved.In terms of artificial nano devices,the energy conversion efficiency of molecular motors is very high.The energy utilization rate of wild-type drive motors is up to 70%,and the rotational ATP synthase is close to 100%.Therefore,the research of biomolecular motor has a wide application prospect in many fields.Based on the random energy theory,langevin equation is used to simulate the directional transport and flow reversal of two-dimensional coupled Brownian particles,and the effects of non-conservative force parameters,spring length and spring coefficient on the average velocity and flow reversal of Brownian ratchet wheel are discussed in detail.Firstly,with the same external force parameters,the average velocity of Brownian particles is studied by exploring the change of coupling force.Finally,the influences of coupling force parameters and non-conservative force parameters on the transport velocity are further discussed.The results show that the coupling force of particles has a great influence on the transport speed of Brownian particles,but it also shows that the coupling force parameter can promote the transport speed under certain conditions.Therefore,overdamped Brownian particles can also change the transport velocity with different coupling force parameters.In addition,the velocity flow can be changed from negative to positive under certain conditions due to the different parameters of non-conservative forces.The effect of flow reversal is produced,so the maximum flow velocity will be achieved with appropriate non-conservative force parameters.The results obtained in this paper not only contribute to the mutual understanding of Brownian particles under the action of multiple gravity and barrier forces,but also provide theoretical and numerical reference for microtubule nanomachines and experimental data.