| Active Brownian particles,also known as self-propelled Brownian particles,unlike passive Brownian particles,can absorb energy from the environment and convert that energy into their own directional motion.But because of the constant transfer of energy,their behavior can only be explained on the basis of non-equilibrium physics.In biological domain,a lot of cells are executing directional movement,for example the cell inside the human body is having oxygen transport moisture to transmit nutrition all the time absorb,and eliminate the job to bacterial virus.Inspired by these microorganisms,researchers have designed and developed artificial self-propelling materials with different mechanisms,and these artificial particles have greatly advanced the study of the kinetic behavior of active matter systems.The researchers used computer simulation to study the mechanism and kinetic behavior behind the active system.In this paper,based on Langevin dynamics,a new kind of spatial regulation and optical regulation is carried out to manipulate the system,so as to observe the self-assembly behavior of particles in and out of the optical field and at the boundary,and study the mechanism of forming collective motion.Specific arrangements are as follows:First of all,we introduce the relevant knowledge and theories about active particles and inactive particles.What are active substances,what are their characteristics and the interesting dynamic behaviors they can show;This paper introduces the Langevin dynamics simulation method adopted in this paper,and introduces the motion equation and detailed operation process based on this method,as well as the concrete implementation of this method in this model.Secondly,we studied the phase and motion of active Brownian particles and passive Brownian particles in the system under the action of light.In the process of simulation,we set up the light field in the center of the system,when the particles into the light field,will be applied to a random direction,and then the Brownian particles becomed active Brownian particles Brownian particles,by changing the light field,namely the width of the active area,and the effect of light intensity in area,namely the size of the active force,light field particle Dr,get 2d system phase diagram under the influence of different factors,through the observation and analysis system of the dynamic behavior of particles,found from the lighting area to the shading area particles have varying degrees of "escape" behavior.Then,on the basis of the static light field regulation in the previous chapter,the active region is moved along the X-axis direction,namely,the dynamic light field regulation,which also changes the width of the active region,the size of the active force,the rotational diffusion coefficient of the particles in the region,and the moving speed of the region,and finally leads to four different particle states,namely:It has no obvious influence,dense shedding,irregular shedding and periodic shedding,and deeply explores the internal mechanism corresponding to different particle states.Finally,the research work and conclusions of this paper are summarized,and the next research work and direction are described,hoping to provide reference for future studies of this kind. |
