A Theoretical Study About The Applications Of Stochastic Dynamics For Two Systems

Because the random-level physics is relatively fitter to describe the properties of a real system,one can use Langevin equation to describe the dynamic behavior and the statistical properties of the system.The purpose of this paper is to use the stochastic dynamics of Langevin to investigate the dynamical properties of two system?nuclear fission and neuron?.In the application to the second system,the influence of the statistical properties of noise on the spike of action potential of neuron have been studied.Within the framework of the combined Langevin dynamical and statistical model?CDSM?,to study the influences of the shell correction and inertia of mass which is deformation dependent on the entrance channel effect of ²⁰⁰Pb produced in three different reaction systems,respectively,firstly the CDSM model and the corresponding improvement have been introduced.The calculated results show that the effect of the emission of prescission neutron is dominated by the emission of the first fission phase.Considering the deformation dependence of the mass tensor,the thermodynamic driving force of the fission process can be reduced.If the shell correction is included based on the modified CDSM model,which will continue to enhance the emission of the prescission neutron.In addition,the effect of the entrance channel controlled by the nuclear deformation is obvious.Taking into account the ion channel noise can greatly influence the firing of neuronal action potentials,the stochastic HH model?SHH model?developed on the basis of a deterministic Hodgkin-Huxley?HH?model have been firstly introduced.Then,the effects of external stimuli on action potential with deterministic and stochastic HH models have been studied,respectively.The results show that there is a threshold for the action potential release,when the external stimulus does not reach the threshold,it will only change the membrane potential,and cannot form action potential.When taking noise into account,the spike behaviors with Gauss white noise are like Uhlenbeck noise is found,and the spike threshold of the system with Uhlenbeck noise is significantly reduced.The spike period is significantly reduced as the increase of stimulation current.the effect of gating current on the action potential is also studied.The results show that the change of gating current has insignificant effect on the action potential threshold,but it can shorten the period of action potential.Compared to the situation with Gauss white noise,the effect of the gating current on the action potential issued only in certain current stimulation,the influence which forms in different situations are not the same.Finally,the effect of noise intensity on the action potential distribution by changing the film area and the ion density of ion-channel is studied.Based on the research of this paper,the important applications of stochastic dynamics in physical and biological systems are recognized,but there also need more research with more physical quantities about more abundant phenomena.