中文摘要：

为了描述无晨昏电场情况下带电粒子在中性片磁场非小扰动区中运动的动力学特征,建立了一个非线性的动力学系统.运用Mawhin重合度理论探讨了一类非线性问题的周期解,然后将其应用于无晨昏电场情况下带电粒子在远磁尾中性片磁场非小扰动区中运动的动力学模型的周期解问题的研究,得出了带电粒子在初始位置逐渐远离中性片运动过程中存在周期轨的结果.在此基础上,还可以进一步探讨该模型同宿轨等其它动力学行为的存在性问题.

英文摘要：

In order to describe the dynamic characteristics of the electric particles sporting in neutral sheet magnetic field without dawn-dusk electric field,a nonlinear motion model was proposed.Based on the Mawhin＇s continuation theorem,the existence of periodic solutions to a class of nonlinear problems was discussed,and wherery,the problem of periodic solution of electric particles sporting in neutral sheet magnetic field without dawn-dusk electric field was investigated.U nder the given initial conditions,a result about the existence of periodic orbits of the model was obtained.Furthermore,based on our result,other dynamic behaviours of the model,such as the homoclinic orbits can are to discussed.