Numerical simulation on modulational instability of ion-acoustic waves in plasma

In this paper, the one-dimensional(1D) particle-in-cell(PIC) simulation is used to study the modulation instability of ion acoustic waves in electron–ion plasmas. The ion acoustic wave is described by using a nonlinear Schr¨odinger equation(NLSE) derived from the reductive perturbation method. Form our numerical simulations, we are able to demonstrate that,after the modulation, the amplitude increases steadily over time. Furthermore, by comparing the numerical results with traditional analytical solutions, we acquire the application scope for the reductive perturbation method to obtain the NLSE.We also find this method can also be extended to other fields such as fluid dynamics, nonlinear optics, solid state physics,and the Bose–Einstein condensate to validate the application scope of the results from the traditional perturbation method.

Effects of the dust size distribution in one-dimensional quantum dusty plasma

灰尘的效果在 ultracold 量缩放分发尘封的血浆被调查。量的振幅 m 和宽度清扫声学的波浪在系统与不同灰尘尺寸分布被学习。 m 并且当全部的数字密度增加，量灰尘，声学的波浪被发现增加。 m 并且比为典型尘封的血浆为不平常的尘封的血浆是更大的。而且当灰尘谷物的费密温度增加，波浪的 m 减少。of 量灰尘波浪的速度 u 0 增加的声学的波浪增加。

Rectification and phase locking of graphite

Rectification phenomena and the phase locking in a two-dimensional overdamped Frenkel-Kontorova model with a graphite periodic substrate were studied. The presence of dc and ac forces in the longitudinal direction causes the appearance of dynamicalmode locking and the steps in the response function of the system. On the other hand, the presence of an ac force in the transverse direction causes the appearance of rectification,even though there is no net dc force in the transverse direction. It is found that whereas the longitudinal velocity increases in a series of steps, rectification in the transverse direction can occur only between two neighbor steps. The amplitude and phase of the external ac driving force affect the depinning force,rectification of the system and particles trajectories.

The Prolongation Structure of a Coupled Kdv Equation

The new coupled KdV equation proposed by Ohta and Hirota, in which the phase shift depends on the mutual positions of solitons at the initial time, is investigated in the framework of prolongation structure theory. Its Lax representation is constructed.