Equilibrium Correlations in a Clustering Universe

It is shown that the observed result of the two-point galaxy correlation function and the three-point correlation function in the Universe agrees with a quasi-equilibrium assumption of mass distribution. Utilizing the form of the three-point correlation, we find that the two-point correlation function can be obtained by solving an equation derived from maximizing entropy under some constraints in a self-gravitating particle model. A generalized non-extensive entropy is also introduced to improve our result.     

线偏振激光在磁化等离子体中的调制不稳定性

 采用洛伦兹变换推导了线性偏振激光在磁化等离子体中的非线性色散关系,根据Karpman方法推导出横波的非线性控制方程,利用线性偏振激光在磁化等离子体中的非线性色散关系和非线性控制性方程,分析了在磁化等离子体中有限振幅的扰动引起的调制不稳定性,得到了线性偏振激光的调制不稳定的时间增长率与扰动波数之间的函数关系。分析结果表明：激光等离子体的临界面附近的磁调制不稳定性的时间增长率显著增大。     

Acceleration of Flare Protons by Langmuir Plasmons

We analytically study the turbulent acceleration of solar protons by strong Langmuir plasmons in Cerenkov processes.It is shown that among the wave spectra with self-retained source only the Pelletier spectrum (Wk ∝ k^-7/2) can result in the energy spectrum of non-relativistic protons,which gives a good fit to that observed from solar flare events.It is quite possible that strong Langmuir turbulence presents in coronal active region,with three-dimensional,isotropic and stationary spectrum proportional to k^-7/2,and is responsible for the acceleration of flare protons.     

Dynamical behaviour of transverse plasmons in pair plasmas

This paper analytically investigates the nonlinear behaviour of transverse plasmons in pair plasmas on the basis of the nonlinear governing equations obtained from Vlasov--Maxwell equations. It shows that high frequency transverse plasmons are modulationally unstable with respect to the uniform state of the pair plasma. Such an instability would cause wave field collapse into a localized region. During the collapse process, ponderomotive expulsion is greatly enhanced for the increase of wave field strength, leading to the formation of localized density cavitons which are significant for the future experimental research in the interaction between high frequency electromagnetic waves and pair plasmas.     

磁化薄吸积盘中的温度分布

研究了薄吸积盘中的磁流体力学过程, 给出了薄盘近似条件下的动量方程和磁感应方程. 在所给定的方程基础之上, 给出了稳态条件下环绕一个年轻恒星周围盘的面密度、速度和温度分布的数值解. 主要结果如下: (ⅰ) 在薄盘近似条件下, 磁场的大小应该有一个上限, 该上限相应于磁场均分值. 当磁场在此上限以内, 盘仍然保持为Kepler盘; (ⅱ) 磁化盘的有效温度随径向方向幂指数递减, 如果磁场强度取某一数值时, 递减指数为-1/2, 其结果符合观测到的辐射流量谱.