极端荷电黑洞引力场中的轨道动力学

运用相平面分析法,通过求解广义相对论运动方程,得到了在极端荷电黑洞引力场中运动的天体的轨道方程,同时作出了轨道相平面图并分析了其轨道的稳定性 关键词： 相平面 稳定性 轨道     

直流清洗电极电场对束流参数影响的测量与研究

 本文采用保角变换法推导了直流清洗电极电场的计算公式,分析和研究了合肥光源直流清洗电极电场对束流参数的影响。例如,直流清洗电场存在垂直方向的二极分量将引起闭轨变化,四分量将产生工作点偏移,六极分量会产生附加校正色品。并给出了一些测量结果。     

Cascade of Random Rotation and Scaling in a Shell Model Intermittent Turbulence

The time behaviors of intermittent turbulence in Gledzer-Ohkitani-Yamada model are investigated. Two kinds of orbits of each shell which is in the inertial range are discussed by portrait analysis in phase space. We find intermittent orbit parts wandering randomly and the directions of unstable quasi-periodic orbit parts of different shells form rotational, reversal and locked cascade of period three with shell number. We calculate the critical scaling of intermittent turbulence and the extended self-similarity of the two parts of orbit and point out that nonlinear scaling in inertial-range is decided by intermittent orbit parts.     

Persistent Homoclinic Orbits for a Perturbed Cubic-quinitic Nonlinear Schrodinger Equation

In this paper, the existence of homoclinic orbits, for a perturbed cubic-quintic nonlinear Schrödinger equation with even periodic boundary conditions, under the generalized parameters conditions is established. More specifically, we combine geometric singular perturbation theory with Melnikov analysis and integrable theory to prove the persistence of homoclinic orbits.     

对高分子体系进行分子动力学模拟方法的研究

以单链聚乙烯为例,研究了多种对高分子体系进行分子动力学模拟的方法.结果表明,不同的力场条件可以导致明显不同的结果.在使用OPLS力场的真空条件下.在100K体系出现了玻璃化现象,在200和300K条件下体系出现了局部结晶现象,而在400和500K体系出现了熔化现象.在给定体系中加入周期性边界和在300K下进行分子动力学模拟,无序和结晶状态都具有一定的稳定性.     

基于不变流形的登月轨道设计

研究了基于三体问题的不变流形设计低成本登月轨道的问题．考虑了黄道面和白道面之间夹角不为零的三维情况,将太阳-地球-月亮-卫星组成的四体问题分解成由太阳-地球-卫星和地球-月亮-卫星组成的非共面的两个限制三体问题．给出了这两个三体系统Halo轨道不变流形与两轨道面相交处进行小的变轨来设计低成本探月轨道的一般方法．比较结果表明用该方法设计的轨道比传统的Hohmann变轨节省约20%的燃料．从轨道能量的角度分析了用流形设计轨道比Hohmann变轨节省燃料的原因,并给出了理论表达式．该方法对于深空探测轨道设计的能量分析具有普遍的适用性,可为设计提供一个选择参数的标准．     

会切磁场中大回旋电子束产生的研究

研究了会切磁场产生的机理。通过对Moster-Molnar 模型的探讨, 建立了会切磁场的物理模型。在会切磁场理论分析和数值模拟基础上, 探讨了影响会切磁场设计的因数; 利用拉格朗日公式求解了会切磁场中电子运动轨迹。探讨了会切磁场与大回旋空心会切电子枪的关系, 得到了改进会切电子枪性能的一些一般性结论。     

椭圆轨道真近点角的级数计算方法

用级数展开方法得到真近点角超越方程,由迭代法求真近点角与时间的关系,讨论迭代收敛的充分条件．对于不满足迭代收敛充分条件情形,列写偏近点角超越方程,用迭代法求偏近点角变化规律,用数值积分方法求出真近点角与时间的关系,指出所有椭圆轨道都满足偏近点角迭代收敛的充分条件．讨论小偏心率椭圆轨道真近点角近似超越方程,由迭代法求真近点角与时间的关系．数值模拟结果表明该方法的有效性．     

Mechanical analysis of orbit tracking movement of feed system in large spherical radio-telescope

The curve equation and its mechanics analysis of suspended-cable under the condition of end load are given. Then on the basis of it, the mechanical analysis of suspended-cable system for large spherical radio-telescope is studied, and procedures of the control for the orbit tracking movement of the line feed in large spherical radiotelescope are given. The validity of the results mentioned above is confirmed by means of computer simulations.     

PO反应中混沌控制的变量交叉反馈方法研究

The variable cross feedback（VCF）method is proposed to control the nonlinear chaos system. The control principle is introduced,and the Peroxidase-Oxidase（PO）system is taken as a typical example to demonstrate the effectiveness of this method. The dynamical behaviors of the PO system controlled using the VCF method are given by computer numerical simulation. The results show that the return map of the system can be changed into the finite isolated points from the assemblage of discrete points having regular distribution and structure by appropriately