用电势能法求带电细圆环与导体球的作用力

本文用电动力学中的镜像法,利用Mathematica软件计算了当导体球的球心在带电细圆环的轴线上时,在均匀带电细圆环作用下处于静电平衡的导体球外空间的电势,同时绘出导体球外空间的电势分布图像;再运用电势能与电场力的关系求出带电细圆环与导体球的相互作用力,并绘出电场力随距离变化的图像.     

带电细圆环与导体球壳系统的场分布

先依电象法,推导均匀带电圆环在金属导体球壳内的"象电荷";再在球坐标系下,根据电场强度的计算公式与Tay-lor展开式,计算出均匀带电细圆环在全空间的电场分布的级数形式解;进而结合唯一性定理和电场的叠加原理,获得带电细圆环与导体球壳系统的空间场分布.     

均匀外电场中带电导体球表面上的电荷分布

本文通过物理上的分析，应用叠加原理、唯一性定理及类比方法得出了均匀外电场中带电导体球表面上电荷的分布规律，从而求出了球外电场的分布．     

带电导体球表面处的电场强度

通过带电导体球阐述了面电荷所在处的电场强度并且对分别采用的面和壳物理模型的结果进行了比较。     

航天器内部孤立导体表面带电面积效应研究

航天器内部孤立导体充放电对航天器的影响更为隐蔽, 造成直接和潜在的伤害更加严重. 综合考虑航天器内部环境中粒子参数及材料二次电子特性等因素, 基于气体动理论, 结合粒子的麦克斯韦速度分布函数, 得出孤立导体球充电电位一般表达式. 利用电位表达式推导得出孤立导体球净电荷量及静电场能量与导体面积关系表达式. 讨论了特殊情况下孤立导体静电场能量与面积及空间环境的关系, 与地面电子元器件电磁脉冲放电损伤值进行了对比, 总结出孤立导体表面带电面积效应规律. 关键词： 孤立导体 表面带电 静电场能量 面积效应     

带电子导体球壳系统的精确解

导出了包围有接了导体球的带电导体球壳与地组成的静电系统的精确解，证明在该系统中，不管球壳与地之间的距离如何，电荷在地面产生的电势与在无限锭产生的电势总是相等，指出不精确解导导致无限远与大地的电势不等的错误结论。     

带电导体球壳系统的精确解

导出了包围有接地导体球的带电导体球壳与地组成的静电系统的精确解．证明在该系统中，不管球壳与地之间的距离如何，电行在地面产生的电势与在无限远产生的电势总是相等．指出不精确解会导致无限远与大地的电势不相等的错误结论．     

带电导体椭球的静电场

根据带电导体椭球电场的对称性,从特殊方向的电场计算出带电导体椭球外的电势与椭球几何特征的关系,然后根据电势计算出带电导体椭球外的电场强度.     

等离子体环境下孤立导体表面充电时域特性研究

航天器在等离子体环境下的表面充放电受到多种因素影响, 其中充电时间是影响静电放电频次的一个重要因素. 本文从等离子体的微观结构出发, 同时考虑材料参数特性, 在对每个粒子运用力学原理的基础上, 以统计方法 推导出孤立导体球表面充电电位时域表达式. 利用电位时域表达式推导出孤立导体球净电荷量时域表达式及静电场能量时域表达式. 以较低非极地地球轨道和较高地球同步轨道为例对孤立导体球电位、 净电荷量及静电场能量的时域特性进行了讨论, 分析了空间环境参数和导体球半径大小对表面充电的影响, 总结出等离子体环境下孤立导体表面充电时域特性规律. 关键词： 等离子体 孤立导体 表面带电 时域     

带电导体的转动对电磁场的影响

讨论了带电导体的转动对其电磁场的影响,分析了导体转动时磁场与电场和电荷分布之间的关系。     

Charge state effect on the K-shell ionization of iron by xenon ions near the Bohr velocity

Fe K-shell ionization cross sections induced by 2.4–6.0 MeV Xe20+are measured and compared with different binaryencounter-approximation(BEA)models.The results indicate that the BEA model corrected both by the Coulomb repulsion and by the effective nuclear charge(Zeff)agrees well with the experimental data.Comparison of Fe K-shell X-ray emission induced by 5 MeV xenon ions with different initial charge states(20+,22+,26+,30+)verifies the applicability of the effective nuclear charge(Zeff)correction for the BEA model.It is found that Zeffcorrection is reasonable to describe direct ionization induced by xenon ions with no initial M-shell vacancies.However,when the M shell is opened,the Zeffcorrected BEA model is unable to explain the inner-shell ionization,and the electron transfer by molecular-orbital promotion should be considered.     

Correlation phenomena in the Cherenkov radiation of accelerated multiply charged ions

Correlation phenomena occurring in Cherenkov radiation are considered which are related to fluctuations of the charge states of multiply charged accelerated ions in a medium. The additional correlation contribution to the radiation is determined by the root-mean-square deviation of the ion charge from its equilibrium value and is responsible for the nonzero radiation yield in the event that the threshold condition is not fulfilled. Numerical estimates of the radiation yield of heavy ions in the optical and X-ray frequency ranges are given. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 41–46, January, 2009.     

正充电聚四氟乙烯薄膜驻极体的电荷储存及其动态特性

研究了栅控恒压正电晕充电的聚四氟乙烯（PTFE）薄膜驻极体的电荷储存与 输运特性.结果显示在100℃以下的较低温区和高于150℃，尤其是高于180℃的较高 温区内慢再俘获效应控制着脱阱电荷的输运；而在约100—150℃的温区内快再俘获效应占主导地位.初始表面电位的增加将导致电荷密度衰减加剧，通过合理控制充电参数和组合 热处理工艺，可使同样储存有足够高的电荷密度的正负充电的PTFE薄膜驻极体既显示出相近 的电荷储存寿命，又具有突出的电荷稳定性. 关键词： 聚四氟乙烯 正充电驻极体 交越现象 电荷稳定性 电荷 输运     

有限长带电导体直线的电荷分布

通过3种方式给出有限长带电导体直线的电荷密度分布,结果表明电荷分布并不均匀.     

用双极坐标求解带电导体圆柱和无限大接地导体平板间的电势

利用双极坐标求解了带电导体圆柱和无限大接地导体平板间的电势分布,并对带电导体圆柱表面的电荷分布及无限大接地导体平板表面的电荷分布作了讨论.     

电矩张量与旋转带电体的磁矩

基于旋转带电体的磁矩与刚体转动惯量之间的类比关系,引入带电体的一个不同于电四极矩的电矩张量的概念,进而引入标量电矩二次曲面及电矩主轴的概念,借助正交变换及电矩张量矩阵的本征值理论,推导出沿任意方向定轴旋转带电体的磁矩的计算公式及电矩张量的若干性质,并举例说明.     

Finite size effect of ions and dipoles close to charged interfaces

The modified dipolar Poisson-Boltzmann(MDPB) equation,where the electrostatics of the dipolar interactions of solvent molecules and also the finite size effects of ions and dipolar solvent molecules are explicitly taken into account on a mean-field level,is studied numerically for a two-plate system with oppositely charged surfaces.The MDPB equation is solved numerically,using the nonlinear Multigrid method,for one-dimensional finite volume meshes.For a high enough surface charge density,numerical results of the MDPB equation reveal that the effective dielectric constant decreases with the increase of the surface charge density.Furthermore,increasing the salt concentration leads to the decrease of the effective dielectric constant close to the charged surfaces.This decrease of the effective dielectric constant with the surface charge density is opposite to the trend from the dipolar Poisson-Boltzmann(DPB) equation.This seemingly inconsistent result is due to the fact that the mean-field approach breaks down in such highly charged systems where the counterions and dipoles are strongly attracted to the charged surfaces and form a quasi two-dimensional layer.In the weak-coupling regime with the electrostatic coupling parameter(the ratio of Bjerrum length to Gouy-Chapman length) Ξ 1,where the MDPB equation works,the effective dielectric constant is independent of the distance from the charged surfaces and there is no accumulation of dipoles near the charged surfaces.Therefore,there are no physical and computational advantages for the MDPB equation over the modified Poisson-Boltzmann(MPB) equation where the effect of dipolar interactions of solvent dipoles is implicitly taken into account in the renormalised dielectric constant.     

Does Charge Contribute to the Frame Dragging of?Spacetime?

Electrically charged systems bound by a strong gravitational force can sustain a huge amount of electric charge (up to 10²⁰ C) against Coulomb repulsion. General relativistically such systems form a stable hydrostatic configuration both in the non-rotating and rotating cases. Here we study the effects of electric charge (electric energy density) on the spacetime outside a rotating electrically charged system bound by a strong gravitational force. In particular we investigate the effect of charge density on frame-dragging of spacetime in the exterior region. Using the coupled Einstein-Maxwell equations it is found that in the slow rotation approximation charge accumulation not only acts like an additional mass, thus modifying the spherically symmetric part of the spacetime, the electric charge also contributes directly to the dragging of spacetime. A modified Lense-Thirring formula for the spacetime frame dragging frequency is obtained and its implication for rotating charged compact stars is discussed.     

有机高分子中光生极化子的物理机制

有机聚合物中光生载流子（荷电极化子）产生的物理机制是一个非常重要的物理问题，但一直存在争议，文章介绍了作者对此问题的最新研究结果：荷电极化子和中性激子一样，是由光激发直接产生的，而不是激子解体的结果，其生成时间在100fs的量级．荷电极化子的量子产率约为25％，并且与激发能量无关，与实验观测的结果一致．     

高电荷态离子129Xe28+与Au和Mo表面作用产生的X射线谱

研究了高电荷态离子129Xe28+轰击金属Au和Mo表面产生的特征X射线谱.实验结果表明,在入射离子的电荷态和能量相同的条件下,对于核电荷数较小、原子质量较轻的靶原子,只有其内壳层的电子才能被激发而产生X射线,而核电荷数较大、原子质量较重的靶原子只有其较外壳层的电子能被激发而产生X射线.特征X射线的产额随入射离子动能的增加而增加.