聚丙烯孔洞驻极体膜的化学表面处理及电荷稳定性

利用热刺激放电(Thermally Stimulated Discharge, TSD)电流谱、在线电荷TSD、电荷等温衰减测量和衰减全反射(Attenuated Total Reflection, ATR)红外光谱分析，本文系统地研究了经化学表面处理(萃取、氧化及氢氟酸)的聚丙烯(PP)孔洞驻极体膜的电荷储存稳定性及电荷稳定性提高的原因.结果表明：经适当地氧化和氢氟酸室温处理试样的TSD电流谱中在温位约为184℃处出现原膜所没有的非常强的新峰，电荷热稳定性得到显著的提高，这一电荷热稳定性通过高温充电工艺得到进一步地改善；适当延长室温下氢氟酸处理的时间或延长氧化时间，都会使处理膜的电荷稳定性得到提高.理论分析表明在线电荷TSD测量法可给出线性升温过程中电荷重心及驻极体电荷量变化的综合信息，结合TSD电流谱和初始电荷重心位置的测量，可精确地考察线性升温过程中电荷重心的在线变化. 关键词： 聚丙烯孔洞膜 表面氧化 氢氟酸处理 电荷稳定性 在线电荷TSD     

聚乙烯空间电荷包行为的形成机理与仿真方法研究

聚乙烯中的空间电荷包行为是空间电荷的一种特殊的输运行为.研究表明,空间电荷包行为由于受材料本身特性、外加电场大小以及环境温度等的影响,导致其产生过程及传输特性上存在较大差异,这些因素给空间电荷包行为产生机理研究带来了较大困难.通过对电荷的电极注入过程、载流子的体内迁移规律及空间电荷与体内陷阱的相互作用机制进行分析,探讨了不同外加电场及不同深度陷阱能级对电荷包行为造成的相关影响,在此基础上建立物理模型来描述电荷包的产生和迁移过程.模型中提出了在高于阈值电场时,载流子迁移速度与电场关系存在负微分迁移率的假设.基于此模型对空间包行为的模拟结果与实验结果取得较好的一致. 关键词： 空间电荷包 数值模拟 负微分迁移率     

异质二聚体反应中心的电荷转移过程

在低温的状态下,类球红细菌内天然叶绿素的反应中心发生的电荷分离对激发波长有较弱的依赖性,而这种依赖可能来源于分子内电荷转移态。我们采用表现出更多的电荷转移态性质的突变叶绿素为反应中心,对这种电荷分离过程中的激发波长依赖和温度依赖的性质做了进一步的研究。研究发现:突变的异质二聚体存在的两种激发态(定域的激发态与分子内电荷转移态)是相互强耦合的,在突变的分子异质二聚体中形成的电荷转移态并不是电荷分离的有效途径。随着温度的降低,异质二聚体的活性降低,从而电荷分离产率下降。     

电晕充电多孔PTFE/PP复合驻极体过滤材料的电荷存储特性

报道采用电晕充电方法，对用高温熔融粘合工艺制备得到的双向拉伸多孔PTFE与PP复合过滤材料进行驻极体改性，并采用热刺激放电和表面电位测量等方法研究了材料的电荷存储稳定性,根据驻极体相关理论，对实验结果进行了解释. 结果表明，电晕充电的多孔PTFE/熔喷或纺粘PP覆膜材料中，既存在空间电荷又存在极化电荷，复合膜的界面是电荷陷阱的主要来源. 从不同面对复合膜材料进行充电时，材料具有完全不同的电荷存储特性. 由于材料体内空间电荷和极化电荷的极性相反、相互补偿，表面电位测定并不能真正反映材料内部电荷的存储状态. 关键词： 驻极体 电晕充电 聚合物复合膜 热刺激放电     

Electrodynamics of effective charge

A portion of the charge induced in an isotropic plasma by an injected charged particle is shown to combine with the particle to form a charged quasi-particle, the effective charge, that is different from the conventional “dressed” charge. The remainder of the induced charge is found in a wake behind the effective charge. Properties of effective charge are described, and the application of this concept to coherent ion acceleration and stopping power is discussed.     

共轭高分子链中极化子间相互作用对电荷迁移率的影响

基于综合考虑了电子与声子以及电子与电子相互作用的理论模型,采用数值方法计算了在外电场作用下共轭高聚物分子中电荷的迁移率,讨论了大小极化子共存并相互作用对分子链内电荷迁移率的影响。研究发现,电荷迁移率明显受大小极化子的载荷性质的影响,当大小极化子具有相同电性时,在低电场范围内,分子内电荷迁移率由大极化子运动性质主导,而在高电场范围内,分子内电荷迁移率由小极化子主导;另一方面,当大小极化子具有相反电性时,电荷迁移率只由大极化子运动性质主导,与电场强度无关。此外,还讨论了电子与电子相互作用对电荷迁移率"的影响。     

基于类耿氏效应的低密度聚乙烯中空间电荷包行为的模拟仿真

低密度聚乙烯材料中的空间电荷包现象通常会引起严重电场畸变而影响其击穿特性. 本文借鉴半导体中的耿氏效应的负微分迁移率机理来描述电荷包的形成机理,并结合载流子的注入条件及体内陷阱对电荷迁移的影响等因素,对文献中报道的两类外加场强不同且迁移趋势各异的空间电荷包行为进行了模拟仿真,模拟的电荷包大小随电场变化规律,电荷包迁移速率随时间变化规律等与相应实验结果符合.模拟结果表明,产生耿氏效应的负微分迁移率是造成电荷包非弥散传输的主要原因,其与材料电极注入情况及体内陷阱态的共同作用导致了空间电荷包行为迁移的多样性. 关键词： 空间电荷包 耿氏效应 模拟仿真 负微分迁移率     

Carriers recombination processes in charge trapping memory cell by simulation

We have evaluated the effects of recombination processes in a charge storage layer, either between trapped electrons and trapped holes or between trapped carriers and free carriers, on charge trapping memory cell＇s performances by numerical simulation. Recombination is an indispensable mechanism in charge trapping memory. It helps charge convert process between negative and positive charges in the charge storage layer during charge trapping memory programming/erasing operation. It can affect the speed of programming and erasing operations.     

Electrostatic Charge Measurement and Charge Neutralization of Fine Aerosol Particles during the Generation Process

An aerosol charge analyzer has been constructed to measure the charge distribution of NaCl particles generated in the laboratory. A radioactive electrostatic charge neutralizer utilizing Po‐210 was used to neutralize the electrostatic charge of the particles. The atomization technique was used to generate NaCl particles with diameters of 0.2 to 0.8 μm, while the evaporation and condensation method was adopted to generate particles of 0.01 to 0.2 μm in diameter. The experimental data demonstrates that the absolute average particle charge depends on the particle diameter, and is higher than that calculated by the Boltzmann charge equilibrium for particles within the range of 0.2 to 0.8 μm. The charge increases with decreasing NaCl concentration. When these particles are neutralized using the Po‐210 neutralizer, it is found that the electrostatic charge reaches the Boltzmann charge equilibrium. For 0.01 to 0.2 μm NaCl particles generated using the evaporation and condensation method, test results show that the absolute average particle charge is higher than that calculated by the Boltzmann charge equilibrium for particles larger than 0.03 to 0.05 μm in diameter, while it is lower than that predicted by the Fuchs theory [1], for particles smaller than 0.03 to 0.05 μm. However, after charge neutralization, particles with diameter above 0.05 μm reach the Boltzmann charge equilibrium condition, and the charges for particles with diameters of 0.010 to 0.05 μm, agree well with Fuchs' theory.     

不可易规范场的对偶荷

本文讨论了不可易SU(2)规范场的各种规范不变物理量——电荷、对偶荷(磁荷)、电磁场以及有质量矢粒子场的表达式与关系,特别是对偶荷(磁荷)与电荷算符同位旋方向的大范围拓扑性质的关系。     

The equivalence principle and an electric charge in a gravitational field

It is shown that there is no violation of the strong principle of equivalence in the case of an electric charge either falling freely or supported in a static uniform gravitational field. For a freely falling charge, the global electromagnetic field distribution at any instant is found to be the same as that of a charge which is moving uniformly with respect to an inertial frame with a velocity equal to the instantaneous velocity of the freely falling charge. In the case of a charge supported in the gravitational field, the total electromagnetic field energy, as measured by freely falling observers instantaneously at rest with respect to the charge, is shown to be equal to the Coulomb field energy of a charge permanently stationary in an inertial frame. The conclusion here, that in neither of the two cases does the charge emit electromagnetic radiation, is independent of our choice of the observer's frame of reference.     

Coulomb law and hypercomplex approach to electrodynamics

For a Coulomb-type field of a single point charge, generalized expressions are considered which are obtained on the basis of a hypercomplex generalization of electrodynamics with magnetic charges [1]. Along with the usual electrostatic field, in this approach a single charge can create a magnetic field, provided that the space points around the charge are oriented in a different way than the field source (charge) itself. Aside from vector fields, such a charge can create scalar and pseudoscalar fields, if time flows differently at the field points around the charge than at the location of the charge, or if the charge itself moves with respect to a fixed reference frame. The sources of the dual symmetry of the Maxwell equations are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 101–104, September, 1990.     

Nonequilibrium charge susceptibility and dynamical conductance: identification of scattering processes in quantum transport

We calculate the nonequilibrium charge transport properties of nanoscale junctions in the steady state and extend the concept of charge susceptibility to the nonequilibrium conditions. We show that the nonequilibrium charge susceptibility is related to the nonlinear dynamical conductance. In spectroscopic terms, both contain the same features versus applied bias when charge fluctuation occurs in the corresponding electronic resonances. However, we show that, while the conductance exhibits features at biases corresponding to inelastic scattering with no charge fluctuations, the nonequilibrium charge susceptibility does not. We suggest that measuring both the nonequilibrium conductance and charge susceptibility in the same experiment will permit us to differentiate between different scattering processes in quantum transport.     

Self-consistent field theory of adsorption of flexible polyelectrolytes onto an oppositely charged sphere

The adsorption of flexible polyelectrolyte （PE） with the smeared charge distribution onto an oppositely charged sphere immersed in a PE solution is studied numerically with the continuum self-consistent field theory. The power law scaling relationships between the boundary layer thickness and the surface charge density and the charge fraction of PE chains revealed in the study are in good agreement with the existing analytical result. The curvature effect on the degree of charge compensation of the total amount of charges on the adsorbed PE chains over the surface charges is examined, and a clear understanding of it based on the dependences of the degree of charge compensation on the surface charge density and the charge fraction of PE chains is established.     

How many electrons can a nucleus bind?

It is shown that negative ions of charge ≤ ? 18 × (charge of the nucleus) do not exist. As the nuclear charge increases our estimate improves, converging asymptotically to -(charge of the nucleus).     

Spatial charge distribution in fibrous dielectrics

In this work, an attempt was made to study the spatial charge distribution in fibrous dielectrics using pulsed electro-acoustic method. The polarized dielectrics displayed in-depth charge polarization and exhibited slow charge decay. The initial charge density was found to increase with an increase in polarization voltage as well as polarization time. The statistical analysis revealed that though the polarization voltage affected the initial charge density significantly, the polarization time was insignificant. A multiple linear regression model of initial charge density was developed and found to predict the experimental results quite satisfactorily.     

Width of the equilibrium charge distribution of heavy ions in solid and gaseous media

Based on an analysis of the experimental data on the charge distributions of ions in gases and solids, the analytical parameterization of the width of the charge distribution as a function of the energy, the average equilibrium ion charge, ion nuclear charge, and nuclear charge of target atom has been obtained. The proposed relations are applicable in a broad energy range and describe the existing experimental data satisfactorily.     

Modified Fowler–Nordheim tunnelling for modelling charge injection into Si3N4 in an Al/Si3N4/Si structure

Charge injection behaviours in silicon nitride of an Al/Si₃N₄/n-Si metal?Cinsulator?Csemiconductor (MIS) device are systematically studied before and after applying different high constant DC bias conditions with the aim of controlling charge accumulation in the dielectric when a high actuation voltage is applied. We found that both polarity and magnitude of charge accumulation in silicon nitride depend on the biasing direction. Charge injection from the semiconductor to the silicon nitride always dominates over charge injection from the Al electrode to the silicon nitride. Negative charge accumulation happens in silicon nitride when the Al electrode is positively biased, and positive charge accumulation occurs in silicon nitride when the Al electrode is negatively biased. The positive charge accumulation is much bigger than the negative charge accumulation under the same magnitude of stress voltage. Furthermore, the experimental results also show that the charge injection level exponentially increases with the applied voltage across the silicon nitride. These observed experimental results can be well explained by a modified Fowler?CNordheim tunnelling charge injection model, which takes into account the roles of both electrons and holes in the process of charge injection.     

与象电荷有关的能量和互作用力问题

指出与象电荷有关的系统的互能、互作用力和真实电荷系统的互能、互作用力分别相等,自能、有一般分别不等。     

The structure of XLPE and the distribution of space charge

The formation and accumulation of space charge under charge treatment are investigated using PWP method. The interaction between space charge and the structure of XLPE is measured using infrared spectroscopy (IR) method. The related mechanism about space charge distribution and the structure of XLPE are discussed.