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     

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.     

Theoretical study of the central depression of nuclear charge density distribution by electron scattering

The charge form factors of elastic electron scattering for isotones with N=20 and N=28 are calculated using the phase-shift analysis method, with corresponding charge density distributions from relativistic mean-field theory. The results show that there are sharp variations at the inner parts of charge distributions with the proton number decreasing. The corresponding charge form factors are divided into two groups because of the unique properties of the s-states wave functions, though the proton numbers change uniformly in two isotonic chains. Meanwhile, the shift regularities of the minima are also discussed, and we give a clear relation between the minima of the charge form factors and the corresponding charge radii. This relation is caused by the diffraction effect of the electron. Under this conclusion, we calculate the charge density distributions and the charge form factors of the A=44 nuclei chain. The results are also useful for studying the central depression in light exotic nuclei.     

Two-step evolution of doping dependent antiferromagnetism and charge imbalance in multilayered cuprates

The properties of the charge imbalance and magnetism are investigated in the multilayered cuprates. The effective Hubbard constants are much reduced and show clear electron-hole asymmetry due to the screening effect. Phase diagrams are obtained, which may give the clue to search for the self-doped cuprates. An unexpected increase of the charge density upon doping in the layer with minority charge is predicted. The antiferromagnetism follows a two-step evolution with respective origin in the layer with minority charge, in contrast to the conventional doping dependence in the layer with major charge.     

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.     

MIE experiments and simultaneous measurement of the transferred charge – A verification of the ignition threshold limits

Using the apparatus for the determination of the MIE a wide series of experiments have been carried out in hydrogen/air, ethene/air, propane/air and acetone/air mixtures. The transferred charge as a criterion to judge the ignition potential is determined to verify the thresholds of transferred charge given in the standards. The stored charge in the capacitance before the discharge is compared to the transferred charge in the spark. The correlation of ignition energy and transferred charge is examined and the thresholds of the transferred charge are discussed. The MIE of the above-mentioned mixtures are reviewed taking into account the measurement uncertainty.     

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。     

密立根油滴实验中油滴带电荷数的辅助分析

本根据密立根油滴实验中计算油滴带电量的公式，利用Matlab编程，分析油滴带电量与油滴下落时间和平衡电压的关系，得到多重曲线，根据曲线可以简洁直观的判断油滴的带电荷数，为选择合适的油滴提供了理论上的判断依据。     

电荷离散化时相干态下介观金属环中电荷与电流以及能量的量子涨落

基于电荷量子化的事实,运用最小平移算符Q∧的性质等,计算对应的相干态下介观金属环中电荷、电流及能量的量子涨落,研究影响量子涨落的因素.结果表明:计及电荷的离散性,在相干态下介观金属环中电荷、能量的量子涨落不为零,分别与电荷量子、相干态参量等因素有关;此外,能量的量子涨落还决定于金属环的电感、外磁通及其时间变化率的大小.     

主客体掺杂型非线性光学聚合物驻极体DR1/PMMA膜中空间和偶极电荷的相互作用特性

运用热刺激放电、表面电位衰减和电光效应的检测等手段,对主客体掺杂型非线性光学聚合物驻极体DR1/PMMA膜中空间和偶极电荷的相互作用特性进行了研究．结果表明,在极化后的样品中,被样品表面或体内的各类陷阱捕获的大部分空间电荷所处的陷阱能级高于极性生色团分子的定向排列产生的偶极电荷的束缚能级,空间电荷对偶极电荷有强烈的束缚作用．空间电荷衰减将导致材料内的电场分布发生变化,并引起极性生色团分子的松弛．空间电荷稳定性决定着偶极电荷的寿命. 关键词：     

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.     

阶梯算符本征态下介观电子谐振腔的量子效应

基于电荷取分立值的事实,运用阶梯算符的性质,计算电荷、电流以及能量的量子涨落,研究介观电子谐振腔的量子效应.结果表明,计及电荷量子化的事实,在阶梯算符本征态下介观电子谐振腔中电流的量子涨落为零,而电荷与能量的量子涨落不为零,分别与电荷的量子化性质有关,大小决定于系统自感、电容、栅压和形状因子以及状态参量等因素.     

Analysis on experimental valence charge density in germanium at RT and 200 K

The electronic structure and hence the valence charge distribution of germanium at 296 and 200 K has been elucidated from structure factors measured by X-ray diffraction experiment using maximum entropy method (MEM) and multipole model. The methods adopted here are used to extract the fine details of the charge density distribution in the valence region. The charge density evaluated using both the models along the bond path and at the mid bond positions are compared and found to confirm the covalent bond existing in the solid. Topology of the charge density in the crystal is analysed and the critical points determined reveal unique spatial arrangement of valence charge in the direction normal to the bonding direction. The Laplacian of the charge density is also analysed for the understanding of the spatial distribution and the partitioning of the valence charge. The local charge concentration and the mapping of the electron pairs of the Lewis and valence shell electron pair repulsion (VSEPR) models have been done using electron localization function (ELF) and localized orbital locator (LOL).     

共振、混沌与束晕形成

研究强流束中的非线性共振、混沌与束晕形成的关系.给出强流束中非线性共振范围的表达式及其随束流空间电荷效应变化的数值结果和图表曲线,提出由非线性共振而激发的束晕形成的空间电荷效应极限,并分析束晕形成的过程.     

Estimating topological charge of propagating vortex from single-shot non-imaged speckle

Encoding information using the topological charge of vortex beams has been proposed for optical communications. The conservation of the topological charge on propagation and the detection of the topological charge by a receiver are significant in these applications and have been well established in free-space. However, when vortex beams enter a diffuser,the wavefront is distorted, leading to a challenge in the conservation and detection of the topological charge. Here, we present a technique to measure the value of the topological charge of a vortex beam obscured in the randomly scattered light. The results of the numerical simulations and experiments are presented and are in good agreement. In particular, only a single-shot measurement is required to detect the topological charge of vortex beams, indicating that the method is applicable to a dynamic diffuser.     

表层氟化聚乙烯中的空间电荷

本文试图简要地汇集近年来与近期我们所取得的关于表面氟化对聚乙烯(PE) 空间电荷行为影响的研究结果, 总结与探讨PE中的空间电荷积累与其氟化层特性和特征间的关联. 这些结果显示在氟化反应气中没有氧存在时一个非常薄的氟化层能产生有效的电荷抑制, 而当氧存在时为达到有效的电荷阻挡、需要一个具有高氟化度的非常厚的氟化层. 在影响空间电荷的诸电学因素中, 氟化层的电荷传导特性比其电荷俘获特性和介电常数或极性对阻止电荷注入材料内部更为重要, 尽管氟化层的高介电常数和被俘获的电荷会降低界面电场、因此减少电荷的电极注入. 氟化层的电荷传导特性密切关联于其自由体积, 反应混合气中存在的氧对减小自由体积、因此对电荷的抑制具有强的负面影响.     

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。     

Localized charge inhomogeneities and phase separation near a second-order phase transition

Localized charge inhomogeneities and phase separation are described in the framework of the phenomenological theory of phase transitions. It is shown that Coulomb interaction determines the charge distribution and the characteristic size of the emerging inhomogeneities. Phase separation associated with charge segregation becomes possible because of a high dielectric constant and a low excess charge density in the localization region. The phase diagram of the system is calculated, and estimates are obtained for the gain in energy associated with the emerging state. The role of Coulomb interaction is exposed, and corresponding estimates are given.     

Transport through a quantum dot subject to spin and charge bias

Spin and charge transport through a quantum dot coupled to external nonmagnetic leads is analyzed theoretically in terms of the non-equilibrium Green function formalism based on the equation of motion method. The dot is assumed to be subject to spin and charge bias, and the considerations are focused on the Kondo effect in spin and charge transport. It is shown that the differential spin conductance as a function of spin bias reveals a typical zero-bias Kondo anomaly which becomes split when either magnetic field or charge bias are applied. Significantly different behavior is found for mixed charge/spin conductance. The influence of electron-phonon coupling in the dot on tunneling current as well as on both spin and charge conductance is also analyzed.