安全膜电容器膜结构分析

用数值计算方法分析在不同膜结构的情况下电容器内部的电场分布。证明在保证电容器容量的前提下,采用菱形导体膜结构可以获得较为均匀的电场分布,从而有利于提高电容器的耐压。     

导体平板上铆钉的电磁散射分析

利用电场积分方程(EFIE)的矩量法分析了导体平板上有铆钉的电磁散射问题.铆钉和平板表面采用三角形面元进行剖分,面元上的电流分布用子域基函数表示,用伽略金法将电场方程转化为矩阵方程求解电流系数.数值计算了导体平板上有无铆钉时的雷达散射截面随入射角的变化,结果显示当平板上有多铆钉时,在一定的角度范围内,铆钉对雷达散射截面的影响非常明显并且与铆钉的分布情况有关.     

基于不等电位模型的接地网电位的数值计算

在接地网的计算模型中,一般是将接地网导体进行微元段的划分,然后求解每段导体注入土壤的泄漏电流,空间任意一点的电位都能够通过求解这些电流的"响应和"得到,从而计算接地网的电位分布、泄漏电流分布以及地表电位分布等。该文通过理论分析,建立了均匀土壤中的接地网不等电位计算模型,对接地网的地表电位分布进行计算。     

静电磁场中存在悬浮电磁导体时的三维场计算

本文讨论了表面密度法在静电磁场数值计算中的应用。给出了在有源场中有多孤立悬浮电位或磁位的导体或导磁体存在情形下静电磁场问题的解。对于磁控反应离子刻蚀机中磁场分布和点电荷产生的电场中的导体电位等问题进行了计算并与实验结果相比较,两者符合得很好。本文提出的方法适用于任何悬浮电位或磁位的导电体或导磁体电位或磁位的计算。     

准分子激光器中张氏面型电极的电场仿真研究

为了获得准分子激光器高脉冲能量输出,采用张氏面型电极的理论,设计了一套能产生大面积均匀电场的紧凑型电极。通过ANSYS软件数值仿真获得了电极表面电场分布,并与紧凑型张氏面型电极的理论计算结果进行了对比验证;分析了紫外火花预电离结构对电极放电的影响,并进行了电位和电场分布仿真。结果表明,预电离板的存在直接影响了电极之间的电位和电场分布;电场仿真结果解释了预电离板的顶端与阳极形成放电的原因。该研究为大面积辉光放电电极设计提供了更深入的理论支持。     

静电屏蔽问题中的部分电容与电场耦合

本文以导体屏蔽壳、壳外导体、壳内导体及参考导体(大地)构成的4导体静电独立系统为例,详细分析了其电位系数、感应系数及部分电容的取值特性。结果表明,无论屏蔽壳体是否接地,壳外导体与壳内导体的互有部分电容均为零;屏蔽壳体不接地时,内外导体之间存在电场耦合;屏蔽壳体接地后,内外导体之间不存在电场耦合。     

用于计算机分析计算静电场电位分布的等效电荷分布方法

本文探索了用于静电电子光学成象系统,计算电位分布的“等效电荷分布方法”。可以适用于包含有圆筒、圆膜片、圆锥和球面形电极的复杂边界系统,并且还考虑了金属电极之间的绝缘介质边界。此方法首先确定界面上的等效电荷分布,然后即可由电荷分布函数的数值积分,计算空间任意点的电位;在计算过程中,将各段边界按需要划分为若干环带,采用高斯—约旦主元素消去法求解电荷分布。本文运用泊松方程,导出了适合于求解介质边界上电位和电荷分布的数值计算公式;在求解过程中,采用高效的“算术—几何平均递推方法”,精确计算第一类完全椭圆积分;并且通过解析分析,成功地解决了计算各电极环带所荷电荷对本环中央周线上电位的贡献时所出现的奇异积分。按照所述方法,已在TQ—16计算机上,编制成功了“使用等效电荷方法的分析计算程序”;并对若干典型系统作了验证计算。     

电极布置对电容器铝箔失重和比容均匀性的影响

研究了ＨＣｌ中５０ Ｈｚ交流电侵蚀下,电解槽电极布置对电解电容器用高纯铝箔的侵蚀均匀性的影响。结果表明, 随电解槽导电石墨电极浸入深度的增加,侵蚀铝箔的失重和比容趋于不均匀分布。随铝箔电解槽石墨间距增大, 侵蚀铝箔的失重和比容趋于均匀分布。直接通电侵蚀铝箔的失重和比容分布均匀性优于铝箔电场通电, 在理论上分析了原因。     

探空气球对空中电场探测的影响分析

为研究气球周围大气电场分布,分析气球对空中大气电场探测的影响,建立了不带电气球和带电气球的电场分布模型,通过边界条件和气球周围电荷分布分别求解拉普拉斯方程和泊松方程,利用MATLAB模拟计算气球周围电场的分布情况,对比分析表明:气球带电后对上下部位的电场有加强作用,对左右两侧的电场分布有削弱的作用.同时,分析了气球升空过程中体积的变化和介电常数的改变对气球周围大气电场强度的影响,结果表明,探空绳长取20 m最优,此时气球造成的电场强度误差为0.33%.     

多导体传输线参数计算

对于具有多导体和多层填充介质的传输线,本文提出了电位-电场混合积分方程的分析途径及其相应的数值解法。此法适用于各种形式的TEM波和准TEM波传输线。     

利用传输线模型的载流子倍增寄存器的频率特性研究

介绍了一种电荷载流子倍增寄存器(CCM)电极问隙的传输线模型,通过求解其波动方程得到了电荷载流子倍增寄存器电极间隙的电势分布及电场分布.模拟分析表明:电荷载流子倍增寄存器电极间隙的电势分布是与电荷载流子倍增寄存器工作频率相关的函数.电势分布沿信号电荷密度流方向衰减且电荷载流子倍增寄存器工作频率越高,电势衰减越快.电荷栽...     

Numerical analysis of silicon-on-lnsulator short channel effects in a radiation environment

Radiation-induced charge build-up in the buried oxide (BOX) of SOI MOSFETs affects device performance through threshold voltage shifts of the back channel. This charge build-up is related to the electric field in the BOX during irradiation. In this paper, we report on the application of a numerical model for the potential distribution in a semiconductor device to the task of determining the electric field in the BOX. This electric field distribution is then combined with a model for charge accumulation as a function of electric field during irradiation to predict the threshold voltage shifts in the back channel of SOI MOSFET devices as a function of channel length. For the device design analyzed here, this model agrees with available experimental data and predicts an increase in back channel threshold shift as the channel length enters the sub-micron regime.     

The effects of electric fields on toner—Carrier adhesion in xerographic development

Centrifuge measurements and electrostatic charge measurements have shown that the force of adhesion of xerographic toner particles to carrier beads can be described by an electrostatic model. In this model the triboelectric charge on the toner particle is attracted by its countercharge residing on the bead surface and during the process of electrostatic development this force of attraction between toner and carrier must be overcome by a competing process. In this paper it is suggested that the applied field lowers the Coulomb barrier that normally constrains the toner to the bead surface, so that under the combined effects of the mechanical impulse and the applied electric field, the less tightly held particles are stripped from the carrier bead surface. A calculation has been made on the potential function adjacent to the bead surface in the presence of an electric field, and an equation is derived for toner detachment. Measurements have been made on xerographic toner of the efficiency of toner release for various drop heights, with field applied, and without field. The results are somewhat difficult to interpret because of the wide distribution in toner mass and charge. Nonetheless, a comparison can be made between theory and experiment, and there is reasonable agreement.     

A data complementary method for thunderstorm point charge localization based on atmospheric electric field apparatus array group

Data loss or distortion causes adverse effects on the accuracy and stability of the thunderstorm point charge localization. To solve this problem, we propose a data complementary method based on the atmospheric electric field apparatus array group. The electric field component measurement model of the atmospheric electric field apparatus is established, and the orientation parameters of the thunderstorm point charge are defined. Based on the mirror method, the thunderstorm point charge coordinates are obtained by using the potential distribution formulas. To test the validity of the basic algorithm, the electric field component measurement error and the localization accuracy are studied. Besides the azimuth angle and the elevation angle, the localization parameters also include the distance from the apparatus to the thunderstorm cloud. Based on a primary electric field apparatus, we establish the array group of apparatuses. Based on this, the data measured by each apparatus is complementarily processed to regain the thunderstorm point charge position. The results show that, compared with the radar map data, this method can accurately reflect the location of the thunderstorm point charge, and has a better localization effect. Additionally, several observation results during thunderstorm weather have been presented.     

TFSOI RESURF器件电势和电场分布的解析研究

在物理模型的基础上,对ＴＦＳＯＩ ＲＥＳＵＲＦ器件的电势和电场分布进行了解析分析,系统研究了漂移区掺杂浓度,漂移区长度,埋层ＳｉＯ２厚度和ＳＯＩ层厚度等结构参数同电势和电场分布的关系,并首次定量分析了在工艺加工过程中必须引入的场ＳｉＯ２界面电荷密度的影响。解析计算结果同ＭＥＤＩＣＩ模拟结果相符。     

芯片毛细管电泳电动进样的数值分析

利用集成毛细管电泳芯片进行生物化学分析时 ,电动进样是重要的操作步骤之一。本文通过建立数学模型 ,对“十”字型进样沟道内的电场分布进行了计算机数值模拟 ,通过改变进样电压和分析沟道内部电场分布 ,得到了进样及分离时的最佳电压组合。试验结果与模拟计算的结果吻合较好     

强流相对论电子束的纵向自群聚

当一束强流相对论电子束穿过一系列等距离排列的等电位导体,如导电或导电栅网时,由于空间电荷效应,将在纵向形成周期性空间电荷静电场,此民场将使强流相对论电子束纵向群聚,本文对这一非线性物理过程进行了理论和粒子模拟计算,基于此机理,有可能研制出一类新型的高功率微波器件。     

平面平行真空微电子二极管中二分之三次方关系式的应用

在一定的假定条件下，考虑空间电荷影响，平面平行真空微电子（P—VMD）二极管中电流一电压近似按二分之三次方关系式工作。本文在此关系式及Forler—Nordheim场发射方程的基础上，通过解简化立方方程，进一步推导出管内的电位、电场强度、电子速度和空间电荷密度的分布函数。P-VMD二极管在保持管内结构与阴极表面电场强度不变，并工作在典型工作状态（归一化电位系数P=2／3）情况下，考虑空间电荷影响时的阳极电压、阳极电场强度和阳极电子速度分别比无空间电荷影响时增加约50．00％，73．21％和22．47％。P—VMD二极管内的空间电荷密度分布函数为正割函数，在阳极表面附近为最小，在阴极表面处为无穷大，这是由于本文假设在阴极表面处的电子初速度为零的缘故。     

Asymmetric electric field enhancement in nanocrystal memories

The electrostatic model for nanocrystal memories is used to illustrate the fundamental difference of the metal nanocrystal memory in low-voltage program/erase (P/E) operations in comparison with semiconductor nanocrystal and trap-based memories. Due to repulsion of potential contours inside conductors, the metal nanocrystals will significantly enhance the electric field between the nanocrystal and the sensing channel set up by the control gate bias and, hence, can achieve much higher efficiency in low-voltage P/E. On the other hand, the electric field originated from the stored charge will only be slightly different for metal and semiconductor nanocrystal cases. We presented the electrostatic models by both approximate analytical formulation and three-dimensional numerical simulation in a nanocrystal array. Operations of P/E and read disturbance were analyzed for the cases of homogeneous charge distribution, silicon, and metal nanocrystals. In the P/E condition of +5/-5 V, the metal nanocrystal memory offers around 1.6 times higher peak fields than Si counterparts and almost three times higher than that from the one-dimensional model for homogeneous charge distribution. The field enhancement factor suggests the design criteria of oxide thickness, nanocrystal size, and spacing. The advantage of asymmetric field enhancement of metal nanocrystals will be even more prominent when high-K gate dielectrics are employed.     

The internal electric field distribution in bilayer organic light emitting diodes

The internal electric field distribution in a bilayer 4,4^′-bis[N-(1-napthyl)-N-phenylamino]-biphenyl/tris-(8-hydroxyquinoline) aluminium organic light emitting diode has been investigated experimentally using electroabsorption spectroscopy. The experimental results have been compared to those obtained from a drift–diffusion device simulation, further validating the model and highlighting the potential worth of such modelling. With the aid of the simulation, the electric field distribution can be explained in terms of charge carrier accumulation at the interface between the two organic layers, due to the HOMO and LUMO band offsets, and charge injection into the device, demonstrating the influence of contact materials on device behaviour.