海底光纤复合电缆金属护套光单元感应电势计算

运行中交变电场在海底光纤复合电缆的光单元金属护套上会产生感应电势,感应电势的大小是决定海底光纤复合电缆内采用何种光单元结构的一个主要因素。给出了金属护套光单元感应电势的计算公式,并举例计算了感应电势及感应电流。计算结果表明,一般长度的海底光纤复合电缆中金属护套光单元的感应电势较小,在安全范围内;具有径向和纵向阻水的普通金属护套光单元可用于海底光纤复合电缆中,不需要采取特殊措施。     

基于表面势的MOSFET模型

基于表面势的模型由于其本质上的优点 ,在小尺寸器件建模中日趋得到重视。文中通过对几种典型的表面势模型的分析 ,论述了基于表面势模型的建模思想、特点和在电路模拟中的优越性。分析表明 ,这是一种基于物理描述的模型 ,具有连续性、物理意义明确、结构简明等特点 ,对建立小尺寸器件整体模型非常适合和有效。     

基于表面势的GaN HEMT 集约内核模型

从器件表面势机理出发,考虑载流子浓度升高时费米势的变化,首次在二维泊松方程中引入新的费米势近似式,重构表面势源头方程,提出了一种直接基于表面势建立氮化镓高电子迁移率晶体管(GaN HEMT)器件模型的方法,建立了包括积累区和过渡区的物理基集约内核模型。表面势引入模型突破了现有的建模技术,给集约模型的建立提供可信的内核模型方程和理论基础。模型采用解析近似求解获得表面势,Pao-Sah模型验证可行性,I-V、C-V特性曲线与TCAD软件仿真的结果有很好的拟合,能准确描述各种偏置条件下GaN HEMT的电流、电荷特性。     

基于“势”最大化的纹理分析方法

“势”是吉布斯随机场中的重要概念,本文提出了一种基于“势”最大化的纹理分析方法,并通过实验证实了这种方法的有效性。     

CdSe的相互作用势研究

提出了一种用于表征硒化镉(CdSe)性质、形式上类似于玻恩-迈耶模型的相互作用势,并用其研究了由压力引起的CdSe从四近邻的纤维锌矿向六近邻的岩盐矿结构的相变.利用该作用势得出了六配位数碱卤化物晶体的性质,并描述了CdSe的三种晶体结构:纤锌矿(Wurtzite)、闪锌矿(Zinc blende)和岩盐矿(Rocksalt)型结构.相变压强和得出的物态方程与实验数据十分吻合.利用新提出的势中的色散项,计算了Hamaker常数.经计算,CdSe的Hamaker常数为0.388 eV.利用Lifshitz理论和微观尺度理论对多种碱卤化物进行了计算和比较,计算结果表明,Lifshitz理论中离子化合物中的多体相互作用项已经被包含在了文中新提出的简单形式的势中,从而证实利用该方法处理"离子"间的势是足够精确的.同时表明,对于离子化合物可忽略多体效应;由晶格动力学给出的范德瓦尔斯相互作用项,同样很好地描述了长程的色散作用.     

CdSe的相互作用势研究

提出了一种用于表征硒化镉(CdSe)性质、形式上类似于玻恩-迈耶模型的相互作用势,并用其研究了由压力引起的CdSe从四近邻的纤维锌矿向六近邻的岩盐矿结构的相变.利用该作用势得出了六配位数碱卤化物晶体的性质,并描述了CdSe的三种晶体结构:纤锌矿(Wurtzite)、闪锌矿(Zinc blende)和岩盐矿(Rocksalt)型结构.相变压强和得出的物态方程与实验数据十分吻合.利用新提出的势中的色散项,计算了Hamaker常数.经计算,CdSe的Hamaker常数为0.388 eV.利用Lifshitz理论和微观尺度理论对多种碱卤化物进行了计算和比较,计算结果表明,Lifshitz理论中离子化合物中的多体相互作用项已经被包含在了文中新提出的简单形式的势中,从而证实利用该方法处理"离子"间的势是足够精确的.同时表明,对于离子化合物可忽略多体效应;由晶格动力学给出的范德瓦尔斯相互作用项,同样很好地描述了长程的色散作用.     

基于势“最大化的纹理分析方法

“势”是吉布期随机场中的重要概念，本文提出了一种基于“势”最大化的纹理分析方法，并通过实验证实了这种方法的有效性。     

用广义势定性分析增强吸收型光双稳

本文从广义势角度对增强吸收型光双稳进行定性分析 ,重点分析了异常开关特性。     

改进人工势场法无人机脱离局部极小值问题

针对现有人工势场法在无人机路径规划应用过程中存在无人机陷入受力平衡,导致目标不可达,且当无人机陷入局部极小值时,该方法无法根据环境信息使无人机脱离力平衡点的问题,提出一种基于自膨胀系数改进的人工势场法。针对无人机陷入局部极小值的问题,建立自膨胀函数;当无人机陷入局部极小值时,针对无人机与目标点的距离为膨胀提供方向。通过改变自膨胀系数增大最近障碍物对无人机产生的斥力从而改变无人机受力形式,解决无人机陷入最优解的问题。仿真实验结果表明,改进后的人工势场法多次改变了无人机陷入最优点的情况,能够解决人工势场法无人机陷入局部极小值无法自主脱离的问题。     

双光镊测量胶体微粒间相互作用势

分析了两个存在相互作用势的胶体微粒的布朗运动,讨论了通过微粒布朗运动的显微观测来测量胶体微粒间相互作用势的实验方法。将双光镊系统与同步斩光器相结合,建立了相应的测量系统。对1μm直径的聚苯乙烯球悬浮液中两个小球之间的静电相互作用势进行了实验研究。实验结果和DLVO(Derjagin-Landau-Verwey-Overbeek)理论符合较好,为DLVO理论提供了直接的微观实验依据。对决定实验精度和效率的一些实验因素,包括测量过程中光镊的开关切换时间、光镊打开和关闭的持续时间、样品离样品池底面高度和实验测量区间划分精度等进行了具体讨论。所建立的实验装置和方法可用于测量不同类型胶体粒子间的相互作用势,这为深入研究决定分散体系宏观性质的微观基础提供了一种有效的手段。     

Longitudinal and transverse waves of the electric field

The importance and features of longitudinal and transverse waves of electric fields in various electric processes and technological applications of these waves are shown. The relationship between longitudinal and transverse waves of electric fields and the relationship between these waves and their sources are theoretically justified.     

Electromagnetic pulse propagation in a weakly nonlinear plasma

An investigation of the propagation of electromagnetic pulses in a weakly nonlinear, cold, collisionless plasma is described. It is found that a transverse electromagnetic pulse generates, through nonlinear effects, a small amplitude, longitudinal electric pulse field. The transient behavior of this longitudinal electric field is studied. One particular case is considered in detail: the nonlinear generation of a longitudinal electric field by a transverse electromagnetic pulse which is excited by a suddenly turned-on cosinusoidal electric field of frequencyomega_{0}. Computer plots of numerical calculations of the second-order transient longitudinal field are presented.     

离子波纹场纵向电场分量对离子波纹激光的影响

通过非线性数值模拟，研究了离子波纹激光（ＩＲＬ）中离子波纹场的纵向电场分量对束－波互作用的影响。结果表明，离子波纹场的纵向分量对ＩＲＬ的工作状况具有较大的影响。其中互作用长度的选择是非常重要的     

场引晶体管理论:Ⅻ.双极飘移扩散电流(薄及厚、纯及不纯基体,单及双MOS栅极)

上篇论文(Ⅺ)报告双极场引晶体管的电化电流理论,这篇论文(Ⅻ)报告飘移扩散理论.两篇都讨论了单栅双栅,纯基不纯基,薄基厚基的情形.两篇都用表面及内部电势作为参变量耦合电压方程和电流方程.在这飘移扩散理论中,有许多电流项,属飘移电流的用迁移率因子标识,属扩散电流的用扩散率因子标识.给出完备飘移扩散解析方程,用以计算四种常用MOS晶体管的直流电流电压特性.飘移电流有四项:一维体电荷漂移项,一维载子空间电荷漂移项,一维横向电场漂移项,二维漂移项.扩散电流有三项:一维体电荷扩散项,一维载子空间电荷扩散项,二维扩散项.现有的晶体管理论都没认识到一维横向电场漂移项.当基区几乎是纯基,这项贡献显著,约总电流的25%.二维项来自纵向电场的纵向梯度,它随德拜长度对沟道长度比率的平方按比例变化.当沟道长度为25nm,几乎纯基时,(LD/L)2=106,杂质浓度1018cm-3时,(LD/L)2=10-2.     

Effect of transverse electric field on the longitudinal current–voltage characteristic of graphene superlattice

The current density induced along the axis of graphene superlattice in the presence of ac and dc electric fields has been calculated. The dc electric field vector is assumed to have both transverse and longitudinal components with respect to the superlattice axis. The constant component of the current density is shown to oscillate with a change in the ac field amplitude. The longitudinal current–voltage characteristic of graphene superlattice contains a portion with negative differential conductivity. The maximum of the longitudinal current–voltage characteristic shifts to larger values of the longitudinal component of dc field with an increase in the transverse component of electric field.     

The Bipolar Field-Effect Transistor: Ⅷ. Longitudinal Gradient of Longitudinal Electric Field (Two-MOS-Gates on Pure-Base)

This paper evaluates the electric current terms from the longitudinal gradient of the longitudinal electric field in Bipolar Field-Effect-Transistors (BiFETs) with a pure base and two MOS gates operating in the unipolar (elec-tron) current mode. These nMOS-BiFETs, known as nMOS-FinFETs, usually have electrically short channels compared with their intrinsic Debye length of about 25 μm at room temperatures. These longitudinal electric current terms are important short-channel current components, which have been neglected in the computation of the long-channel elec-trical characteristics. This paper shows that the long-channel electrical characteristics are substantially modified by the longitudinal electrical current terms when the physical channel length is less than 100 nm.     

The effect of a quantizing electric field on the transverse mobility of electrons in a superlattice

The effect of a quantizing static electric field parallel to the axis of a semiconductor superstructure on the charge-carrier mobility in the direction perpendicular to this axis is studied. The transverse conductivity of charge carriers was calculated on the basis of a quantum-mechanical kinetic equation. Using the results of the numerical analysis, the dependences of the time of the carriers’ momentum relaxation on their transverse energy and also the dependences of the charge-carrier mobility on the strength of the longitudinal quantizing electric field were plotted. It is shown that the dependence of the density of current flowing perpendicularly to the superlattice axis on the strength of the longitudinal electric field is oscillatory.     

TriPle-TEM ceLL的三维场模拟与测试

采别采用理论模拟（FDTD）和实际测量的方法给出了不同频率（30MHz、150MHz）正弦信号激励下TTEM cell横截面的场分布和纵向场分布，理论计算与实测结果基本吻合。所得结论为TTEM cell的几何结构的完善提供了设计依据。也为定性地预测TTEM cell的空间场分布提供了有效手段。     

Electric field dependence of the positions and amplitudes of magnetophonon oscillations in n-InSb at 77 K

The influence of pulsed electric fields on the magnetophonon structure in the transverse and longitudinal magnetoresistance of n-InSb at 77 K has been reexamined using a magnetic field modulation technique. For the transverse configuration, a shift to higher magnetic fields with increasing electric field is observed for the resistance maxima up to N = 8. The amplitudes decrease monotonously and disappear at about 60V/cm for N = 3. In the longitudinal case, the extrema shift to lower magnetic fields as the electric field is increased. In contrast to the transverse case, the amplitudes increase by a factor of 1.8 up to 15V/cm, and then either decrease or become saturated, depending on the harmonic number of the extremum under consideration. These experimental results are discussed within the context of calculations based on a quantum kinetic equation approach and predictions obtained from a simplified analytical theory.     

Nonohmic quasi-2D hopping conductance and the kinetics of its relaxation

The nonohmic properties of a quasi-2D hopping-conductance channel are studied. The channel is formed in a p-Si layer by a field effect in the region where the Fermi level crosses the impurity band. It is shown that the dependence of conductance σ on a longitudinal electric field E has a threshold character and obeys the law lnσ(E) ∝ E^1/2. The dependences of the conductance of the quasi-2D channel on temperature and the electric field are satisfactorily explained using the concepts of nonlinear screening and of nonohmic properties of disordered systems with a random Coulomb potential. This mechanism of nonlinearity is confirmed by specific features of the mesoscopic fluctuations in the off-diagonal component of resistance, which reflect the reconstruction of a percolation cluster under the action of the longitudinal electric field. A long-term relaxation in conductance is observed during transition from a nonohmic to ohmic mode, which indicates that the system exhibits properties corresponding to electronic glass and that the current paths are significantly modified in a strong electric field.