Results 31 to 40 of about 95,142 (166)
一、基本原理 电磁场的数值分析法,可分为两大类:一类是先把待求电磁场问题提成偏微分方程和边界条件组成的定解问题,然后用差分法或有限元法求解;另一类则先用积分方程表示场源和场量之间的关系,再用矩量法或模拟电荷法等计算待求场量。 根据等效场源的观点,可把同一电场看成由单层形式分布的表面电荷或双层形式分布的表面电荷或点电荷、线电荷、面电荷等不同形式电荷分布的某种组合激发的。由于场源分布的不同,联系场量和场源的积分方程也不同。
陆忠亮, 肖衍明
doaj
ABSTRACT Bio‐inspired artificial vision systems have made significant progress, but most focus on photo‐receptors, neglecting the hardware implementation of the efficient downstream neural circuits for complex computations like motion detection. To overcome this bottleneck, we demonstrate a neuromorphic vision system that mimics Drosophila's motion ...
Xianyu Hu +4 more
wiley +1 more source
在TSS计算方法的基础上,考虑了空气分子转动和振动松弛速率与温度场的相互影响,模拟了美国电波衰减飞行试验(RAM C-II)过渡流区的电子密度分布,电场采用Langmuir and Tonks公式计算,比较了考虑电场与不考虑电场情况下对电子数密度分布的影响,同时跟美国电波衰减飞行试验(RAM C-Ⅱ)数据做了比较 ...
张羽淮, 樊菁, 蒋建政
core
中国铁路接触网腕臂绝缘子冬季面临“雪闪”问题,研究多种积雪条件下,对平、斜安装腕臂绝缘子的电场特性影响,为绝缘子选型及优化提供理论依据。以QBG-25型棒式瓷绝缘子为研究对象,建立有限元电场模型,分析温度、积雪厚度、融雪覆冰厚度及污秽类型对绝缘子电场特性的影响。仿真结果表明:当温度低于0℃时,绝缘子电场强度随温度的降低先增大后减小,在-2℃时电场强度达到峰值;积雪厚度对电场强度影响呈现先增长后减小的变化趋势,各个伞裙电场强度与伞裙表面积雪形态有关,表面积雪程度严重但未完全覆盖时,电场强度畸变最严重 ...
李刚, 李彦哲, 李宝学
doaj
ABSTRACT The composition and structural characteristics of metacomposites are crucial for tuning their negative electromagnetic parameters; however, the lack of a clear structure–property relationship severely limits their application in dielectric and magnetic fields.
Chunyuan Deng +9 more
wiley +1 more source
外加电场下垂直腔面发射激光器的偏振转换电流(英文) [PDF]
计算了作用在垂直腔面发射激光器(VCSEL)的上面的分布喇格反射镜(DBR)上的外加电场产生的双折射,并在此基础上通过对自旋反转模型(SFM)的修正 ...
武术 +4 more
core
Wafer‐Scale Amorphous g‐C3N4 With Broadly Tunable Dielectric Properties for 2D Electronics
ABSTRACT Two‐dimensional (2D) semiconductors are regarded as promising candidates for next‐generation electronics due to their superior electrostatic control; however, their performance is severely constrained by the lack of suitable dielectric materials.
Binyin Gao +13 more
wiley +1 more source
利用电池实难方法考察了直通道流场的通道深度、流场细密化、通道宽度以及分配沟宽度等结构参数对128cm^2氢,空PEM电池性能的影响.同时与数学模型的计算结果相比较.二者表现出相同的变化趋势,实验结果表明,在一定范围内,随着流场通道宽度和通道深度的减小、分配沟宽度的增大.电池性能上升 ...
李云峰 +4 more
core
ABSTRACT Improving catalytic activity for volatile organic compounds (VOCs) oxidation and enhancing water‐tolerance stability remain challenging in practical applications. Herein, a composite catalyst integrating Pt/CoOx‐NiOx mesoporous nanorods (MNRs) with a phenyltriethoxysilane (PhTES)‐modified surface was fabricated via a facile route for toluene ...
Jiaqin He +13 more
wiley +1 more source
本实用新型涉及燃料电池的流场结构,具体地说是一种质子交换膜燃料电池流场结构,流场面沿其横向或纵向平均分成n等份,n≥2,每份上的流场由一条折回的螺旋型流道组成。各流道长度相同,气体阻力均匀。流道的进口段与出口段相邻,反应生成的水在水含量不同的相邻流道之间,只有一条脊的距离间隔,电池的进出口部分都有一定湿度的气体通过,整个流场各部分的湿度均匀化,具有自增湿作用。由于流道的折回,温度和气体浓度和气体湿度在整个流场平面得到均衡,有利于提高电池的性能和电池运行的稳定性 ...
燕希强 +4 more
core

