教学课程资源库 更多>>

关键词： 磁控电抗器(MCR)   磁阀   Ansoft   电磁场   仿真  

摘要： 电力系统中的三相磁控电抗器都采用每个铁芯柱加磁阀的三相六柱式磁控电抗器,这种电抗器的铁芯柱磁阀加工过程复杂,并且运行中噪音较大,为了克服这种缺陷,提出了一种新型三相磁控电抗器.使用电磁场分析软件Ansoft对该新型磁控电抗器模型进行了仿真,得到了其工作状况的一些仿真数据和结果.仿真分析结果验证了通过调节晶闸管的触发角可以平滑地调节电抗器的电抗的特性,同时也对该三相磁控电抗器的电磁场分布情况进行了仿真分析.

关键词： 莲房原花青素   极低频电磁场   星形胶质细胞   预防作用  

摘要： 目的:研究极低频电磁场(extremely low frequency electromagnetic fields,ELF-EMF)对星形胶质细胞的氧化损伤及莲房原花青素(procyanidins from lotus seedpod,LSPC)的预防作用。方法:以原代培养的SD大鼠星形胶质细胞建立ELF-EMF损伤模型,检测经LSPC预处理前后的细胞生存率、星形胶质细胞内活性氧(Reactive oxygen species,ROS)、超氧化物歧化酶(Super oxide dismutase,SOD)、丙二醛(MDA)和Ca2+含量。结果:辐射模型组的细胞生存率为54.38%,极显著下降(与正常对照组相比,p<0.01);经5、10、20μg/mLLSPC预处理后,细胞生存率分别为65.09%、75.34%和90.78%,显著上升(与辐射模型组相比,p<0.05);ELF-EMF引起细胞内SOD活力下降,MDA、ROS和Ca2+含量上升,经5、10、20μg/mLLSPC预处理,能有效阻止SOD活力下降并显著抑制MDA、ROS和Ca2+含量的上升(与辐射模型组相比,p<0.05)。结论:LSPC对ELF-EMF导致的星形胶质细胞氧化损伤有明显的预防作用。

关键词： 《电磁场与电磁波》   教学改革   教学方法  

摘要： 《电磁场与电磁波》课程是电子信息类本科专业的重要专业基础课程,但教学中普遍出现难教、难学的问题。为此,我们从教材体系、教学内容、教学方法与手段、考核方式等方面在教学过程中进行了一些改革,取得了较好的教学效果。

关键词： 离子液体   电磁场   洛伦磁力   流速  

摘要： 室温离子液体是新兴的绿色环保材料,具有液态温度范围广、不易挥发、良好的导电性和导光性等优点,是微流控技术和光电子器件中良好的流体介质。近年来,温室离子液体在能源设备、光电子、微流控光器件等领域应用蓬勃开展。离子液体的驱动是微流控光学应用中的一项新技术。提出了一种电磁驱动离子液体的方法,无需机械移动装置,可双向驱动,稳定性好。通过设计实验测量出了电磁场对离子液体的驱动速度并与理论值相比较。

关键词： Fe3O4   微波加热   电磁场   数值模拟  

摘要： 采用FDTD方法,利用C语言编写电磁场和温度场耦合程序,对微波单模腔中加热的Fe3O4的电磁场、温度场的变化进行数值模拟.结果显示,在Fe3O4微波加热过程中,电场强度逐渐减小,而磁场强度逐渐增大;磁损耗功率远大于电损耗功率,因此总的损耗功率和磁损耗功率随时间的变化趋势一致,说明在Fe3O4微波加热过程中磁损耗起主要作用;而Fe3O4微波加热升温的模拟值与实验值的变化趋势相符.

关键词： Maple   带电粒子   正交电磁场   运动轨迹  

摘要： 通过对带电粒子在正交匀强电磁场中运动轨迹的求解，介绍了Maple在中学物理教学中的运用．并且利用Maple软件绘制了带电粒子在此正交场中的运动轨迹．

关键词： 微波炉   演示实验   趣味   电磁波理论   物理实验   电磁场  

摘要： 本文介绍了用微波炉开展的8则趣味探究物理实验，目的是加深对电磁场与电磁波理论的认识和理解。

关键词： Electromagnetic fields  

摘要： In this paper, the problems of calculating and solution about electromagnetic fields were studied. In the circumstances of the static electromagnetic field that is limited and differentiable on a symmetric axis, it provides a new theory and technique and method on measurement axial symmetric and passive and static electromagnetic field by making use of the Maxwell's equations and calculus. Out-of-axis electromagnetic field can be transformed into series by means of the method. The series include the electromagnetic field on the symmetric axis and its all order derivative. Applying the method is very easy, quick and exact to perform numerical calculation. For the authors provide series form, we need to prove that it meets the Maxwell's equations. This paper provided the strict proof by means of series and calculus operation. Therefore, the theory, method and results given by this paper are not only certain theoretical meaning, but also quite great-applied value. © 2013 by Binary Information Press.

关键词： La-Sr-Mn-Cu perovskite   Magnetic hyperthermia   Curie temperature   Temperature control   Sphere  

摘要： La0.666Sr0.373Mn0.943Cu0.018O3 spheres (average diameter: 2.4 mm) were used as magnetic hyperthermia mediators. They were prepared by the polymerized complex method and alginate gelation. A starch paste containing nine such spheres (0.1034 g) was maintained at a constant temperature when it was exposed to an alternating current magnetic field (frequency: 1 MHz;magnetic field strength: 20-55 Oe-rms). After exposure to a magnetic field with a field strength of 55 Oe-rms for 60 min, a temperature of T-60 = 73.5 degrees C was obtained. T-60 for field strengths of 40 and 55 Oe-rms differed by only 2.6 degrees C. La0.666Sr0.373Mn0.943Cu0.018O3 spheres satisfy the following important requirements for heating mediators: their amount can be controlled in tumors, their temperature can be controlled without monitoring, and their heating ability is independent of the field strength and direction. Thus, La0.666Sr0.373Mn0.943Cu0.018O3 spheres are promising heating mediators for inducing magnetic hyperthermia. (C) 2012 Elsevier B.V. All rights reserved.

关键词： Coupling   Electromagnetic field (EMF)   Twisted conducting line   Transmission line (TL)   Baum-Liu-Tesche (BLT) equation   Chain matrix   Multi-conductor transmission line (MTL)  

摘要： In the current paper, we propose a new modeling algorithm to analyze the coupling between an incident electromagnetic field (EMF) and a twisted conducting line, which is a kind of non-uniform line. Typically, analysis of external field coupling to a uniform transmission line (TL) is implemented by the Baum-Liu-Tesche (BLT) equation so that the induced load responses can be obtained. However, it is difficult to apply this method to the analysis of a twisted conducting line. To overcome this limitation, we used a chain matrix composed of ABCD parameters. The proposed algorithm expands the dimension of the previous chain matrix to consider the EMF coupling effectiveness of each twisted pair, which is then applied to multi-conductor transmission line (MTL) theory. In addition, we included a comparative study that involves the results of each method applied in the conventional BLT equation and new proposed algorithm in the uniform two-wire TL case to verify the proposed method.