一对点电荷电场的MATLAB模拟实验

设计了应用MATLAB对两个点电荷的电场强度和电势进行模拟的实验,对电场和电势的数值进行计算,绘制出相应电场线和等势线的图形。     

两个不等量异种点电荷的等势线

在全日制普通高级中学物理教科书·必修加选修(人民教育出版社,2006年11月第2版)第116页,分别介绍了孤立点电荷、等量异种点电荷和等量同种点电荷的电场线与等势线,并形象、直观地把等势线与等高线进行了对比示意,如图1所示。现行不同版本的高中物理教科书一般不介绍不等量点电荷的电场线与等势线。但是,在2009年普通高考试题中,北京卷和上海卷分别根据不等量异种点电荷的电场线分布(如图2所示)和不等量同种点电荷的等势线分布(如图3所示),考查了静电场中的场强与电势。由图1可知,两个等量异种点电荷在平面中的等势线,对于二者连线的中垂线呈对称分布,且中垂线为零等势线,那么两个不等量异种点电荷的等势线及零等势线的二维分布如何呢?     

The MATLAB Simulation of Plotting the Electric Field Experiment

设计了应用MATLAB对两个点电荷的电场强度和电势进行模拟的实验,对电场和电势的数值进行计算,绘制出相应电场线和等势线的图形。     

如何求解未知电场

一、求解未知大小和方向的匀强电场。1．等势线法。匀强电场的等势线(面)与电场线垂直，且沿电场线方向由电势较高的等势线(面)指向电势较低的线(面)．     

半圆柱壳电容器

利用复数坐标系z上的保角变换,计算半圆柱壳电容器内的电势、场强分布及电容,给出等势线和电场线方程,并绘制出电场线和等势线图。     

电场“三线”问题的解法

带电粒子在电场中运动,电场线、等势线和轨迹线密切相关,“三线”的意义和联系如图1所示．     

窥探电场的窗口——辨两线识电场

电场是存在于电荷周围的一种特殊物质,既看不见,又摸不着,同学们在学习电场的概念时遇到很大困难.电场线与等势线(面)是直观反映电场的两种图象,通过对电场线与等势线(面)这两个概念的学习,可深入理解电场力和电势能两方面的性质,化抽象为形象,两者好比是观察电场的两个"窗口".     

线电荷与带有低脊的接地导体薄圆筒所形成的电场及其数值模拟(上)

通过保角变换研究线电荷带与有低脊接地导体薄圆筒所形成的电场,给出其电势分布函数,并利用数学软件Matlab对场分布进行数值模拟,绘制出电场线和等势线(面)图,实现了电场分布的可视化。为边界复杂的静电场边值问题的求解提供了一种思路与方法,可供电线电缆中相关问题的研究借鉴和参考。     

粒子运动轨迹隐含的信息

根据带电粒子在电场中的运动轨迹,结合电场线和等势线的分布情况,可分析粒子所受电场力、电势能、动能的变化．分析带电粒子在电场中运动的轨迹问题,用到以下知识点：     

电场单元检测题

一、选择题1、关于静电场的说法中正确的是A、带电粒子沿电场线运动,电势能一定要改变;B、匀强电场中,两点间的电势差与两点间的距离成正比;C、正电荷的电势沿电场方向降低,负电荷的电势沿电场线方向升高;D、一点电荷在电场中由口点移动到6,电势能增量为零,则该点电荷一定是沿着等势线移动的。     

Lines of Testimony

The topic of testimony has gained increased prominence in recent years in epistemology, where it is typically taken to refer to the possible acquisition of knowledge through the understanding and acceptance of someone else's judgement. There is no doubt that learning in this way is a prominent feature of education. This conception of testimony contrasts, however, with the more restricted way in which it is commonly understood: everyday usage situates the concept in such contexts as places of worship and courts of law. Testimony in these contexts is likely to be seen by the epistemologist as a special case of testimony in the wider sense, but is this accurate? With reference to contrasting traditions in philosophy and drawing on examples from film and literature, this paper considers the relationship between the epistemological and the everyday senses of testimony, exploring the significance of these matters for questions of teaching and learning as well as for the understanding of language as a whole.     

早春诗行

I heard a thousand blended notes,While in a grove I sate reclined,In that sweet mood when pleasant thoughtsBring sad thoughts to the mind.To her fair works did Nature linkThe human soul that through me ran;And much it grieved my heart to thinkWhat man has…     

Trace Lines for Classification Decisions

Referral, placement, and retention decisions were analyzed using item response theory (IRT) to investigate whether classification decisions could be placed on the latent continuum of ability normally associated with test items. A second question pertained to the existence of classification differential item functioning (DIF) for the various decisions. When the decisions were calibrated, the resulting "item" parameters were similar to those that might be expected from conventional test items. For classification DIF analyses, referral decisions for ethnicity were found to be functioning differently for Whites versus non-Whites. Analyzing decisions represents a new unit of analysis for IRT and represents a powerful methodology that could be applied to a variety of new problem types.