旋转带电体的磁矩二次曲面及其零磁矩条件

旋转带电体的磁矩二次曲面及其零磁矩条件 Magnetic Moment Quadric of Rotational Charged Body and Its Condition of Zero Magnetic Moment 周国全 ZHOU Guoquan 1 first-author 武汉大学物理科学与技术学院,湖北,武汉,430072 武汉大学物理科学与技术学院,湖北,武汉,430072 School of Physics and Technology, Wuhan University School of Physics and Technology, Wuhan University 基于带电体的一个不同于电四极矩的电矩张量的性质,引入了标量电矩二次曲面及电矩主轴的概念,根据标量电矩与旋转带电体的磁矩之间的线性关系,运用二次曲面的解析理论,得到了旋转带电体的磁矩二次曲面分布律的分类判别关系式,推导出任意旋转带电体的零磁矩条件.理论分析的结果表明在磁矩二次曲面中任意一条通过原点O的渐近线都代表着一个导致零磁矩的转轴方向. Based on the property of the electrical moment tensor （which is different from the existent electric multiple moment） of a charged body, new concepts such as principal axes, principal-axis scalar charge moment and charge moment quadric are proposed in this paper. According to the linear relationship between the scalar charge moment and the magnetic moment of a rotational charged body, by means of analytic spatial geometry, the criterion formulae determining the correspondence relationship between quadric distributive laws of magnetic moment and the parameters of tensor are obtained and classified in detail in a table. The condition of zero magnetic moment for an arbitrary rotational body with given charge distribution has been derived. We conclude that any rotation axis which passes through origin O and along with any asymptotic line of the quadric （hyperboloids or hyperbolic cylinders, etc.） can lead to a vanishing magnetic moment. 磁矩 电矩张量 磁矩二次曲面 主轴 magnetic moment charge moment tensor magnetic moment quadric principal axis O441 国家自然科学基金资助项目（10775105） 2008-01-01 2021-04-01 1