旋转带电体磁矩的推广的平行轴定理

The generalized parallel-axes theorem for the magnetic moment of a rotational charged body

首先推导出二阶标量电矩在任意两个平行轴之间的移轴定理(平行轴定理)的最一般的表达形式;再通过旋转带电体的定轴磁矩与其二阶标量电矩的简单比例关系,推导出定轴旋转带电体的磁矩在任意两个平行轴之间的移轴定理的推广形式;再具体讨论了过电荷中心的轴与其平行轴之间的移轴定理,并特别给出了旋转带电体的磁矩的平行轴定理在如下三种特定情形的具体形式:1)总电荷为零,2)电偶极矩为零,3)总电荷与电偶极矩均为零.最后澄清了若干文献中有关平行轴定理的含糊不清之处,并更正其错讹之处.

The most general expression of the axis-translation theorem（parallel-axis theorem）for the 2-order scalar charge moment of a charge system around any two parallel axes is deduced. The generalized axis-translation theorem of the magnetic moment of a rotational charged body around any two parallel axes is derived through the simple proportionate relation between the fixed-axis magnetic moment and the 2-order scalar charge moment for the same charge system. The specific conclusions of axis translation theorem are demonstrated and discussed under three cases：1）the total charge（0-order charge moment）is zero;2）the electric dipole moment（1-order charge moment）is zero;3）both the total charge and electric dipole moment are zero. The ambiguities are clarified and the mistakes in some references are corrected.