【摘要】 设想一种模型:电流从a点流至b点,且保持恒定,则在a、b分别堆积起等量异号之电荷,此时空间各点的电场在变化,而磁场则稳定。于是从Biot-Savart定律可导出: 任何场都可认为是有源无旋场(纵场)和有旋无源场(横场)的迭加。对应于可变有源无旋电场的位移电流不激发磁场。电磁波的激发和传播取决于有旋无源电场的位移电流。我们通常所说的电容器中的位移电流就是对应于可变有源无旋电场的位移电流。若把电场和磁场都可变的普遍情况下的Maxwell方程作为此模型 (1) 式的自然推广,则不必引进位移电流的概念。最后,文中论述了电磁场理论的逻辑结构。更多还原

【Abstract】 Assume a model to be that the current flows from point a to point b and keeps constant, so the charges with same quantities and opposite signature will pile up at a and b respectively and under this condition, the electric fields of various points in the space are changing, while magnitic field keeps stationary. Thereupon, from Biot—Savart law, we can derive the equation Any field can be considered as the superpositon of an irrotational field (longitudinal field) and a solenoidal field (transverse field). The displacement current corresponding to a variable irrotational electric field does not excite any magnetic field. Therefore, the excitation and propagation of electromagnetic wave is based on the displacement current corresponding to the variable solenoidal electric field. The displacement currents in capacitors, which are of common speaking, correspond to the irrotational electric field. If we assume that Maxwell’s equation that is tenable under thc common condition, in which both electric and magnetic field are changeable, can be seemed to be the natural generalization of the equation (1) of this model, then it is not necessary to introduce the conception of the displacement current. Finally, the logical structure of the theory of the electromagnetic field was discussed in this paper.更多还原