3．2用变分法解析二元场的方法用有限元素法解析电磁场时，如2．2节所述，必须建立如（2．6）式那样的全体节点方程式。现在叙述用变分法解析线性二元场的有关步骤。对非线性场的解析在7．1节中叙述。3．2．1能量的偏微分如前所述，在有限元素法中，求解（1．42）式结出的泊极 3.2 Method of Analyzing Binary Fields by Variational Method When analyzing the electromagnetic field by the finite element method, as in Section 2.2, we must establish the equation of the whole node like (2.6). Described now with variational analytical linear binary field related steps. The analysis of nonlinear fields is described in Section 7.1. 3.2.1 Partial Differentiation of Energy As mentioned above, in the finite element method, the solution of the (1.42)