(一)关于变形的几何条件 诚如原文在导得其式(3)后所述,由于在式(3)中有二个未知量,需再另外找出一个独立方程式才能解。这个方程式是通过变形的几何条件得到的。 原文以其图5(本文图1)为基础导得了其式(4),即变形的几何条件。 笔者基本上同意原文的上述出发点。但原文对 (a) Geometrical conditions of deformation As stated in the original text after the expression (3), since there are two unknowns in equation (3), it is necessary to find another independent equation to solve it. This equation is derived from the deformed geometry. The original text is based on its figure 5 (Fig. 1 in this article), which leads to its formula (4), that is, the geometric conditions of deformation. The author basically agrees with the above starting point of the original text. But the original pair