When it is curved, the law of its curvature seems to be at the least of the first and at the most of the second order.
当它是曲线的时候，其弯曲的法则看起来至少是一阶至多是二阶。
2
The curvature is the second order derivative of displacement. Also, it has a liner relationship with stain.
曲率又是位移的二阶导数，同时曲率又与应变存在着一一对应关系。
3
Through the analysis and test of original serial program system, curvature computing and first difference, second difference etc. are defined as key objects.