磁盘文件恢复源代码，用来将误删除的磁盘文件恢复的程序-restore disk document source code, to be used for finite disk file recovery procedures

弹塑性力学的方法在解决实际问题上是不能与有限元法相提并论的。所以，...理论只能是解析的，而有限元法只不过是一种现在应用得很成功的技术手段而已-Elastic-plastic mechanics, in solving practical problems are not comparable with the finite element method. Therefore, the ... theory can only be resolved, and the finite element