偏移程序小集成，里面包括F-K偏移，深度偏移等很多有用的源程序。,Small offset integration process, which includes FK migration, depth migration, and many other useful source.

单例模式双重检查机制失效，如何编写正确的单例模式？一文解决(l mamjkshjjdk djdjb dkkd didk dkkd dkkdu d kd fk)