The purpose is to make an easy-to-understand note of "Special Topics in Finite Element Methods." There might be typos and mistakes. Therefore, I do not take any responsibility for unauthorised use.

翻译：本文旨在为“有限元方法专题”课程撰写一份易于理解的笔记。文中可能存在拼写错误或疏漏，因此本人对未经授权的使用不承担任何责任。