9.2.4 Some basic formal characters of wave equation

In order to as far as possible avoid any confusion caused by a few easily intuitivelyaccepted concepts,or only try to reveal other most essential things usually unconsciouslyneglected or forgotten by us,it would be worth for us to use formal languages to ......（本文共 15482 字 , 9 张图）     [阅读本文] >>