Array ( [0] => Array ( [title] => L4A [link] => https://www.youtube.com/embed/p8caVLLxrGQ ) [1] => Array ( [title] => L4B [link] => https://www.youtube.com/embed/RkzqpSJL0Qg ) [2] => Array ( [title] => L4C [link] => https://www.youtube.com/embed/YdR2N6yLmyw ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第4講 crystal symmetry 介紹多種晶體對稱