Array ( [0] => Array ( [title] => L49A [link] => https://www.youtube.com/embed/gAHVFSkIKHU ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第49講|Lecture 9 Electromagnetic Waves|9_4B 9_4_3 The Frequency Dependence of Permittivity