Solution to Natural Frequency of Longitudinal Vibration for a Nonuniform Nonhomogeneous Bar with Variable Cross Section by Finite Segments Method是什么意思_Solution to Natural Frequency of Longitudinal Vibration for a Nonuniform Nonhomogeneous Bar with Variable Cross Section by Finite Segments Method在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句