The BET of Al powder is increased from 1.46 m~2/g to 13.74 m~2/g, after coated with nanometer film.是什么意思_The BET of Al powder is increased from 1.46 m~2/g to 13.74 m~2/g, after coated with nanometer film.在线翻译_英语_读音_用法_例句