Two amide type double armed crown ethers containing dibenzo 18 crown 6 unit were synthesized and their structures were confirmed by IR, 1HNMR,MS and elemental analysis.是什么意思_Two amide type double armed crown ethers containing dibenzo 18 crown 6 unit were synthesized and their structures were confirmed by IR, 1HNMR,MS and elemental analysis.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句