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Analysis of optical impurity of ephedrine levorotatory by capillary electrophoresis .

毛细管电泳法检查左旋麻黄碱中对映异构体杂质的研究。

Machining the levorotatory cylindrical gears by using a right-hand hob .

左旋滚刀加工右旋圆柱齿轮。

Machining the levorotatory cylindrical gears by using a levorotatory hob .

左旋滚刀加工左旋圆柱齿轮。