Sodium ethylate was used as catalyst in Baker - Venkataraman of cyclization, and all factors were studied.环合反应采用乙醇钠作为Baker-Venkataraman重排反应的催化剂, 研究了影响反应的各个因素....
今天的理事会会议已经过精心安排，以避免爆出令人难堪的讯息或显示出内部不和的迹象。Today's council sessions have been carefully stage-managed to avoid embarrassing disclosures or signs of internal dissent.打印数据或显示数据中的小写字母及大写字母.Small letters as well as capital...
铰孔是孔的精加工手法之一.Reaming is one of the finish machining methods of hole.铰孔或攻丝时,不要用力过猛, 以免折断铰刀或丝锥.Do not overexert when reaming holes or threading, lest breaking off the reamer or the tap.点位系统适用于钻孔 、 锪 孔、扩孔 、 铰孔 、 镗孔 、 攻丝等孔加工...