Effects of derivation time, extraction time and amount of derivation agent on the recovery were discussed.

对样品的衍生化反应时间、萃取时间和衍生化试剂用量对回收率的影响进行了详细的讨论。

youdao

I will try to finish every lecture on time, but sometimes if I'm in the middle of a sentence or the middle of a derivation, I may have to go over by a couple of minutes; there's no need to shuffle your feet and move stuff around.

我会尽量准时下课的,但是有时候如果我正在讲解一个概念,或者正在推导一个公式,我会稍微多讲几分钟,你们不用来回蹭脚,收拾东西什么的

耶鲁公开课 - 基础物理课程节选

There is good news, though, because the approaching holiday season is exactly the right time for the wearing of black in every derivation.

WSJ: Tina Gaudoin on Style: Back to Black