turning point

The process of disarmament is at a crucial turning point.

裁军正处一个转点。

His induction as a teacher was a turning point in his life.

他就任教师工作是他一生转点。

But for benzene, when treated with SDM-A there was a turning point in its adsorption isotherm, which corresponding to the dividing point between monomolecular and multimolecular layer adsorption.

用SDM-A处理苯吸附时，出现形吸附等温，转点正好是单分子层吸附与多分子层吸附分界点。