turning point

The process of disarmament is at a crucial turning point.

裁军正处一个关键转折点。

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

他就任教师工作是他一生转折点。

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处理苯吸时，出现折线形吸等温线，折线转折点正好是单子层吸与多子层吸界点。