Hello. Recently I am studing the biochemical_MD12 module of the SCOPE model, and in the function MD12, it writes" fs1 = ps * (kf/kps) / (1- Ja/Jms)".

This equation makes me confused. I can understand it if it goes like "fs1 = ps * (kf/kps) /(Ja/Jms)", but why should it be devided by (1- Ja/Jms)?

In addition, how to understand the equations for the "PSII fluorescence yield under light-limited conditions"?

Is there anyone who can help me？ Thanks.