Привет всем!

I'm working on a translation and have come accross some lovely abbreviations. I have already found several but I have no idea where to begin to find a solution for the following.

в/о союзсортсемовощ
чл.-корр. АН СССР

There's also one phrase I don't know how to translate:

на рационализаторское предложение

Спасибо заранее!