I got admission in post doctor,if i will get visit visa, can i convert it in study visa in china

I got admission in post doctorate for 1 year scholarship, but I need to get study visa by myself because due to university policy they could not issue visa application form for post doctorate, so they want me to solve this visa issue by myself. what i do?i have admission letter and invitaion letter by international student office. My wife also studying in the same university.which visa is suitable for me?