Mr.adrian, you and your friend in China should organize the required documents together:
you can prepare the following documents:
One completed visa application form, one recent passport-size photo, your passport with at least 6 months remaining validity and at least two blank visa pages, round-trip flight ticket, copy of Russian student visa.

your friend should send the below 2 documents to you:
1. invitation letter from him
2. copy of his residence permit and his passport.