The answer is yes for both Mobile and Unicom, but my understanding is that only handsets which support TD-LTE (odds are high that yours DOES not) work. See here for example:

http://www.techinasia.com/china-unicom-rolls-out-4g/

This, and the fact that TD-LTE is brand new, helps explain why penetration is so low (e.g. check out the comparative numbers in the following article):

http://www.bloomberg.com/news/2014-0...into-text.html