Export to BibTeX (Chinese characters)

I'm using the newest zotero 1.5-sync3.5 and it works perfect in firefox, but I encountered a problem when I tried to export the entries containing Chinese characters to BibTex. No matter what export encoding I chose(UTF-8, GB18030, GB23112, GBK……), I just got a lot of question marks instead of Chinese characters like this:
@article{_sip_2008,
title = {{??????SIP} {DoS?????????}},
volume = {20},
number = {4},
journal = {??????????????},
author = {??},
year = {2008}
}

How can export them correctly? I've read this thread, but I still don't know whether it's possible to export Chinese.

Thanks for your help!

This is an old discussion that has not been active in a long time. Instead of commenting here, you should start a new discussion. If you think the content of this discussion is still relevant, you can link to it from your new discussion.