There is a few sources on Jane
Where it cited the missile has been spotted many times on Chinese aircraft.
As for Russian missile complex are ahead, you can say the same for everything else for Russia... 20 years ago, the whole point of this discussion is saying that China is moving ahead, and they have indeed officially received Kh-31 in 1997, but chances are they have receive the technology much earlier than that, so it gives them plenty of time to work on it.
And lastly, Kh-31 is the last ramjet missile of smaller size being produced in USSR/Russia, they have not come up with another new ramjet missile since that. Correct me if I'm wrong on this.
Janes also cited a 140mm armed Chinese tank... 10 years ago. Surprisingly, Jane's reliability when it comes to Chinese weapons is between 'non-existent' and 'nil'. If you seriously think it exists, shouldn't be hard to show us a single photo of this YJ-12.
And I don't know why you are focusing on ramjet missile of small size, either, given that the discussion is on AShM in general.