Seems to me that there are three general ways of handling it:
1. This occurs on something that is the real world, but with the wizard inserted into it. There is no magic or planes or incorporality or way to trump physics by staying alive at thousands of degrees celsius. The wizard (who would still be a pf wizard despite not being able to use his magic) loses.
2. This occurs on something that is basically the DnD world (or the real world made to function by DnD rules), with the chinese inserted into it. The Chinese' understanding of the way the world functions is wrong and their weapons don't have the effects they ordinarily would. The Chinese have no opportunity to learn how to function on this world or to interact (resist or control) the new concepts therein. The Chinese lose.
3. This occurs on a hypothetical world where DnD concepts such as magic, planes and incorporality exist and are known to exist. Both sides have the opportunity to adapt to the altered surroundings. For example, if the rules of this world are that nuclear radiation effect incorporeals the wizard would probably know this and would not rely on incorporeality to avoid nuclear blasts, it may even research a resist radiation type spell. The Chinese would not employ magic themselves (that going against the core concept here) but may develop technological solutions to deal with some of the new concepts this world entails - maybe a technological way to change planes.
It seems to me that the first and second are like the shark and bear fight in deep water or on land. In either case the result is obvious because the environment stacks the deck. The third is far from perfect (what happens when physics conflicts with magic?, what tech solutions would the chinese have is they existed in the alternative world?) but it seems to be to be the only scenario where both parties have the opportunity to bring their power to bear on the other in any meaningful way. Maybe analogous to the shark vs bear in shallow water.
The original poster has clarified that he was thinking of the second scenario, or a variation thereof. That's fine, it's his thread. But in that case I think the answer is obvious.