I dont know if we can even begin to fully understand what is going on with your Wife/your relationship, these are difficult and complex matters and for us to attempt to theorise about mental/medical conditions and treatments is unwise and unsafe.
But lets be very clear....when you arrive at physical violence, then you are a long way down a very slippery slope.
If you cant get your wife to acknowlege a problem and go to see a Doctor about it, maybe you can find some local Counselling Service that has Chinese Counsellors who may be able to begin a process, leading to a more rational approach to acceptance.
After about 5 months in US it is possible that she is in the train-wreck where reality meets unrealistic expectations.....especially from her perspective. Only you can fully understand what may have changed...have you looked deeply at yourself ?, have you continued to behave towards her in your "normal" day to day life as you did when you were courting her in China ? Do you feel that she had genuine expectations of life (prosperity) in US that are not being met ?. Has she become secondary to your daily grind of work, money and all the trivia that gets in the way...as we all know !!
If, on the other hand, she secretly had expectations of her new life that were totally unrealistic, then she will inevietably come to internal conflict at some time...maybe this is the time....how to fix this is impossible to say.....either she deals with the changes, or she doesn't. You cannot be responsible for her expectations UNLESS you led her to believe that her life would be something different to what it now is.
Either which way, it is essential that she gets some help. I regret to say that packing her off to China for a "rest" would not be my preferred strategy...you are putting a band-aid on a Cancer and hoping for a miracle cure !!!
For myself.....if my wife ever got to hit me, it would be a signal that a lot, lot, lot of other things have gone wrong before this....and she would only hit me once !!!...because the single air fare to China would be purchased the same day !!!
You need to deal with this quickly, personally and ultimately be prepared to walk away if all else fails
Just my 2 cents worth