XI’AN, China — In the heart of one of China’s famed dynastic capitals, now a modern metropolis of eight million, Li Jianli lay partially paralyzed on a hospital bed with his skull smashed in and his speaking ability reduced to a few simple phrases — “yes,” “thank you” and so on. Only recently has Mr. Li begun to regain his ability to move and talk. The recovery has been slow and painful and tenuou