This author has not been identified. Look up 'Songbing Wu' in GoogleThis author has not been identified. Look up 'Chun Du' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Hao Chen' in GoogleThis author has not been identified. Look up 'Yingxiao Xu' in GoogleThis author has not been identified. Look up 'Ning Guo' in GoogleThis author has not been identified. Look up 'Ning Jing' in Google