This author has not been identified. Look up 'Bingbing Ni' in GoogleThis author has not been identified. Look up 'Mengdi Xu' in GoogleThis author has not been identified. Look up 'Bin Cheng' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Meng Wang' in GoogleThis author has not been identified. Look up 'Shuicheng Yan' in GoogleThis author has not been identified. Look up 'Qi Tian' in Google