This author has not been identified. Look up 'Li Chen' in GoogleThis author has not been identified. Look up 'Ling Yang' in GoogleThis author has not been identified. Look up 'Juan Du' in GoogleThis author has not been identified. Look up 'Chao Sun' in GoogleThis author has not been identified. Look up 'Shenglei Du' in GoogleThis author has not been identified. Look up 'Haipeng Xi' in Google