This author has not been identified. Look up 'Qi-dong Liu' in GoogleThis author has not been identified. Look up 'Cheng Long' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Jie Zhang' in GoogleThis author has not been identified. Look up 'Mingliang Xu' in GoogleThis author has not been identified. Look up 'Pei Lv' in Google