作者机构:[1]Beijing City Key Lab of Medical Physics and Engineering, Peking University, Beijing 100871, China, [2]China National Digital Switching System Engineering and Technological Research Center, Zhengzhou 450002, China
相关基金:Project supported by the National Natural Science Foundation of China (Grant Nos. 60672104 and 10527003), the National Basic Research Program of China (Grant No. 2006CB705705) and the Joint Research Foundation of Beijing Education Committee, China (Grant No. JD100010607).