基金Supported by National Basic Research Program of China (973 Program) (2007CB814904), National Natural Science Foundation of China (10671112, 10701050), and Natural Science Foundation of Shandong Province (Z2006A01)
基金Supported by the Key Science and Technology Project of Ministry of Education(207407) NSF of Anhui Educational Bureau(2006kj251B)the Special Project Grants of AnhuiNormal University (2006xzx08)