基金Supported by the National Natural Science Foundation of China under Grant No.60773212 (国家自然科学基金)the National Research Foundation for the Doctoral Program of the Ministry of Education of China under Grant No.20050497006 (国家教育部博士点基金)+1 种基金the Program for New Century Excellent Talents in University of China under Grant No.NCET-05-0657 (新世纪优秀人才支持计划)the Foundation for Distinguished Young Scientists of Hubei Province of China under Grant No.2006ABB028 (湖北省青年杰出人才基金)