国家自然科学基金项目.30500325,30771400;国家"863"计划项目N0.2007AA10Z430.霍英东教育基金会高等院校青年教师基金项目111032;福建省高校新世纪优秀人才支持计划资助 Supported by the National Natural Sciences Fundation ofChina.30500325,30771400;the National Hightech R & D Program of China"863"Program 2007AA10Z430;the Fok Ying Tong Education Foundation111032;the New Century Excellent Talents in Universities of Fujian,China