国家重点基础研究发展(973)规划项目(No.2002CB513107);国家自然科学基金项目(No.30528012);海南省教育厅高校科研基金项目(No.HjKj200747);Supported by the Major State Basic Research Development Program of China(No.2002CB513107);National Natural Science Foundation of China(No.30528012);the Research Fund of Higher Education of Hainan Ministry of Education(No.Hjkj200747)