基金This study is supported jointly by the funds for Supporting Project for State Science and Technology (No.2006BAB01B09)the Natural Science Foundation of Yunnan Province (No.99D0003G)+1 种基金the Collaboration Program sponsored by the colleges and universities of Yunnan Province (No. 2002UBBEA05B004)the funds for Program for New Century Excellent Talents in University (No.NCET- 04- 917).