基金National Natural Science Foundation of P. R. China (60084002 and 60174018) National Key Project for Basic Research of P. R. China ( G2002cb312205) +1 种基金 National Excellent Doctoral Dissertation Foundation of P. R.China (200041) and National Natural Sci
基金This work was supported by the National Natural Science Foundation (No.10261001) and the Guangxi Province Natural Science Foundation (No.0236001,0249003) of China.