Supported by Hong Kong Special Administrative Region(CUHK 4163/03E);Ministry of Science and Technology,The People's Republic of China(International S&T Cooperation Projects 2006DFB73360);National Natural Science Foundation of China(60602043)
Supported by the grant from the Research Grants Council of the Hong Kong Special Administrative Region(CUHK4163 /03E);Hong Kong Innovation and Technology Fund under grant ITS/140 /01