supported by National Natural Science Foundation of China(11231005,11226251);Doctoral Program Foundation of the Ministry of Education of China(20110076110004);"the Fundamental Research Funds for the Central Universities"
Supported by the Natural Science Foundation of Tianjin(08JCYBJC02200);the Natural Science Foundation of China(10871102);National Basic Research Program of China(973 Program) (2007CB814905)