国家自然科学基金81372065,21313089;广州市科技信息局重大项目201300000091,33115055;广东省自然科学基金S2013010015264;This work was supported by the National Natural Science Foundation of China 81372065,21313089,the Major Program of Guangzhou Science and Technology Information Bureau 201300000091,33115055,and the Natural Science Foundation of Guangdong Province S2013010015264