基金
This work was supported by the National Natural Science Foundation of China (NSFC) (61107017, 81301318), the Start-up grant (M4080141.040) from Nanyang Technological University, Tier 1 Academic Research Funds (M4010360.040 RG29/10) from Singapore Ministry of Education and partially from the Singapore Ministry of Education under a Tier 2 Research Grant MOE2010-T2-2-010 (4020020.040 ARC2/11) and the grant from the Shenzhen Basic Research Project (JC201005280391A)