Funding for this research was provided by:
Northeastern University Fundamental Research Grant (N140404017)
Northeastern University Fundamental Research Grant (N110404023)
National Natural Science Foundations of China (60804006)
National Natural Science Foundations of China (61273029)
National Natural Science Foundations of China (61273027)
National Natural Science Foundations of China (61203026)
National Natural Science Foundations of China (61104080)