Scientific Reports 6: Article number: 26879; published online: 27 May 2016; updated: 07 July 2016

The Acknowledgements section in this Article is incomplete.

“This work is continuously supported by the National Natural Science Foundation of China (Grant nos 21171019, 51373023), and the Fundamental Research Funds for the Central Universities and NCET-11-0584.”

should read:

“This work is continuously supported by the National Natural Science Foundation of China (Grant nos 21171019, 51373023, 31271284, 31571235), and the Fundamental Research Funds for the Central Universities and NCET-11-0584.”