Scientific Reports 7: Article number: 38706; published online: 31 January 2017; updated: 14 March 2017

The Acknowledgements section in this Article was omitted. The Acknowledgements should read: “This work was supported by the National 863 Hi-tech Project (2015AA033703), National Natural Science Foundation of China (NO. 81601882, NO. 81572108) and Specialized Research Fund for the Doctoral Program of Higher Education (NO. 20120071110067)”.