1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
2. State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, P. R. China
3. University of the Chinese Academy of Sciences, Beijing 100049, P. R. China
4. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, P. R. China