1. MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical University Xi'an 710072 P. R. China
2. College of Physics and Optoelectronic EngineeringShenzhen University Shenzhen 518060 P. R. China
3. Mechanical and Construction Engineering Faculty of Engineering and EnvironmentUniversity of Northumbria Newcastle upon Tyne NE1 8ST UK