1. Department
of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
2. Key
Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and
Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
3. University of Chinese Academy of Sciences, Beijing 100049, China
4. Departments
of Chemistry and Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
5. Department
of Physics and Astronomy, University of Pittsburgh, Pittsburgh Pennsylvania 15260, United States