1. Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
2. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, United States
3. Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
4. State Key
Laboratory
for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China