1. College of Resource and Environment Science, Chongqing University, Chongqing 400044, China;
2. AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
3. e-mail: AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China;
4. Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
5. College of Resource and Environment Science, Chongqing University, Chongqing 400044, China