1. School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, P. R. China
2. Research Institute for Structure Technology of Advanced Equipment, Hebei University of Technology, Tianjin 300401, P. R. China
3. School of Economics and Management, Tianjin University of Science and Technology, Tianjin 300222, P. R. China
4. Key Laboratory for Micro/Nano Technology and Systems of Liaoning Province, Dalian University of Technology, Dalian, Liaoning 116024, P. R. China