1. Group of Mechanical and Biomedical Engineering, College of Mechanical and Electronic Engineering, Xi’an Polytechnic University, Xi’an, Shaanxi 710048, P. R. China
2. Zhejiang Linix Motor CO., LTD, Hengdian Movie Zone, Dongyang, Zhejiang 322118, P. R. China
3. College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China