1. National Research Center of Pumps & Pumping System Engineering & Technology, Jiangsu University, Zhenjiang 212013, China; Department of Mechanical Engineering & Materials Science, Washington University in St. Louis, St. Louis, MO 63130 e-mail:
2. e-mail:
3. National Research Center of Pumps & Pumping System Engineering & Technology, Jiangsu University, Zhenjiang 212013, China
4. Department of Mechanical Engineering & Materials Science, Washington University in St. Louis, St. Louis, MO 63130