1. College of Materials Science and Engineering; Southwest Petroleum University; ChengDu 610500 People's Republic of China
2. Nanchong Unicizers Chemical Industrial Co, Ltd; No.150 Hexi Ave, Hexi Town, Jialing Dist, Nanchong Sichuan 637000 People's Republic of China
3. Institut für Physik, Universität Rostock; Albert-Einstein-Str. 23-24 18051 Rostock Deutschland