1. College of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian, Liaoning 116034, P. R. China
2. College of International Education, Dalian Polytechnic University, Dalian, Liaoning 116034, P. R. China
3. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian, Liaoning 116023, P. R. China