1. Department of Mechanical Engineering; Indiana University-Purdue University Indianapolis; Indianapolis IN 46202 USA
2. College of Chemistry and Chemical Engineering; Anyang Normal University, Anyang; Henan 455000 P.R. China
3. Department of Physics; University of Wisconsin-Eau Claire; Eau Claire WI 54702 USA
4. Department of Chemistry and Biochemistry, Materials Science Institute; University of Oregon; Eugene OR 97403 USA
5. Materials Science and Engineering; University of Wisconsin-Eau Claire; Eau Claire WI 54702 USA