1. University of Arkansas,Dept. Materials Science and Engineering,Fayetteville,USA
2. University of Arkansas,Dept. Physics,Fayetteville,USA
3. University of Arkansas,Physics,Fayetteville,USA
4. University of Arkansas,Dept. Institute for Nanoscience and Engineering,Fayetteville,USA
5. University of Arkansas,Dept. Mechanical Engineering,Fayetteville,USA