1. College of SciencesChongqing University of Posts and Telecommunications Chongqing 400065 People's Republic of China
2. Vinča Institute of Nuclear SciencesUniversity of Belgrade, P.O. Box 522 Belgrade 11001 Serbia
3. MOE Key Laboratory of Bioinorganic and Synthetic ChemistrySchool of ChemistrySun Yat-Sen University Guangzhou 510275, People's Republic of China
4. Institute of PhysicsUniversity of Tartu, W. Ostwald Str. 1 Tartu 50411 Estonia
5. Institute of PhysicsJan Długosz University, Armii Krajowej 13/15 PL-42200 Częstochowa Poland
6. GE Global ResearchOne Research Circle, Niskayuna New York 12309 USA