1. Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, P. R. China
2. Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan, Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan, Department of Applied Chemistry, National Chiao-Tung University, Hsin-Chu 300, Taiwan, and Department of Chemistry and Biochemistry, Florida International University, 11200 SW Eighth Street, Miami, Florida 33199