1. Graduate School of Science and Technology, Kobe University, Nada, Kobe 657-8501
2. Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe 657-8501
3. Department of Physics, Keio University School of Medicine, Hiyoshi, Yokohama 223-8521
4. Department of Physics, Faculty of Science, Kobe University, Nada, Kobe 657-8501