1. Department of Chemistry, Keio University, Hiyoshi, Kohoku-ku, Yokohama 223-8522,
Japan
2. Hitachi Research
Laboratory, Hitachi, Ltd., 832-2 Horiguchi,
Hitachinaka, Ibaraki
312-0034, Japan
3. Hitachi Plant Technologies, Ltd., 603 Kandatsu-machi, Tsuchiura, Ibaraki 300-0013,
Japan