1. Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan; Fundamental and Environmental Research Laboratories, NEC Corporation, 34, Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan; and Corporate Planning Department, Nippon Kasei Chemical Co., Ltd., 1-8-8 Shinkawa, Chuoku, Tokyo 104-0033, Japan