1. Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, Department of Environmental Conservation and Development, Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan, and Unisoku Co. Ltd., 2-4-3 Kasugano, Hirakata 573-0131, Japan