1. Hokkaido University Catalysis Research Center, Kitaku Sapporo 060, Japan
2. Hakodate National College of Technology Tokuracho Hakodate 042, Japan
3. Hokkaido University Faculty of Engineering, Kitaku Sapporo 060, Japan
4. Hokkaido University School of Dentistry, Kitaku Sapporo 060, Japan
5. Hokkaido National Industrial Research Institute Toyohiraku Sapporo 062, Japan