国际固态离子学会前主席Osamu Yamamoto（山本治）

　　I am grieved over Prof. Guo’s death. He is my most important friend. I have met him at least one time each year for 30 years. I have a long history with Prof. Guo. I met him more than 30 years ago, when I visited Shanghai Institute of Ceramics to disuse with the late Prof. Zuxiang Lin. She was working on solid electrolyte of βAl₂O₃ and Na/S batteries using βAl₂O₃. She is pioneer in the Na/S batteries and presented interesting results. My research field is solid electrolyte and its application on batteries. I had a good discussion with her group’s researchers. At that time, Prof. Guo was the director of the Institute. Prof. Lin introduced me to Prof. Guo. The research field of Prof. Guo is a little bit far from my topic. After I met Prof. Guo on my visit of the institute, many researchers of Shanghai Institute of Ceramic had stayed at Mie University for one or more years and presented many excellent papers with me. The post doctors of Mie University from China were given positions in the institute by a recommendation of Prof. Guo. I was nominated as the visiting professor of Shanghai Institute of Ceramic by Prof. Guo according to the close relation between me and the institute. It is quite honorable for me to be a visiting professor of the distinguished institute of China.

　　I do not well recognize Prof. Guo’s scientific activity, because my research topic is different from his one. My old friend, the late Prof. P. Hagenmuller of the previous director of Institute of Solid State Chemistry, CNRS, at Bordeaux, France, whose research topic is more closed to Prof. Guo, said frequently to me that the scientific activity of Prof. Guo is very high. Prof. Hagenmuller had stayed at Shanghai in every Christmas seasons for about one week. He was also a good friend of Prof. Guo.

　　I visited many places in China such as Dunhuang and Kunming and several times at Hangzhou and Suzhou with Prof. Guo. During the stay at Dunhuang, my daughter took an ill. I decided to come back to Japan soon, but I could not find a flight. Prof. Guo arranged everything for us. We took a train from Dunhuang to Chengdu and then to Japan by flight. We come back to Japan without trouble by the good arrangement of Prof. Guo. We sincerely thank Prof. Guo and his wife. Prof. Guo is quit gentle and have many hobbies such as panting. In my room at home, I look every day at a painting of Prof. Guo and I standing at the coast of West Lake, which was painted from a photo of us at West Lake. It is a good memory for me. I will be with Prof. Guo.

　　I do hope Prof. Guo passes away peacefully.

August 20, 2021

Osamu Yamamoto

Professor Emeritus Mie University