Obituary

ProfessorⅠra H.Gewolb at Michigan State University,a foreign member of the Editorial Board of our journal,passed away in the United States on October 20,2021,at the age of 71.Professor Gewolb had been a foreign member of the Editorial Board of our journal since its establishment.For more than 20 years,he had been committed to helping the development of our journal,and had made great contributions to the development of our journal.We express our sincere condolences to his death.