Excuse me, which calligrapher's seal is this?

Tian Zhizhen is a native of Yunxian County, Hubei Province. Retired senior teacher of Wuhan primary school, member of Hubei Calligraphers Association, member of Hubei Couplet Association, member of China Bangshu Art Research Association, director of Shaoshan Mao Zedong Calligraphy Art Research Association, member of Hubei Old People Calligraphy Research Association, and member of Hubei Mao Zedong Calligraphy Art Research Association. His works won the Excellent Works Award in the 3rd China Book List Competition to celebrate the 60th anniversary of the founding of the People's Republic of China, the third prize in the brush group of primary and secondary school teachers in the 6th National Teachers' Calligraphy Competition, the Silver Award in the National Calligraphy and Painting Competition to celebrate the 70th anniversary of the Long March, and the Excellent Works Award in the 1st National Calligraphy and Painting Competition of Shaoshan Mao Zedong Art Museum, which was permanently treasured by Shaoshan Municipal People's Government. He won the Bronze Award in the first China Hairstyle Calligraphy Competition, the Excellence Award in the Wuhan Excellent Calligraphy Exhibition to celebrate the 55th anniversary of the founding of the People's Republic of China, the Gold Award in the National Advanced Calligraphy Competition such as Sunset Red, and the second prize in the 4th China Calligraphy Exhibition. His works were selected in China's "Sunset Red" and many other calligraphy competitions for the elderly.