Xiao Gang: A mathematician of the era

　　There is a famous inequality on algebraic surfaces that reflects the relationship between the relative invariants of surface fibrosis, this inequality is called Xiao Gang inequality, proposed by Xiao Gang around 1990, and was not promoted to high dimension until 2013 by Professor Xu Chenyang of the International Center for Mathematics at Peking University and his collaborators.

　　Xiao Gang is mainly engaged in the research of algebraic surfaces, and has made outstanding contributions in the fibrosis of algebraic surfaces, high-order exemplary divisors, surface automorphism groups, etc., and is recognized as one of the few genius mathematicians, and is known as prince charming of algebraic geometry by his peers.

　　Born in 1951 in Wuxi, Jiangsu Province, Xiao Gang was the earliest graduate student after China's reform and opening up, and was admitted to the Department of Mathematics of the University of Science and Technology of China with a junior high school degree. In the 1980s, he received his Ph.D. degree from the University of Paris 11 in France by the masters of algebraic geometry Raynaud and Beauville, and was a re-disciple of Grothendieck, the leader of modern algebraic geometry. Xiao Gang then returned to China and taught in the Department of Mathematics of East China Normal University.

　　Despite his outstanding achievements as a returnee doctor, Xiao Gang never made any requests in life, titles, and awards during his teaching at East China Normal University. He was indifferent to fame and fortune, but he took it as his mission to train the first batch of algebraic geometrists in China. Among the master's and doctoral students it has trained, 3 have won the Outstanding Youth Fund, and 2 have become Jiang Scholar Distinguished Professors of the Ministry of Education, gradually forming two bases in the north, algebraic geometry supported by Peking University and the Chinese Academy of Sciences, and east China Normal University in the south. It is no exaggeration to say that Xiao Gang is the pioneer and guide of algebraic geometry in China.

　　Xiao Gang's interests extended not only to algebraic geometry, but also to languages, electronics, computers, and even solar energy. He believes that learning French should memorize 1,000 words a day. He set a record for memorizing 5,000 words in French in two weeks and understanding 70% of the contents of French radio stations, and his French level was greatly appreciated by his French tutors and colleagues. As early as the 1970s, Xiao Gang taught himself radio technology, and assembled radios, televisions, and even invented high-sensitivity transistor meters and pocket transistor oscilloscopes. After October 1992, Xiao gang went to france to teach at the University of Nice, and during his teaching at the University of Nice, he designed the examination and test system, which has been used in France to this day. Xiao Gang has even made great achievements in the field of solar energy, committed to building a cost-effective solar receiver, has written more than 30 pages of teaching materials, designed a projectile cylindrical solar receiver at a cost of about 100 euros per square meter, and even personally built a prototype of about one square meter as a textbook diagram.

　　Xiao Gang has always insisted on "doing more and talking less", which is vividly demonstrated in his academic career. On June 27, 2014, Xiao Gang unfortunately passed away, and the algebraic geometry community at home and abroad was strongly shaken. Although He has left us, his many qualities such as academic excellence, indifference to fame and fortune, pragmatic practice, active cultivation of juniors, and a wide range of hobbies provide a model for future generations of scholars, and are more worthy of learning from contemporary students of basic disciplines.