Photo taken on Dec. 23, 2019 shows a set of research apparatus in the field of quantum anomalous Hall effect (QAHE) at the National Museum of China, Beijing, China. A total of 8 key scientific research apparatus in the field of QAHE, developed and donated by a QAHE research team of Tsinghua University, was included in the collection of the National Museum of China on Monday. (Xinhua/Jin Liangkuai)