Shopping malls in Heze in Shandong, Hulunbuir in Inner Mongolia and Hefei in Anhui took down expensive commercial ads and put up giant public-service posters honouring scientists such as Qian Xuesen, Deng Jiaxian, Qian Sanqiang and Guo Yonghuai. Zhengzhou, Nanchang and Xiangyang soon followed, with outdoor screens rotating the portraits and giving these figures the city's centre stage. In fact, in Zhengzhou, the busiest, most visible metro advertising slots were set aside for researchers. And ever since, the trend has reached Hangzhou.