Gu Qiyue, staff member from Xinjiang Institute of Ecology and Geography of Chinese Academy of Science, explains science knowledge to the visiting children during the academy's 15th Public Science Day event in Urumqi, northwest China's Xinjiang Uygur Autonomous Region, May 19, 2019. (Xinhua/Wang Fei)

　　Yin Hui, staff from Xinjiang Institute of Ecology and Geography of Chinese Academy of Science, presents Atmospheric particulate sampler to the visiting children during the academy's 15th Public Science Day event in Urumqi, northwest China's Xinjiang Uygur Autonomous Region, May 19, 2019. (Xinhua/Wang Fei)

　　Cao Qiumei, staff member from Xinjiang Institute of Ecology and Geography of Chinese Academy of Science, explains the specimen making method to the visiting children during the academy's 15th Public Science Day event in Urumqi, northwest China's Xinjiang Uygur Autonomous Region, May 19, 2019. (Xinhua/Wang Fei)

　　Chen Haiyan, staff member from Xinjiang Institute of Ecology and Geography of Chinese Academy of Science, explains the working principles of isotope function tester to the visiting children during the academy's 15th Public Science Day event in Urumqi, northwest China's Xinjiang Uygur Autonomous Region, May 19, 2019. (Xinhua/Wang Fei)