A visitor watches the exhibits at Tianjin Electric Power Science and Technology Museum in Tianjin, north China, Sept. 28, 2019. The Tianjin Electric Power Science and Technology Museum reopened to the public on Saturday after a half-year long upgrade. The museum displays more than 100 cultural relics and models, and organizes over 40 interactive activities of science popularization. (Xinhua/Li Ran)

A visitor experiences an interactive project of science popularization at Tianjin Electric Power Science and Technology Museum in Tianjin, north China, Sept. 28, 2019. The Tianjin Electric Power Science and Technology Museum reopened to the public on Saturday after a half-year long upgrade. The museum displays more than 100 cultural relics and models, and organizes over 40 interactive activities of science popularization. (Xinhua/Li Ran)

A visitor experiences an interactive project of science popularization at Tianjin Electric Power Science and Technology Museum in Tianjin, north China, Sept. 28, 2019. The Tianjin Electric Power Science and Technology Museum reopened to the public on Saturday after a half-year long upgrade. The museum displays more than 100 cultural relics and models, and organizes over 40 interactive activities of science popularization. (Xinhua/Li Ran)

A visitor watches the exhibits at Tianjin Electric Power Science and Technology Museum in Tianjin, north China, Sept. 28, 2019. The Tianjin Electric Power Science and Technology Museum reopened to the public on Saturday after a half-year long upgrade. The museum displays more than 100 cultural relics and models, and organizes over 40 interactive activities of science popularization. (Xinhua/Li Ran)