Three years ago, a Weibo posted by Pan Shiyi brought PM2.5 into the public eye.In the past three years, he has never stopped paying attention to air quality, and has integrated energy conservation and environmental protection, the Internet, and art into SOHO China's projects.The famous director Jia Zhangke created a micro-movie based on Pan Shiyi's Weibo-"Lao Pan's Day and Night".