In taking care of the contaminants, a coating of titanium dioxide did in minutes what the environment does in months, says Jimmy Chai-Mei Yu, a chemist at the Chinese University of Hong Kong.

• 香港中文大学的化学家余济美说，用二氧化钛涂敷层对付污染物，几分钟内就可以完成环境得花上几个月的工作。