Something personal

In my spare time, I enjoy watching videos on solving math puzzles. Here are some excellent examples: MindYourDecisions, 3blue1brown, Michael Penn, Jian Sun, and many others. 

I also like playing Shengji (a variant of bridge).   

A short essay (in Chinese) in celebration of the 10th anniversary of the School of Social Science, Tsinghua University: [Tsinghua news] [pdf]

It outlines how I spent the ten years after my graduation in 2012.