I am on a 3-year postdoc contract with the NSF-funded Arizona Teacher Initiative of Institute for Mathematics and Education, from 2007 to 2010. During the years from 2002 to 2007, I was a graduate student at the Department of Mathematics, Brandeis University, working with my thesis advisor Ira M. Gessel in the area of algebraic combinatorics and enumerative combinatorics. Before that, I got my Bachelor's degree in mathematics in Nankai University, China.