sentences:  A doubles specialist on the world circuit, Xie has regularly partnered Guo Zhendong in men's doubles and Zhang Yawen in mixed doubles over the past several years.Xie and Guo have won the Polish International (2004), the China Masters (2005), and the India Open (2008) together.They were quarter-finalists at 2007 BWF World Championships, and at the 2008 Beijing Olympics narrowly lost to the eventual gold medalists, Indonesia's Markis Kido and Hendra Setiawan, in the round of sixteen.