Chinese President Xi Jinping (C) visits Imperial College London, in London, Britain, Oct. 21, 2015. (Xinhua/Yao Dawei)

Chinese President Xi Jinping (R, front) visits Imperial College London, in London, Britain, Oct. 21, 2015. (Xinhua/Yao Dawei)

Chinese President Xi Jinping (R, front) visits Imperial College London, in London, Britain, Oct. 21, 2015. (Xinhua/Xie Huanchi)

Chinese President Xi Jinping (R, front) talks with a faculty member during his visit to Imperial College London, in London, Britain, Oct. 21, 2015. (Xinhua/Xie Huanchi)

Combination photo shows Chinese President Xi Jinping (L) waving hands to people during his visit to Imperial College London, in London, Britain, Oct. 21, 2015. (Xinhua/Xie Huanchi)