Cheng Guangxu (L), vice president of Xi'an Jiaotong University, presents the certificate of Honorary Professor to Nobel laureate Martin J. Evans at Xi'an Jiaotong University in Xi'an, capital of northwest China's Shaanxi Province, April 26, 2012. Evans won 2007 Nobel Prize in Physiology or Medicine. [Photo:Xinhua]

Nobel laureate David J. Gross delivers a speech at Xi'an Jiaotong University in Xi'an, capital of northwest China's Shaanxi Province, April 26, 2012. Gross, who won the 2004 Nobel Prize in Physics, was appointed the Honorary Professor of Xi'an Jiaotong University on Thursday. [Photo:Xinhua]