Hu Jintao denounced during the Cultural Revolution, an event that (together with his relatively humble origins) apparently had a deep effect upon Hu, who diligently tried to clear his father's name. He joined the Communist Party of China (CPC) in April 1964 and began to work as an engineer in July 1965 after he graduated from the Water Conservancy Engineering Department at Tsinghua University, where he majored in the study of hub hydropower stations. During his time at Tsinghua, he met his wife Liu Yongqing. In 1968, Hu volunteered for his service in Gansu and worked on the construction of Liujiaxia Hydroelectric
Hu Jintao four times (2008, 2007, 2005 and 2004) on the Time 100 annual list of most influential people. Political observers indicate that Hu distinguished himself from his predecessor in both domestic and foreign policy. Hu's political philosophy during his leadership is summarized by three slogans — a "Harmonious Socialist Society" domestically and "Peaceful Development" internationally, the former aided by the Scientific Development Concept, which seeks integrated sets of solutions to arrays of economic, environmental and social problems, and recognizes, in inner circles, a need for cautious and gradual political reforms. The Scientific Development doctrine has been written into the Communist Party