President Xi Jinping awards medals and certificates to the recipients of the Order of August 1 – the latest and highest military decoration – at the Bayi Building in Beijing in July 2017. (Photo: Xinhua)

On Wednesday, President Xi Jinping highlighted efforts to build China's scientific and technological self-reliance, and enhance cultural confidence. In his reply letter to young Nanjing University-based scholars returning from overseas study, Xi mentioned two scientists: Li Siguang and Cheng Kaijia.

Cheng (1918-2018) was a nuclear physicist devoted to nuclear weapons research and testing for almost 60 years. After he obtained a doctoral degree overseas, Cheng returned to China in the 1950s and in 1960 began to research nuclear weapons. He planned China's first original and precise nuclear weapon test. Cheng is one of China's most respected scientists and made pioneering contributions to nuclear experiments and satellite development.

He was also one of the scientists awarded the Two Bombs and One Satellite Merit Award in 1999.

In January 2013, together with physical chemist Zhang Cunhao, Cheng won China's top science award for their outstanding contributions to scientific and technological innovation. The pair, both members of the Chinese Academy of Sciences, were presented with certificates by President Xi Jinping at an annual ceremony honoring distinguished scientists and research achievements.

Cheng Kaijia receives a doctorate of philosophy at the University of Edinburgh in 1948.

In 1946, Cheng went to the United Kingdom to study at the University of Edinburgh. In 1950, despite the favorable treatment and research conditions of the Royal Institute of Chemical Technology in the UK, Cheng returned to the motherland. Cheng was assigned to work at Nanjing University. He joined the Communist Party of China in 1956.

In 1958, the department of physics of Nanjing University set up a nuclear physics teaching and research section, and the school entrusted the establishment to Cheng.

In July 2017, President Xi awarded Cheng the Order of August 1 – the highest Chinese military decoration – for his outstanding contributions to national defense and military modernization.

"The value of life lies in contribution: contribution to the people, contribution to the country. This is the value," Cheng said.