Zhang Cunhao (FILE)	Cheng Kaijia (FILE)

Physical chemist Zhang Cunhao (left) and nuclear weapons expert Cheng Kaijia won China's top science award for their outstanding contributions to scientific and technological innovation on January 10.

The pair, both academicians with the Chinese Academy of Sciences (CAS), was presented with certificates by President Xi Jinping at an annual ceremony. Winners are also entitled to an award of 5 million yuan ($820,000) each.

Zhang, 85, went to the United States to further his studies in the 1940s and obtained a master's degree in 1950. He then returned to China despite hard living conditions, and devoted himself to scientific research at the Dalian Institute of Chemical Physics of the CAS in the northeastern port city.

Zhang has focused on many pioneering technologies, including rocket propellants and lasers.

Cheng, 96, has participated in more than 30 of China's nuclear experiments. He also played a key role in developing the country's first atomic and hydrogen bombs, as well as the combination of the two bombs.

Cheng devoted years to living in the vast Gobi Desert in northwest China's Xinjiang Uygur Autonomous Region beginning in 1963.

Cheng also participated in writing China's first academic document for atomic bomb research and experiments, designing a plan for setting off an atomic bomb at an iron tower higher than 100 meters, and planning the missions and the establishment of an institute dedicated to nuclear weapons experiments.

His team established China's understanding of nuclear explosions, the research into them, different kinds of nuclear experiments, and technical safety standards.