Cosmic Ray

Xiao Jian, also known as Ji Jian, was born in Changsha on July 19, 1920. He was frail since he was a child, so his parents named him Jijian, hoping that he would grow up healthily. His father, Xiao Baowen, is an industrialist. He studied in Japan in his early years and has been working at Jiuda Wynn Company since returning to China. He is a very pragmatic person. His mother, Luo Zhengbi, came from a scholarly family. She was good at calligraphy and painting, had progressive ideas, and was enthusiastic about others. She had close contacts with Cai Chang. His father died of illness in December 1949. After the founding of New China, my mother donated all her house in Changsha to the country and came to Beijing to work in the Museum of Culture and History. The influence of his family has made Xiao Jian develop a pragmatic character, not seeking fame or fortune, and being enthusiastic towards others.

In September 1938, Xiao Jian transferred to Hechuan National No. 2 Middle School in Sichuan. In the autumn of 1939, he was admitted to the Department of Electrical Engineering of Southwest Associated University. He became interested in basic science in the first grade, and decided to switch to physics at the beginning of the second year. Since the time for changing departments had passed, he did not transfer to the physics department until the autumn of 1941, and graduated in the summer of 1944. In October 1943, the Ministry of Education issued an order to recruit fourth-year male students from several universities to serve as translators for the US military. Upon completion of their service, they would be issued diplomas. Xiao Jian was first assigned to a field hospital in India, and a year later he was transferred to the Kunming U.S. Army Material Supply Office. In 1945, when the Anti-Japanese War was victorious, Xu Huiying, who was studying in the Chemistry Department of Southwest Associated University, happened to graduate. They had been in love for many years, returned to Chongqing together, and got married in January 1946. After getting married, they both taught in Chongqing Pragmatic Middle School. Xiao Jian saw that the Kuomintang government was becoming more and more corrupt and was wondering about its future. It happened that at that time, Jiuda Wynn Company had a benefit for employees with more than 30 years of service, which could sponsor their children to study abroad. Therefore, in 1947, Xiao Jian was sent to study abroad by the Huanghai Chemical Research Society of Jiuda Yongli Company, while Xu Huiying returned to Pinghu, Zhejiang to teach.

After Xiao Jian arrived in the United States, he first studied theory at Stanford University for one semester. Later, he felt that physics is a science based on experiments. Chinese students in the United States learn more theories, but their hands-on ability is still good, so he decided to engage in experimental physics research. In view of the poor experimental conditions at Stanford University at that time, he transferred to the California Institute of Technology in 1947 and conducted cosmic ray research under the guidance of Professor C.D. Anderson. This school's method of training students is quite practical. They first let students manage instruments and find ways to find or make whatever they lack. Xiao Jian learned to make his own instruments, which was very helpful for his future entrepreneurial work in China. In 1947, strange particles (mesons and hyperons) were discovered in cosmic ray research. Under the guidance of Anderson, Xiao Jian and other students used a cloud chamber to obtain more examples of strange particles and quantitatively measured mesons and hyperons. properties such as quality, lifespan and main decay modes. This work made an important contribution to confirming the existence of strange particles and understanding the properties of these new particles. It is a classic result of early research. In searching for decay cases of strange particles, he fully demonstrated his unique talents in experimental technology. Prior to this, Xiao Jian also measured the decay electron spectrum of muons for the first time. While studying in the United States, Xiao Jian often read articles about the Communist Party of China and news about the liberated areas from the Overseas Chinese Daily. This news encouraged him and gave him hope for the future of his motherland. As soon as New China was founded, he immediately prepared to return to China. Although his doctoral thesis was basically completed at that time, he was afraid that he would be blocked if he missed the opportunity to return to China, so he resolutely gave up the doctorate he was about to obtain and returned to the motherland on April 12, 1950.