Briefly introduce a scientist 5, briefly introduce a scientist

Archimedes was a great mathematician and mechanic in ancient Greece. Born in Sygura, Sicily, circa 287 BC, died in the same place in 212 BC.

Archimedes studied with Euclid in his early years in Alexandria, the cultural center of the time, and there is no detailed account of his life, but many stories about him have been widely circulated. He established the law of leverage and said, "Give me a fulcrum, and I will move the earth"; discovered the basic principle of hydrostatics - Archimedes' principle, and used it to identify the authenticity of the crown; He has designed many war machines to counter enemy offensive ......

Later generations spoke highly of Archimedes, often calling him, along with Newton and Gauss, the mathematician who made the greatest contribution in history.

Qian Xuesen (1911-) is a modern Chinese scientist. His ancestral home is Hangzhou, Zhejiang, and he was born in Shanghai. He studied in the United States and engaged in rocket research under the guidance of Carmen, the founder of modern mechanics.

After returning to China in 1955, he devoted himself to the creation of China's mechanics and aerospace industry. He is a member of the Department of Mathematical Physics of the Chinese Academy of Sciences, a researcher and the first director of the Institute of Mechanics, and the first chairman of the Chinese Society of Mechanics. Since 1958, he has served as deputy director of the National Defense Science and Technology Committee of the Chinese People's Liberation Army and has done a great deal of work for the development of our army's scientific and technological undertakings.

Yuan Longping is an agronomist and hybrid rice breeding expert. Jiangxi De'an people. Born on September 7, 1930.

In 1953, he graduated from the Department of Agronomy of Southwest Agricultural College. He has served as a researcher, director of the Hunan Hybrid Rice Research Center, honorary president of the Hunan Academy of Agricultural Sciences, director of the National Hybrid Rice Engineering Technology Research Center, and was elected as an academician of the Chinese Academy of Engineering in 1995.

In 1964, he first proposed the idea of cultivating a three-line method of "sterile line, maintainer line, and restorer line" to use rice heterosis and carried out scientific experiments. In 1970, together with his assistants Li Bihu and Feng Keshan, they discovered a male sterile wild rice plant with pollen abortion in Hainan, which became the key to breaking through the "three-line" matching. In 1972, the first large-scale application of rice male sterility line "Erjiunan No. 1 A" and the corresponding maintenance line "Erjiunan No. 1 B" in China were bred, and the following year, the first large-scale promotion of the strong combination "Nanyou No. 2" was bred, and a complete set of seed production technology was developed.

In 1986, the strategic idea of hybrid rice breeding was proposed, which was divided into "heterosis utilization between varieties by three-line method, heterosis utilization between subspecies by two-line method and distantly related heterosis utilization by one-line method". He is known as the "father of hybrid rice" by his peers.