Dear friends, today is Thursday, September 12, 2019, the fourteenth day of August in the lunar calendar.
"Taking people as a mirror can make clear gains and losses; taking history as a mirror can know the rise and fall." Looking back at history today, some people should not be forgotten, and some things should not be erased. As the years pass and the clock goes by, they will eventually remain in our memories. "Let's pay attention to what are the selected events of today in history.
On September 12, 1897, the French scientist Iren Joliot Curie was born
Irena Jolioz Curie: The famous French scientist chemist, (1897.9.12--1956.3.17) discovered artificial radioactive materials, won the Nobel Prize in Chemistry, and built the first nuclear reactor in France. In collaboration with Fjorie Curie, in collaboration with Fjori Curie, a highly penetrating radiation was discovered in 1932, which was later identified as neutron; in 1934, artificial radioactive material was discovered and the phenomenon of fission was studied. In 1935, the couple won the Nobel Prize in Chemistry.
Scientific Achievements:
The main achievement of the Joliot-Curie couple was the discovery of artificial radioactivity. In 1934, they bombarded the aluminum foil with α rays of polonium and found that when the α source was removed, the aluminum foil was radioactive; its intensity also decreased exponentially over time. This radioactivity is formed by α particles hitting aluminum-27 to emit a neutron to form phosphorus-30, which is unstable and emits positrons. In fact, they have discovered a new radioactive substance, phosphorus-30:
This is the artificial radioactivity discovered by I. Curie. They also found other artificial radioisotopes produced by nuclear reactions caused by α particles. For this discovery, they were awarded the Nobel Prize in Chemistry in 1935. Later, F. Joliot Curie was elected a member of the French Academy of Medical Sciences for his research on the medical application of radioisotopes.
The Joliot-Curies contributed to the study of positron annihilation, the conversion of photons into electron pairs, the extraction of polonium from radium D (210Pb), the use of α particles to bombard light elements to produce nuclear reactions, the discovery of artificial radioactivity, and the radioactive products generated after uranium bombardment by neutrons.
Together, the Jolio-Curies won the 1935 Nobel Prize in Chemistry for synthesizing new radionuclides.
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Photo: Meng Tian
Typography: Hu Xiaoyu