Who has a profile of physicist J. Frank?

Frank (James Franck, 1882 ~ 1964.1925)

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Frank has been engaged in scientific activities for more than 6 years, from the foundation of atomic physics and quantum theory in the early 2th century to the perfection of these disciplines. Frank is basically a physicist, but his research on the transformation of solar energy into the basic process of maintaining life on earth has far-reaching influence on the branches of chemistry and biology.

from 191 to 192, Frank studied chemistry at Heidelberg University for two semesters, during which he met Max Born and established a lifelong friendship with him. In 192, he transferred to Berlin University and began to study and study physics seriously. At that time, the center of world physics was in Germany. Rubens, Emil Warburg and Planck were all professors at the University of Berlin [and later Drude and Einstein], and their joint seminar had a great influence on Frank's life. In 196, after receiving a doctorate in philosophy from the University of Berlin, Frank worked as a physics assistant at the University of Frankfurt for a short time. Later, he returned to his alma mater, the University of Berlin, as a teaching assistant of Professor Rubins. In 1911, he was promoted to a lecturer in physics. In 1917, he was appointed as an assistant professor and head of the department of Kaiser Wilhelm Institute of Physics and Chemistry (later changed to Planck Institute) until 192, when the director of the institute was freese Haber. In 1921, Born served as the head of physics department and professor of theoretical physics at the University of G? ttingen. He successfully persuaded the Minister of Education to re-divide the department, and invited his old friend Frank to G? ttingen as professor of experimental physics and director of Zwitt Institute of Physics. At that time, R·Pohl had been a special professor there and concurrently served as the director of the First Institute of Physics. The two research institutes are located in the same building. This arrangement made by Born enabled the three professors to get their places in the three departments and to make contact with each other easily, so that the research work was carried out satisfactorily. They often co-organize seminars and take turns as chairmen. During his twelve years in G? ttingen, Frank and Born became close partners and shared the same interest in scientific research, forming the core of active scientific groups in this region.

During this period, Frank published a large number of various articles, the central theme of which can be described as the composition and separation of atoms and molecules in collisions and their vibration and rotation. In two papers, Bourne and Frank developed the use of the now familiar potential energy curve to deal with the two-atom system. They introduced the concept of excimer and applied it to the energy conversion from electron motion to vibration motion in molecular spectrum. Frank introduced the method of determining the separation energy of molecules by extrapolating the vibration energy level, and made this method become the famous "Frank-Condon principle" after Condon's wave mechanics formula. In 1926, his only work was a book co-written with P·Jordan, which contained the basic concepts of most of his work during that period.

After Hitler came to power in 1933, although Frank was Jewish, he was still allowed to continue working, but all his colleagues and students who were not Aryans or so-called politically problematic were dismissed and expelled, so he resigned as a professor. He opposed the new law and made a brave declaration. A few months later, he left Germany with Born and many other colleagues.

After staying in Copenhagen for one year, Frank went to the United States in 1935 and became a professor at Johns Hopkins University in Baltimore. In 1938, he was appointed professor of physical chemistry at the University of Chicago. There, SamueI Fels Foundation once established a photosynthesis laboratory, and Frank served as the director of this laboratory until his retirement in 1949. In Gottingen and Baltimore, Frank and his colleagues once extended the ionization and photosynthesis mechanism in diatomic molecules to liquid mixed solids, and finally extended it to the photosynthesis process of plants. Although this work includes all the complexity of biochemistry, Frank still concentrates most of his time on the study of photosynthesis. In addition, during this period, he and Teller also contributed to the motivation theory and photography process.

Because of the study of photosynthesis, Frank was involved in many debates. In experiment, he resisted warburg's measurement, because it contradicted the basic principles of thermodynamics and was inconsistent with the work of other laboratories. In theory, Frank created a model, that is, assuming a two-step process in a single chlorophyll molecule. Although some details of his view are still controversial, this assumption has been confirmed by most experimental facts. In 19S5, the American Academy of Arts and Sciences awarded him the Langford Medal in recognition of his contribution to expanding the research field of photosynthesis.

Professor Frank's greatest contribution to physics is the great discovery he made when he worked in Berlin University in his early days. During this period, he went deep into warburg's laboratory and began to study corona discharge. He soon gave up this topic and turned to more basic research on ion mobility. He found that the collision between electrons and inert gas atoms is mainly elastic collision and does not lose kinetic energy. At that time, his young colleague Gustav Hertz participated in his research on this very accurate elastic collision. This work led to the discovery of quantum energy transfer between electrons and atoms in inelastic collisions. In their famous experiment, Frank and Hertz determined how much energy is needed to ionize electrons from atoms. They let electrons with certain energy collide with mercury vapor molecules to calculate the changes of electron energy before and after the collision. The experimental results clearly show that when an electron collides with a mercury atom, the electron strictly loses 4.9 electron volts, that is, the mercury atom can only receive 4.9 electron volts. This fact justifiably shows that the mercury atom has the "completely determined and separated energy state" as Bohr envisioned. Therefore, the Frank-Hertz experiment is the first proof of the quantization characteristics of energy transformation and the first decisive evidence of Bohr's quantized energy level.

Frank and Hertz won the Nobel Prize in Physics in 1925 because they discovered the laws governing the collision between electrons and atoms. In 1926, Frank briefly described the problem of electron collision in the Nobel Prize-awarding speech in Stockholm.

In addition to winning the Nobel Prize, Frank also won many honors and was admitted as a member of many societies, including the Royal Society of London. After World War II, Germany also awarded him many honors. He won the Planck Medal of the German Physical Society and became an honorary citizen of G? ttingen.

in 1964, he traveled all over the motherland and visited old friends, but unfortunately he died during the trip at the age of 82.