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Bunsaku Arakatsu
was a Japanese physics professor in the World War II Japanese Atomic Energy Research Program of the Imperial Japanese Navy. Arakatsu was a former student of Albert Einstein. Career In 1928, Arakatsu became a professor in Taihoku Imperial University (now called National Taiwan University). In 1934 Arakatsu built a particle accelerator at Taihoku Imperial University in Taipei, Taiwan, and performed the first atomic nucleus collision experiment in Asia there, right after the experiment performed in Cavendish Laboratory of University of Cambridge. He discovered that each nuclear fission of a U-235 atom yields, on average, 2.6 neutrons. In 1936, he became a professor in Kyoto Imperial University (now called University of Kyoto). In 1943, during World War II, he ran the Japanese Naval research program into nuclear technology, known as the F-Go Project. Next to Yoshio Nishina, Arakatsu was the most notable nuclear physicist in Japan. His team included Hideki Yukawa, who would bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himeji, Hyōgo
260px, Himeji City Hall is a city located in Hyōgo Prefecture in the Kansai region of Japan. , the city had an estimated population of 525,682 in 227,099 households and a population density of 980 persons per km². The total area of the city is . Geography Himeji is located in the central western part of the Harima Plain in the western part of Hyogo Prefecture, and is the central city of the Harima region of the prefecture. The Ichikawa River is located in the central eastern part of the city, and the Senba River and Noda River are located in the center. The Ieshima Islands in the Seto Inland Sea are within the city limits and are located off the coast of Harima Bay. The city is surrounded by the mountains and the sea. Neighbouring municipalities Hyōgo Prefecture * Kakogawa * Takasago * Kasai * Tatsuno * Shisō * Taishi * Kamikawa * Ichikawa Climate Himeji has a humid subtropical climate (Köppen climate classification ''Cfa'') with hot summers and cool winters. Sum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitsumasa Yonai
was a Japanese general and politician. He served as admiral in the Imperial Japanese Navy, Minister of the Navy, and Prime Minister of Japan in 1940. Early life and career Yonai was born on 2 March 1880, in Morioka, Iwate Prefecture, the first son of former samurai Yonai Nagamasa. Nagamasa had formerly served the Nanbu clan of the Morioka Domain. He entered Kajichō Elementary School in 1886, and entered Morioka Middle School in 1890. After graduating from Morioka Middle School, he entered the Imperial Japanese Naval Academy. He graduated from the 29th class Imperial Japanese Naval Academy in 1901, ranked 68 of 125 cadets (Japan Center for Asian Historical Records, n.d.). After midshipman service on the corvette , and cruiser he was commissioned as ensign in January 1903. He served in administrative positions until near the end of the Russo-Japanese War of 1904–1905, when he went to sea again on the destroyer and the cruiser . After the war, he served as chief gunnery of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Bombings Of Hiroshima And Nagasaki
The United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August 1945, respectively. The two bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the only use of nuclear weapons in armed conflict so far. In the final year of World War II, the Allies prepared for a costly invasion of the Japanese mainland. This undertaking was preceded by a conventional and firebombing campaign that devastated 64 Japanese cities. The war in the European theatre concluded when Germany surrendered on 8 May 1945, and the Allies turned their full attention to the Pacific War. By July 1945, the Allies' Manhattan Project had produced two types of atomic bombs: "Fat Man", a plutonium implosion-type nuclear weapon; and "Little Boy", an enriched uranium gun-type fission weapon. The 509th Composite Group of the United States Army Air Forces was trained and equipped with the specialized Silverplate version of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultracentrifuge
An ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as (approx. ). There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both classes of instruments find important uses in molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ..., biochemistry, and polymer science.Susan R. Mikkelsen & Eduardo Cortón. Bioanalytical Chemistry, Ch. 13. Centrifugation Methods. John Wiley & Sons, Mar 4, 2004, pp. 247-267. History In 1924 Theodor Svedberg built a centrifuge capable of generating 7,000 g (at 12,000 rpm), and called it the ultracentrifuge, to juxtapose it with the Ultramicroscope that had been developed previously. In 1925-1926 Svedberg constructed a new ultracen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize
The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfred Nobel was a Swedish chemist, engineer, and industrialist most famously known for the invention of dynamite. He died in 1896. In his will, he bequeathed all of his "remaining realisable assets" to be used to establish five prizes which became known as "Nobel Prizes." Nobel Prizes were first awarded in 1901. Nobel Prizes are awarded in the fields of Physics, Chemistry, Physiology or Medicine, Literature, and Peace (Nobel characterized the Peace Prize as "to the person who has done the most or best to advance fellowship among nations, the abolition or reduction of standing armies, and the establishment and promotion of peace congresses"). In 1968, Sveriges Riksbank (Sweden's central bank) funded the establishment of the Prize in Economi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hideki Yukawa
was a Japanese theoretical physicist and the first Japanese Nobel laureate for his prediction of the pi meson, or pion. Biography He was born as Hideki Ogawa in Tokyo and grew up in Kyoto with two older brothers, two older sisters, and two younger brothers. He read the Confucian ''Doctrine of the Mean'', and later Lao-Tzu and Chuang-Tzu. His father, for a time, considered sending him to technical college rather than university since he was "not as outstanding a student as his older brothers". However, when his father broached the idea with his middle school principal, the principal praised his "high potential" in mathematics and offered to adopt Ogawa himself in order to keep him on a scholarly career. At that, his father relented. Ogawa decided against becoming a mathematician when in high school; his teacher marked his exam answer as incorrect when Ogawa proved a theorem but in a different manner than the teacher expected. He decided against a career in experimental physics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yoshio Nishina
was a Japanese physicist who was called "the founding father of modern physics research in Japan". He led the efforts of Japan to develop an atomic bomb during World War II. Early life and career Nishina was born in Satoshō, Okayama. He received a silver watch from the emperor as he graduated at the top of his class at Tokyo Imperial University as an electrical engineer in 1918. He became a staff member at the Institute of Physical and Chemical Research (now RIKEN) where he began studying physics under Hantaro Nagaoka. In 1921, he was sent to Europe for research. He visited some European universities and institutions, including Cavendish Laboratory, Georg August University of Göttingen, and University of Copenhagen. In Copenhagen, he did research with Niels Bohr, and they became good friends. In 1928, he wrote a paper on incoherent or Compton scattering with Oskar Klein in Copenhagen, from which the Klein–Nishina formula derives. In 1929, he returned to Japan, where he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Kyoto
, mottoeng = Freedom of academic culture , established = , type = Public (National) , endowment = ¥ 316 billion (2.4 billion USD) , faculty = 3,480 (Teaching Staff) , administrative_staff = 3,978 (Total Staff) , students = 22,615 , president = Nagahiro Minato , city = Kyoto , state = Kyoto , country = Japan , coor = , undergrad = 13,038 , postgrad = 9,308 , campus = Urban,, , colors = Dark blue , nickname = Kyodai , mascot = None , free_label = Athletics , free = 48 varsity teams , affiliations = Kansai Big Six, ASAIHL , logo = , website www.kyoto-u.ac.jp , or , is a public research university located in Kyoto, Japan. Founded in 1897, it is one of the former Imperial Universities and the second oldest university in Japan. KyotoU is consistently ranked amongst the top two in Japan, the top ten in Asia, and the world's top fifty institutions of higher education. Founded upon the principles of its motto, “fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron
The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks. The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, which is determined by the number of protons, or atomic number. The number of neutrons is the neutron number. Neutrons do not affect the electron configuration, but the sum of atomic and neutron numbers is the mass of the nucleus. Atoms of a chemical element t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Multiplication Factor
In nuclear physics, a nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series of these reactions. The specific nuclear reaction may be the fission of heavy isotopes (e.g., uranium-235, 235U). A nuclear chain reaction releases several million times more energy per reaction than any chemical reaction. History Chemical chain reactions were first proposed by German chemist Max Bodenstein in 1913, and were reasonably well understood before nuclear chain reactions were proposed. It was understood that chemical chain reactions were responsible for exponentially increasing rates in reactions, such as produced in chemical explosions. The concept of a nuclear chain reaction was reportedly first hypothesized by Hungarian scientist Leó Szilárd on September 12, 1933. Szilárd that morning had been reading in a London paper of an experiment in which protons f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide. Uranium-235 has a half-life of 703.8 million years. It was discovered in 1935 by Arthur Jeffrey Dempster. Its fission cross section for slow thermal neutrons is about 584.3±1 barns. For fast neutrons it is on the order of 1 barn. Most but not all neutron absorptions result in fission; a minority result in neutron capture forming uranium-236. Natural decay chain :\begin \ce \begin \ce \\ \ce \end \ce \\ \ce \begin \ce \\ \ce \end \ce \end Fission properties The fission of one atom of uranium-235 releases () inside the reactor. That corresponds to 19.54 TJ/ mol, or 83.14 TJ/kg. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
