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Japanese Nuclear Weapons Program
During World War II, Japan had several programs exploring the use of nuclear fission for military technology, including nuclear reactors and nuclear weapons. Like the similar wartime programs in Nazi Germany, it was relatively small, suffered from an array of problems brought on by lack of resources and wartime disarray, and was ultimately unable to progress beyond the laboratory stage during the war. Today, Japan has no known nuclear weapons programs. It is a signatory in good standing of the Nuclear Non-Proliferation Treaty and has enacted domestic legal prohibitions against producing nuclear weapons. However, it is unique among non-nuclear weapons states in that it possesses a full nuclear fuel cycle, as part of its civilian nuclear energy industry, and advanced developments in the industries necessary to make nuclear weapons. As a result, it is often cited as a primary example of a latent or threshold nuclear state, capable of developing weapons in a very short timespa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empire Of Japan
The also known as the Japanese Empire or Imperial Japan, was a historical nation-state and great power that existed from the Meiji Restoration in 1868 until the enactment of the post-World War II 1947 constitution and subsequent formation of modern Japan. It encompassed the Japanese archipelago and several colonies, protectorates, mandates, and other territories. Under the slogans of and following the Boshin War and restoration of power to the Emperor from the Shogun, Japan underwent a period of industrialization and militarization, the Meiji Restoration, which is often regarded as the fastest modernisation of any country to date. All of these aspects contributed to Japan's emergence as a great power and the establishment of a colonial empire following the First Sino-Japanese War, the Boxer Rebellion, the Russo-Japanese War, and World War I. Economic and political turmoil in the 1920s, including the Great Depression, led to the rise of militarism, nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all isotopes of uranium are unstable; the half-lives of its naturally occurring isotopes range between 159,200 years and 4.5 billion years. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead, and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238 (99. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Physics
Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and bosons (force-carrying particles). There are three generations of fermions, but ordinary matter is made only from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons, and electrons and electron neutrinos. The three fundamental interactions known to be mediated by bosons are electromagnetism, the weak interaction, and the strong interaction. Quarks cannot exist on their own but form hadrons. Hadrons that contain an odd number of quarks are called baryons and those that contain an even number are called mesons. Two baryons, the proton and the neutron, make up most of the mass of ordinary matter. Mesons are unstable and the longest-lived last for only a few hundredths of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klein–Nishina Formula
In particle physics, the Klein–Nishina formula gives the differential cross section (i.e. the "likelihood" and angular distribution) of photons scattered from a single free electron, calculated in the lowest order of quantum electrodynamics. It was first derived in 1928 by Oskar Klein and Yoshio Nishina, constituting one of the first successful applications of the Dirac equation. The formula describes both the Thomson scattering of low energy photons (e.g. visible light) and the Compton scattering of high energy photons (e.g. x-rays and gamma-rays), showing that the total cross section and expected deflection angle decrease with increasing photon energy. Formula For an incident unpolarized photon of energy E_\gamma, the differential cross section is: : \frac = \frac r_e^2 \left(\frac\right)^ \left frac + \frac - \sin^2(\theta)\right where * r_e is the classical electron radius (~2.82 fm, r_e^2 is about 7.94 × 10−30 m2 or 79.4 mb) * \lambda/\lambda' is the ratio of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory of relativity, but he also made important contributions to the development of the theory of quantum mechanics. Relativity and quantum mechanics are the two pillars of modern physics. His mass–energy equivalence formula , which arises from relativity theory, has been dubbed "the world's most famous equation". His work is also known for its influence on the philosophy of science. He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect", a pivotal step in the development of quantum theory. His intellectual achievements and originality resulted in "Einstein" becoming synonymous with "genius". In 1905, a year sometimes described as his ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niels Bohr
Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research. Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a wave or a stream of particles. The notion of complementarity dominated Bohr's thinking in both science and philosophy. Bohr founded the Institute of Theoretical Physics at the University of Cope ... [...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] |
Masatoshi Okochi
Masatoshi (written: , , , , , , , , , , , , or ) is a masculine Japanese given name. Notable people with the name include: *, Japanese politician *, Japanese film director *, Japanese politician *, Japanese comedian *, Japanese samurai *, Japanese ''daimyō'' *, Japanese cyclist *, Japanese samurai and ''daimyō'' * Masatoshi Ishida (other), multiple people *, Japanese businessman *, Japanese manga artist *, Japanese physicist *, Japanese footballer *, Japanese politician *, Japanese guitarist *, Japanese footballer *, Japanese footballer *, Japanese footballer *, Japanese diplomat *, Japanese actor *Masatoshi Nagatomi Masatoshi Nagatomi (September 1, 1926 – June 3, 2000) was Japanese professor of Buddhist studies at Harvard University. He was also known by his nickname "Mas." Nagatomi is remembered for introducing the term ''Nikaya Buddhism'' as a replacement ... (1926–2000), Japanese professor of Buddhist studies at Harvard University *, Japanese photographer *, Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Chain Reaction
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] |
The Making Of The Atomic Bomb
''The Making of the Atomic Bomb'' is a contemporary history book written by the American journalist and historian Richard Rhodes, first published by Simon & Schuster in 1987. It won the Pulitzer Prize for General Non-Fiction, the National Book Award for Nonfiction, and a National Book Critics Circle Award. The narrative covers people and events from early 20th century discoveries leading to the science of nuclear fission, through the Manhattan Project and the atomic bombings of Hiroshima and Nagasaki. Praised both by historians and former Los Alamos weapon engineers and scientists, the book is considered a general authority on early nuclear weapons history, as well as the development of modern physics in general, during the first half of the 20th century. Nobel Laureate I. I. Rabi Isidor Isaac Rabi (; born Israel Isaac Rabi, July 29, 1898 – January 11, 1988) was an American physicist who won the Nobel Prize in Physics in 1944 for his discovery of nuclear magnetic re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Rhodes
Richard Lee Rhodes (born July 4, 1937) is an American historian, journalist, and author of both fiction and non-fiction, including the Pulitzer Prize-winning ''The Making of the Atomic Bomb'' (1986), and most recently, ''Energy: A Human History'' (2018). Rhodes has been awarded grants from the Ford Foundation, the Guggenheim Foundation, the MacArthur Foundation, and the Alfred P. Sloan Foundation among others. Rhodes is an affiliate of the Center for International Security and Cooperation at Stanford University. He also frequently gives lectures and talks on a broad range of subjects, including testimony to the U.S. Senate on nuclear energy. Biography Richard Rhodes was born in Kansas City, Kansas, in 1937. Following his mother's suicide on July 25, 1938, Rhodes and his older brother Stanley were raised in the Kansas City, Missouri, area by his father, a railroad boilermaker with a third-grade education. When Rhodes was ten, their father remarried. The new wife starved, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 ''Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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