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Quebec Agreement
The Quebec Agreement was a secret agreement between the United Kingdom and the United States outlining the terms for the coordinated development of the science and engineering related to nuclear power, nuclear energy and specifically nuclear weapons. It was signed by Winston Churchill and Franklin D. Roosevelt on 19 August 1943, during World War II, at the First Quebec Conference in Quebec City, Quebec, Canada. The Quebec Agreement stipulated that the US and UK would pool their resources to develop nuclear weapons, and that neither country would use them against the other, or against other countries without mutual consent, or pass information about them to other countries. It also gave the United States a veto over post-war British commercial or industrial uses of nuclear energy. The agreement merged the British Tube Alloys project with the American Manhattan Project, and created the Combined Policy Committee to control the joint project. Although Canada was not a signatory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mackenzie King
William Lyon Mackenzie King (December 17, 1874 – July 22, 1950) was a Canadian statesman and politician who was the tenth prime minister of Canada for three non-consecutive terms from 1921 to 1926, 1926 to 1930, and 1935 to 1948. A Liberal, he was the dominant politician in Canada from the early 1920s to the late 1940s. King is best known for his leadership of Canada throughout the Great Depression and the Second World War. He played a major role in laying the foundations of the Canadian welfare state and establishing Canada's international position as a middle power. With a total of 21 years and 154 days in office, he remains the longest-serving prime minister in Canadian history and as well as the longest-serving Liberal leader, holding the position for exactly 29 years. King studied law and political economy in the 1890s and later obtained a PhD, the first of only two Canadian prime ministers to have done so. In 1900, he became deputy minister of the Canadian governmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavendish Laboratory
The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the School of Physical Sciences. The laboratory was opened in 1874 on the New Museums Site as a laboratory for experimental physics and is named after the British chemist and physicist Henry Cavendish. The laboratory has had a huge influence on research in the disciplines of physics and biology. The laboratory moved to its present site in West Cambridge in 1974. , 30 Cavendish researchers have won Nobel Prizes. Notable discoveries to have occurred at the Cavendish Laboratory include the discovery of the electron, neutron, and structure of DNA. Founding The Cavendish Laboratory was initially located on the New Museums Site, Free School Lane, in the centre of Cambridge. It is named after British chemist and physicist Henry Cavendish for contributions to science and his relative William Cavendish, 7th Duke of Devonshire, who served as chancellor of the university and donated fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Nucleus
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford at the Department_of_Physics_and_Astronomy,_University_of_Manchester , University of Manchester based on the 1909 Geiger–Marsden experiments, Geiger–Marsden gold foil experiment. After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickly developed by Dmitri Ivanenko and Werner Heisenberg. An atom is composed of a positively charged nucleus, with a cloud of negatively charged electrons surrounding it, bound together by electrostatic force. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud. Protons and neutrons are bound together to form a nucleus by the nuclear force. The diameter of the nucleus is in the range of () for hydrogen (the diameter of a single proton) to about for uranium. These dimensions are much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Frisch
Otto Robert Frisch (1 October 1904 – 22 September 1979) was an Austrian-born British physicist who worked on nuclear physics. With Otto Stern and Immanuel Estermann, he first measured the magnetic moment of the proton. With his aunt, Lise Meitner, he advanced the first theoretical explanation of nuclear fission (coining the term) and first experimentally detected the fission by-products. Later, with his collaborator, Rudolf Peierls, he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940. Leading the Los Alamos Critical Assemblies experiments in 1945, he oversaw the world's first prompt criticality in the Dragon device. Early life Otto Robert Frisch was born in Vienna in 1904 to a Jewish family, the son of Justinian Frisch, a painter, and Auguste Meitner Frisch, a concert pianist. He himself was talented at both but also shared his maternal aunt Lise Meitner's love of physics and commenced a period of study at the University of Vienna, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lise Meitner
Elise Lise Meitner ( ; ; 7 November 1878 – 27 October 1968) was an Austrian-Swedish nuclear physicist who was instrumental in the discovery of nuclear fission. After completing her doctoral research in 1906, Meitner became the second woman from the University of Vienna to earn a doctorate in physics. She spent much of her scientific career in Berlin, where she was a physics professor and a department head at the Max Planck Institute for Chemistry, Kaiser Wilhelm Institute for Chemistry. She was the first woman to become a full professor of physics in Germany. She lost her positions in 1935 because of the anti-Jewish Nuremberg Laws of Nazi Germany, and the 1938 Anschluss resulted in the loss of her Austrian citizenship. On 13–14 July 1938, she fled to the Netherlands with the help of Dirk Coster. She lived in Stockholm for many years, ultimately becoming a Swedish citizen in 1949, but relocated to Britain in the 1950s to be with family members. In mid-1938, chemists Otto H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium
Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are barite ( barium sulfate, BaSO4) and witherite ( barium carbonate, BaCO3). The name ''barium'' originates from the alchemical derivative "baryta", from Greek (), meaning 'heavy'. ''Baric'' is the adjectival form of barium. Barium was identified as a new element in 1772, but not reduced to a metal until 1808 with the advent of electrolysis. Barium has few industrial applications. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. It is a component of YBCO (high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Barium compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element; it has chemical symbol, 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 radioactive decay, radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes of uranium, isotopes, making them useful for dating the age of the Earth. 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 primordial nuclide, 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 notation#Parts-per expressions, parts per million in soil, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin-Dahlem
Dahlem ( or ) is a locality of the Steglitz-Zehlendorf borough in southwestern Berlin. Until Berlin's 2001 administrative reform it was a part of the former borough of Zehlendorf. It is located between the mansion settlements of Grunewald and Lichterfelde West. Dahlem is one of the most affluent parts of the city and a center for academic research. It is home to the Freie Universität Berlin, with its architecturally significant Philological Library ''("The Brain")''. Several other research institutions and museums, as well as parts of the Grunewald forest with its renaissance hunting lodge, are located in Dahlem. The U3 line of the Berlin U-Bahn system connects Dahlem to central Berlin. History The first written account of Dahlem dates to the year 1275. The history of the village is connected to the Dahlem Demesne (''Domäne Dahlem'') first mentioned in 1450. Its estates were sold to the state of Prussia in 1841 and developed by dividing it into lots for building vil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fritz Strassmann
Friedrich Wilhelm Strassmann (; 22 February 1902 – 22 April 1980) was a German chemist who, with Otto Hahn in December 1938, identified the element barium as a product of the bombardment of uranium with neutrons. Their observation was the key piece of evidence necessary to identify the previously unknown phenomenon of nuclear fission, as was subsequently recognized and published by Lise Meitner and Robert Frisch. In their second publication on nuclear fission in February 1939, Strassmann and Hahn predicted the existence and liberation of additional neutrons during the fission process, opening up the possibility of a nuclear chain reaction. Early life Friedrich Wilhelm (Fritz) Strassmann was born in Boppard, Germany, to Richard Strassmann and Julie Strassmann (née Bernsmann). He was the youngest of nine children. Growing up in Düsseldorf, he developed an interest in chemistry at a young age and conducted chemistry experiments in his parents' home. His family was of modes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Hahn
Otto Hahn (; 8 March 1879 – 28 July 1968) was a German chemist who was a pioneer in the field of radiochemistry. He is referred to as the father of nuclear chemistry and discoverer of nuclear fission, the science behind nuclear reactors and nuclear weapons. Hahn and Lise Meitner discovered isotopes of the radioactive elements isotopes of radium, radium, Isotopes of thorium, thorium, isotopes of protactinium, protactinium and isotopes of uranium, uranium. He also discovered the phenomena of atomic recoil and nuclear isomerism, and pioneered rubidium–strontium dating. In 1938, Hahn, Meitner and Fritz Strassmann Discovery of nuclear fission, discovered nuclear fission, for which Hahn alone was awarded the 1944 Nobel Prize in Chemistry. A graduate of the University of Marburg, which awarded him a doctorate in 1901, Hahn studied under Sir William Ramsay at University College London and at McGill University in Montreal under Ernest Rutherford, where he discovered several new radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton
A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an electron (the proton-to-electron mass ratio). Protons and neutrons, each with a mass of approximately one Dalton (unit), dalton, are jointly referred to as ''nucleons'' (particles present in atomic nuclei). One or more protons are present in the Atomic nucleus, nucleus of every atom. They provide the attractive electrostatic central force which binds the atomic electrons. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol ''Z''). Since each chemical element, element is identified by the number of protons in its nucleus, each element has its own atomic number, which determines the number of atomic electrons and consequently the chemical characteristi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactivity (chemistry), reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. It exhibits a metallic luster (mineralogy), luster. It corrosion, corrodes quickly in air to a dull silvery gray, then black tarnish. It does not occur freely in nature, but occurs mainly as pegmatite, pegmatitic minerals, which were once the main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines. Lithium metal is isolated electrolysis, electrolytically from a mixture of lithium chloride and potassium chloride. The Atomic nucleus, nucleus of the lithiu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
