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Nuclear Weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). A thermonuclear weapon weighing as little as can release energy equal to more than . A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Warfare
Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear warfare can produce destruction in a much shorter time and can have a long-lasting radiological result. A major nuclear exchange would likely have long-term effects, primarily from the fallout released, and could also lead to secondary effects, such as " nuclear winter", nuclear famine and societal collapse. A global thermonuclear war with Cold War-era stockpiles, or even with the current smaller stockpiles, may lead to various scenarios including the extinction of the human race. To date, the only use of nuclear weapons in armed conflict occurred in 1945 with the American atomic bombings of Hiroshima and Nagasaki. On August 6, 1945, a uranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapon Yield
The explosive yield of a nuclear weapon is the amount of energy released when that particular nuclear weapon is detonated, usually expressed as a TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge), either in kilotonnes (kt—thousands of tonnes of TNT), in megatonnes (Mt—millions of tonnes of TNT), or sometimes in terajoules (TJ). An explosive yield of one terajoule is equal to . Because the accuracy of any measurement of the energy released by TNT has always been problematic, the conventional definition is that one kilotonne of TNT is held simply to be equivalent to 1012 calories. The yield-to-weight ratio is the amount of weapon yield compared to the mass of the weapon. The practical maximum yield-to-weight ratio for fusion weapons (thermonuclear weapons) has been estimated to six megatonnes of TNT per tonne of bomb mass (25 TJ/kg). Yields of 5.2 megatonnes/tonne and higher have been reported ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Reaction
In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two atomic nucleus, nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another. If a nucleus interacts with another nucleus or particle and they then separate without changing the nature of any nuclide, the process is simply referred to as a type of nuclear scattering, rather than a nuclear reaction. In principle, a reaction can involve more than two particles collision, colliding, but because the probability of three or more nuclei to meet at the same time at the same place is much less than for two nuclei, such an event is exceptionally rare (see triple alpha process for an example very close to a three-body nuclear reaction). The term "nuclear reaction" may refer either to a change in a nuclide induced by collision with another particle or to a spontaneous change of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surrender Of Japan
The surrender of the Empire of Japan in World War II was announced by Emperor Hirohito on 15 August and formally signed on 2 September 1945, bringing the war's hostilities to a close. By the end of July 1945, the Imperial Japanese Navy (IJN) had become incapable of conducting major operations and an Allied invasion of Japan was imminent. Together with the United Kingdom and China, the United States called for the unconditional surrender of the Japanese armed forces in the Potsdam Declaration on 26 July 1945—the alternative being "prompt and utter destruction". While publicly stating their intent to fight on to the bitter end, Japan's leaders (the Supreme Council for the Direction of the War, also known as the "Big Six") were privately making entreaties to the publicly neutral Soviet Union to mediate peace on terms more favorable to the Japanese. While maintaining a sufficient level of diplomatic engagement with the Japanese to give them the impression they might be wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Effects Research Foundation
The Radiation Effects Research Foundation (RERF) is a joint U.S.-Japan research organization responsible for studying the medical effects of radiation and associated diseases in humans for the welfare of the survivors and all humankind.Introduction to Radiation Effects Research Foundation. (1995). Radiation Effects Research Foundation, pp.1-3. Available at: http://rerf.jp/shared/introd/introRERFe.pdf ccessed 26 February 2018 The organization's scientific laboratories are located in Hiroshima and Nagasaki, Japan. RERF's studies into radiation health effects have continued for more than 70 years, making RERF unique for its conduct of epidemiological and other research on such a large population (more than 120,000 individuals) over such a long timeframe.A Brief Description. (2014). Radiation Effects Research Foundation, p.1. Available at: http://rerf.jp/shared/briefdescript/briefdescript_e.pdf ccessed 26 February 2018 RERF continues its research with the aim of further elucidating t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Personnel
Military personnel are members of the state's armed forces. Their roles, pay, and obligations differ according to their military branch (army, navy, marines, air force, space force, and coast guard), rank (officer, non-commissioned officer, or enlisted recruit), and their military task when deployed on operations and on exercise. Overview Those who serve in a typical large ground or land force are soldiers, making up an army. Those who serve in seagoing forces are seamen or sailors, and their branch is a navy or coast guard. Naval infantry or marines serve in land and sea, and their branch is the marine corps. In the 20th century, the development of powered flight aircraft prompted the development of air forces, serviced by airmen. The United States Space Force service members are known as guardians. Designated leaders of military personnel are officers. These include commissioned officers, warrant officers and non-commissioned officers. For naval forces, non-commissioned o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civilians
Civilians under international humanitarian law are "persons who are not members of the armed forces" and they are not "combatants if they carry arms openly and respect the laws and customs of war". It is slightly different from a non-combatant, because some non-combatants are not civilians (for example, military chaplains who are attached to the belligerent party or military personnel who are serving with a neutral country). Civilians in the territories of a party to an armed conflict are entitled to certain privileges under the customary laws of war and international treaties such as the Fourth Geneva Convention. The privileges that they enjoy under international law depends on whether the conflict is an internal one (a civil war) or an international one. In some nations, uniformed members of civilian police or fire departments colloquially refer to members of the public as civilians. Etymology The word "civilian" goes back to the late 14th century and is from Old French '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nagasaki
is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan. It became the sole port used for trade with the Portuguese and Dutch during the 16th through 19th centuries. The Hidden Christian Sites in the Nagasaki Region have been recognized and included in the UNESCO World Heritage List. Part of Nagasaki was home to a major Imperial Japanese Navy base during the First Sino-Japanese War and Russo-Japanese War. Near the end of World War II, the American atomic bombings of Hiroshima and Nagasaki made Nagasaki the second and, to date, last city in the world to experience a nuclear attack (at 11:02 am, August 9, 1945 'Japan Standard Time (UTC+9)'). , the city has an estimated population of 407,624 and a population density of 1,004 people per km2. The total area is . History Nagasaki as a Jesuit port of call The first contact with Portuguese explorers occurred in 1543. An early visitor was Fernão Mendes Pinto, who came from Sagres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fat Man
"Fat Man" (also known as Mark III) is the codename for the type of nuclear bomb the United States detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation marked the third nuclear explosion in history. It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site, and it was dropped from the Boeing B-29 Superfortress '' Bockscar'' piloted by Major Charles Sweeney. The name Fat Man refers to the early design of the bomb because it had a wide, round shape. Fat Man was an implosion-type nuclear weapon with a solid plutonium core. The first of that type to be detonated was the Gadget in the Trinity nuclear test less than a month earlier on 16 July at the Alamogordo Bombing and Gunnery Range in New Mexico. Two more were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946, and some 120 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutonium
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous. Plutonium was first synthetically produced and isolated in late 1940 and early 1941, by a deuteron bombardment of uranium-238 in the cyclotron at the University of California, Berkeley. First, neptunium-238 ( half-life 2.1 days) was synthesized, which subsequently beta-decayed to form the new element with atomic number 94 and atomic weight 238 (half-life 88 years). Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hiroshima
is the capital of Hiroshima Prefecture in Japan. , the city had an estimated population of 1,199,391. The gross domestic product (GDP) in Greater Hiroshima, Hiroshima Urban Employment Area, was US$61.3 billion as of 2010. Kazumi Matsui has been the city's mayor since April 2011. Hiroshima was founded in 1589 as a castle town on the Ōta River delta. Following the Meiji Restoration in 1868, Hiroshima rapidly transformed into a major urban center and industrial hub. In 1889, Hiroshima officially gained city status. The city was a center of military activities during the imperial era, playing significant roles such as in the First Sino-Japanese War, the Russo-Japanese War, and the two world wars. Hiroshima was the first military target of a nuclear weapon in human history. This occurred on August 6, 1945, at 8:15 a.m., when the United States Army Air Forces (USAAF) dropped the atomic bomb "Little Boy" on the city. Most of Hiroshima was destroyed, and by the end of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Boy
"Little Boy" was the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II, making it the first nuclear weapon used in warfare. The bomb was dropped by the Boeing B-29 Superfortress ''Enola Gay'' piloted by Colonel Paul W. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces and Captain Robert A. Lewis. It exploded with an energy of approximately and caused widespread death and destruction throughout the city. The Hiroshima bombing was the second man-made nuclear explosion in history, after the Trinity nuclear test. Little Boy was developed by Lieutenant Commander Francis Birch (geophysicist), Francis Birch's group at the Manhattan Project's Los Alamos Laboratory during World War II, a reworking of their unsuccessful Thin Man (nuclear bomb), Thin Man nuclear bomb. Like Thin Man, it was a gun-type fission weapon, but it derived its explosive power from the nuclear fission of uranium-235, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
