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Hans Henrik Andersen
Hans Henrik Andersen (May 1, 1937 in Frederiksberg, Denmark – November 3, 2012) was a professor at the Niels Bohr Institute at the University of Copenhagen (emeritus since 2004). He was the founder and subsequently co-editor of the scientific journal "Nuclear Instruments and Methods in Physics Research B". He has made important contributions to various fields of atomic physics and solid state physics, especially in the field of the stopping power of matter for fast charged particles. The accuracy (0.3–0.5%) of his measurements is unsurpassed even today (2006). They were done by measuring the amount of heat deposited in a foil at the temperature of liquid helium (−269 °C). Together with his collaborators, he succeeded in showing in 1969 that the stopping power for fast alpha particles is more than four times as large as that for protons. Since the atomic number (''Z'') of alpha particles is exactly twice as big as that of protons, that means that the stopping power i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frederiksberg
Frederiksberg () is a part of the Capital Region of Denmark. It is formally an independent municipality, Frederiksberg Municipality, separate from Copenhagen Municipality, but both are a part of the City of Copenhagen. It occupies an area of less than 9 km2 and had a population of 103,192 in 2015. Frederiksberg is an enclave surrounded by Copenhagen Municipality. Some sources ambiguously refer to Frederiksberg as a quarter or neighbourhood of Copenhagen, being one of the four municipalities that constitute the City of Copenhagen (the other three being Copenhagen, Tårnby and Dragør). However, Frederiksberg has its own mayor and municipal council, and is fiercely independent. Frederiksberg is an affluent area, characterised by its many green spaces such as the Frederiksberg Gardens, Søndermarken, and Hostrups Have. Some institutions and locations that are widely considered to be part of Copenhagen are actually located in Frederiksberg. For example, Copenhagen Zo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Number
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of every atom of that element. The atomic number can be used to uniquely identify ordinary chemical elements. In an ordinary electric charge, uncharged atom, the atomic number is also equal to the number of electrons. For an ordinary atom, the sum of the atomic number ''Z'' and the neutron number ''N'' gives the atom's atomic mass number ''A''. Since protons and neutrons have approximately the same mass (and the mass of the electrons is negligible for many purposes) and the Binding energy#Mass change, mass defect of the nucleon binding is always small compared to the nucleon mass, the atomic mass of any atom, when expressed in Atomic mass unit, unified atomic mass units (making a quantity called the "atomic mass, relative isotopic mass"), is within ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2012 Deaths
This is a list of deaths of notable people, organised by year. New deaths articles are added to their respective month (e.g., Deaths in ) and then linked here. 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 See also * Lists of deaths by day * Deaths by year {{DEFAULTSORT:deaths by year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1937 Births
Events January * January 1 – Anastasio Somoza García becomes President of Nicaragua. * January 5 – Water levels begin to rise in the Ohio River in the United States, leading to the Ohio River flood of 1937, which continues into February, leaving 1 million people homeless and 385 people dead. * January 15 – Spanish Civil War: Second Battle of the Corunna Road ends inconclusively. * January 20 – Second inauguration of Franklin D. Roosevelt: Franklin D. Roosevelt is sworn in for a second term as President of the United States. This is the first time that the United States presidential inauguration occurs on this date; the change is due to the ratification in 1933 of the Twentieth Amendment to the United States Constitution. * January 23 – Moscow Trials: Trial of the Anti-Soviet Trotskyist Center – In the Soviet Union 17 leading Communists go on trial, accused of participating in a plot led by Leon Trotsky to overthrow Joseph Stalin's regime, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springer-Verlag
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in Berlin, it expanded internationally in the 1960s, and through mergers in the 1990s and a sale to venture capitalists it fused with Wolters Kluwer and eventually became part of Springer Nature in 2015. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. History Julius Springer founded Springer-Verlag in Berlin in 1842 and his son Ferdinand Springer grew it from a small firm of 4 employees into Germany's then second largest academic publisher with 65 staff in 1872.Chronology ". Springer Science+Business Media. In 1964, Springer expanded its business internationall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Physics A
''Nuclear Physics A'', ''Nuclear Physics B'', ''Nuclear Physics B: Proceedings Supplements'' and discontinued ''Nuclear Physics'' are peer-reviewed scientific journals published by Elsevier. The scope of ''Nuclear Physics A'' is nuclear and hadronic physics, and that of ''Nuclear Physics B'' is high energy physics, quantum field theory In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. QFT is used in particle physics to construct physical models of subatomic particles and ..., statistical systems, and mathematical physics. ''Nuclear Physics'' was established in 1956, and then split into ''Nuclear Physics A'' and ''Nuclear Physics B'' in 1967. A supplement series to ''Nuclear Physics B'', called ''Nuclear Physics B: Proceedings Supplements'' has been published from 1987 onwards. ''Nuclear Physics B'' is part of the SCOAP3 initiative. Abstracting and indexing ''Nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barkas Effect
Barkas may refer to: * Barkas (van manufacturer), a van manufacturer in the German Democratic Republic *Barkas, Hyderabad, a neighbourhood of Hyderabad, India *Barkas (surname) Barkas is a surname. Notable people with the surname include: *Harry Barkas (1906–1974), English footballer *Mary Barkas Mary Rushton Barkas (7 September 1889 – 17 April 1959) was a psychiatrist, physician and author from New Zealand. She ... See also * Barcas, a notable family in the ancient city of Carthage {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bethe Formula
The Bethe formula or Bethe-Bloch formula describes the mean energy loss per distance travelled of swift charged particles ( protons, alpha particles, atomic ions) traversing matter (or alternatively the stopping power of the material). For electrons the energy loss is slightly different due to their small mass (requiring relativistic corrections) and their indistinguishability, and since they suffer much larger losses by Bremsstrahlung, terms must be added to account for this. Fast charged particles moving through matter interact with the electrons of atoms in the material. The interaction excites or ionizes the atoms, leading to an energy loss of the traveling particle. The non-relativistic version was found by Hans Bethe in 1930; the relativistic version (shown below) was found by him in 1932.Sigmund, Peter ''Particle Penetration and Radiation Effects. Springer Series in Solid State Sciences, 151.'' Berlin Heidelberg: Springer-Verlag. (2006) The most probable energy loss differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton
A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ratio). Protons and neutrons, each with masses of approximately one atomic mass unit, 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 has a unique number of protons, each element has its own unique atomic number, which determines the number of atomic electrons and consequently the chemical characteristics of the element. The word ''proton'' is Greek language, G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denmark
) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , established_title = Consolidation , established_date = 8th century , established_title2 = Christianization , established_date2 = 965 , established_title3 = , established_date3 = 5 June 1849 , established_title4 = Faroese home rule , established_date4 = 24 March 1948 , established_title5 = EEC accession , established_date5 = 1 January 1973 , established_title6 = Greenlandic home rule , established_date6 = 1 May 1979 , official_languages = Danish , languages_type = Regional languages , languages_sub = yes , languages = GermanGerman is recognised as a protected minority language in the South Jutland area of Denmark. , demonym = , capital = Copenhagen , largest_city = capital , coordinates = , ethnic_groups = , ethnic_gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Particle
Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as or indicating a helium ion with a +2 charge (missing its two electrons). Once the ion gains electrons from its environment, the alpha particle becomes a normal (electrically neutral) helium atom . Alpha particles have a net spin of zero. Due to the mechanism of their production in standard alpha radioactive decay, alpha particles generally have a kinetic energy of about 5 MeV, and a velocity in the vicinity of 4% of the speed of light. (See discussion below for the limits of these figures in alpha decay.) T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stopping Power (particle Radiation)
In nuclear and materials physics, stopping power is the retarding force acting on charged particles, typically alpha and beta particles, due to interaction with matter, resulting in loss of particle kinetic energy. Its application is important in areas such as radiation protection, ion implantation and nuclear medicine.ICRU Report 73: Stopping of Ions heavier than Helium, Journal of the ICRU, 5 No. 1 (2005), Oxford Univ. Press Definition and Bragg curve Both charged and uncharged particles lose energy while passing through matter. Positive ions are considered in most cases below. The stopping power depends on the type and energy of the radiation and on the properties of the material it passes. Since the production of an ion pair (usually a positive ion and a (negative) electron) requires a fixed amount of energy (for example, 33.97 eV in dry air), the number of ionizations per path length is proportional to the stopping power. The ''stopping power'' of the material is num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
