翻訳と辞書 Words near each other ・ Alpha Phi Omega ・ Alpha Phi Omega (Philippines) ・ Alpha Phi Omega national conventions ・ Alpha Phi Sigma ・ Alpha Phi Sorority House (Eugene, Oregon) ・ Alpha Phoenicis ・ Alpha Pi Delta Sorority, Inc ・ Alpha Pi Mu ・ Alpha Pi Omega ・ Alpha Pictoris ・ Alpha Piscium ・ Alpha Plus ・ Alpha Plus Group ・ Alpha Polaris ・ Alpha Prime ・ Alpha process ・ Alpha Protocol ・ Alpha Psi Lambda ・ Alpha Psi Omega ・ Alpha Psi Rho ・ Alpha Pup Records ・ Alpha Pyxidis ・ Alpha Ralpha Boulevard ・ Alpha recursion theory ・ Alpha Regio ・ Alpha Repertory Television Service ・ Alpha Reticuli ・ Alpha Rev ・ Alpha Rho Chi ・ Alpha Rho Chi Fraternity House (Champaign, Illinois) Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Alpha process ： ウィキペディア英語版 Alpha process The alpha process, also known as the alpha ladder, is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple-alpha process. While the triple-alpha process only requires helium, once some carbon is present, these other reactions that consume helium are possible: :$\backslash mathrm\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmO\}\; +\; \backslash gamma$, Q = 7,16 МeV :$\backslash mathrm\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmNe\}\; +\; \backslash gamma$, Q = 4,73 МeV :$\backslash mathrmNe\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmMg\}\; +\; \backslash gamma$, Q = 9,32 МeV :$\backslash mathrmMg\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmSi\}\; +\; \backslash gamma$, Q = 9,98 МeV :$\backslash mathrmSi\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmS\}\; +\; \backslash gamma$, Q = 6,95 МeV :$\backslash mathrmS\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmAr\}\; +\; \backslash gamma$, Q = 6,64 МeV :$\backslash mathrmAr\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmCa\}\; +\; \backslash gamma$, Q = 7,04 МeV :$\backslash mathrmCa\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmTi\}\; +\; \backslash gamma$, Q = 5,13 МeV :$\backslash mathrmTi\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmCr\}\; +\; \backslash gamma$, Q = 7,70 МeV :$\backslash mathrmCr\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmFe\}\; +\; \backslash gamma$, Q = 7,94 МeV :$\backslash mathrmFe\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmNi\}\; +\; \backslash gamma$, Q = 8,00 МeV Energy Q  is produced principally in gamma ray ($\backslash gamma$) In the center of large and old stars, alpha ($\backslash mathrm$) particles are needed for those alpha reactions and by inverses reactions, like photodisintegration of nuclei available in the center. $\backslash mathrmNi\}$ is the lighter per nucléons alpha nuclei. Production of heavier nuclei requires energy. Ex: $\backslash mathrmNi\}\; +\; \backslash mathrm\; \backslash rightarrow\; \backslash mathrmZn\}\; +\; \backslash gamma$, Q = 2,71 МeV Energy is produced in the isolated fusion reaction of nickel-56 with helium-4, but less than consumed to product of helium-4 by photodisintegration of heavier nuclei, causing alpha buildup of nickel-56 to be shut off due to the essential fact that nickel-56 has nucleon binding energy less zinc-60. All these reactions have a very low rate at the temperatures and densities in stars and therefore do not contribute significantly to a star's energy production; with elements heavier than neon (atomic number > 10), they occur even less easily due to the increasing Coulomb barrier. Alpha process elements (or alpha elements) are so-called since their most abundant isotopes are integer multiples of four, the mass of the helium nucleus (the alpha particle). Stable alpha elements are: C, O, Ne, Mg, Si, S, Ar, Ca. They are synthesized by alpha capture prior to the silicon fusing process, a precursor to Type II supernovae. Silicon and calcium are purely alpha process elements. Magnesium can be burned by proton capture reactions. As for oxygen, some authors consider it an alpha element, while others do not. Oxygen is surely an alpha element in low-metallicity population II stars. It is produced in Type II supernovae and its enhancement is well correlated with an enhancement of other alpha process elements. Sometimes carbon and nitrogen are considered alpha process elements, since they are synthesized in nuclear alpha-capture reactions. The abundance of alpha elements in stars is usually expressed in a logarithmic manner: :$()\; =\; \backslash log\_\}\backslash right)\_\}\; -\; \backslash log\_\}\backslash right)\_\}$, Here $N\_$ and $N\_$ are the number of alpha elements and iron nuclei per unit volume. Theoretical galactic evolution models predict that early in the universe there were more alpha elements relative to iron. Type II supernovae mainly synthesize oxygen and the alpha-elements (Ne, Mg, Si, S, Ar, Ca and Ti) while Type Ia supernovae mainly produce elements of the iron peak (Ti, V, Cr, Mn, Fe, Co and Ni) but also alpha-elements. ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alpha process」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.