ऀ in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92).
All the transuranium elements of the actinide series were discovered as synthetic radioactive isotopes at the Univ. of California at Berkeley or at Argonne National Laboratory; in order of increasing atomic number they are neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and lawrencium. Of these only neptunium and plutonium occur in nature; they are produced in minute amounts in the radioactive decay of uranium. 1 䴀甀挀栀 漀昀 琀栀攀 猀琀甀搀礀 漀昀 琀栀攀 琀爀愀渀猀甀爀愀渀椀甀洀 攀氀攀洀攀渀琀猀 栀愀猀 琀愀欀攀渀 瀀氀愀挀攀 愀琀 琀栀攀 䰀愀眀爀攀渀挀攀 䈀攀爀欀攀氀攀礀 一愀琀椀漀渀愀氀 䰀愀戀漀爀愀琀漀爀礀 ⠀愀琀 䈀攀爀欀攀氀攀礀Ⰰ 䌀愀氀椀昀⸀⤀ 愀渀搀 愀琀 琀栀攀 䨀漀椀渀琀 䤀渀猀琀椀琀甀琀攀 昀漀爀 一甀挀氀攀愀爀 刀攀猀攀愀爀挀栀 椀渀 䐀甀戀渀愀Ⰰ 刀甀猀猀椀愀㬀 眀漀爀欀攀爀猀 愀琀 戀漀琀栀 氀漀挀愀琀椀漀渀猀 猀栀愀爀攀 挀爀攀搀椀琀 昀漀爀 琀栀攀 椀渀搀攀瀀攀渀搀攀渀琀 搀椀猀挀漀瘀攀爀礀 漀昀 爀甀琀栀攀爀昀漀爀搀椀甀洀Ⰰ 搀甀戀渀椀甀洀Ⰰ 愀渀搀 猀攀愀戀漀爀最椀甀洀 ⠀愀琀⸀ 渀漀⸀ 㐀Ⰰ 㔀Ⰰ 愀渀搀 㘀Ⰰ 爀攀猀瀀攀挀琀椀瘀攀氀礀⤀Ⰰ 眀栀椀挀栀 愀爀攀 琀栀攀 昀椀爀猀琀 琀栀爀攀攀 琀爀愀渀猀愀挀琀椀渀椀搀攀 攀氀攀洀攀渀琀猀⸀ 䄀 䜀攀爀洀愀渀 琀攀愀洀 愀琀 琀栀攀 䤀渀猀琀椀琀甀琀攀 昀漀爀 䠀攀愀瘀礀 䤀漀渀 刀攀猀攀愀爀挀栀 愀琀 䐀愀爀洀猀琀愀搀琀 搀椀猀挀漀瘀攀爀攀搀 戀漀栀爀椀甀洀Ⰰ 栀愀猀猀椀甀洀Ⰰ 洀攀椀琀渀攀爀椀甀洀Ⰰ 搀愀爀洀猀琀愀搀琀椀甀洀Ⰰ 爀漀攀渀琀最攀渀椀甀洀Ⰰ 愀渀搀 甀渀甀渀戀椀甀洀 ⠀愀琀⸀ 渀漀⸀ 㜀 琀栀爀漀甀最栀 ㈀⤀⸀ 吀栀攀 䐀甀戀渀愀 氀愀戀漀爀愀琀漀爀礀Ⰰ 眀椀琀栀 愀猀猀椀猀琀愀渀挀攀 昀爀漀洀 䈀攀爀欀攀氀攀礀Ⰰ 挀氀愀椀洀猀 琀漀 栀愀瘀攀 猀礀渀琀栀攀猀椀稀攀搀 甀渀甀渀焀甀愀搀椀甀洀 ⠀愀琀⸀ 渀漀⸀ 㐀⤀Ⰰ 愀渀搀 眀漀爀欀椀渀最 樀漀椀渀琀氀礀 眀椀琀栀 琀栀攀 䰀愀眀爀攀渀挀攀 䰀椀瘀攀爀洀漀爀攀 一愀琀椀漀渀愀氀 䰀愀戀漀爀愀琀漀爀礀 ⠀愀琀 䰀椀瘀攀爀洀漀爀攀Ⰰ 䌀愀氀椀昀⸀⤀ 挀氀愀椀洀猀 琀漀 栀愀瘀攀 瀀爀漀搀甀挀攀搀 甀渀甀渀琀爀椀甀洀 ⠀愀琀⸀ 渀漀⸀ ㌀⤀ 愀渀搀 甀渀甀渀瀀攀渀琀椀甀洀 ⠀愀琀⸀ 渀漀⸀ 㔀⤀⸀ 吀栀攀 䈀攀爀欀攀氀攀礀 琀攀愀洀 挀氀愀椀洀攀搀 琀漀 栀愀瘀攀 瀀爀漀搀甀挀攀搀 甀渀甀渀栀攀砀椀甀洀 ⠀愀琀⸀ 渀漀⸀ 㘀⤀ 愀渀搀 甀渀甀渀漀挀琀椀甀洀 ⠀愀琀⸀ 渀漀⸀ 㠀⤀Ⰰ 戀甀琀 氀愀琀攀爀 爀攀琀爀愀挀琀攀搀 琀栀攀 挀氀愀椀洀 昀漀爀 甀渀甀渀漀挀琀椀甀洀 愀昀琀攀爀 漀琀栀攀爀 氀愀戀漀爀愀琀漀爀椀攀猀 昀愀椀氀攀搀 琀漀 爀攀瀀爀漀搀甀挀攀 䈀攀爀欀攀氀攀礀ᤀ猀 爀攀猀甀氀琀猀 愀渀搀 愀 爀攀愀渀愀氀礀猀椀猀 漀昀 琀栀攀椀爀 搀愀琀愀 搀椀搀 渀漀琀 猀栀漀眀 琀栀攀 瀀爀漀搀甀挀琀椀漀渀 漀昀 琀栀攀 攀氀攀洀攀渀琀⸀ 伀琀栀攀爀 爀攀猀攀愀爀挀栀 琀攀愀洀猀 栀愀瘀攀 猀椀渀挀攀 猀礀渀琀栀攀猀椀稀攀搀 甀渀甀渀栀攀砀椀甀洀 搀椀爀攀挀琀氀礀⸀ऀ ㈀ऀ Up to and including fermium (at. no. 100), the transuranium elements are produced by the capture of neutrons;
the transfermium elements are synthesized by the bombardment of transuranium targets with light particles or, more recently, by projecting medium-weight elements at targets of other medium-weight elements (see also synthetic elements). 3 䤀猀漀琀漀瀀攀猀 漀昀 琀栀攀 琀爀愀渀猀甀爀愀渀椀甀洀 攀氀攀洀攀渀琀猀 愀爀攀 爀愀搀椀漀愀挀琀椀瘀攀 戀攀挀愀甀猀攀 琀栀攀椀爀 氀愀爀最攀 渀甀挀氀攀椀 愀爀攀 甀渀猀琀愀戀氀攀Ⰰ 愀渀搀 琀栀攀 琀爀愀渀猀愀挀琀椀渀椀搀攀Ⰰ 漀爀 猀甀瀀攀爀栀攀愀瘀礀Ⰰ 攀氀攀洀攀渀琀猀 椀渀 瀀愀爀琀椀挀甀氀愀爀 栀愀瘀攀 瘀攀爀礀 猀栀漀爀琀 栀愀氀昀ⴀ氀椀瘀攀猀⸀ 䠀漀眀攀瘀攀爀Ⰰ 漀渀 琀栀攀 戀愀猀椀猀 漀昀 琀栀攀漀爀椀攀猀 漀昀 渀甀挀氀攀愀爀 猀琀爀甀挀琀甀爀攀Ⰰ 瀀栀礀猀椀挀椀猀琀猀 栀愀瘀攀 瀀爀攀搀椀挀琀攀搀 琀栀愀琀 挀攀爀琀愀椀渀 琀爀愀渀猀愀挀琀椀渀椀搀攀 攀氀攀洀攀渀琀猀 洀愀礀 栀愀瘀攀 爀攀氀愀琀椀瘀攀氀礀 猀琀愀戀氀攀 椀猀漀琀漀瀀攀猀⸀ 䘀漀爀 攀砀愀洀瀀氀攀Ⰰ 愀渀 椀猀漀琀漀瀀攀 漀昀 攀氀攀洀攀渀琀 㐀 眀椀琀栀 洀愀猀猀 渀甀洀戀攀爀 ㈀㤀㠀 ⠀挀漀洀瀀爀椀猀椀渀最 㐀 瀀爀漀琀漀渀猀 愀渀搀 㠀㐀 渀攀甀琀爀漀渀猀⤀ 猀栀漀甀氀搀 戀攀 瘀攀爀礀 猀琀愀戀氀攀 愀渀搀 爀攀猀攀洀戀氀攀 氀攀愀搀 椀渀 椀琀猀 挀栀攀洀椀挀愀氀 瀀爀漀瀀攀爀琀椀攀猀⸀ 䠀漀眀攀瘀攀爀Ⰰ 琀栀攀 琀栀爀攀攀 椀猀漀琀漀瀀攀猀 漀昀 攀氀攀洀攀渀琀 㐀 琀栀愀琀 愀爀攀 挀氀愀椀洀攀搀 琀漀 栀愀瘀攀 戀攀攀渀 猀礀渀琀栀攀猀椀稀攀搀 栀愀瘀攀 昀攀眀攀爀 琀栀愀渀 琀栀攀 爀攀焀甀椀猀椀琀攀 㠀㐀 渀攀甀琀爀漀渀猀⸀
Edwin Mattison McMillan was born on 18th September, 1907, at Redondo Beach, California. He is the son of Dr. Edwin Harbaugh McMillan, a physician, and his wife, Anne Marie McMillan, née Mattison, who both came from the State of Maryland and were both of English and Scottish descent. The boy spent his early years in Pasadena, California, and obtained his education in that state. 㰀⼀瀀㸀㰀瀀㸀 McMillan attended the California Institute of Technology, obtaining a B.Sc. degree in 1928, and taking his M.Sc. degree a year later, then transferring to Princeton University for Ph.D. in 1932. The same year he entered the University of California at Berkeley as a National Research Fellow. The thesis he submitted for Ph.D. was in the field of molecular beams, and the problem he undertook as a National Research Fellow was the measurement of the magnetic moment of the proton by a molecular beam method. After two years on this work and one as a research associate he became a Staff Member of the Radiation Laboratory under Professor E.O. Lawrence, studying nuclear reactions and their products, and helping in the design and construction of cyclotrons and other equipment, and a member of the Faculty in the Department of Physics at Berkely, being appointed Instructor in 1935, Assistant Professor in 1936, Associate Professor, 1941, and Professor in 1946. 㰀⼀瀀㸀㰀瀀㸀 During the Second World War, McMillan was on leave from November, 1940, to September, 1945, engaged on national defence research, serving (1940-1941) in the Radiation Laboratory, Massachusetts Institute of Technology; (1941-1942) U. S. Navy Radio and Sound Laboratory, San Diego; (1942-1945) Manhattan District, Los Alamos. 㰀⼀瀀㸀㰀瀀㸀 It was during 1945 that he had the idea of "phase stability" which led to the development of the synchroton and synchro-cyclotron; these machines have already extended the energies of artificially accelerated particles into the region of hundreds of MeV and have made possible many important researches. 㰀⼀瀀㸀㰀瀀㸀 McMillan returned to the University of California Radiation Laboratory as Associate Director from 1954-1958, when he was raised to Deputy Director and finally Director, in the same year. 㰀⼀瀀㸀㰀瀀㸀 In 1951 he received the 1950 Research Corporation Scientific Award, and in 1963 he shared the Atoms for Peace Award with Professor V. I. Veksler. 㰀⼀瀀㸀㰀瀀㸀 Professor McMillan is a Fellow of the American Physical Society and the American Academy of Arts and Sciences, a member of the National Academy of Sciences and the American Philosophical Society, and from 1954-1958 he served on the General Advisory Committee to the Atomic Energy Commission. In 1960 he was appointed to the Commission on High Energy Physics of the International Union of Pure and Applied Physics. 㰀⼀瀀㸀㰀瀀㸀 An honorary doctorate in science was awarded to him by the Rensselaer Polytechnic Institute in 1961, and by Gustavus Adolphus College in 1963. 㰀⼀瀀㸀㰀瀀㸀 While serving in the Faculty of Physics at Berkeley, McMillan married Elsie Walford Blumer, a daughter of Dr. George Blumer, Dean Emeritus of the Yale Medical School. There are three children of the marriage - Ann Bradford (1943), David Mattison (1945) and Stephen Walker (1949).
sponsors link òþíèíã àâòî
òþíèíã ìàøèí