〈湯姆生 Joseph John Thomson〉的留言 /highscope/%e6%b9%af%e5%a7%86%e7%94%9f-joseph-john-thomson/ 科學Online Wed, 06 Oct 2021 08:24:06 +0000 hourly 1 https://wordpress.org/?v=6.9 留言者: jtchen /highscope/%e6%b9%af%e5%a7%86%e7%94%9f-joseph-john-thomson/comment-page-1/#comment-1751 Sat, 24 Aug 2013 18:31:31 +0000 http://case.ntu.edu.tw/highscope/?p=35443#comment-1751 http://en.wikipedia.org/wiki/Mass_spectrometry#History

In 1886, Eugen Goldstein observed rays in gas discharges under low pressure that traveled away from the anode and through channels in a perforated cathode, opposite to the direction of negatively charged cathode rays (which travel from cathode to anode). Goldstein called these positively charged anode rays “Kanalstrahlen”; the standard translation of this term into English is “canal rays”. Wilhelm Wien found that strong electric or magnetic fields deflected the canal rays and, in 1899, constructed a device with parallel electric and magnetic fields that separated the positive rays according to their charge-to-mass ratio (Q/m). Wien found that the charge-to-mass ratio depended on the nature of the gas in the discharge tube. English scientist J.J. Thomson later improved on the work of Wien by reducing the pressure to create the mass spectrograph.

The first application of mass spectrometry to the analysis of amino acids and peptides was reported in 1958.[12] Carl-Ove Andersson highlighted the main fragment ions observed in the ionization of methyl esters.[13]

Some of the modern techniques of mass spectrometry were devised by Arthur Jeffrey Dempster and F.W. Aston in 1918 and 1919 respectively. In 1989, half of the Nobel Prize in Physics was awarded to Hans Dehmelt and Wolfgang Paul for the development of the ion trap technique in the 1950s and 1960s. In 2002, the Nobel Prize in Chemistry was awarded to John Bennett Fenn for the development of electrospray ionization (ESI) and Koichi Tanaka for the development of soft laser desorption (SLD) and their application to the ionization of biological macromolecules, especially proteins.[14]

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留言者: 學生 /highscope/%e6%b9%af%e5%a7%86%e7%94%9f-joseph-john-thomson/comment-page-1/#comment-1750 Sat, 17 Aug 2013 11:51:49 +0000 http://case.ntu.edu.tw/highscope/?p=35443#comment-1750 請問一下 質譜儀究竟是誰發明的?本頁寫是湯姆生
(http://case.ntu.edu.tw/hs/wordpress/?p=35443#more-35443)
維基百科卻寫是弗朗西斯·阿斯頓
(http://zh.wikipedia.org/zh-tw/%E5%8E%9F%E5%AD%90%E8%B4%A8%E9%87%8F%E5%8D%95%E4%BD%8D)

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