翻訳と辞書
Words near each other
・ X Singles
・ X Social Group
・ X SS Corps
・ X Stands for Unknown
・ X Sydney International Piano Competition
・ X tax
・ X terminal
・ X the album
・ X the Unknown
・ X to Y
・ X Toolkit Intrinsics
・ X Tour
・ X Tour (Ed Sheeran tour)
・ X Train
・ X Trianguli Australis
X unit
・ X v Bedfordshire CC
・ X v Canada (Commissioner of Patents)
・ X v United Kingdom
・ X video extension
・ X Vietnam (album)
・ X Visual Shock DVD Box 1989–1992
・ X Window authorization
・ X window manager
・ X Window selection
・ X Window System
・ X Window System core protocol
・ X Window System protocols and architecture
・ X woman
・ X X (band)


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

X unit : ウィキペディア英語版
X unit

: ''For the software testing tools, see xUnit.''
The x unit (symbol xu) is a unit of length approximately equal to 0.1 pm (10−13 m). It is used to quote the wavelength of X-rays and gamma rays.
Originally defined by the Swedish physicist Manne Siegbahn (1886–1978) in 1925, the x unit could not at that time be measured directly; the definition was instead made in terms of the spacing between planes of the calcite crystals used in the measuring apparatus. One x unit was set at of the spacing of the (200) planes of calcite at 18 °C.
In modern usage, there are two separate x units, which are defined in terms of the wavelengths of the two most commonly used X-ray lines in X-ray crystallography:
* the copper x unit (symbol xu(Cu Kα1)) is defined so that the wavelength of the 1 line of copper is exactly 1537.400 xu(Cu Kα1);
* the molybdenum x unit (symbol xu(Mo Kα1)) is defined so that the wavelength of the Kα1 line of molybdenum is exactly 707.831 xu(Mo Kα1).
The 2006 CODATA recommended values for these units are:
:1 xu(Cu Kα1) = ,
:1 xu(Mo Kα1) = .
== See also ==

* Ångström

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「X unit」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.