WordNet

(physical chemistry) a sample of matter in which substances in different phases are in equilibrium; "in a static system oil cannot be replaced by water on a surface"; "a system generating hydrogen peroxide"
instrumentality that combines interrelated interacting artifacts designed to work as a coherent entity; "he bought a new stereo system"; "the system consists of a motor and a small computer"
a group of independent but interrelated elements comprising a unified whole; "a vast system of production and distribution and consumption keep the country going" (同)scheme
a complex of methods or rules governing behavior; "they have to operate under a system they oppose"; "that language has a complex system for indicating gender" (同)system of rules
a group of physiologically or anatomically related organs or parts; "the body has a system of organs for digestion"
a procedure or process for obtaining an objective; "they had to devise a system that did not depend on cooperation"
the living body considered as made up of interdependent components forming a unified whole; "exercise helped him get the alcohol out of his system"
of or relating to or shaped like a quadrilateral

PrepTutorEJDIC

〈C〉(関連した部分から成る)『体系』,系統,組織[網],装置 / 〈C〉(教育・政治などの)『制度』,機構;《the~》体制 / 〈C〉(思想・学問などの)『体系』,学説 / 〈C〉(…の)『方法』,方式,やり方《+of doing》 / 〈U〉正しい方針(筋道,順序) / 〈U〉《the~》(身体の)組織,系統 / 〈U〉《the~,one's~》身体,全身

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2018/02/22 11:29:46」(JST)

wiki en

[Wiki en表示]

An example of the tetragonal crystals, wulfenite

In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (a by a) and height (c, which is different from a).

Bravais lattices

Two-dimensional

There is only one tetragonal Bravais lattice in two dimensions: the square lattice.

Three-dimensional

There are two tetragonal Bravais lattices: the simple tetragonal (from stretching the simple-cubic lattice) and the centered tetragonal (from stretching either the face-centered or the body-centered cubic lattice). One might suppose stretching face-centered cubic would result in face-centered tetragonal, but face-centered tetragonal is equivalent to body-centered tetragonal, BCT (with a smaller lattice spacing). BCT is considered more fundamental, so that is the standard terminology.^[1]

Bravais lattice	Primitive tetragonal	Body-centered tetragonal
Pearson symbol	tP	tI
Unit cell

Crystal classes

The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.^[2]^[3]

#	Point group					Example	Space groups
#	Class	Intl	Schoen.	Orb.	Cox.	Example	Space groups
75–80	Tetragonal pyramidal	4	C₄	44	[4]⁺	pinnoite, piypite	P4, P4₁, P4₂, P4₃ I4, I4₁
81–82	Tetragonal disphenoidal	4	S₄	2×	[2⁺,4⁺]	cahnite, tugtupite	P4 I4
83–88	Tetragonal dipyramidal	4/m	C_4h	4*	[2,4⁺]	scheelite, wulfenite, leucite	P4/m, P4₂/m, P4/n, P4₂/n I4/m, I4₁/a
89–98	Tetragonal trapezohedral	422	D₄	224	[2,4]⁺	cristobalite, wardite	P422, P42₁2, P4₁22, P4₁2₁2, P4₂22, P4₂2₁2, P4₃22, P4₃2₁2 I422, I4₁22
99–110	Ditetragonal pyramidal	4mm	C_4v	*44	[4]	diaboleite	P4mm, P4bm, P4₂cm, P4₂nm, P4cc, P4nc, P4₂mc, P4₂bc I4mm, I4cm, I4₁md, I4₁cd
111–122	Tetragonal scalenohedral	42m	D_2d	2*2	[2⁺,4]	chalcopyrite, stannite	P42m, P42c, P42₁m, P42₁c, P4m2, P4c2, P4b2, P4n2 I4m2, I4c2, I42m, I42d
123–142	Ditetragonal dipyramidal	4/mmm	D_4h	*224	[2,4]	rutile, pyrolusite, zircon	P4/mmm, P4/mcc, P4/nbm, P4/nnc, P4/mbm, P4/mnc, P4/nmm, P4/ncc, P4₂/mmc, P4₂/mcm, P4₂/nbc, P4₂/nnm, P4₂/mbc, P4₂/mnm, P4₂/nmc, P4₂/ncm I4/mmm, I4/mcm, I4₁/amd, I4₁/acd

References

^ Cubic-to-Tetragonal Transition
^ Webmineral data
^ Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 73–78, ISBN 0-471-80580-7

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 神経系のライム病 nervous system lyme disease
2. ペーシングシステムの誤作動：評価およびマネージメント pacing system malfunction evaluation and management
3. 自然免疫系の概要 an overview of the innate immune system
4. 免疫系におけるサイトカインの役割 role of cytokines in the immune system
5. 肺癌の腫瘍・リンパ節・転移（TNM）分類 tumor node metastasis tnm staging system for lung cancer

English Journal

TiO2 and ZrO2 in biomass conversion: why catalyst reduction helps.

Tosoni S1, Chen HT1,2, Ruiz Puigdollers A1, Pacchioni G3.
Philosophical transactions. Series A, Mathematical, physical, and engineering sciences.Philos Trans A Math Phys Eng Sci.2018 Jan 13;376(2110). pii: 20170056. doi: 10.1098/rsta.2017.0056.
PMID 29175816

Ferroelectric spontaneous polarization steering charge carriers migration for promoting photocatalysis and molecular oxygen activation.

Huang H1, Tu S2, Du X3, Zhang Y2.
Journal of colloid and interface science.J Colloid Interface Sci.2018 Jan 1;509:113-122. doi: 10.1016/j.jcis.2017.09.005. Epub 2017 Sep 6.
PMID 28898731

TiO2 nanoparticles supported on PMMA nanofibers for photocatalytic degradation of methyl orange.

Li Y1, Zhao H2, Yang M3.
Journal of colloid and interface science.J Colloid Interface Sci.2017 Dec 15;508:500-507. doi: 10.1016/j.jcis.2017.08.076. Epub 2017 Aug 23.
PMID 28866458