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1、McGraw-HillDictionaryofScientific&TechnicalTermslong-rangeorder(solid-statephysics)Atendencyforsomepropertyofatomsinalattice(suchasspinorientationortypeofatom)tofollowapatternwhichisrepeatedeveryfewunitcells.long-rangeorderAtomicpositionsinacrystalexhibitapropertycalledlong-rangeorderortransla
2、tionalperiodicity;positionsrepeatinspaceinaregulararray.EncyclopædiaBritannicaWikipediaTheordercanconsisteitherinafullcrystallinespacegroupsymmetry,orinacorrelation.Dependingonhowthecorrelationsdecaywithdistance,onespeaksoflong-rangeorderorshort-rangeorder.longrangeorder，结晶学概念。指整体性的有序现象。例如在一个单
3、晶体的范围内,质点的有序分布延伸到整个晶格的全部,亦即从整个晶体范围来看,质点的分布都是有序的。百度百科在晶体中若每种质点(黑点或圆圈)在整个图形中各自都呈现规律的周期性重复。把周期重复的点用直线联结起来，可获得平行四边形网格。可以想像，在三维空间，这种网格将构成空间格子，这种在图形中贯彻始终的规律称为远程规律或长程有序。教科书上（李胜荣，2012）长程有序(long-rangeorder)即晶体内部的原子排列具有延绵不断的有序性;反之叫短程有序（罗谷风，2010）EncyclopædiaBritannicaquasicrystal,alsocalledquasi-periodic
4、crystal,matterformedatomicallyinamannersomewherebetweentheamorphoussolidsofglasses(specialformsofmetalsandotherminerals,aswellascommonglass)andtheprecisepatternofcrystals.Likecrystals,quasicrystalscontainanorderedstructure,butthepatternsaresubtleanddonotrecuratpreciselyregularintervals.Wikiped
5、iaAquasiperiodiccrystal,or,inshort,quasicrystal,isastructurethatisorderedbutnotperiodic.Aquasicrystallinepatterncancontinuouslyfillallavailablespace,butitlackstranslationalsymmetry（平移对称）.Whilecrystals,accordingtotheclassicalcrystallographicrestrictiontheorem,canpossessonlytwo,three,four,andsix
6、-foldrotationalsymmetries,theBraggdiffractionpatternofquasicrystalsshowssharppeakswithothersymmetryorders,forinstancefive-fold.准晶体Quasicrystal：McGraw-HillScience&TechnologyEncyclopedia：Quasicrystal：Asolidwithconventionalcrystallinepropertiesbutexhibitingapoint-groupsymmetryinconsistentwithtran
7、slationalperiodicity.Likecrystals,quasicrystalsdisplaydiscretediffractionpatterns,crystallizeintopolyhedralforms,andhavelong-rangeorientationalorder,allofwhichindicatethattheirstructureisnotrandom.Buttheunusualsymmetryandthefindingthatt
