ISO/IEC 14834-1996 信息技术分布式事务处理XA规范

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【英文标准名称】:StandardGuideforX-RayComptonScatterTomography
【原文标准名称】:X射线康普顿散射断层摄影的标准指南
【标准号】:ASTME1931-2009
【标准状态】:现行
【国别】:美国
【发布日期】:2009
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E07.01
【标准类型】:(Guide)
【标准水平】:()
【中文主题词】:
【英文主题词】:back-scatter;comptonscattertomography;computedtomography;CST;radiologic;radioscopic;sliceimage;tomography;CST(Comptonscattertomography);Imageanalysis;Radioisotopes;Radiologicalexamination;Sliceimage;Tomography;X-rayComptonscatter
【摘要】:PrincipalAdvantageofComptonScatterTomography8212;TheprincipaladvantageofCSTistheabilitytoperformthree-dimensionalX-rayexaminationwithouttherequirementforaccesstothebacksideoftheexaminationobject.CSToffersthepossibilitytoperformX-rayexaminationthatisnotpossiblebyanyothermethod.TheCSTsub-surfacesliceimageisminimallyaffectedbyexaminationobjectfeaturesoutsidetheplaneofexamination.Theresultisaradioscopicimagethatcontainsinformationprimarilyfromthesliceplane.Scatteredradiationlimitsimagequalityinnormalradiographicandradioscopicimaging.ScatterradiationdoesnothavethesamedetrimentaleffectuponCSTbecausescatterradiationisusedtoformtheimage.Infact,themoreradiationtheexaminationobjectscatters,thebettertheCSTresult.LowsubjectcontrastmaterialsthatcannotbeimagedwellbyconventionalradiographicandradioscopicmeansareoftenexcellentcandidatesforCST.VeryhighcontrastsensitivitiesandexcellentspatialresolutionarepossiblewithCSTtomography.Limitations8212;Aswithanynondestructivetestingmethod,CSThasitslimitations.Thetechniqueisusefulonreasonablythicksectionsoflow-densitymaterials.Whilea25mm(1in.)depthinaluminumor50mm(2in.)inplasticisachievable,theexaminationdepthisdecreaseddramaticallyasthematerialdensityincreases.Properimageinterpretationrequirestheuseofstandardsandexaminationobjectswithknowninternalconditionsorrepresentativequalityindicators(RQIs).Theexaminationvolumeistypicallysmall,ontheorderofafewcubicinchesandmayrequireafewminutestoimage.Therefore,completelyexamininglargestructureswithCSTrequiresintensivere-positioningoftheexaminationvolumethatcanbetime-consuming.Aswithotherpenetratingradiationmethods,theradiationhazardmustbeproperlyaddressed.1.1Purpose8212;ThisguidecoversatutorialintroductiontofamiliarizethereaderwiththeoperationalcapabilitiesandlimitationsinherentinX-rayComptonScatterTomography(CST).AlsoincludedisabriefdescriptionofthephysicsandtypicalhardwareconfigurationforCST.1.2Advantages8212;X-rayComptonScatterTomography(CST)isaradiologicnondestructiveexaminationmethodwithseveraladvantagesthatinclude:1.2.1TheabilitytoperformX-rayexaminationwithoutaccesstotheoppositesideoftheexaminationobject;1.2.2TheX-raybeamneednotcompletelypenetratetheexaminationobjectallowingthickobjectstobepartiallyexamined.Thickexaminationobjectsbecomepartoftheradiationshieldingtherebyreducingtheradiationhazard;1.2.3Theabilitytoexamineandimageobjectsubsurfacefeatureswithminimalinfluencefromsurfacefeatures;1.2.4Theabilitytoobtainhigh-contrastimagesfromlowsubjectcontrastmaterialsthatnormallyproducelow-contrastimageswhenusingtraditionaltransmittedbeamX-rayimagingmethods;and1.2.5Theabilitytoobtaindepthinformationofobjectfeaturestherebyprovidingathree-dimensionalexamination.Theabilitytoobtaindepthinformationpresupposestheuseofahighlycollimateddetectorsystemhavinganarrowangleofacceptance.1.3Applications8212;Thisguidedoesnotspecifywhichexaminationobjectsaresuitable,orunsuitable,forCST.Aswithmostnondestructiveexaminationtechniques,CSTishighlyapplicationspecifictherebyrequiringthesuitabilityofthemethodtobefirstdemonstratedintheapplicationlabor......
【中国标准分类号】:N78
【国际标准分类号】:35_240_80
【页数】:13P.;A4
【正文语种】:英语


Product Code:SAE AIR1489
Title:Aerospace Landing Gear Systems Terminology
Issuing Committee:A-5 Aerospace Landing Gear Systems Committee
Scope:This report has been compiled by the Landing Gear Systems Terminology panel of SAE Committee A-5 (Aerospace Landing Gear Systems). It represents an effort to gather together those terms commonly used within the discipline. Some terms are of course common to other disciplines as well. Others, however, are unique in form and/or meaning to the Landing Gear discipline. The need has been noted to set these terms down and provide a standard definition in order that communication within the discipline may be conducted with a common understanding. Full use has been made of available published information, and a list of references is provided.