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【英文标准名称】:StandardPracticesforExtractionofTraceElementsfromSediments
【原文标准名称】:萃取沉积物中痕量元素的标准实施规程
【标准号】:ASTMD3974-1981(2003)e1
【标准状态】:现行
【国别】:
【发布日期】:1981
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:D19.07
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:萃取;沉积物;工艺;痕量元素;水
【英文主题词】:extraction;sediments;toxic;traceelements;
【摘要】:Industrializedandurbanareashavebeenfoundtodepositanumberoftoxicelementsintoenvironmentswherethoseelementswerepreviouslyeithernotpresentorwerefoundintraceamounts.Consequently,itisimportanttobeabletomeasuretheconcentrationofthesepollution-depositedelementstoproperlystudypollutioneffects.Thisprocedureisconcernedwiththepollution-relatedtraceelementsthataredescribedin4.1ratherthanthoseelementsincorporatedinthesilicatelatticesofthemineralsfromwhichthesedimentswerederived.Thesepollution-relatedtraceelementsarereleasedintothewaterandreadsorbedbythesedimentswithchangesingeneralwaterquality,pHinparticular.Theseelementsareaserioussourceofpollution.Theelementslockedinthesilicatelatticesarenotreadilyavailableinthebiosphere(1-8).Whencomparingthetraceelementconcentrations,itisimportanttoconsidertheparticlesizestobeanalyzed(8,9).5.3.1Thefinertheparticlethegreaterthesurfacearea.Consequently,apotentiallygreateramountofagiventraceelementcanbeadsorbedonthesurfaceoffine,particulatesamples(4).Forparticlesizessmallerthan80mesh,metalcontentisnolongerdependentonsurfacearea.Therefore,ifthisportionofthesedimentisused,theanalysiswithrespecttosampletype(thatis,sand,salt,orclay)isnormalized.Ithasalsobeenobservedthatthegreatestcontrastbetweenanomalousandbackgroundsamplesisobtainedwhenlessthan80-meshportionofthesedimentisused(4,5).5.3.2Afterthesampleshavebeendried,caremustbetakennottogrindthesampleinsuchawaytoalterthenaturalparticle-sizedistribution(14.1).Fracturingaparticledisruptsthesilicatelatticeandmakesavailablethoseelementswhichotherwisearenoteasilydigested(6).Normally,aggregatesofdried,naturalsoils,sediments,andmanyclaysdissociateoncethereagentsareadded(14.3and15.2).1.1Thesepracticesdescribethepartialextractionofsoils,bottomsediments,suspendedsediments,andwaterbornematerialstodeterminetheextractableconcentrationsofcertaintraceelements.1.1.1PracticeAiscapableofextractingconcentrationsofaluminum,boron,barium,cadmium,calcium,chromium,cobalt,copper,iron,lead,magnesium,manganese,molybdenum,nickel,potassium,sodium,strontium,vanadium,andzincfromtheprecedingmaterials.Othermetalsmaybedeterminedusingthispractice.Thisextractionisthemorevigorousandmorecomplicatedofthetwo.1.1.2PracticeBiscapableofextractingconcentrationsofaluminum,cadmium,chromium,cobalt,copper,iron,lead,manganese,nickel,andzincfromtheprecedingmaterials.Othermetalsmaybedeterminedusingthispractice.ThisextractionislessvigorousandlesscomplicatedthanPracticeA.1.2Thesepracticesdescribethreemeansofpreparingsamplespriortodigestion:1.2.1Freeze-drying.1.2.2Air-dryingatroomtemperature.1.2.3Acceleratedair-drying,forexample,95C.1.3Thedetectionlimitandlinearconcentrationrangeofeachprocedureforeachelementisdependentontheatomicabsorptionspectrophotometricorothertechniqueemployedandmaybefoundinthemanualaccompanyingtheinstrumentused.AlsoseevariousASTMtestmethodsfordeterminingspecificmetalsusingatomicabsorptionspectrophotometrictechniques.1.3.1Thesensitivityofthepracticecanbeadjustedbyvaryingthesamplesize(14.2)orthedilutionofthesample(14.6),orboth.1.4Extractabletraceelement......
【中国标准分类号】:G04
【国际标准分类号】:13_060_30
【页数】:4P.;A4
【正文语种】:


【英文标准名称】:Energy-EfficientDesignofLow-RiseResidentialBuildings
【原文标准名称】:低层住宅建筑能效设计
【标准号】:ANSI/ASHRAE90.2i-2004
【标准状态】:作废
【国别】:美国
【发布日期】:2004
【实施或试行日期】:
【发布单位】:美国国家标准学会(ANSI)
【起草单位】:ANSI
【标准类型】:()
【标准水平】:()
【中文主题词】:
【英文主题词】:Domesticfacilities;Energyconservations;Low-energyhouses;Thermalenvironmentsystems
【摘要】:
【中国标准分类号】:P31
【国际标准分类号】:91_010_30;91_040_30;91_140_99
【页数】:
【正文语种】:英语