简介:RapidsolidificationofCu-Pbmonotecticalloyshasbeenaccomplishedduringfreefallina3mdroptube.BothmacrosegregatedanduniformlydispersedstructuresareobservedinCu-40wtpctPballoydroplets,whereasdropletsofcompositionCu-64wtpctPbexhibitonlymacrosegregationmorphologies.Themicrostructuresarestronglydependentondropletsize.Thehigherundercoolingtendstofacilitateliquidphaseseparationandresultsinmoreextensivemacrosegregationinsmallerdroplets.ThereexistsapronouncedtendencyforthePb-richliquidtooccupythesurfaceofthedropletsofbothcompositions,resultingfromthequitelowersurfacetensionofthePb-richphaseandcausingaPb-richlayeratthesurfaceofthesolidifieddroplet.ThenucleationofmonotecticcellsintheCu-40wtpctPbdropletswithdispersedstructurespreferentiallyoccursatthedropletsurface.Asinglenucleationeventtakesplacemorefrequentlyasdropletsizeisreduced.
简介:ThetreatmentoftheGacuncomplexCu-PbbulkconcentratewithhighZn,Ag,etc.,byoxygenpressureacidleachingwasstudied.Theprimarycopperandleadmineralsintheconcentratearetetrahedriteandgalena.Thetreatmentoftetrahedritewasrarelystudied,andmostofsilveroccurredinthemineraltoo.Theoptimumoperatingparametersofoxygenpressureacidleachingwereestablishedbyconditionaltests.Undertheseparameters,theresultofpilotscaletestshowedthattheleachingpercentagesofcopperandzincwereseparatelyashighas98.9wt.%and94.9wt.%,whileleadandsilverweretransformedintosulfateandsulfideprecipitations,respectively.Thecopperandzincinlixiviumwerereclaimedbyextraction-electrowinningandpurification-electrowinning,respectively,andtheleadandsilverintheresiduewerereclaimedseparatelybycarbonatetransformation-silicofluoricacidleachingandthiourealeaching.
简介:Al-4。5Cu-5Pb合金被扔的沙和寒冷准备。一样的合金也是在1.6MPa的一个煤气的压力扔的水花。微结构特征展览一对为沙和寒冷铸石金的好树枝状的形态学粗糙。Equiaxed谷物被观察因为水花形成了合金。穿测试采用一根大头针--在圆盘上类型安装,揭示更加更低与寒冷和沙铸石金的相比水花穿扔的合金。词法特征在显示的标本和碎片上穿轨道混合oxidative-cum-adhesive为在现在的调查测试的这些合金穿机制。(编辑作者摘要)36个裁判员。
简介:摘要;本设计采用电感耦合等离子发射光谱法(ICP—OES)对岩石样品中的Cu,Pb,Zn,Mn,Ni进行了测定,样品用四酸()熔矿,不经分离杂质,即可直接测定。该方法选择Cu,Pb,Zn,Mn,Ni的测定分析波长分别为324.7nm,220.3nm,202.5nm,257.6nm,221.6nm分析了用HCl提取与用王水提取,样品首先经磨样机碎至200目,用去离子水湿润后,用四酸熔矿,再将坩埚放置恒温电热板上加热,最后分别用王水或盐酸提取再定容,对其中的Cu,Pb,Zn,Mn,Ni做探究实验。
简介:建立起HNO3-H2O2-HF体系微波消解前处理样品,利用电感耦合等离子体质谱(ICP—MS)同时测定土壤中的铬(Cr)、镍(Ni)、铜(Cu)、砷(As)、铊(Tl)、铅(Pb)6种重金属元素含量的方法。该方法的相关系数在0.9996~1.000,相对标准偏差在0.669%~3.02%,加标回收率为94.68%~115.5%,检出限为2.004~312.4ng/L,结果表明该方法满足重金属分析的要求。用建立起的方法测定了来自湖南、湖北、云南、贵州、河南、福建、辽宁7个省45个产区烟田土壤中的Cr、Ni、Cu、As、田和Pb6种重金属元素含量;与对应烟叶中的6种重金属含量相比,聚类分析结果表明不同省区间土壤中的重金属含量无明显差异,而烟叶中却差异明显。
简介:TheadsorptionkineticsofPb^2+ondifferentsoilsandmineralswithvariablechargeswasstudiedbythetwoion-selectiveelectrodetechniqueatdifferentpHandconcentrations.Theresultsshowedthatmorethan95%ofadsorptiononallthesamplesoccurredduringthefirst5minutes.Alladsorptiontime-dependentdatacouldfitthesurfacesecond-orderequationverywell.ThevaluesofXmweregoethite>kaolinite,andlatosol>redsoilatthesameinitialreactionconcentration.Thevaluesofkwerekaolinite>>goethite,andlatosol>redsoilatthesamereactionpHandinitialconcentration.ThehigherthesuspensionpH,thefastertheadsorptionoccurred.ThemeaningofXmgotbythetwoion-selectiveelectrodetechnique(onekindofbatchtechnique)wasdifferentfromthatbythemiscibledisplacementtechniqueinthattheformerwasonlytheequilibriumadsorptionamountatadefiniteconcentrationandpH,butthelatterwasalmostequaltotheadsorptioncapacityatadefinitepHwithmuchlessinfluenceofconcentration.OnePb^2+wassupposedtooccupytwoadsorptionsitesastheadsorptionmechanismisconcerned.
简介:UltrasonicvelocitieshavebeenmeasuredinsinglephaseBi1.7Pb0.3Sr2CaCu2O8+xandBi1.7Pb0.3Sr2Ca2O10+xpolycrystallinesamples.Anomalouschangesofbothlongitudinalandtransversevelocitieswereobservednear200K,whichindicatesthatsomestructuralphasetransitiomightoccur.Theelasticconstantsofthesesampleshavebeendeterminedfromthemeasuredultrasonicvelocitydata,whicharemuchsmallerthanthoseofYBa2Cu3O7-yandBaTiO3,manifestingthattheinterlayercoup-lingwilldramaticallydecreasewhenthec-axesoftheunitcellsoftheseperovstite-likemultilayerceramicsincrease.ThevaluesofPoissonratio,however,ofthoseceramicsareveryclose,implyingsimilarinteratomicbondingforces.Correctedtovoid-freestate,theDebyetemperatureofthesematerialsisestirnatedas270±20k.ThetemperaturedependenceofDebyetemperaturesforthesematerialsisalsocalculatedbyusingthesamemethodandreportedforthefirsttime.
简介:TheprocesstoobtainhighT(110K)phasequickly,themicrostructureandpropertiesofAg-sheathedBi(Pb)-Sr-Ca-Cu-Osuperconductortapeshavebeenstudied.ItwasfoundthattheformationtimeofthehighTcphasewasgreatlyshortenedbytheadditionofmoreCaandCutothenominalcompositionofBi(Pb):Sr:Ca:Cu=2:2:2:3andtheadoptionofappropriatesinteringtemperatureandcoolingrate.SuperconductorpowderwithpredominanthighT,phasewaspreparedaftera840C/50htreatment.TheJoftheAg-sheathedtapesandthemagneticfielddependenceofJwereobviouslyimprovedbyrepeatedlypres-singandsintering.Themaximumtransportcurrentdensityat77Kinazeromagneticfieldwas12,200A/cm2.ThemagneticdependenceofJwassummarizedasfollows:6.450A/cm2(B⊥1.B∥S.0.1T)1,810A/cm2(B⊥1.B∥S,1T),390A/cm2(B⊥1.B∥S,2T)(B:magneticfield.1:electriccurrent.S:surfaceoftapes).TheimprovementofJwasattributedtotheformationoftheplate-likestructurewithhomogeneouscompositiondistributionandthestrongc-axistexture.
简介:TheTruongSonFoldBelt,locatedatthenortheasternmarginoftheIndochinaBlock,isconsideredtobetectonicallylinkedtothesubductionofthePaleotethysOceanandsubsequentcollision.SeponisoneofthemostimportantsuperlargedepositsoftheTruongSonFoldBelt.OurLA-ICP-MSzirconU-PbdatingresultsshowthatgranodioriteporphyrysamplesfromtheSepondeposithaveagesof302.1-4-2.9Ma,whichisacrucialphaseformagmatic-tectonicalactivitiesfromtheLateCarboniferoustoEarlyPermianandhasavitalinfluenceonthemineralizationofcopperandgold.ZirconfromgranodioriteporphyryyieldsεHf(t)valuesof4.32to9.64,andTDM2hasanaverageageof914Ma,suggestingthatthesourceofthegranodioriteporphyryintheregionweremainlymantlecomponentsbutunderwentmixingandcontaminationofcrustmaterials.TheCe^4+/Ce^3+valueofzirconinthegranodioriteporphyryvarysgreatlyfrom2.4to1438.29,whichshowsmagmamixingmightoccur.Consideringthecharacteristicsoftraceelementsinthezirconandthewholerockgeochemicalcharacteristicsofintrusionrocksaswellasthecharacteristicsofregionalvolcanic-sedimentaryassociation,itisindicatedthatthetectonicsettingmaybethecontinentalarcenvironment.TheSeponAu-Cudepositisderivedfromemplacementofcalc-alkalineintermediate-acidmagmawithcomingfromdeepsourcesinthesubductionprocessofthePaleotethysOcean,formingporphyryMo-Cu,skamCu-Aumineralizationandahydrothermalsedimentary-hostedAumineralizationinthewallrocks.