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500 个结果
  • 简介:我们综合有单个多孔的壳和Ag@Au/Ag@Au的空结构的Ag@Aunanoparticles由使用流电的代替反应加倍壳并且调查他们的线性、非线性的光性质。我们的结果证明空多孔的nanoparticles的表面电浆子回声波长能被控制HAuCl4的体积容易在可见、近的红外线的区域在一个宽范围调节。双shelledAg@Au/Ag@Aunanoparticles的非线性的光折射被电浆子回声显著地提高。我们的调查结果可以在生物传感器和非线性的光nanodevices发现应用。

  • 标签: 金纳米粒子 双壳 光学响应 非线性光学性质 合成 表面等离子体
  • 简介:CrystallineTiO2(P25)andisolatedtitanatespeciesinaZSM-5structure(TS-1)weremodifiedwithAuandAg,respectively,andtestedinthegas-phasephotocatalyticCO2reductionunderhighpurityconditions.Thenoblemetalmodificationwasperformedbyphotodeposition.LightabsorbancepropertiesofthecatalystsareexaminedwithUV–Visspectroscopybeforeandaftertheactivitytest.Inthegas-phasephotocatalyticCO2reduction,itwasobservedthatthecatalystswithAgnanostructuresaremoreactivethanthosewithAunanostructures.Itisthusfoundthattheenergeticdifferencebetweenthebandgapenergyofthesemiconductorandthepositionoftheplasmonisinfluencingthephotocatalyticactivity.Potentially,plasmonexcitationduetovisiblelightabsorptionresultsinplasmonresonanceenergy,whichaffectstheexcitationofthesemiconductorpositively.Therefore,anoverlapbetweenbandgapenergyofthesemiconductorandmetalplasmonisneeded.

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  • 简介:本文利用XRF金标样的多元素回归方程,对Pt、Pd的荧光强度进行修正,修正后的荧光强度当作AuAg的荧光强度代入回归方程中,利用计算机编程计算铂制品中的Pt、Au、Pd、Ag、Cu、Ni等6种元素的含量.该法测定的准确度优于0.5%,适用于Pt的测定范围为85%~99.92%,具有无损、快速、准确、可靠等优点.

  • 标签: 能量色散X-荧光光谱 铂制品 成份 检测
  • 简介:ThispaperreportstheuseofAufilmstoimprovetheperformanceofthestackedsolidoxidefuelcell(SOFC)basedonthecharacterizationoftheinterfaceandtheadhesionbetweentheelectrodesoftheSOFCsandtheAgpaste.Thespecimensweremanufacturedtoperformtheexperimentasfollows.ASiO2waferwitha300mmnotchwasattachedtotheelectrodesofaSOFCbyaAgpasteandAufilm,whichweredepositedontheelectrodesbysputteringfor1minor5mindepositiontimeandannealedat300Cfor1h.Thefour-pointbendingtestwasperformed,whichresultedintheformationofanextendedcrackatthetiponthewafernotch,andthecrackpropagationwasobservedusingastereomicroscopeequippedwithacharge-coupleddevice(CCD).Consequently,theinterfacialadhesionenergyandtheeffectoftheAufilmbetweentheeachelectrodeandtheAgpastecanbeevaluated.Onthecathode,theinterfacialadhesionenergywithoutAufilmwas2.59J/m2(uppervalue)andtheadhesionenergyincreasedto11.59J/m2(uppervalue)and15.89J/m2(lowervalue)withtheAufilm.Ontheanode,theinterfacialadhesionenergywithoutAufilmwas1.74J/m2(uppervalue),whichincreasedto11.07J/m2(uppervalue)and14.74J/m2(lowervalue)withtheAufilm.Inaddition,theinterfaceareaswereanalyzedbyscanningelectronmicroscopy(SEM)andenergydispersivespectroscopy(EDS)toestimatetheinterfacedelamination.

  • 标签: Solid oxide fuel cell AU film
  • 简介:Itisawellknownfactthatmagnaticcryoto-explosion,asaspeeialformofmagmatismunderthenear-surfacecondition,hasacloseconncctionwithcdogcnicmctaldcposits,particularlywiththoseofporphyrytyPe,suchaSporphyryCu-Mo,Pb-Zn,W-SnandUdcposits’However,onlyinrcccntyearsbavetheChineseoregeologistsandpetrologistsgivenin

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  • 简介:COandformaldehyde(HCHO)oxidationreactionswereinvestigatedovermesoporousAg/Co3O4catalystspreparedbyone-pot(OP)andimpregnation(IM)methods.Itwasfoundthattheone-potmethodwassuperiortotheimpregnationmethodforsynthesizingAg/Co3O4catalystswithhighactivityforbothreactions.ItwasalsofoundthatthecatalyticbehaviorofmesoporousCo3O4andAg/Co3O4catalystsforthebothreactionswasdifferent.AndtheadditionofsilveronmesoporousCo3O4didnotalwaysenhancethecatalyticactivityoffinalcatalystforCOoxidationatroomtemperature(20C),butcouldsignificantlyimprovethecatalyticactivityoffinalcatalystforHCHOoxidationatlowtemperature(90C).Thehighsurfacearea,uniformporestructureandtheprettygooddispersiondegreeofthesilverparticleshouldberesponsiblefortheexcellentlow-temperatureCOoxidationactivity.However,forHCHOoxidation,theadditionofsilverplayedanimportantroleintheactivityenhancement.AndthesilverparticlesizeandthereducibilityofCo3O4shouldbeindispensableforthehighactivityofHCHOoxidationatlowtemperature.

  • 标签: MESOPOROUS materials Co3O4 AG CO OXIDATION
  • 简介:RE-dopedNi-basedcatalystswerepreparedbysol-gelmethod.ThesecatalystswereappliedtothereactionofCO2reformingCH4tosyngas.ThestudiesrevealthatRE-doped(RE=La,Ce,Sm,Yb)Ni-basedcatalystsshowhighercatalyticactivitythanundopedNi-basedcatalyst,andwiththeincreasingofRE-dopedquantity,thecatalyticactivityofcatalystsexhibitsregularchanges.WhenRE-dopedquantityis0.2%(molarratio),thecatalystsshowthebestcatalyticactivity.

  • 标签: DOPE BATIO3 CATALYST RARE earths
  • 简介:摘 要:高温合金材料的落后制约了我国在燃气发动机及能源领域的发展,新型Co-Re基超高温合金的出现为制备兼具抗高温氧化性能及优异机械性能的高温材料提供了可能,本文主要综述了几种典型的合金元素Co-Re基合金抗氧化性为的影响,以及预氧化处理对其的作用,最后对Co-Re基合未来发展方向做了相应的展望。

  • 标签: Co-Re基合金 合金化 预氧化处理
  • 简介:本文通过原子吸分光光度等方法,测定了人皂甙-Re及其制剂Re注射液中的Zn、Cu等12种金属无机元素。二者均含有Na、K、Mg、Ca等常量元素及Fe、Cu、Zn、Mn等人体必需微量元素,而有害元素Cd、Pd、Hg、As含量极低或未检出,结果表明这些无机元素符合药品质量要求。

  • 标签: 人参皂甙-Re 无机元素 注射液 药品质量检验
  • 简介:Ithaslongbeenacontroversyaboutthesourceofore-formingmaterialsofAu-Agpolymetallicdepositsbothinmetallogenictheoryandinore-searchingpractice.IntermsofalargewealthoftheisotopicstatisticsdatafromIndosinian-YanshanianendogenicoredepositsinnorthernHebei(generallyreferringtotheareasalongthenorthernpartofTaihangMountainsandnorthernHebei,thesamebelow),itisconsideredthattheore-formingmaterialscamefromthedeepinterioroftheEarth,whichhadmigratedthroughplumestotheEarthsurfacewhileex-periencedmulti-stageevolutionandthenemplacedprogressivelyinfavorablestructurallocitoformores.Theirisotopedatashowthat559sulfurisotopicdatafrom40oredepositsare,forthemostpart,withintherangeof-5‰-5‰,withahighdegreeofhomogenization,indicatingthatthesulfurisderivedmainlyfrommagma;200leadisotopedatafrom37oredepositsindi-catethattheore-formingmaterialsareprincipallyofmantlesourcethoughsomecrust-sourcema-terialwasinvolved;96oxygen,hydrogenandcarbonisotopedatafrom34oredepositsillustratethattheore-formingfluidsaredominatedbymagmaticwaterwhileothersourcesofwaterwouldbeinvolved.Itmaythereforebeseenthattheformationofendogenicdepositshasnothingtodowiththestrata.

  • 标签: 同位素特征 中生代 金-银多金属矿床 内生矿床 河北 Indosinian-Yanshanian周期
  • 简介:AseriesofnovelAgCl/Ag2CO3heterostructuredphotocatalystswithdifferentAgClcontents(5wt%,10wt%,20wt%,and30wt%)werepreparedbyfacilecoprecipitationmethodatroomtemperature.TheresultingproductswerecharacterizedbypowderX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),X-rayphotoelectronspectroscopy(XPS),andultraviolet–visiblediffusereflectancespectroscopy(UV–VisDRS),respectively.Thephotocatalyticactivityofthesampleswasevaluatedbyphotocatalyticdegradationofmethylorange(MO)underUVlightirradiation.WiththeoptimalAgClcontentof20wt%,theAgCl/Ag2CO3compositeexhibitsthegreatestenhancementinphotocatalyticdegradationefficiency.Itsfirst-orderreactionrateconstant(0.67h-1)is5.2timesfasterthanthatofAg2CO3(0.13h-1),and16.8timesfasterthanthatofAgCl(0.04h-1).TheformationofAgCl/Ag2CO3heterostructurecouldeffectivelysuppresstherecombinationofthephoto-generatedelectronandhole,resultinginanincreaseinphotocatalyticactivity.

  • 标签: 异质结构 光催化剂 氯化银 光催化性能 光催化降解效率 X射线光电子能谱
  • 简介:采用沉积沉淀法,将金负载在复合氧化物载体MOx/Al2O3上,制备得到了Au/MOx/Al2O3催化剂的活性要高于Au/Al2O3催化剂.Au/FeOx/Al2O3催化剂能够在低于223K的温度下实现CO完全催化氧化.TEM图像分析表明,纳米级高分散的金颗粒是金催化剂高活性的前提,但载体的选择,以及复合氧化物载体中过渡金属氧化物的选择,也会对金催化剂的活性产生明显的影响.

  • 标签: Au/MOx/A1203 催化剂 CO 低温氧化 催化反应 一氧化碳
  • 简介:AnAu/ceria(0.44%,massfraction)catalystcontaininggoldionswaspreparedbyamodifieddepositionprecipitationmethod,andtheevolutionofgoldionsinthecatalystanditsinfluenceonthecatalysisofCOoxidationwereinvestigated.Itwasfoundthattheas-preparedcatalystcontaininggoldionswithhighvalencecouldfullyoxidizeCOat–10°CinitiallybutwasdeactivatedgraduallyatlowtemperaturesduringthereactionwithCOortreatmentbyunpurifiedair.ThedeactivationofthecatalystduringCOoxidationortreatmentofitbyunpurifiedairwasindependentandprogressiveatlowtemperatureswhiletheactivityofthecatalystatrelativelyhightemperatureswasmaintainedwell.DuringthereactionwithCOortreatmentbyunpurifiedair,theXPSresultsindicatethatgoldspeciesevolvedfromhighvalencetolowvalenceandthediffusereflectanceUV-Visspectrashowthathighvalencegoldwasreducedtochargedgoldclusters,goldclustersgrewtosmallgoldcrystalsandsmallgoldcrystalsgrewtolargegoldparticles.Accordingly,thehighvalencegoldcorrespondedtotheactivityatlowtemperaturesandthemetallicgoldwasactiveandrelativelystableathightemperatures.Theturnoverfrequencies(TOF)ofthecatalyststreatedbydifferentmethodsat273Kdecreasedwiththeevolutionofgoldspeciesfromhighvalencetolowvalence,nomaximumofTOFwasobservedalthoughgoldparticlesinthecatalystattainedtoabout2―3nmduringthetreatment.AnAu/ceriacatalystwithagoldloadof0.87%(massfraction)maintainedagoodactivityforCOoxidationwithin18hatroomtemperature.Thecatalystswerecharacterizedviatransmittedelectronicmicroscopy(TEM),inductivelycoupledplasmaopticalemissionspectrometry(ICP-OES),X-raydiffraction(XRD)andBETspecificsurfaceareaandUV-VisDRSaswell.

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  • 简介:源于空气包裹扩大/压缩的密度效果的修正在当开路径的系统被使用时,解释水汽和公司2的旋涡协变性流动是重要的。到为这些效果的报道,干空气的密度的吝啬的垂直速度和不安是在对待为密度变化负责的那些物理进程的二个批评参数。基于各种各样的内在的假设,不同研究为干空气的密度的吝啬的垂直速度和不安获得了不同公式,导致很多条途径改正密度效果。在这研究,我们再考与被做到的不同假设有关的物理过程提出密度效果。明确地,我们覆查零干空气流动的假设和在表面层的零湿空气流动,使用为改正密度效果对待密度变化,和他们的含意。在与零干空气流动的假设的关系的物理过程说明对密度变化的干空气扩大/压缩的影响,这被发现。同时,在与零湿空气流动的假设的关系的物理进程说明对密度变化的湿空气扩大/压缩的影响。在这研究,我们另外覆查混合比问题。我们的结果显示零干空气流动的假设相对干空气赞成混合比的使用,当零湿空气流动的假设相对全部的湿空气赞成混合比的使用时。另外,我们为吝啬的垂直速度比较不同公式,由空气包裹扩大/压缩产生了,并且为使用的密度效果修正,旋涡协变性数据测量了超过三个北方的生态系统。

  • 标签: 海气CO2交换速率 通量 测量 估量 海洋气象学
  • 简介:借助于G03W程序包,对系列氨基羧酸分子的羰基铼配合物进行了结构优化,并对其中的相关能量、键长、键角、布局数等进行了研究.计算结果表明:各配合物相对于羰基铼中间体均具有一定的稳定性;配体分子结构中含有杂环或者较多数目杂原子时,有形成相对更稳定配合物的趋势;配体分子结构中应含有适宜的间隔体,否则需经较大的结构扭转或局部原子的拥挤方可形成相应配合物.

  • 标签: 羰基铼 成键 结构 G03W 配合物
  • 简介:BondedtypeRE3+dopedluminescentco-polymerwassynthesizedbysolutionfreeradicalcopolymerization.Theinfluenceofchargesequence,monomersandco-polymerizedmethodonpropertiesandstructuresoftheco-polymerswasstudied.Theemissionintensityoftheco-polymersatdifferentRE3+concentrationswastested.Theresultsshowedthattheco-polymersofEu-PStandEu-PMMAbothhadwideabsorptionpeakat200-400nmandthestrongestpeakappearedat235nm.ThefluorescentintensityofEu3+dopedpolystyreneco-polymerwasstrongerthanthatofEu3+dopedPMMAcopolymer.Thecharacteristicemissionofeuropiumionswasobservedintheco-polymers.Thecopolymerdopedwithrareearthelementsshowedthe"sensitizationeffect"forthecentralions.Thebonded-typerareearthcopolymernotonlyenhancedtheenergytransferefficiency,butalsoimprovedthefluorescenceintensitybyiacreasmgtherigidityofmainandsidechain.

  • 标签: luminescence bonded-type rare earth CO-POLYMERS RADICAL
  • 简介:采用扫描电镜、能谱仪以及X射线衍射仪对具有WC+β(β为钴基粘结相)两相结构的WC-11Co-0.71Cr3C2-0.06RERE为含La、Ce、Pr、Nd的混合稀土)硬质合金烧结体表面进行观察与分析。结果表明,在烧结过程中合金中的La、Ce、Pr、Nd通过定向迁移与烧结炉内气氛中的S、O等杂质元素结合,在合金烧结体表面形成RE2S3(主)和RE2O2S(少量)弥散相。从合金中Cr3C2的热力学稳定性、Cr在Co中的溶解度特性以及稀土原子激发等3个方面,对稀土迁移活性的激发机制和稀土原子的定向迁移机制进行分析与讨论。

  • 标签: RE2S3 硬质合金 烧结 稀土定向迁移 原子极化 RE2S3
  • 简介:针对化探样品批量大,元素多,检出限低等特点,采用水平电极撒料法,对化探样中多种微量元素进行了光谱定量分析。将样品与缓冲剂1:1混匀,采用W-100光栅摄谱仪(光栅刻线1200条,毫米,二级光谱)进行水平撒样摄谱,谱板经暗室处理后,在东德GFE760u测微光度计上用P标尺测光,以AP—logc绘制工作曲线,查出含量。本法采用了特制的撒样漏斗,改善了下料的均匀性,提高了分析精度;以Ge和Pd作内标消除工作条件变化对谱线强度的影响;同时还试选了SiO2:C:Na2SO4=61:30:9的混合物作缓冲剂,提高了弧烧的稳定性,获得了较高的再现性。本文还采用了一种单元素线减光器对Ag3382.9进行减光,使舷的测定上限由5×10-6提高到30×10-6。本法操作简便快速,成本较低,一次可测定Ag、W、Mo、Sn、Bi、Cu、Pb、Zn、Ni、Co、Cr等多种元素,检出限为Ag0.03×10-6,W0.5×10-6,Mo0.05×10-4,Sn0.4×100-6,Ph1×10-6,Zn3×10-6,Cu0.5×10-6,Bi0.1×10-6,Ni0.3×10-6,Co0.3×10-6,Cr1×10-6,基本上达到了化探普查找矿定量分析的要求。

  • 标签: 微量元素 定量分析 水平电极撒料法
  • 简介:采用化学镀技术在膨胀石墨表面包覆Ag及Ni-Co-Fe合金,用扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线衍射仪(XRD)及振动磁强计等方法对镀层形貌、组分、结构及磁性能进行表征,结果表明,膨胀石墨表面镀层较平整光滑,厚度均匀,包覆银后的膨胀石墨没有磁性能,而包覆镍铁钴、镍铁钴/银、银/镍铁钴后的膨胀石墨磁性能明显增强,饱和磁化强度σs-Ni-Fe-Co=10.2emu/g、σs-Ni-Fe-Co/Ag=6.3emu/g、σs-Ag/Ni-Fe-Co=2.4emu/g。

  • 标签: 膨胀石墨 化学镀 AG Ni-Co-Fe合金 表征 磁滞回线