学科分类
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208 个结果
  • 简介:AnewapproachtoproducesuperfineWC-Copowderbydirectreductionandcarbonizationisproposed.Water-solublesaltscontainingWandCowereusedasrawmaterials.Tungstenandcobaltoxidepowder(CoWO4/WO3)wasfirstformedbyaspray-pyrolysistechnique,whichwasthenmixedwithcarbonblackandconvertedtoWC-Cocompositepowderat950℃for4hinN2atmosphere.Theresultingpowderhasaparticlesizeof100-300nm.

  • 标签: 碳化钨 碳化 合成粉末 干馏技术 高温分解 微观结构
  • 简介:Wehaveinvestigatedthephysicalproperties,includingthemorphology,texture,adhesionandchemicalquality,ofhigh-frequencychemicalvapourdepositeddiamondcoatingsonWC-6%Cosubstrates,whichwerepre-treatedbyatwo-stepetchingmethod.TheresultsindicatethattheincreasingCocontentfrom0.12to3.05%withintheetchingdepthof5μmcausedamorphologytransformationfromprismdiamondtospheruliticdiamond,andatexturetransformationfroma{111}orientationtoa{110}orientation.TheRamanspectrumshowsthatthespheruliticdiamondfilmcontainsmorenon-diamondphases(graphite,amorphouscarbonanddiamond-likecarbon,etc)andhaslowerchemicalqualitythandiamondfilmsonaWC-6%Cosubstrate.Thediamondcoatinggrainsizesbecameaboutfourtimessmallerwhenthedepositiontemperaturesonthesubstratesurfacewerereducedfrom1000to900℃.Comparedwithspheruliticdiamondfilms,theprismdiamondfilmsexhibitbetteradhesionontheWC-6%Cosubstrate.

  • 标签: 金刚石 化学汽相淀积 金刚石薄膜
  • 简介:Twoseriesofmixedoxides,CoAlMandMgAlM(M=Cr,Mn,Fe,Co,Ni,Cu),werepreparedbycalciningtheircorrespondinghydrotalcite-likecompounds(HTLc).TheratioofMg:Al:M(orCo:Al:M)was3:1:1.ThecatalyticactivityofallsamplesforthereactionofNO+COwasinvestigated.TheresultsshowedthattheactivityofCoAlMwasmuchhigherthanthatofMgAlM.ThestructureandthepropertyofredoxwerecharacterizedbyXRDandH2-TPR.TheresultsindicatedthatonlyMgOphasewasobservedaftercalciningMgAlMhydrotalcites,andthetransitionmetalsbecamemorestable.Thespinel-likephaseappearedinallofCoAlMsamplesafterthecalcination,andthetransitionmetalswerechangedtobemoreactive,andeasilyreduced.TheactivitiesofthreeseriesofmixedoxidesCoAlCuobtainedfromdifferentpreparationmethods,differentratioofCo:Al:Cuandatdifferentcalcinationtemperatures,werestudiedindetailforproposingthemechanismofreaction.TheabilityofadsorptionofNOandCO

  • 标签: Hydrotalcite-like compounds NO reduction by CO
  • 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:Dopantsanddefectsareimportantinsemiconductorandmagneticdevices.Strategiesforcontrollingdopinganddefectshavebeenthefocusofsemiconductorphysicsresearchduringthepastdecadesandremaincriticaleventoday.Co-dopingisapromisingstrategythatcanbeusedforeffectivelytuningthedopantpopulations,electronicproperties,andmagneticproperties.Itcanenhancethesolubilityofdopantsandimprovethestabilityofdesireddefects.Duringthepast20years,significantexperimentalandtheoreticaleffortshavebeendevotedtostudyingthecharacteristicsofco-doping.Inthisarticle,wefirstreviewthehistoricaldevelopmentofco-doping.Then,wereviewavarietyofresearchperformedonco-doping,basedonthecompensatingnatureofco-dopants.Finally,wereviewtheeffectsofcontaminationandsurfactantsthatcanexplainthegeneralmechanismsofco-doping.

  • 标签: co-doping fully compensated PARTIALLY compensated non-compensated
  • 简介:利用methoxysilyl一半的水解作用和冷凝作用,器官无机的混血儿(N-isopropylacrylamide-co-acrylamide-co-3-(trimethoxysilyl)propylmethacrylate)poly,P(NIPAM-co-AM-co-TMSPMA)microgels经由二个不同方法被准备。第一个方法是microgels是从crosslinkable的fabricated以后线性P(NIPAM-co-AM-co-TMSPMA)terpolymer在terpolymer的更低的批评答案温度(LCST)上面的水的答案。为第二个方法,microgels被常规表面活化剂直接综合NIPAM,AM,和TMSPMA的免费乳剂copolymerization。结果的P(NIPAM-co-AM-co-TMSPMA)microgels的水动力学直径和稳定性强烈取决于microgel的pH和温度水的答案。microgels的水动力学直径与增加测量温度减少了。microgels的阶段转变温度被发现在34附近吗??

  • 标签: NIPAM 微凝胶 有机无机 共聚合成 CO 低临界溶液温度
  • 简介:制备了几种CU-CO尖晶石,并用于催化CO2加氢合成低碳醇反应。结果表明,Cu-Co尖晶石是一种极具潜力的催化剂前驱体,具有出色的C2+醇合成能力。但是,当在该催化剂中加入KOH时,这种能力下降。XRD表征表明,KOH的加入破坏了CU-Co合金的生成。一些结果被讨论。更多还原

  • 标签: Cu-Co催化剂 CO2加氢 低碳醇合成
  • 简介:Ba1.0Co0.7Fe0.2Nb0.1O3-δ(BCFN)oxidewithperovskitecubicstructurewassynthesizedbysolidstatereactionmethod.CO2corrosionofBCFNmembranewasinvestigatedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),diffusereflectanceinfraredFouriertransformedspectroscopy(DRIFT)andX-rayabsorptionfinestructurespectroscopy(XAFS).Cobalt(Co)K-edgeabsorptionspectraofBCFNannealedinCO2revealthattheoxidationstatesofCoinallthesampleswerelargerthan+3andtheydecreasedwiththeincreaseofcalcinationtime.At800℃,1%CO2introducedintoHecouldspeedupthereductionofCocationsincomparisonwithpureHe.Inaddition,sulfateionsinthebulkofBCFNmembranepreferredtomigratetothesurfaceunderCO2calcinationandformmonoclinicBa(CO3)0.9(SO4)0.1besidesorthorhombicwitherite.Moreover,SEMresultsindicatethatthenucleationandgrowthofcarbonatesgrainsstartedatthegrainboundaryofthemembrane.

  • 标签: 钙钛矿型氧化物 CO2 氧化态 组织演变 退火 X射线吸收精细结构
  • 简介:ThebindingofCo(bpy)2dppz3+tocalfthymusDNAwasinvestigatedbyusingabsorptionandemissionspectroscopy,DNAmeltingtechniques,cyclicvoltammetry,viscosityandelectro-phoresismeasurements,wherebpyis2,2’-bipyridyl,dppzisdipyrido[3,2-o:2’,3’-c]phenazine.Thebindingcompoundshowsabsorptionhypochromicity,fluorescenceenhancement,andincreasingofDNAmeltingtemperatureandthespecificviscosity.CVmeasurementshowstheshiftsinoxidation-reductionpotentialandchangeinpeakcurrentwithadditionofDNA.ThecompoundisalsoshowntobemoreefficientphotosensitisersforstrandbreaksinplasmidDNA.

  • 标签: Cobalt (Ⅲ) COORDINATION compound CALF THYMUS
  • 简介:在这份报纸,活跃光学和合作焦点,分割的镜子的试验性的系统被造。第一,分割的镜子的支持结构被设计,为分割的镜子的试验性的系统满足要求被模拟验证。在这个系统,大散焦并且倾斜/付小费给分割的镜子的错误被观察密度调整并且基于等斜的干扰理论干扰穗形成对照直到defocus并且倾斜/付小费给错误在Shack-Hartmann的侦探范围。然后,Shack-Hartmann被用来测量他们,他们被致动器调整。致动器被活跃光学控制为分割的镜子的好合作焦点认识到靠近环的调整和维护。并且干扰穗被利用验证Shack-Hartmann的侦探精确。在分割的镜子调整的合作焦点以后,倾斜/付小费给剩余表面错误比RMS好;defocus剩余表面错误比RMS好。

  • 标签:
  • 简介:让Λ=kQ/I是有限维的Nakayama代数学,在Q是一个欧几里德几何学的图Yun徐舸电子邮件的地方:xuy@hubu.edu.cn参考书[1]。马克·莱恩,S.:相同,Grundlehren数学。Wiss。114,Springer,柏林,1975[2]。Happel,D.:有限维的代数学的Hochschildcohomology。在数学的讲课笔记,1404,108126(1989)[3]。Skowroński,A.:简单地连接的代数学和Hochschildcohomology。Proc。ICRAIV(渥太华,1992),能。数学。Soc。Proc,14,431447(1993)[4]。Assem,I.,delaPeña,J.A.:三角形的代数学的foundamental组。Comm。代数学,24,187208(1996)[5]。Gerstenhaber,M.:在戒指和代数学的变丑上。安。数学,79,59103(1964)[6]。Igusa,K.:笔记在上没有环推测。J。纯Appl。代数学,69,161176(1990)[7]。刘,S.X.,张,P.:截断的代数学的Hochschild相同。公牛。伦敦数学。Soc,26,427430(1994)[8]。Avramov,L.L.,Vigueé-Poirrier,M.:为光滑的Hochschild相同标准。Internat。数学。研究通知,1,1725(1992)[9]。汉,Y.:Hochschild(co)相同尺寸。J.伦敦数学。Soc,73(2),657668(2006)[10]。凯勒,B.:为DG代数学的周期的相同的不变性和本地化。J。纯Appl。代数学,123,223273(1998)[11]。Erdmann,K.,河边肥沃的低地T.:为班的self-injective代数学的扭曲的双性人模块和Hochschildcohomology一。论坛数学,11,177201(1999)[12]。Bardzell,M.J.,Locateli,A.C.,Marcos,E.N.:在截断的周期代数学的Hochschildcohomology上。CommAlg,28(3),16151639(2000)[13]。Assem,I.,Simson,D.,Skowroński,A.:联合代数学的表示理论的元素,伦敦数学。Soc。学生文章65,剑桥大学出版社,剑桥,2005[14]。Snashall,N.,Solberg,Ø.:支持变化和Hochschildcohomology

  • 标签: 同源现象 代数 上同调 数学分析
  • 简介:Co2(CO)8与CH3CSNH2反应制得产物Ⅰ,又用Na2Fe(CO)4与Ⅰ反应制得产物Ⅱ(Ⅰ:Co3(μ3-S)(CO)7(CH3CSNH),Ⅱ:Co2Fe(μ3-S)(CO)7(CH3CSNH).通过元素分析。IR、UV、1HNMR、MS表征并用X射线衍射法测得Ⅱ的单晶结构.该簇合物属三斜晶系、PT空间群,晶胞参数:a=0.9203(1),b=1.1296(2),c=1.1425(2)nm;α=116.40°(2),β=101.92°(2),γ=92.58°(1);z=2,V=1.2162nm3,Dc=1.698cm3,μ=21.89cm-1.结构分析表明,Co2FeS构三角锥分子骨架,所有CO均为端基配体,S1为面桥基配体,CH3CSNH为双齿配体,与Co、Fe形成五元环结构.

  • 标签: 簇合物 三角锥分子骨架 硫代乙酰胺
  • 简介:TwopossiblereactionmechanismsofVS~+(~3∑~-,~1Γ)withCOinthegasphasehavebeenstudiedbyusingB3LYP/TZVPandCCSD(T)/6-311+G(3dr,3pd)methods:theO/Sexchangereaction(VS~++CO→VO~++CS)andtheS-transferreaction(VS~++CO→V~++COS).Thetworeactionsproceedviatwo-stepandone-stepmechanism,respectively.ThebarriersofthetripletandsingletPESsare30.6and50.9kcal/mol,respectively,forO/Sexchangereactionand7.3and50.2kcal/mol,respectively,fortheS-transferreaction.Theresultsindicatethatthetripletgroundstatereactionismorefavorable,andtheS-transferreactionismorefavorablethantheO/Sexchangereaction,whichisingoodagreementwiththeexperimentalobservation.

  • 标签: 钒元素 铅矿 硫化物 理论研究
  • 简介:<正>LetRbeanassociativeringnotnecessarilypossessinganidentityand(S,≤)astrictlytotallyorderedmonoidwhichisalsoartinianandsatisfiesthat0≤sforanys∈S.AssumethatMisaleftR-modulehavingproperty(F).ItisshownthatMisaco-HopfianleftR-moduleifandonlyif[MS,≤]isaco-Hopfanleft[[RS,≤]]-module.

  • 标签: Co-Hopfian MODULE GENERALIZED power series GENERALIZED
  • 简介:在这份报纸,我们基于范围的楔学习comultiplications的homotopy逆和co-H-spaces的代数学的环的性质。我们也调查一个方法由使用一个组行动从旧的构造新comultiplications。我们首先对有的代数学的环感兴趣反向,力量联合并且为某comultiplications的Moufang性质。

  • 标签: CO-H-空间 代数 c循环
  • 简介:CO2-copolymerbasedpolyurethanefoamsweresynthesizedandcharacterizedinthispaper.Thefoamswerefoundtohavehigherstrengthandlowerheatofcombustionthantheconventionalpolyetherpolyurethanefoams.Theymayfindwideapplicationsinmanyfields.

  • 标签: 合成 CO2 环氧化物 共聚物 聚氨酯泡沫 聚碳酸酯