学科分类
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500 个结果
  • 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:摘要将程序升温方式和阀切时间的优化相互结合到一起,采用此种方式,把微量COCO_2从液态烃中分离出来,这样既能够缩短分析时间,还减少了乙烯/丙烯进入TDX-1型色谱柱中。在具体分析过程中,新优化的方法和出厂设置的恒温控制、恒定阀切时间分析样品相比较而言,并没有出现较大程度的基线漂移过低以及色谱柱分析效果降低的情况,从一定程度上提升了分析效率,并且可以延长色谱的使用寿命,对仪器维护有着十分重要的作用。

  • 标签: CO CO_2 乙烯丙烯 分析方法 液态烃 优化
  • 简介:TheCurietemperatureof(Nd1-xPrx)2Fe14CoyBcompounds(x=0,0.2,…,1.0andy=O,2,4,6,14)hasbeendeterminedwithACinitialsusceptibilitymeasurement.ItwasfoundthatthevariationsofCurietempera-turewithxisnotlinearfory=0and14,whereasitislinearforothervaluesofy.Thelatticeconstantsof(Nd1-xPrx)2Fet14BweredeterminedbyusingX-raydiffraction.Thelatticeexpansionwasmostlyalongthecaxis,whereasthatalongthea-axisremainedpracticallyzeroforthewholeseries.ItissuggestedthatPratomsmayshowsitepreferenceinR2M14Bcompounds(M=FeorCo).DuetothesubstitutionofCoforFe.thetendencyofsitepreferenceofPrbecomeslesspronounced,whichmaybeattributedtothedecreaseofdiffer-enceofcrystalelectricfield(CEF)actingonthetworareearthsiteswiththeintroductionofCoorFe.Incon-trasttothatofthePratoms,thesitepreferenceofCoiu(Nd(1-x)Prx)2Fe(14-y)CoyBcompoundsdoesnotdependonthecompositionoftherareearthsublattice(R=NdorPr).

  • 标签: CURIE temperature Site PREFERENCE Rare earth-transition
  • 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:隔热原理:太阳光谱由紫外线、可见光以及红外线组成,各部分热能量分配分别为3%、44%和53%。太阳是通过阻隔不同波长范围的热能量,达到最终的隔热效果。美国产的因为其中有各种金属镀膜隔热层,能双管齐下,从两大源头,即可见光和红外线,截住热量。

  • 标签: 隔热效果 太阳膜 原理 建筑 太阳光谱 波长范围
  • 简介:FormerlyNo.713Factory,HuaxingMetallur-gical&ChemicalCo.underChinaNuclearIndustryGeneralCorporationwasestablishedin1958andputintooperationin1962.ThecorporationislocatedinShangrao,JiangxiProvinceandwasoriginallydesignedtoproducerawmaterialsformillitaryuse.Inkeepingupwiththepaceofthedevelopmentofthenationaleconomy,

  • 标签: originally NUCLEAR keeping CORPORATION BEGINNING JIANGXI
  • 简介:纽约即将举办一场海难纪念品拍卖会,此次拍卖会将是泰坦尼克号遗物有史以来最大规模的拍卖,

  • 标签: 高一 英语 双语阅读 报刊文摘
  • 简介:问:能不能用硫酸代替盐酸?为什么?答:不能。实验室制取CO2一般采用稀盐酸和大理石(或石灰石,下同)反应,因为生成的氯化钙易溶于水,从而脱离大理石固体表面,使反应能得以继续进行。而硫酸与大理石反应,反应后生成的硫酸钙则会沉积在大理石固体表面,会

  • 标签: CO2 制备方法 二氧化碳 向上排气法 初中 化学实验
  • 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:案例1:1995年元月6日,韦某,男,32岁,与爱人在一房间内同宿,当晚在房间内有一炭火取暖炉,早上6时左右其爱人(30岁)感胸闷、恶心、四肢无力,并起床呕吐少量胃内容物,同时发现丈夫已死亡。现场房间12m^2,门窗密闭较好,现场整齐,床前有一炉已燃尽的炭灰,床上有呕吐物,尸体为男性,全身赤,尸斑呈暗红色,尸表未见损伤,肌肉、肝、肺、肾等呈浅红色,血液呈红色流动性,提取心血作CO定量检验为50%。

  • 标签: CO中毒 检验 法医学鉴定
  • 简介:摘要:随着绿建工程的不断普及,绿色工程的验收标准也有了新的定义,即:在全寿命期内、节约资源、保护环境、减少污染,为人们提供健康、适用、高效的使用空间,最大限度地实现人与自然和谐共生的高质量建筑。

  • 标签: CO监测系统 CO浓度控制 CO浓度探测器
  • 简介:Amethodbasedupontheweightedtotalcrosssection(WTCS)theoryisproposedtocalculatethephoto-ionisationcrosssectionsandtheradiativerecombinationratecoefficientsbetweenthefundamentallevelofCOandthemainelectronicstatesofitscorrespondingion.Totalphoto-ionisationcrosssectionsandradiativerecombinationratecoefficientsaredeterminedfromthecalculationofelementaryvibrationalphoto-ionisationcrosssections.TransitionsbetweenCO~+(X,AandB)andCO(X)areconsidered.Totalphoto-ionisationcrosssectionsandrecombinationcoefficientsarecomputedinthetemperatureinterval500-15000K.

  • 标签: 复合速率系数 光电离截面 CO2 计算 辐射 分子
  • 简介:Byemployingaradiofrequency(RF)feedbackchain,theself-interferencecanbecanceledefficientlyinco-timeco-frequencyfullduplex(CCFD).However,theevitablesignalcrosstalkwhichiscausedbytheimperfectRFfeedbackchainisolationusuallydamagestheself-interferencecancelation(SIC)performance.Todealwiththisproblem,firstly,weanalyzetheimpactofRFfeedbackchainisolationonSICperformance.ThenadigitalpreprocessingschemewithRFfeedbackchainisproposedinthemultiple-antennaCCFDarchitecture.Usingbothanalyticalandexperimentalmethods,wefindthattheproposedschemeachievesabetterperformanceonSIC.

  • 标签: Co-time co-frequency full DUPLEX full DUPLEX
  • 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:摘要:煤制天然气一般是指煤炭经气化、净化和甲烷化等工艺过程制造合成天然气,其核心技术之一就是CO2/CO的甲烷化技术。煤制甲烷的研究始于20世纪40年代,随着世界能源结构中天然气所占比例的增高,煤制合成气甲烷化的研究从20世纪70年代开始进入高速发展时期。合成气的甲烷化过程属于典型的选择性催化反应,而且反应放热量大,绝热温升快,操作温度的升高使得反应产品纯度下降、催化剂失活。因此甲烷化反应器设计和催化剂是煤制天然气工艺的两大核心技术,国内外对此开展了大量的基础研究和应用开发。

  • 标签: 甲烷化 催化剂 反应机理
  • 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:Dynamicnodecreationandfastlearningalgorithmforahybridfeedforwardneuralnetwork.Flight-pathanglecontrolvianeuro-adaptiveBackstepping.Locallearningframeworkforhandwrittencharacterrecognition.Maximizingmarginsofmultilayerneuralnetworks.ModularnetworkSOMself-orgmlizingmapofasystemsgroupinfunctionspace.

  • 标签: 多层神经网络 前馈 动力节点 手写识别