简介：

简介：以硅酸钠为原料,CTAB为模板剂,水热法合成MCM-41介孔分子筛,采用浸渍法制备负载钴的介孔分子筛（Co/MCM-41）,并将其作为催化剂,CVD法热解无水乙醇制备CNTs.利用XRD、TEM、比表面积和孔径分布测定和Raman光谱等方法对所合成的介孔分子筛和纳米碳管进行了表征.结果表明：所制备的Co/MCM-41样品具有典型的MCM-41的介孔结构;当热解反应温度为750℃下所制备出的纳米碳管的品质最好.

简介：用离子交换法将具有Keggin结构TBA4H3PW7Mo3Cu2O38（H2O）2（M=Fe2＋，Co2＋，Cu2＋，Ni2＋和Mn2＋）嵌入到Zn2A1黏土中，得到层状化合物LDH-PW7Mo3Cu2O38（H2O）2（M=Fe2＋，Co2＋，Cu2＋，Ni2＋和Mn2＋），并用XRD，IR，uV对其进行了表征．结果表明：杂多阴离子进入黏土后，仍保留了其Keggin结构．利用合成的层状化合物为催化剂，以顺丁烯二酸与HzO。的环氧化反应为模型反应考察其催化活性，结果表明：层状化合物在环氧化反应中显示优良的催化性能．

简介：

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.

简介：Inco-ionicconductingsolidoxidefuelcell(SOFC),bothoxygenion(O2)andproton(H+)cantransportthroughtheelectrolyte,generatingsteaminboththean-odeandcathode.ThusthemasstransportphenomenonintheelectrodesisquitedifferentfromthatinconventionalSOFCwithoxygenionconductingelectrolyte(O-SOFC)orwithprotonconductingelectrolyte(H-SOFC).Thegenerationofsteaminbothelectrodesalsoaffectstheconcentrationover-potentiallossandfurthertheSOFCperformance.However,nodetailedmodelingstudyonSOFCswithco-ionicelectrolytehasbeenreportedyet.Inthispaper,anewmathematicalmodelforSOFCbasedonco-ionicelectrolytewasdevelopedtopredictitsactualperformanceconsideringthreemajorkindsofoverpotentials.Ohm'slawandtheButler-Volmerformulawereusedtomodeltheionconductionandelectrochemicalreactions,respectively.Thedustygasmodel(DGM)wasemployedtosimulatethemasstransportprocessesintheporouselectrodes.Parametricsimulationswereperformedtoinvestigatetheeffectsofprotontransfernumber(tH)andcurrentdensity(jtotal)onthecellperformance.Itisinterestingtofindthattheco-ionicconductingSOFCcouldperformbetterthanO-SOFCandH-SOFCbychoosinganappropriateprotontransfernumber.Inaddition,theco-ionicSOFCshowssmallerdifferencebetweentheanodeandcathodeconcentrationoverpotentialsthanO-SOFCandH-SOFCatcertaintHvalues.TheresultscouldhelpmaterialselectionforenhancingSOFCperformance.

简介：为研制具有较宽频带微波吸收性能的材料,采用机械合金化法制备CoxFe80-xSi20（x=0,6,10,14摩尔百分数）合金粉体,使用SEM、XRD和矢量网络分析仪等测试手段,研究了合金粉体微观结构及Co-Fe-Si合金微波吸收性能。结果表明：制备的合金粉末呈片状,主要由-Fe相组成;Co的添加使Co-Fe-Si合金出现两个微波吸收峰。在较高频段处的微波吸收峰值随Co的添加先增大后减小。在涂层厚度为1.8mm时,x=10的合金低频处的反射率最小值最小,合金吸波峰频率和峰值分别为6.2GHz和-14.8dB,合金在高频处吸波峰频率和峰值分别为18GHz和-8.8GHz,合金反射率低于-5dB的带宽达14GHz,具有良好的微波吸收宽频效应。

简介：在Hilbert空间中定义了K-g-框架,研究了Hilbert空间中K-g-框架扰动的稳定性,利用分析与框架理论上的方法和技巧,得到了K-g-框架满足扰动稳定性的一些充分条件,所得的结论推广了g-框架扰动稳定性的相关结果.

简介：Effectsofspacevelocity,reactiontemperatureandsupportacidityonproductdistributionandinductionperiodin1-buteneisomerizationandmetathesisoverMo/mordenite-aluminawereinvestigated.Asrevealedbythecatalyticperformanceresults,inductionperiodandobjectiveproductwerecloselyrelatedtothereactionconditions.Lowerspacevelocityledtolongerinductionperiodandhigherpropeneyield.Theoptimalreactiontemperatureforpropeneproductionisaround150Canditshiftedto100Cforetheneproduction.1-Buteneauto-metathesispredominatedinthereactionnetworkifthesupportwithlowerdegreeofsodiumexchanged.Andpropenegraduallybecamethedominantproductuponincreasingthesupportsodiumexchangedegree.6Mo/H100Na0M-30Alcatalystwithasupportoffullsodiumexchangedegreeexhibitedthehighestpropeneyield.

简介：IncorporationofstrontiumintoV-Moalumina-supportedcatalystenhanceditsperformance(increasedconversionandselectivity,decreasedreducibilityandimprovedstability)inpropaneoxydehydrogenationtopropylene.12.5%SrloadingwasshowntobetheoptimumcontenttotheV-Mocatalyst.Theresultsweresupportedbyvariouscharacterizationtechniques,namely,BET,XRD,SEM,FTIRandTPD.

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.

简介：Bimetalliccobalt-rutheniumnanocatalystssupportedoncarbonnanotubes(CNTs)arepreparedusingmicroemultiontechniquewithwater-to-surfactantratiosof0.5—1.5.ThenanocatalystswereextensivelycharacterizedbydifferentmethodsandtheiractivityandselectivityinFischer-Tropschsynthesis(FTS)havebeenassessedinafixed-bedmicroreactor.Thephysicochemicalpropertiesandperformanceofthenanocatalystswerecomparedwiththecatalystpreparedbyimpregnationmethod.Verynarrowparticlesizedistributionhasbeenproducedbythemicroemulsiontechniqueatrelativelyhighloadingsofactivemetals(15wt%Coand1wt%Ru).AccordingtoTEMimages,smallCoparticles(2—7nm)weremostlyconfinedinsidetheCNTs.Comparingwiththecatalystpreparedbyimpregnation,theuseofmicroemulsiontechniquewithwatertosurfactantratioof0.5decreasedtheaveragecobaltoxideparticlesizeto4.8nm,thedispersionwasalmostdoubledandthereductionincreasedby28%.Activityandselectivitywerefoundtobedependentonthecatalystpreparationmethodandwater-to-surfactantratio(aswellascobaltparticlesizes).COconversionincreasedfrom59.1%to75.1%andtheFTSrateincreasedfrom0.291to0.372gHC/(gcath).C5+liquidhydrocarbonsselectivitydecreasedfrom92.4%to87.6%.

简介：Recentadvancesontheuseofnanocarbon-basedelectrodesfortheelectrocatalyticconversionofgaseousstreamsofCO2toliquidfuelsarediscussedinthisperspectivepaper.Anovelgas-phaseelectrocatalyticcell,differentfromthetypicalelectrochemicalsystemsworkinginliquidphase,wasdeveloped.Thereareseveraladvantagestoworkingasphase,e.g.noneedtorecovertheproductsfromaliquidphaseandnoproblemsofCO2solubility,etc.Operatingundertheseconditionsandusingelectrodesbasedonmetalnanoparticlessupportedovercarbonnanotube(CNT)typematerials,longC-chainproducts(inparticularisopropanolunderoptimizedconditions,butalsohydrocarbonsuptoC8-C9)wereobtainedfromthereductionofCO2.Pt-CNTaremorestableandgiveinsomecasesahigherproductivity,butFe-CNT,particularusingN-dopedcarbonnanotubes,giveexcellentpropertiesandarepreferabletonoble-metal-basedelectrocatalystsforthelowercost.ThecontrolofthelocalizationofmetalparticlesattheinneroroutersurfaceofCNTisanimportactfactorfortheproductdistribution.ThenatureofthenanocarbonsubstratealsoplaysarelevantroleinenhancingtheproductivityandtuningtheselectivitytowardslongC-chainproducts.TheelectrodesfortheelectrocatalyticconversionofCO2arepartofaphotoelectrocatalytic(PEC)solarcellconcept,aimedtodevelopknowledgeforthenewgenerationartificialleaf-typesolarcellswhichcanusesunlightandwatertoconvertCO2tofuelsandchemicals.TheCO2reductiontoliquidfuelsbysolarenergyisagoodattempttointroducerenewablesintotheexistingenergyandchemicalinfrastructures,havingahigherenergydensityandeasiertransport/storagethanothercompetingsolutions(i.e.H2).

简介：

简介：W，N共同做TiO2nanoparticles被一个solgel方法综合。准备样品被X光检查衍射(XRD)描绘，域排放扫描电子显微镜学(FE-SEM)，传播电子显微镜学(TEM)，Fourier变换红外线的光谱学(英尺红外)，X光检查光电子光谱学(XPS)和弥漫的反射spectrophotometry(医生)。结果证明共同做的光催化剂是有22.5nm的最小的粒子尺寸的实质上一致的球形的粒子。比作未做的TiO2，N-TiO2和P-25，W的吸收边，N共同做转移到更长的波长的TiO2和它为在Xe灯(350W)下面的甲基橘子(瞬间)的降级的photocatalytic活动更高。

简介：K-phillipsite用一个热水的方法被准备。可溶的玻璃和钠铝酸盐当一个器官的模板不在时被用作原料。关于K+离子的调查在房间温度被进行在海水样品和混合K+Na+答案的选择系数决定离子交换能力。样品被X光检查衍射(XRD)描绘，扫描电子显微镜学(SEM)，和精力分散光谱学(版本)。K+离子交换能力是在海水的51mg/g，选择系数在混合K+Na+答案是75.1。样品为K+有选择偏爱，并且能因此被用来有选择地从海水提取钾。由Si，艾尔，K，Na，和O组成的样品展出跨like形状并且是典型K-phillipsite结构。

简介：Thearomatizationoflightalkenesinliquefiedpetroleumgas(LPG)withandwithoutdimethylether(DME)additioninthefeedwasinvestigatedonamodifiedZSM-5catalyst.Theresultsshowedthatunderthegivenreactionconditionstheselectivityofalkenestohigh-octanegasolineblendingcomponentswasmarkedlyenhancedandtheformationofpropaneandbutaneswasgreatlysuppressedwiththeadditionofDME.ItwasalsofoundthatthedistributionofC5+componentswaschangedalotwithDMEadditionintotheLPGfeed.Theformationofbranchedhydrocarbons(mainlyC6C8i-paraffin)andmulti-methylsubstitutedaromatics,whicharehighoctanenumbergasolineblendingcomponents,waspromotedsignificantly,whilethecontentofn-paraffinsandolefinsinC5+componentswasdecreasedobviously,indicatingthatinadditiontotheoligomerization,cracking,hydrogen-transferanddehydrogenation-cyclizationofalkenes,themethylationoftheformedaromaticsandolefinsintermediatesalsoplaysanimportantroleindeterminingtheproductdistributionduetothehighreactivityofsurfacemethoxygroupsformedbyDME.Andthisprocess,incombinationwiththesyngas-to-methanol/DMEtechnology,providesanalternativewaytotheproductionofhigh-octanegasolinefromcoal,naturalgasorrenewablerawmaterials.

简介：Au/Ce1xZrxO2catalysts(x=0-0.8)werepreparedbyadeposition-precipitationmethodusingCe1xZrxO2nanoparticlesassupportswithvariableCeandZrcontents.TheirstructureswerecharacterizedbycomplimentarymeanssuchasX-raydiffraction,Raman,scanningtransmissionelectronmicroscopyandX-rayphotoelectronspectroscopy(XPS).TheseAucatalystspossessedsimilarsizesandcrystallinephasesofCe1xZrxO2supportsaswellassimilarsizesandoxidationstatesofAunanoparticles.TheoxidationstateofAunanoparticleswasdominatedbyAu0especiallyinCOoxidation.TheiractivitieswereexaminedinCOoxidationatdifferenttemperaturesintherangeof303333K.TheCOoxidationratesnormalizedperAuatomsincreasedwiththeincreasingCecontents,andreachedthemaximumvalueoverAu/CeO2.Suchchangewasinparallelwiththechangeintheoxygenstoragecapacityvalues,i.e.theamountsofactiveoxygenspeciesonAu/Ce1xZrxO2catalysts.TheexcellentcorrelationbetweenthetwopropertiesofthecatalystssuggeststhattheintrinsicsupporteffectsontheCOoxidationratesisrelatedtotheeffectsontheadsorptionandactivationofO2onAu/Ce1xZrxO2catalysts.SuchunderstandingonthesupporteffectsmaybeusefulfordesigningmoreactiveAucatalysts,forexample,bytuningtheredoxpropertiesofoxidesupports.

简介：在生物教学中，教师针对课程创设出相应的教学情境，并用各种方法让学生的思维逐渐进入情境，为完成课时目标创造条件。

简介：Removalofcarbonylsulfide(COS)fromCO2streamissignificantfortheproductionandutilizationoffoodgradeCO2.ThisstudyinvestigatestheadsorptionperformanceofAg/NaZSM-5asadsorbentpreparedbyincipientwetnessimpregnationfortheremovalofCOSfromaCO2streaminafixed-bedadsorptionapparatus.Effectsofvariousconditionsonthepreparationofadsorbent,adsorptionanddesorptionwereintensivelyexamined.TheresultsrevealedthatCOScanberemovedtobelow1×10-9fromaCO2stream(1000ppmCOS/CO2)usingAg/NaZSM-5(10wt%AgNO3)withanadsorptioncapacityof12.86mg·g-1.Theadsorbentcanbefullyregeneratedusinghotairat450C.Theadsorptionabilityremainedstableevenaftereightcyclesofregeneration.