简介：Fourkindsofpalladiumcatalystsdispersedonpoly-N-vinyl-2-pyrrolidonewerepreparedbyusingCH3OH-NaOH,NaBH4,H2OorCH3OH-H2Oasthereducingagentintheprocessofcatalystpreparation.ThecatalystswerecharacterizedbyXPS,TEM,XRDandusedforthehydrogenationofmethylacrylate.Itwasfoundthatthevalencestateofpalladiumanddistributionofpalladiumparticlesaswellasthehydrogenationrateweregreatlyaffectedbythereducingagent.ThebestevenlydispersedpalladiumcatalystshowinghighhydrogenationactivitywaspreparedusingCH3OH-NaOHasthereducingagent.

简介：Anewkindofmonomerswassuccessfullysynthesizedbythereactionbetween2-chloromethylcycloketalandtrimethylsilylcyanide,followedbyringclosureanddehaiogenation.Polymerizationsofthemonomerswerecarriedoutinbenzenesolutionat80℃withbenzoylperoxideasinitiator.BoththestructuresofmonomersandpolymerswerecharacterizedbyIR,1HNMR,13CNMRandelementalanalysis.

简介：作者首先给定义微弱地堕落(K1，K2)用外面的力量和外面的微分形式的技术的-quasiregular地图砰，然后，用McShane扩展的方法，有用不平等被获得，它能被用来导出自我改进的整齐。

简介：忍受2,6二度(imino)的一系列钴建筑群含苯氧基的ligands，LCoCl2[L=2,6-(ArNCH)2CH3C6H2OH]被ligand2,6二度(imino)的反应综合有钴二氯化物的相等的鼹鼠的酚，和这些建筑群被元素的分析描绘，1HNMR，MS和红外系列。一建筑群的结构被单个水晶X光检查衍射分析决定。

简介：Superconvergenceofthemixedfiniteelementmethodsfor2-dMaxwellequationsisstudiedinthispaper.Twoorderofsuperconvergentfactorcanbeobtainedforthek-thNedelecelementsontherectangularmeshes.

简介：DistributionofmetalsonPd-SnO2/D3520catalystsandstateofthecatalystswrerstudiedwithSEM,XRD.TheinteractionbetweenmetalsandsupportorbetweenPdandSnorPbwerestudiedbyIR,XPS.Inaddition,therelationshipoftheactivityforcatalytichydrogenationoftheolefinsandouterlayervalenceelectrondensityofPdwasdiscussed.Theresultsshowedthatthesecatalystshadsuitablesurfacestate,themetalswereuniformlydispersedonthesurfacelayerofthesupport.Therewerenotobviousinteractionbetweenthemetalsandthesupport.TherewasstronginteractionbetweenPdandSn(orPb)inthecatalysts.ThecatalyticactivityforhydrogenationwasrelatedtoouterlayervalenceelectrondensityofPd.

简介：Themonitoringoftheradiationenvironmentofearth’sspacehasimportantsignificancefordevelopingspacescienceandapplicationtechniques.Themeasurementofspaceradiationincludesmainlytwoaspects:(1)measurementofenergyspectraandfluxofprotonandelectron,(2)theidentificationofparticlespecieslighter

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简介：DistributionofmetalsonPd-SnO2/D3520catalystsandstateofthecatalystswerestudiedwithSEM,XRD.TheinteractionbetweenmetalsandsupportorbetweenPdandSnorPbwerestudiedbyIR,XPS.Inaddition,therelationshipoftheactivityforcatalytichydrogenationoftheolefinsandouterlayervalenceelectrondensityofPdwasdiscussed.Theresultsshowedthatthesecatalystshadsuitablesurfacestate,themetalswereuniformlydispersedonthesurfacelayerofthesupport.Therewerenotobviousinteractionbetweenthemetalsandthesupport.TherewasstronginteractionbetweenPdandSn(orPb)inthecatalysts.ThecatalyticactivityforhydrogenationwasrelatedtoouterlayervalenceelectrondensityofPd.

简介：在通常用于合成中孔ＭＣＭ－４１分子筛的反应体系中，用氨水、ＮａＯＨ或四乙基氢氧化胺作催化剂，在较低的ｐＨ值下合成出具有独特Ｎ２吸附等温线和狭窄双峰中孔分布的双中孔ＳｉＯ２材料。实验表明，在所使用的反应体系中，双中孔ＳｉＯ２结构是一种必然的物相，且反应体系的ｐＨ值调节在合成中起决定性作用。当反应体系的ｐＨ值从约９．５增加到１１时，相应产物的孔径分布由双中孔转变为单中孔分布。这些结果为进一步深入理解中孔材料的形成机理提供了新的视野。合成样品用ＸＲＤ和Ｎ２吸附等温线进行了表征。更多还原

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简介：InT12SO4+Na2SO4+di(2-ethylhexyl)dithiophosphoricacid+n-CsH18+watersystem,theT1^+equilibriummolalitiesweremeasuredationicstrengthfrom0.1to2.0mol·kg^-1containingNa2SO4assupportingelectrolyteinaqueousphaseandatconstantmolalityofextractantattemperaturesfrom278.15to303.15Kinorganicphase.ThestandardextractionconstantsK^0atvarioustemperatureswereobtainedbymethodsofextrapolationandpolynomialapproximation.Thermodynamicquantitiesfortheextractionprocesswerecalculated.

简介：Wepresenttheextendedhydrogenatomandmonopole-hydrogenatomtheorythroughgeneralizingtheusualhydrogenatommodelandwithamonopolemodelrespectively,inwhichY(sl(2))algebrasarerealized.WederivetheHamiltoniansofthetwomodelsbasedontheY(sl(2))andthegeneralizedPauliequation.TheenergyspectraofthesystemsarealsogivenintermsofYangianalgebraandquantummechanics.

简介：Thecoordinationpolymer,(Nd(H2O)5)2(2,6-AQDS)3·2H2Owhere2,6-AQDS=2,6-anthraquinonedisulfonate,hasbeensynthesisedviaahydrothermalroute.Structurally,itconsistsoflayersofmonomericNdpolyhedrawhicharelinkedby2,6-AQDSanionsformingapolymeric,three-dimensionalnetwork.EachNdatomisninecoordinate,bondingtofivewatermoleculesandtofouroxygenatomsfromfour2,6-AQDSanionswhichinturnpillarthelayersbybridgingtwoNdatomsinonelayer,andcoordinatingtoasingleNdintheother.

简介：Weinvestigateanewclassofperiodicsolutionsto(2+1)-dimensionalKdVequations,byboththelinearsuperpositionapproachandthemappingdeformationmethod.Thesenewperiodicsolutionsaresuitablecombinationsoftheperiodicsolutionstothe(2+1)-dimensionalKdVequationsobtainedbymeansoftheJacobianellipticfunctionmethod,buttheypossessdifferentperiodsandvelocities.

简介：NanocrystallineSnO2wassynthesizedbydirectmixingandgrindingofSnCI4-5H2OandNaOHatroomtemperature,followedbycalcinationatdifferenttemperaturesfordifferenttimesinair.ProductsampleswerecharacterizedbyX-raydiffractionandtransmissionelectronmicroscope,revealingthattheamorphousprecursorSnO2wastransformedtocrystalsat200℃for3h,andthattheaverageparticlesizeincreaseduponraisingthecalciningtemperatureorprolongingthecalciningtime.Themechanismofthephasetransformationoftheproductsisdiscussed.

简介：Anefficientsyntheticmethodwasdevelopedtosynthesize2-substitutedbenzimidazolesandbenzo-xazoleswithβ-ketoestersasstartingmaterialsundermildreactionconditions,duringwhichotherfunctionalgroupsarebearablefromreactantstoproducts.

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简介：Theboundaryelementmethodisusedforthemodalanalysisoffreevibrationof2-Dcompositestructuresinthispaper.Sincetheparticularsolutionmethodisusedtotreatthetermsofbodyforces(inertialforces)intheequationofmotion,onlystaticfundamentalsolutionsareneededinsolvingtheproblem.Foranisotropiccantileverbeam,thenumericalresultsobtainedbyusingtheBEMpresentedinthispaperareingoodagreement,withthoseofusingFEMorotherBEM,butthisBEMcanalsobeusedtoanalyzeproblemsforanisotropicmaterials.Forsimplysupportedcompositelaminatedbeams,thecomparisonsofthenumericalresultsobtainedbythismethodwiththeanalyticalresultsobtainedby1-Dlaminatedbeamtheoryindicatethatiftheratiooflength/thicknessisgreaterthan20,theresultsofthetwomethodsareingoodagreement,butiftheratiooflength/thicknessislessthan20,bigerrorswilloccurfor1-Dlaminatedbeamtheory.

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