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500 个结果
  • 简介:Thesolidaddofthefirstprotonatedzincoborophosphate,(H3O)Zn(H2O)2BP2O8·H2O(1),wassoventothermallysyn-thesizedbythereactionofZn(NO3)2·6H2OandH3BO3withH3PO4inamixedsolvent,andstructurallycharacterizedbysingle-ystalX-raydiffractionanalysis.ItcrystallizesinthehexagonalP6122,a=0.9604(4)nm,c=1.5297(6)nm,V=1.2218(8)nm^3,Dc=2.921g/cm^3,Z=6,F(000)=1080,μ=3.495mm^-1.Thestmchwefeaturesthatthetetrahedra-te-trahedrahdlcesinterconnectedbyoctahedraandstronghydro-gembondinteractionsformathree-dimensionalframework.Theprotonatedwatermoleculesarelocatedatuniquepositions.othercharacterizationsbyIRandthermalanalysisarealsode-scribed.

  • 标签: (H3O)Zn(H2O)2BP2O8·H2O 合成 结构 质子化 螺旋带状物 硼磷酸锌化合物
  • 简介:Aquantumdynamiccalculationonafive-dimensionalO2/LiF(001)modelsystemisperformedusingthemulti-configurationtime-dependentHartreemethod.Theobtainedresultsshowthatthemechanismofrotationalanddiffractiveexcitationindetails:Comparisonwiththerotationalexcitedstate,theinitiallynon-rotationalstateisseentofavortheinelasticscatteringintherotationalexcitationprocess.Thesurfacecorrugationcandampthequantuminterferencesandproduceagreateramountofrotationalinelasticscatteringattheexpenseoftheelasticprocessintherotationalexcitationprocess.Thediffractionprocessandtheaverageenergytransferredintotherotationalanddiffractivemodearealsodiscussed.

  • 标签: 非弹性散射 旋转状态 衍射过程 表面波纹 氟化锂 氧气
  • 简介:NOVELOXIDATIONOFHEXABENZYLHEXAAZA-ISOWURTZITANEBYMeCHNO/CuCl/Py/OXiaoPeiGUAN;HongYAN;JianGuangSUN;YongZhongYU(ScholofChe?..

  • 标签: CUCL
  • 简介:TheeffectofthecoadsorptionofCOandO2ontheZiff-Gulari-BarshadsurfacecatalyticreactionsysteminstudiedbyMonteCarlosimulation.ThecoadsorptionofbothspeciesaddsanextrareactionsteptotheclassicalZiff-Gulari-Barshadmodel.Itisshownthatthesecond-orderphasetransitionfromthereactivestatetotheO-passivatedstateintheZiff-Gulari-Barshadmodeliseliminated,andtheproductionrateofCO2increaseslinearlyalongthefractionycoofCOingasphasewhenitislow,inagreementwithexperimentalresults.WealsofindthattheincreaseoftheprobabilityofthecoadsorptionleadstothedecreaseofthecriticalvalueofycoofthediscontinuousphasetransitiontotheCO-passivatedstate.

  • 标签: 分子 O2 吸附效应 相图
  • 简介:Asasuccessiveworkofourpreviouspaper,^1theelectrontransfermatrixelement(Vrp)intheoxidationofthesimplifiedmodelmoleculeofα-aminocarbon-centeredradicalbyO2hasbeeninvestigatedwithabinitiocalculationatthelevelofUHF/6-31G**.Basedontheoptimizedgeometriesofthereactgantandtheion-paircomplexobtainedpreviously,thereactionheatandtheiunerreorganizationenergyhavebeenobtainedbyconstructingthepotentialenergycurvesofreactantandproductstatesconsideringthesolventeffectwiththeconductor-likescreeningmodel(COSMO).ThesolventreorganizationenergyhasbeenestimatedusingLippert-Matagarelationship.ThecalculatedresultsshowthatthevalueofVrpisseveraltimeslargerthanthatofRT,whichmeansthatthemodelreactionisanadiabaticone.Theoreticalinvestigationindicatesthatthesolventeffectonthedirectelectrontransfer(ET)processofoxidationofα-aminocarbon-centeredradicalbyoxygenisremarkable.

  • 标签: 溶解能 电子转移 理论研究 基体元素 氧化物 反应机理
  • 简介:Usingfirst-principlescalculations,wesystematicallystudythedissociationsofO2moleculesondifferentultrathinPb(111)films.AccordingtoourpreviousworkrevealingthemolecularadsorptionprecursorstatesforO2,wefurtherexplorewhytherearetwonearlydegenerateadsorptionstatesonPb(111)ultrathinfilms,butnoprecursoradsorptionstatesexistingatallonMg(0001)andAl(111)surfaces.Thereasonisconcludedtobethedifferentsurfaceelectronicstructures.FortheO2dissociation,weconsiderboththereactionchannelsfromgas-likeandmolecularlyadsorbedO2molecules.WefindthattheenergybarrierforO2dissociationfromthemolecularadsorptionprecursorstatesisalwayssmallerthanthatfromO2gas.ThemostenergeticallyfavorabledissociationprocessisfoundtobethesameondifferentPb(111)films,andtheenergybarriersarefoundtobeinfluencedbythequantumsizeeffectsofPb(111)films.

  • 标签: 第一原理计算 超薄膜 氧分子 无铅 平面波 表面电子结构
  • 简介:本文通过电化学测量(循环伏安法)和量子化学计算(CNDO/2法)对几种原子簇化合物[(MoS4)2FeL]3-(其中配位体L为O2CH3CN,O2,O)的氧化还原活性进行了研究.实验测量与理论计算所得结果相符.研究结果表明这几种阴离子的还原皆为不可逆的单电子转移过程.它们接受电子的能力按如下次序递增:[(MoS4)2FeO2CH3CN]3-<[(MoS4)2FeO2]3-<[(MoS4)2FeO]3-

  • 标签: 氧化还原活性 Mo-Fe-S MoS4 eL 原子簇 单电子转移
  • 简介:阴极材料李[CoxNiyMn1?x?y]为锂的O2第二等的电池被一条新线路作为一位先锋用分层的双氢氧化物(LDH)准备了。结果有-NaFeO2结构的分层的阶段在菱形的系统结晶,与有到0.47nm的夹层间距结束的空格组R-3m。X光检查光电子光谱学(XPS)被用来测量公司,Ni和Mn的氧化状态。在结构和李的电气化学的性质上改变Co/Ni/Mn比率的效果[CoxNiyMn1?x?y]O2被X光检查衍射和电气化学的测试调查了。产品表明了相当稳定的骑车行为,与为有Co/Ni/Mn=1/1/1的分层的材料的118mAh/g的一个可逆能力。

  • 标签: 层状正极材料 层状双金属氢氧化物 层状前体 O2 X射线光电子能谱 合成
  • 简介:ThecrystalgrowthprocessofZn(Leu)SO4·0.5H2OformwaterandacetonewasinvestigatedusingaCalvetmicrocalorimeter.Theheatandtherateofheatproductionduringthecrystalgrowthprocessat293.15K,295.15K,298.15Kand300.15Kweremensured.Onthebasisofexperimentalandcalculatedresults,therateconstantandthekineticparameters(theactivationenergies,thepre-exponential)duringthecrystalgrowthprocesswereobtained.Theresultsshowthatthecrystalgrowthprocesswereobtainged.TheresultsshowthatthecrystalgrowthprocessaccordedwiththeBurton-Cabrera-Franddislocationtheory.

  • 标签: 结晶动力学 Zn(Leu)SO4·0.5H2O 晶体生长 丙酮 亮氨酸
  • 简介:AlaminarpremixedPropane/Airflamewithafuelequivalenceratioof2.1wasemployedforanalysisofsootparticles.Zeroth-orderIognormaldistributions(ZOLD)wereusedintheanalysisofexperimentaldistributionphenomenaatdifferentresidencetimesduringsootformationintheflame.Rayleigh'stheoryandMie'sscatteringtheorywerecombinedwithagglomerateanalysisusingscatteringandextinctiondatatodeterminethefollowingsootcharacteristics:agglomerateparameters,volumetricfractions,massflowratesandsurfacegrowthrate.Sootdensitymeasurementswerecarriedouttodeterminedensityvariationsatdifferentstagesofgrowth.Themeasuredresultsshowthatmetricfractionandmassflowrateindicatethatthesurfacegrowthrateofsootparticlesexceedstheoxidationratesintheflamestudied.Thedataobtainedinthisworkwouldbeusedtostudysootoxidationrateunderflamingcondition.

  • 标签: 烟灰颗粒 凝聚参数 表面生长速率 密度 ZOLD 零次对数正态分布
  • 简介:用微波高温固相法合成了Er^3+单掺Lu2O3,Li^+与Er^3+共掺Lu2O3及Li^+,Zn^2+,Mg^2+掺杂Lu2O3∶Er^3+的荧光粉。实验表明金属离子Li^+、Zn^2+、Mg^2+、Er^3+掺杂Lu2O3,不影响Lu2O3的立方晶相。扫描电子显微镜测量表明,Li^+掺杂可以有效改善粉体的分散性和形貌,Li^+,Zn^2+,Mg^2+共掺杂获得的粉体颗粒分布更加均匀,粒径范围为80~100nm。379nm激发下,Li^+与Er^3+共掺样品发光较单掺Er^3+样品在565nm处的发光增强了4.5倍,而Li^+、Zn^2+、Mg^2+与Er^3+共掺样品较其发光增强5.3倍。980nm激发下,Li^+与Er^3+共掺样品,Li^+、Zn^2+、Mg^2+与Er^3+共掺样品的发光分别比单掺Er^3+样品在565nm处发光增强23倍与39倍,在662nm处发光强度分别增强20倍与43倍。379nm激发下,较单掺Er3+的样品,掺杂Li^+的样品和Li^+,Zn^2+,Mg^2+和Er^3+共掺的样品荧光寿命均有所增加,而Zn^2+、Er^3+共掺及Mg^2+、Er^3+共掺样品的荧光寿命则有所缩短。

  • 标签: 微波高温固相法 Li^+ Zn^2+ Mg^2+掺杂Lu2O3∶Er^3+荧光粉 发光强度 上转换发光 荧光寿命
  • 简介:通过Cu纳米颗粒掺杂制备了Li[(Ni0.6Co0.2Mn0.2)1-xCux]O2三元正极材料,并通过调节Cu的掺杂量,讨论了Cu的掺入对Li[(Ni0.6Co0.2Mn0.2)1-xCux]O2三元正极材料晶体结构、表面形貌、电化学性能和循环性能等一系列性能的影响,铜掺杂量为x=0.01时,在0.2C倍率下的首次放电比容量达到了219.1mAh/g,经过50次充放电循环之后,剩余比容量为115.4mAh/g。最终结果为Li[(Ni0.6Co0.2Mn0.2)1-xCux]O2中Cu的掺入量为x=0.01时,所得正极材料的电化学性能和循环性能最为优异。

  • 标签: 锂离子电池 三元正极材料 纳米Cu掺杂 电化学性能 循环性能
  • 简介:Three-dimensional(3D)flowerlikehierarchicalZn2GeO4andMn2+-dopedZn2GeO4microstructureshavebeenpreparedbyafacilehydrothermalapproach.X-Raydiffraction(XRD),fieldemissionscanningelectronmicro-scopy(FESEM),transmissionelectronmicroscopy(TEM)andphotoluminescence(PL)spectrometrywereemployedtocharacterizethesamples.SuchflowerlikehierarchicalZn2GeO4microstructureswithanaveragediameterof3―4μmwerefoundtobeconstructedbyabundantsinglecrystallinenanorodsofabout90nmindiameter.TheluminescentpropertiesofZn2GeO4:xMnphosphorswithdifferentcontentsofMn2+asanactivatorwereinvestigated.TheMn2+-dopedsamplesshowedgreenluminescencecorrespondingtothed-dtransitionofMn2+undertheirradiationofUVlight.Theredshift(from531nmto538nm)inλemwithincreasingMn2+contentwasobservedintheluminescentspectra,whichshouldbeattributedtoaweakcrystalfieldbecauseofthesubstitutionofZn2+byMn2+atadistortedtetrahedrallatticesite.

  • 标签: 锰掺杂 体系结构 场发射扫描电子显微镜 水热法 透射电子显微镜 X-射线衍射
  • 简介:Quasiclassicaltrajectorycalculation(QCT)isusedfrequentlyforstudyingcollisionalenergytransferbetweenhighlyvibrationallyexcitedmoleculesandbathgases.Inthispaper,theQCToftheenergytransferbetweenhighlyvibrationallyexcitedC6F6andN2,O2andgroundstateC6F6wereperformed.TheresultsindicatethathighlyvibrationallyexcitedC6F6transferredvibrationalenergytovibrationaldistributionofN2,O2andgroundstateC6F6,sotheyareV-Venergytransfer.EspeciallyitismainlyV-VresonanceenergytransferbetweenexcitedC6F6andgroundstateC6F6,excitedC6F6transfersmorevibrationalenergytogroundstateC6F6thantoN2andO2.ThevaluesofQCT,-〈△Evib〉ofexcitedC6F6aresmallerthanthoseofexperiments.

  • 标签: 准经典轨道计算 碰撞能转换 C6F6 N2 O2 氟苯
  • 简介:Theobjectinthispaperistoconsidertheproblemofexistence,uniqueness,explicilrepresentationof(0,2)-interpolationonthezerosof(1-x2)Pn-1(x)/xwhennisodd,wherePn-1denotesLegendrepolynomialofdegreen-1,andtheproblemofconvergenceofinterpolatorypolynomials.

  • 标签: INTERPOLATION CONST UNIQUENESS details polynomial arbitrary