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500 个结果
  • 简介:Platinumwassupportedonγ-A1203andultra-stableYzeolite(USY)byanincipientwetnessimpregna-tionmethod.Thecatalystswerecharacterizedbynitrogenphysisorption,transmissionelectronmicroscopy(TEM),CO/C3H8isothermaloxidations,NH3temperature-pro-grammeddesorption(NH3-TPD)andinfrared(IR)spec-troscopyofadsorbedprobemolecules(CO,C3H8andC3H8+02).ComparedwithPt/Al2O3,PtUSYcatalystshowsobviouslyhigheractivityforthecombustionofpropane.AfterestimatingthesizeeffectofPtparticlesandpropaneadsorptioncapacityofUSY,theexcellentactivityofPtUSYisalsoattributedtothestronginteractionsbetweenthepreciousmetalandtheacidiczeolite.Itinhi-bitstheoxidationofPtinanoxygen-richatmosphereathightemperatures,whichfacilitatetheinitialoxidationstepinvolvingtheC-HbondactivationonmetallicPtasreflectedbyinsitudiffusereflectanceinfraredFourier-transformed(DRIFT)spectra.

  • 标签: PLATINUM ZEOLITE PROPANE COMBUSTION Adsorption Metallic
  • 简介:Na离子电池由于他们的低费用和自然许多Na资源为大规模精力存储系统被认为一种有希望的选择到Li离子电池。大努力全球正在做为Na离子电池开发高效的电极材料,它为Na离子电池是批评的。这评论基于Na存储机制为Na离子电池提供阳极材料的全面概述:基于插入的材料,基于合金的材料,基于变换的材料和器官的composites。并且我们总结那些阳极材料的Na存储机制并且讨论他们的失败机制。而且,与那些阳极联系的问题和挑战被指出,并且可行策略为设计高效的阳极材料被建议。根据研究的当前的状态,尽管实质的进步被获得了,为为Na离子电池的合适的阳极材料的搜索仍然是挑战性的。不过,我们相信高效的Na离子电池在不久的将来将为在大规模精力存储系统的实际应用程序是有希望的。

  • 标签: 阳极材料 电池开发 NA 离子 存储机制 存储系统
  • 简介:2016年8月16日1时40分,我国在酒泉卫星发射中心用长征二丁运载火箭成功将世界首颗量子科学实验卫星“墨子”(简称“量子卫星”)发射升空。此次发射任务的圆满成功,标志着我国空间科学研究又迈出重要一步。中国科学院上海硅酸盐研究所研制的量子卫星全部柔性薄膜热控涂层以及下裙铝合金光亮氧化热控涂层获得了成功应用。

  • 标签: 科学实验卫星 上海硅酸盐所 中国科学院上海硅酸盐研究所 量子 墨子 酒泉卫星发射中心
  • 简介:Nickelhydroxidedopedwithmulti-wallcarbonnanotubes(MCNTs)wassynthesizedbychemicalcoprecipitationmethod.TheMCNTsdopednickelhydroxidewasusedastheelectrochemicalactivematerialinthepositiveelectrodesofrechargeablealkalinebatteries.ThepowderX-raydiffraction(XRD)analysisshowsthattheadditionofMCNTsinducesmorestructuraldefectwithinthecrystallatticeofthenickelhydroxide.Thecyclicvoltammetry(CV)andelectrochemicalimpedancespectroscopy(EIS)testsdemonstratethebetterreactionreversibilityandlowerelectrochemicalimpedanceofMCNTsdopednickelhydroxideascomparedwiththepurenickelhydroxide.Thecharge/dischargetestsshowthatMCNTsadditioncanimprovethespecificdischargecapacityandincreasethedischargevoltageofthenickelhydroxideelectrode.

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  • 简介:Automaticgastungstenarc(GTA)weldinghasbeenutilizedtoconnectAZ31magnesiumalloybuttedplateswithAZ61andAZ61-1.0Sbfillerwire.ContrastedtoAZ61fillerwire,theAZ61-1.0Sbfillerwireholdsacomponentof1wt%antimony(Sb).Inthepresentwork,properweldingtechnologyparaneterswereexplored.AndthemicrostructureandperformanceofweldedjointswereanalyzedtoresearchtheinfluenceofSbonmagnesiumalloyweldedjoint.Observedfromthemicrostructureofweldedjoint,additionofSbhasrefinedcrystalgrainsandchangedthepatternofeutecticinbeadandheataffectedzone(HAZ)adjacenttobeadfromdiscontinuousreticulartograininessstructure,whichstrengthentheweaknessofjoint.Inaddition,becauseoftheanchoringactionofMg3Sb2phasesaswellashamperingactiontocrystalboundaryslip,theperformanceofjointweldedbyAZ61-1.0Sbfillerwirehasbeenimproved.

  • 标签: 镁合金 填充线 焊接性质 微结构
  • 简介:Usingdensityfunctionalmethods,somepropertieswerestudiedsuchastheenergiesandcompositionsoffrontiermolecularorbitalsandtheatomiccharges,whicharerelatedtothereactivebehaviorofthioureascontainingdifferentN-substituentgroupings.ThecalculationresultsindicatethattheN-substituentgroupingshavesignificanteffectontheflotationperformanceofthioureacollectors.Theorderofelectron-donatingabilityisN-propyl-N'-benzyl-thiourea(PBZYTU)>N-propyl-N'-ethyl-thiourea(PETU)>N-propyl-N'-allyl-thiourea(PALTU)>>N-propyl-N'-acetyl-thiourea(PACTU)>N-propyl-N'-ethoxycarbonyl-thiourea(PECTU)>N-propyl-N'-benzoyl-thiourea(PBZOYTU),andtheorderoffeedback-electron-acceptingabilityisPBZOYTU>PACTU>PECTU>>PALTU>PETU>PBZYTU.ThisimpliesthatPBZOYTU,PACTUorPECTUcanreactwithcopperatomshaving(t2g)6(eg)3Cu(II)ort6e4Cu(I)configurationonthesurfacesofcoppersulfidemineralsthroughnormalcovalentbondandbackdonationcovalentbond,andexhibitexcellentlycollectingperformanceforcoppersulfideminerals.Theseareconsistentwiththeexperimentaldatareportedintheliteratures.

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  • 简介:Chemicalreductionmethodwasemployedtopreparenano-sizedSn2SbNialloycompositesusedasanodematerialforrechargeablelithiumionbatteries.Thisstrategywasadoptedtocombinethevirtuesofbothactive/inactiveandactive/activealloystofabricateaSn2SbNialloypowderwithtwoactivecomponentsandoneinactivecomponent.Thetwoactivecomponentscanrealizethehighcapacityfeatureofelectrodeandcanmakethevolumechangeofelectrodetakeplaceinastepwisemannerduetothedifferentlithiationpotentialsoftwoactivecomponents,leadingtoastablecyclingperformance.Sn2SbNialloyprovidesareversiblespecificcapacityover640mA·h/gwithanexcellentcyclicability.TheSn-Sb-Nialloycompositematerialshowstobeagoodcandidateanodematerialforthelithiumionbatteries.

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  • 简介:阐述了逆向工程自由曲面拟合的曲面重构和多个曲面整合两方面内容。曲面重构可分为插值和逼近两种方法。其中插值的方法有样条插值、基于散乱点数据的三角曲面插值;而逼近的方法有最小二乘逼近、基于能量原理的曲面逼近、微分方程逼近和小波理论的逼近方法等。则多个曲面整合包括几何连续性和参数连续性。本文对它们分别进行了介绍归类和比较,并且得出了有关的结论。

  • 标签: 逆向工程 曲面拟合 曲面重构 几何连续性 参数连续性
  • 简介:Rareearthelementgadolinium-dopedaluminum–zincoxide(Gd–AZO)semiconductorthinfilmmaterialwasdepositedonbothsiliconandglasssubstratebyradiofrequency(RF)sputteringatroomtemperature.ElectricalpropertiesandmicrostructureofGd–AZOthinfilmweremainlymodulatedbyalteringO2partialpressure(OPP)duringtheRFsputteringprocess.Scanningelectronmicroscope(SEM)andX-raydiffraction(XRD)testwerecarriedouttouncoverthemicrostructurevariationtrendwiththesputteringOPP,andamorphousstructurewhichisbeneficialtolargemassindustrymanufacturewasalsodemonstratedbytheXRDpattern.TransmittanceinvisiblelightspectrumimpliesthepotentialapplicationforGd–AZOtobeusedintransparentmaterialfield.Finally,bottomgate,topcontactdevicestructurethinfilmtransistors(TFTs)withGd–AZOthinfilmastheactivechannellayerwerefabricatedtoverifythesemiconductoravailabilityofGd–AZOthinfilmmaterial.Besides,theGd–AZOTFTsexhibitpreferabletransferandoutputcharacteristics.

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  • 简介:AseriesofnovelAgCl/Ag2CO3heterostructuredphotocatalystswithdifferentAgClcontents(5wt%,10wt%,20wt%,and30wt%)werepreparedbyfacilecoprecipitationmethodatroomtemperature.TheresultingproductswerecharacterizedbypowderX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),X-rayphotoelectronspectroscopy(XPS),andultraviolet–visiblediffusereflectancespectroscopy(UV–VisDRS),respectively.Thephotocatalyticactivityofthesampleswasevaluatedbyphotocatalyticdegradationofmethylorange(MO)underUVlightirradiation.WiththeoptimalAgClcontentof20wt%,theAgCl/Ag2CO3compositeexhibitsthegreatestenhancementinphotocatalyticdegradationefficiency.Itsfirst-orderreactionrateconstant(0.67h-1)is5.2timesfasterthanthatofAg2CO3(0.13h-1),and16.8timesfasterthanthatofAgCl(0.04h-1).TheformationofAgCl/Ag2CO3heterostructurecouldeffectivelysuppresstherecombinationofthephoto-generatedelectronandhole,resultinginanincreaseinphotocatalyticactivity.

  • 标签: 异质结构 光催化剂 氯化银 光催化性能 光催化降解效率 X射线光电子能谱
  • 简介:2010年3月29日海关总署发布《关于对重点固体废物实施分类装运管理》的公告,自2010年6月1日起,对废金属、废塑料、废纸(以下简称“重点固体废物”)进口实施分类装运管理。该新规对重点固体废物进口的运输装载形式作了较为明确规定,没有按规定实行分类装运的进口重点固体废物将无法顺利通关。

  • 标签: 固体废物 装运 分类 解读 废物进口 海关总署
  • 简介:Thispaperstudiedthespotweldingstructureofultra-highstrengthsteel22MnB5.ANSYSsoftwarewasadoptedtosimulateitsstaticstrength;BS5400algorithmwasusedtocalculatethefatiguelife;andthegroupingmethodwasusedtotestthefatigueperformanceoftensileshearspotweldspecimens.Thesimulationresultswereingoodagreementwiththeexperimentalvalues.Basedonthevalidationofthesimulationmethod,influencesofdifferentstructuralparametersonstaticstrengthandfatiguelifewereexploredbyadoptingsinglefactor.Theresultsshowedthatwithintheselectedstructureparameterrange,increaseofthesheetthickness,nuggetdiameter,sheetwidthandoverlappinglengthcanleadtolongerfatiguelife.Besides,thefatiguelifeofspotweldtookonalinearrelationshipwiththeoverlappinglength,aDoseResprelationshipwiththesheetthickness,andasingleexponentialdecayrelationshipwiththesheetwidthandthenuggetdiameter.Moreover,inordertoestimatetheimpactfromvariousparametersonthefatiguelifeofthespecimens,theTaguchiorthogonaldesignmethodwasappliedinthesimulationdesign.Thesimulatingresultindicatedthatinfluenceofthesheetthicknessonfatiguelifewasthemostsignificant.Inaddition,theeffectsofnuggetdiameter,sheetwidthandoverlappinglengthonfatiguelifewerereducedinturn.

  • 标签: 疲劳寿命 超高强度钢 点焊接头 性能影响 几何参数 ANSYS软件
  • 简介:TheHAZmicrostructureandperformanceofQuenchingandTemperingmodetemperbeadweldingandgeneralweldedjointswhichweremadeonSA508-3steelof60mmthicknesswerecomparedinthisarticle.Theresultshowsthattemperingsorbitewhichhasexcellentoverallperformancewasobtainedinbothmodes.ThemicrostructureofQuenchingandTemperingmodeweldedjointsgotmorefinegrain.Eventhoughthehardnessoftemperingbeadweldedjointsishigherthanthegeneralone,itstillmeetsthestandardswhichislowerthan350HV.TheimpactabsorbingenergyofeachdistrictoftemperingbeadweldedjointsHAZreached170J,whichisequaltogeneralone.

  • 标签: SA508 -3 steel TEMPER BEAD welding
  • 简介:深圳雷地科技实业公司收到中国人民解放军总装备部航天医学工程研究所的感谢信,感谢雷地公司“协作配套研制的产品参加了我国首次载人航天飞行任务。在神舟五飞船测试、发射、运行和回收的各个阶段,产品性能稳定,工作正常,有力地配合了我所圆满完成本次意义重大的参试任务。”原来,航天员杨利伟头盔面罩上的“保护膜”及宇航服上金属部件的表面处理,就是雷地公司研制完成的。

  • 标签: 深圳雷地科技实业公司 载人航天工程 “神舟五号”飞船 配套件
  • 简介:金刚石锯条属于金刚石工具类。该发明的金刚石线锯条用在作高速自转,并作往复直线运动的设备上,用在石材开板、切断,以及板材的拼花、镶嵌的分切专用设备上。该发明金刚石带锯条还用于高速金刚石带锯机上对石材切板之用。

  • 标签: 金刚石锯条 加工工具 应用 性能
  • 简介:Au/-Al2O3催化剂被免职降水方法为低集中白酒溪流(甲醇,乙醇,iso-propanol和n-propanol)的催化燃烧作好准备。催化剂被X光检查光电子描绘光谱学(XPS),X光检查diffractometry(XRD)和精力散X光检查微分析(版本)技术。XPS结果证明仅仅催化剂的表面上有Au0。XRD模式证明Au高度大概在-Al2O3上被驱散。为有2.0g/m3的集中的甲醇,乙醇,iso-propanol和n-propanol的完全的变换的温度是60,155,170和137?,分别地但是他们完全在60,220,260和217点被使矿物化进CO2和H2O吗?分别地在优化催化剂上。催化剂的活动在130h是稳定的。为催化甲醇消除的动力学跟随了伪--首先订表示为r=0.6528c0+0.084的反应2。明显的激活精力的价值是在反应温度的范围的54.7kJ/mol。

  • 标签: 光催化 催化性能 Γ-AL2O3 活性催化剂 X射线光电子能谱 X射线显微分析