简介:前不久,中国航天科技集团公司第六研究院第十一研究所发来感谢信,对中国科学院兰州化学物理研究所为2016年6月25日长征七号运载火箭的成功发射所作出的贡献表示感谢。
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.
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。
简介:Nickelhydroxidedopedwithmulti-wallcarbonnanotubes(MCNTs)wassynthesizedbychemicalcoprecipitationmethod.TheMCNTsdopednickelhydroxidewasusedastheelectrochemicalactivematerialinthepositiveelectrodesofrechargeablealkalinebatteries.ThepowderX-raydiffraction(XRD)analysisshowsthattheadditionofMCNTsinducesmorestructuraldefectwithinthecrystallatticeofthenickelhydroxide.Thecyclicvoltammetry(CV)andelectrochemicalimpedancespectroscopy(EIS)testsdemonstratethebetterreactionreversibilityandlowerelectrochemicalimpedanceofMCNTsdopednickelhydroxideascomparedwiththepurenickelhydroxide.Thecharge/dischargetestsshowthatMCNTsadditioncanimprovethespecificdischargecapacityandincreasethedischargevoltageofthenickelhydroxideelectrode.
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.
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.
简介:Chemicalreductionmethodwasemployedtopreparenano-sizedSn2SbNialloycompositesusedasanodematerialforrechargeablelithiumionbatteries.Thisstrategywasadoptedtocombinethevirtuesofbothactive/inactiveandactive/activealloystofabricateaSn2SbNialloypowderwithtwoactivecomponentsandoneinactivecomponent.Thetwoactivecomponentscanrealizethehighcapacityfeatureofelectrodeandcanmakethevolumechangeofelectrodetakeplaceinastepwisemannerduetothedifferentlithiationpotentialsoftwoactivecomponents,leadingtoastablecyclingperformance.Sn2SbNialloyprovidesareversiblespecificcapacityover640mA·h/gwithanexcellentcyclicability.TheSn-Sb-Nialloycompositematerialshowstobeagoodcandidateanodematerialforthelithiumionbatteries.
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.
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.
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.
简介:TheHAZmicrostructureandperformanceofQuenchingandTemperingmodetemperbeadweldingandgeneralweldedjointswhichweremadeonSA508-3steelof60mmthicknesswerecomparedinthisarticle.Theresultshowsthattemperingsorbitewhichhasexcellentoverallperformancewasobtainedinbothmodes.ThemicrostructureofQuenchingandTemperingmodeweldedjointsgotmorefinegrain.Eventhoughthehardnessoftemperingbeadweldedjointsishigherthanthegeneralone,itstillmeetsthestandardswhichislowerthan350HV.TheimpactabsorbingenergyofeachdistrictoftemperingbeadweldedjointsHAZreached170J,whichisequaltogeneralone.
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。在神舟五号飞船测试、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。
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。