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:采用溶胶-凝胶法制备了Mn离子摩尔掺杂比.32分别为0,2%,4%,6%,8%的Ba(Ti1-xMnx)O3铁电薄膜。研究发现:当x为6%时,漏电流和矫顽场均达到最小,与未掺杂时相比,漏电流降低了约3个量级,矫顽场电场强度降低了约60%,P—E回线的矩形度增加。实验结果表明:通过适量掺杂Mn离子,可以改善BaTiO3铁电薄膜电学性能,提高铁电薄膜的极化,降低薄膜的漏电流。
简介:Nanosheet(S)andnanoplate(P)γ-Al2O3weresynthesizedbysimplehydrothermalmethodsandemployedassupportsforNicatalystsinCO2methanation.BothofthenanostructuredNi/Al2O3catalystsdisplayedgoodactivity.Incomparison,theNi/Al2O3-ScatalystshowedhigherCO2conversionthantheNi/Al2O3-Pcounterpartatthereactiontemperaturerangingfrom250to400°C.ThephysicalandchemicalpropertiesofthecatalystsweresystematicallycharacterizedbyN2sorption,X-raydiffraction(XRD),highresolution-transmissionelectronmicroscopy(HR-TEM),hydrogentemperature-programmedreduction(H2-TPR)andCO2temperature-programmeddesorption(CO2-TPD)techniques.Higherspecificsurfaceareaandstrongermetal-supportinteractionswereconfirmedontheNi/Al2O3-Scatalyst,whichmayleadtosmallerparticlesizeofNinanoparticles.Moreover,theNi/Al2O3-Scatalystpossessedmoreabundantweakandmediumbasicsites,whichwouldbenefittheactivationofCO2.ThesmallerNisizeandmoresuitablebasicsitesmayrationalizethesuperioractivityoftheNi/Al2O3-Scatalyst.Besides,theNi/Al2O3-Scatalystexhibitedexcellentstabilityat325°Cfor40h.
简介:Thispaperdescribesanewmethodwhichhasbeendevelopedforthesolutionofdirectandinverseproblemsof3-Dcompressibleflowsinturbomachinery.Twotypesofstreamfunctionsarepropsedinthepaperandtheatreamfunction-coordinatesystemisappliedinnumericalcomputations,Thealgorithmisappliedtostatorbladesandtheresultsarecomparedwithexperimentaldata.Itisthownthatthecomparisonsareverysatisfactory.
简介:Duringthepastyear,biophysicsgroupatInstituteofModernPhysics(IMP)obtainedlotsofachievementsintheresearchofheavy-ionmutationbreedingandproductionchainofsweetsorghum.Infundamentalresearchfield,amutantpopulationofArabidopsisthalianainducedbycarbonionbeamradiationwasestablishedinM2generation.Thetotalmutationratewas4.77%.Amutantmarked197#,whichhadfrostbite-like,palegreen,wrinkledandunevenleavesanddisplayedloosebractsandlatematuration,wasobtainedandreportedforthefirsttime.Generoughmappingresultsdemonstratedthatthereweretwomutationsitesinthe1stand4thchromosomeof197#mutant,indicatingheavyionradiationmightinducemorecomplicatedmutationsbeyondourcurrentrecognition.Thewholegenomeresequencingofthismutantisstillinprogress.Inaddition,high-yieldstrainsofmicrobeswhichhavepotentialvalueforcommercialapplication,suchasCorynebacteriumglutamicumandLacbobacillusthermophiles,werescreenedusingheavy-ionmutationtechnique.
简介:Duetotheiruniqueadvantagesinphysicsandbiology,heavyionbeams,withhighmutationrateandwidemutationspectrum,havebeenwidelyusedinplantbreedingasanovelandefficientphysicalmutagen.Inthiswork,Arabidopsisthaliana(197#),whichdisplayeddecreasedfertility,wasinducedbycarbonionbeamsacceleratedbytheHeavyIonResearchFacilityinLanzhou(HIRFL).InordertodeterminethediscrepanciesbetweenWTandmutantplants,aseriesofdevelopmentindexeswereanalyzedduringthereproductivegrowthstage.
简介:Recently,bismuthsulfide(Bi2S3)hasattractedmuchattentioninthethermoelectriccommunityowingtoitsabundance,lowcost,andadvancedproperties.However,itspoorelectricaltransportpropertieshavepreventedBi2S3devicesfromrealizinghighthermoelectricperformance.Inthiswork,ourmotivationistodecreasethelargeelectricalresistivity,whichisrecognizedastheoriginofthelowZTvalueinundopedBi2S3.Wecombinedmeltingandsparkplasmasintering(SPS)inacontinuousfabricationprocesstoproduceBi2S3–xSex(x=0,0.09,0.15,0.21)andBi2S2.85–ySe0.15Cly(y=0.0015,0.0045,0.0075,0.015,0.03)samples.OurresultsshowthatSealloyingatSsitescannarrowthebandgapandactivateintrinsicelectronconduction,leadingtoahighpowerfactorof~2.0μW·cm–1·K–2atroomtemperatureinBi2S2.85S0.15,about100timeshigherthanthatofundopedBi2S3.Moreover,ourfurtherintroductionofClatomsintotheSsitesresultedinasecond-stageoptimizationofcarrierconcentrationandsimultaneouslyreducedthelatticethermalconductivity,whichcontributedtoahighZTvalueof~0.6at723KforBi2S2.835Se0.15Cl0.015.OurresultsindicatethathighthermoelectricperformancecouldberealizedinBi2S3withearth-abundantandlow-costelements.
简介:Wehavestudiedthetwo-andthree-photonabsorption(2PAand3PA)propertiesofMn-dopedCsPbCl3twodimensionalnanoplatelets(2DNPs)andcubicnanocrystals.Comparedwiththeircubiccounterparts,theMn-doped2DNPsexhibitstrongerquantumconfinementeffectsthatcanmoreefficientlyenhancetheirdopantcarrierexchangeinteractionsandmultiphotonabsorption.Morespecifically,themaximumvolume-normalized2PAand3PAcrosssectionsofthe2DNPswere6.8and7.2timesgreaterthanthoseoftheircubiccounterparts,respectively,reachingupto1237GM∕nm3inthevisiblelightbandand2.24×10-78cm6·s2·photon-2∕nm3inthesecondbiologicalwindow,respectively.
简介:在模拟球面元件曲率半径的仿面形夹具上镀制了AlF3单层薄膜,并对不同口径位置上的薄膜进行了比较,以表征球面元件表面镀制薄膜的光学特性和微观结构。首先,采用紫外可见光分光光度计测量了不同口径位置上薄膜样品的透射和反射光谱,反演得出AlF3的折射率和消光系数。然后,使用原子力显微镜观察了样品的表面形貌和表面粗糙度。最后,使用X射线衍射仪对薄膜的内部结构进行了表征。实验结果表明:在球面不同位置镀制的AlF3单层薄膜样品的光学损耗随着所在位置口径的增大而增大。口径为280mm处的消光系数是中心位置处消光系数的1.8倍,表面粗糙度是中心位置的17.7倍。因此,球面元件需要考虑由蒸汽入射角不同带来的光学损耗的差异。