简介:Two-dimensional(2D)periodicalAuandindiumtinoxide(ITO)nanocompositearrayshavebeenfabricatedbasedonaself-assemblednanospherelithographytechnique.Abutton-shapedAunanoparticlewasformedoneachhollowhemisphere-shapedITOshell.Importantly,theunderlyingformationmechanismduringthethermaltreatmenthasbeenthoroughlyexploredbycomparingstructuresresultingfromdifferentdepositionconditionsindetail.ComparedtotheAunanoparticlearrayswithoutITOshells,theAu/ITOnanocompositearraysshowedastrongerlocalizedsurfaceplasmonresonanceeffectandhigherabsorptioninthenear-infrared(NIR)region,benefitingfromthefree-electroninteractionenhancementbetweenAuandITO.Thenonlinearopticalpropertieswereinvestigatedusingamodifiedfemtosecondintensity-scansystem,andtheresultsdemonstratedAu/ITOnanocompositearrayswitharemarkabletwo-photonabsorptionsaturationeffectforfemtosecondpulsesat1030nm.TheversatileNIRopticalresponsesindicatethegreatpotentialoftheelaboratelyprepared2DperiodicalAu/ITOnanocompositearraysinmanyapplicationssuchassolarcells,photocatalysis,andnovelnanooptoelectronicdevices.
简介:WereportontheoperationofpassivelyQ-switchedwaveguidelasersat1μmwavelengthbasedonagraphene∕WS2heterostructureasasaturableabsorber(SA).ThegainmediumisacrystallineNd:YVO4claddingwaveguideproducedbyfemtosecondlaserwriting.Thenanosecondwaveguidelaseroperationat1064nmhasbeenrealizedwiththemaximumaverageoutputpowerof275mWandslopeefficiencyof37%.IncomparisonwiththesystemsbasedonsingleWS2orgrapheneSA,thelasingQ-switchedbyagraphene∕WS2heterostructureSApossessesadvantagesofahigherpulseenergyandenhancedslopeefficiency,indicatingthepromisingapplicationsofvanderWaalsheterostructuresforultrafastphotonicdevices.
简介:近似所有人的癌症表演正常TP53基因表示的一半但是MDM2或MDMX的异常overexpression。这个事实建议有希望的癌症在指向在p53和MDM2/MDMX之间的相互作用的治疗学的策略。为了帮助,实现开发有效禁止者破坏p53-MDM2/MDMX相互作用的目标,我们系统地调查了结构并且有它和从用随机的分子的动力学模拟的一个原子论的观点的MDM2和MDMX的相互作用的禁止者的p53的相互作用特征。我们发现在MDM2和MDMX玩的结构的某特定的helices在他们的绑定给角色调音到禁止者,并且氢契约在MDM2或MDMX与它的对应物由p53的Trp23残余形成了,这在vivo从MDM2-p53建筑群决定MDM2-p53相互作用的混乱和p53的代替的动态比赛过程。结果在这报导纸被期望为设计功能的禁止者并且认识到癌症基因治疗的新策略提供基本信息。
简介:Thethird-ordernonlinearopticalpropertiesofwater-solubleCu2-xSenanocrystalsarestudiedinthenearinfraredrangeof70-980nmusingafemtosecondpulsedlaserbytheZ-scantechnique.ItisobservedthatthenonlinearopticalresponseofCu2-xSenanocrystalsissensitivelydependentontheexcitationwavelengthandexhibitstheenhancednonlinearitycomparedwithotherselenidessuchasZnSeandCdSe.TheW-shapedZ-scantrace,amixtureofthereversedsaturatedabsorptionandsaturatedabsorption,isobservedneartheplasmonresonancebandofCu2-xSenanoerystals,whichisattributedtothestate-fillingoffreecarriersgeneratedbycoppervacancies(self-dopingeffect)ofCu2-xSenanoerystalsaswellasthehotcarrierthermaleffectuponintensefemtosecondlaserexcitation.ThelargenonlinearopticalresponseandtunableplasmonicbandmakeCu2-xSenanocrystalspromisingmaterialsforapplicationsinultra-fastall-opticalswitchingdevicesaswellasnonlinearnanosensors.
简介:Ceria-zirconiasolidsolutionhasbeenpreparedbytheureagrindcombustionandcitricacidsol-gelmethodsforcatalyticapplicationsasoxygenstorage/releasematerialsinthisstudy.Thepropertiesandoxygenstorage/releasecapacitiesofsampleswithdifferentZrcontentswerecharacterizedandevaluatedbyX-raydiffraction(XRD),N2adsorption,scanningelectronmicroscopy(SEM),Ramanspectroscopy,andinsituCO–CO2loopingtest.Theresultsdemonstratethatthesamplespreparedbytwomethodsareallofexcellentlattice[O]release/storagepropertiesandmaintaingoodlong-termcyclestability.ButthepreparationmethodsignificantlyimpactsthehomogeneityofsamplesrelatedtotheirredoxpropertiesandthecontentofZrover20%,whichgreatlychangedthepropertiesofceria-zirconiasolidsolutionsandcausedtheirchangingofcrystallinesymmetryfromcubictotetragonal.Thesamplespreparedbycitricacidsolgelmethodareofmorehomogeneousparticlesizesandhigherspecificsurfaceareasthanthatbyureagrindcombustionmethod,whichisbenefittotheoxygenreleaseratherthanoxygenstorage.ThebulkoxygenamountmigratedtosurfaceincreaseswiththeincreasingZrcontent,however,theamountoflatticeoxygenmigrationdecreaseswhenZrcontentisover20%.WhenZrcontentis20%,thedifferencesofstorage/releasecapacitiesfromtwodifferentpreparationmethodsarereducedathightemperatureinthelong-termloopreaction.
简介:Transversemodeinstability(TMI)hasbecomethemajorlimitationforpowerscalingoffiberlaserswithnearlydiffraction-limitedbeamquality.Comparedwithaco-pumpedfiberlaser,acounter-pumpedfiberlaserrevealsTMIthresholdenhancementthroughasemi-analyticalmodelcalculation.Wedemonstrateda2kWhigh-powercounter-pumpedall-fiberizedlaserwithoutobservationofTMI.Comparedwiththeco-pumpedscheme,theTMIthresholdisenhancedatleast50%incounter-pumpedscheme,moreover,stimulatedRamanscatteringandfour-wavemixingaresuppressedsimultaneously.
简介:目的:探究季铵型聚合物CO2解吸附过程温度和CO2浓度等变量对解吸附热力学和动力学的影响;研究空气CO2捕集供给植物增产的耦合方法,降低空气CO2捕集与利用的能耗与成本。创新点:1.基于变湿吸附技术,探究了季铵型聚合物CO2解吸附过程的热力学及动力学特性;2.获得了CO2作为气肥供给植物增产的关键影响参数;3.建立并优化了空气CO2捕集与植物利用的耦合模型。方法:1.通过CO2吸附平衡与动力学实验,获得季铵型聚合物CO2解吸附的平衡常数和动力学常数的影响参数;2.通过植物CO2吸收实验,获得CO2供给植物增产过程中CO2浓度和光照强度对吸收速率的影响;3.通过理论推导,构建解吸附CO2浓度与吸附剂质量、温度以及吹扫气流量等的关系,获得空气CO2捕集与植物增产的耦合模型并计算CO2捕集的能耗与成本。结论:1.季铵型聚合物材料吸附CO2的平衡常数随温度的升高而降低;吸附、解吸附动力学常数随温度的升高而升高。2.CO2供给植物增产的最佳浓度和光照强度为1000ppm和8000lux。3.基于优化的空气捕集与植物利用的耦合算法,CO2的捕集能耗与成本分别为35.67kJ/mol和34.68USD/t。
简介:ThreephasePebax?MH1657/PEG-ran-PPG/CuBTC(polymer/liquid/solid)wassuccessfullydepositedasaselectivelayeronaporousPolysulfone(PSF)support.Infact,thebeneficialpropertiesofPEG(highselectivity)withthoseofPPG(highpermeability,amorphous)havebeencombinedwithsuperiorpropertiesofmixedmatrixmembrane(MMMs).ThemembraneswerecharacterizedbyDSC,TGAandSEM,whileCuBTCwascharacterizedbyCO2andCH4adsorptiontest.Statisticallybasedexperimentaldesign(centralcompositedesign,CCD)wasappliedtoanalyzeandoptimizetheeffectofPEG-ran-PPG(10–50wt%)andCuBTC(0–20wt%)masscontentsontheCO2permeanceandCO2/CH4idealselectivity.Basedontheregressioncoefficientsoftheobtainedmodels,theCO2permeancewasnotablyinfluencedbyPEG-ran-PPG,whileCuBTChasthemostsignificanteffectontheCO2/CH4idealselectivity.Undertheoptimumconditions(PEG-ran-PPG:32.76wt%andCuBTC:20wt%),nearly620%increaseintheCO2permeanceand43%enhancementintheCO2/CH4idealselectivitywasobservedcomparedtotheneatPebax.Theeffectofpressure(3,9and15bar)onthepureandmixedgasseparationperformanceofthecompositemembraneswasalsoinvestigated.ThehighsolubilityofCO2inthemembranesresultedintheenhancementofCO2permeabilitywithincreaseingaspressure.
简介:CrystallineTiO2(P25)andisolatedtitanatespeciesinaZSM-5structure(TS-1)weremodifiedwithAuandAg,respectively,andtestedinthegas-phasephotocatalyticCO2reductionunderhighpurityconditions.Thenoblemetalmodificationwasperformedbyphotodeposition.LightabsorbancepropertiesofthecatalystsareexaminedwithUV–Visspectroscopybeforeandaftertheactivitytest.Inthegas-phasephotocatalyticCO2reduction,itwasobservedthatthecatalystswithAgnanostructuresaremoreactivethanthosewithAunanostructures.Itisthusfoundthattheenergeticdifferencebetweenthebandgapenergyofthesemiconductorandthepositionoftheplasmonisinfluencingthephotocatalyticactivity.Potentially,plasmonexcitationduetovisiblelightabsorptionresultsinplasmonresonanceenergy,whichaffectstheexcitationofthesemiconductorpositively.Therefore,anoverlapbetweenbandgapenergyofthesemiconductorandmetalplasmonisneeded.
简介:Carbondioxide(CO2)captureusingmagnesiumoxide(MgO)-basedadsorbentsatintermediatetemperatureshasbeenregardedasaveryprospectivetechnologyfortheirrelativelyhighadsorptioncapacity,lowcost,andwideavailability.Duringthepastfewyears,greatefforthasbeendevotedtothefabricationofmoltensalts-modifiedMgO-basedadsorbents.TheextraordinaryprogressachievedbycoatingwithmoltensaltsgreatlypromotestheCO2capturecapacityofMgO-basedadsorbents.Therefore,wefeelitnecessarytodeliveratimelyreviewonthistypeofCO2capturingmaterials,whichwillbenefittheresearchersworkinginbothacademicandindustrialareas.Inthiswork,weclassifiedthemoltensaltsmodifiedMgOadsorbentsintofourcategories:(1)homogenousmoltensalt-modifiedMgOadsorbents,(2)moltensalt-modifieddoublesalts-basedMgOadsorbents,(3)mixedmoltensalts-modifiedMgOadsorbents,and(4)moltensalts-modifiedMgO-basedmixedoxidesadsorbents.Thiscontributioncriticallyreviewstherecentdevelopmentsinthesyntheticmethod,adsorptioncapacity,reactionkinetics,promotionmechanism,operationalconditionsandregenerabilityofthemoltensalts-modifiedMgOCO2adsorbents.Thechallengesandprospectsinthispromisingfieldofmoltensalts-modifiedMgOCO2adsorbentsinrealapplicationsarealsobrieflymentioned.
简介:HierarchicalporousTiO2nanopillsweresynthesizedusingatitaniummetal-organicframeworkMIL-125(Ti)asprecursor.Theas-synthesizedTiO2nanopillsownedalargespecificsurfaceareaof102m2/ganduniqueporousstructure.Furthermore,theobtainedTiO2nanopillswereappliedasanodematerialsforNa-ionbatteriesforthefirsttime.Theas-synthesizedTiO2nanopillsachievedahighdischargecapacityof196.4mAh/gatacurrentdensityof0.1A/g.Adischargecapacityof115.9mAh/gwasobtainedatahighcurrentdensityof0.5A/gandthecapacityretentionwasremainedashighas90%evenafter3000cycles.Theexcellentelectrochemicalperformancecanbeattributedtoitsuniquehierarchicalporousfeature.
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简介:One-potachievementofethyllevulinatefromcassavawasconductedinethanol-watersystemoverseveralsimplesulfatesaltcatalysts.Al2(SO4)3catalysthadthebestperformanceinsynthesizingethyllevulinatecomparingwiththoseofaseriesofsulfatesalts.Thehighestyieldsofethyllevulinatewasupto39.27%aswellas7.78%levulinateacidwhencassavawascatalyzedinethanolmediumbyadding10wt%water.13Cand1HNMRspectroscopicinvestigationsconfirmedthatisomerizationofglucosetofructoseoverAl2(SO4)3catalystisanimportantstepinproducingethyllevulinateandlevulinateacid.DuetoaggregationsofAl3+underhydrothermalconditions,tinyamountofAl3+weredetectedinfiltrateatthepercentageof0.32%evenifinabsolutewater.BronstedandLewisacidscouldimprovetheyieldofethyllevulinateandlevulinateacidbysynergisticeffect.AllresultssuggestedthatA12(SO4)3wasasimpleandefficientcatalystforethyllevulinateandlevulinateacidproduction.
简介:ThemorphologyeffectofZr-dopedCeO2wasstudiedintermsoftheiractivitiesintheselectiveoxidationofstyrenetostyreneoxideusingtert-butylhydroperoxideastheoxidant.Inthepresentwork,ZrdopedCeO2nanorodsexhibitedthehighestcatalyticperformance(yieldofstyreneoxideandTOFvalue)followedbynanoparticlesandnanocubes.FortheZr-dopedCeO2nanorods,theapparentactivationenergyis56.3kJ/mol,whichismuchlowerthanthevaluesofcatalystssupportedonnanoparticlesandnanocubes(73.3and93.4kJ/mol).Thehighresolutiontransmissionelectronmicroscopyresultsindicatedthat(100)and(110)crystalplanesarepredominantlyexposedforZr-dopedCeO2nanorodswhile(100)and(111)fornanocubes,(111)fornanoparticles.TheremarkablyincreasedcatalyticactivityoftheZrdopedCeO2nanorodsismainlyattributedtothehigherpercentageofCe3+speciesandmoreoxygenvacancies,whichareassociatedwiththeirexposed(100)and(110)crystalplanes.Furthermore,recyclingstudiesprovedthattheheterogeneousZr-dopedCeO2nanorodsdidnotloseitsinitialhighcatalyticactivityafterfivesuccessiverecycles.
简介:Wereportonbroadlywavelength-tunablepassivemode-lockingwithhighpoweroperatingatthe2μmwaterabsorptionbandinaTm:CYAcrystallaser.Withasimplequartzplate,stablemode-lockingwavelengthscanbetunedfrom1874to1973nm,withatunablewavelengthrangeupto~100nmandmaximumoutputpowerupto1.35W.Thebandwidthisnarrowas~6GHz,correspondingtoahighcoherence.Toourknowledge,thisisthefirstdemonstrationofwavelength-tunablemode-lockingwithwatt-levelinthe2μmwaterabsorptionband.Thehightemporalcoherentlasercanbefurtherappliedinspectroscopy,theefficientexcitationofmolecules,sensing,andquantumoptics.
简介:Adoubleactivecentersystem,namelySalen-Cu(Ⅱ)@MIL-101(Cr),wassuccessfullysynthesizedviathe“shipinabottle”approach,whichactedasabifunctionalmaterialforbothcaptureandconversionofCO2inasingleprocess.Forthefirsttime,Salen-Cu(Ⅱ)@MIL-101(Cr)catalystwasdevelopedforthesynthesisofpropylenecarbonatefromCO2andpropyleneoxideunderroomtemperatureandambientpressurewithayieldof87.8%over60h.Furthermore,thereactionmechanismwasalsodiscussed.
简介:Thehighharmonicgeneration(HHG)fromtheCS2moleculeinintenselaserfieldsisinvestigatedusingtheextendedLewensteinmethod.Tileinitialstateisthehighest-occupiedmolecularorbitaloftheCS2molecule,whichcanbewelldescribedbyGaussianwavepacketusingGAMESS-UKpackage.Comparedwiththecaseoftheellipticallaser,theHHGcanbeextendedintwo-colorcircularlypolarizedlaserfield.Thetime-frequencyanalysisandclassicalelectrontrajectoryaswellastheionizationyieldcurvearealsopresentedtofurtherexplaintheunderlyingmechanism.Afteraddingastaticelectricfieldonthez-direction,thesinglequantumpathcontrolisrealizedandthesupercontinuumspectraareobtained.Moreover,anisolated110aspulsecanbeobtainedbysuperposingtheharmonicsfrom130thto1SOthorder.
简介:Theefficiencyofthepoly(3-hexylthiophene)(P3HT)and[6,6]-phenylC61-butyricacidmethylester(PC61BM)basedorganicsolarcellswasenhancedbyusing1,2,4-trichlorobenzene(TCB)asaprocessingadditivetocontroltheblendmorphology.TheadditionofTCBimprovedthearrangementofP3HTwhichresultedingoodphaseseparatedblendfilms.Correspondingly,theoptimizedsolarcellsshowedapowerconversionefficiency(PCE)of4.17%withafillfactor(FF)of0.69,whichwerehigherthanthoseofcommonthermalannealingdevices(PCE3.84%,FF0.67).Theefficiencywasfurtherimprovedto4.74%bythermalannealingat150°Cfor10minwithahigherFFof0.74.