简介:Theresultsonadissociationbehaviorofpropanehydratespreparedfrom'drywater'andcontainedunreactedresidualwaterintheformoficeinclusionsorsupercooledliquidwater(watersolutionofgas)werepresentedfortemperaturesbelow273K.Thetemperaturerampingorpressurereleasemethodwasusedforthedissociationofpropanehydratesamples.Itwasfoundthatthemechanismofgashydratedissociationattemperaturesbelow273Kdependedonthephasestateofunreactedwaterinthehydratesample.Gashydratesdissociatedintoiceandgasiftheiceinclusionswereinthehydratesample.Thesamplesofpropanehydrateswithinclusionsofunreactedsupercooledwateronly(withouticeinclusions)dissociatedintosupercooledwaterandgasbelowthepressureofthesupercooledwater-hydrate-gasmetastableequilibrium.
简介:Inthispaper,bothnonlinearsaturableabsorptionandtwo-photonabsorption(TPA)offew-layermolybdenumdiselenide(MoSe2)wereobservedat1.56μmwavelengthandfurtherappliedtomode-lockedultrafastfiberlaserforthefirsttimetoourknowledge.Few-layerMoSe2nanosheetswerepreparedbyliquid-phaseexfoliationmethodandcharacterizedbyxraydiffractometer,Ramanspectroscopy,andatomicforcemicroscopy.TheobtainedfewlayerMoSe2dispersionisfurthercompositedwithapolymermaterialforconvenientfabricationofMoSe2thinfilms.Then,weinvestigatedthenonlinearoptical(NLO)absorptionpropertyofthefew-layerMoSe2filmusingabalancedtwin-detectormeasurementtechnique.BoththesaturableabsorptionandTPAeffectsofthefew-layerMoSe2filmwerefoundbyincreasingtheinputopticalintensity.Thesaturableabsorptionshowsamodulationdepthof0.63%andalownonsaturablelossof3.5%,correspondingtotherelativemodulationdepthof18%.TheTPAeffectoccurredwhentheinputopticalintensityexceeds260MW∕cm2.Furthermore,weexperimentallyexploitthesaturableabsorptionoffew-layerMoSe2filmtomodelockanall-fibererbium-dopedfiberlaser.Stablesolitonmodelockingat1558nmcenterwavelengthisachievedwithpulsedurationof1.45ps.ItwasalsoobservedthattheTPAprocesssuppressesthemode-lockingoperationinthecaseofhigheropticalintensity.OurresultsindicatethatlayeredMoSe2,asanothertwo-dimensionalnanomaterial,canprovideexcellentNLOproperties(e.g.,saturableabsorptionandTPA)forpotentialapplicationsinultrashortpulsegenerationandopticallimiting.
简介:一个非水的暂停polycondensation方法被建议继续为准备的p-phenylenediamine和terephthaloyl氯化物的反应poly(p苯撑terephthalamide)(PPTA)。系统与NMP-CaCl被操作<潜水艇class=“a-plus-plus”>是的2答案驱散的阶段和是的惰性的液体石蜡连续阶段。每NMP-CaCl<潜水艇class=“a-plus-plus”>在石蜡推迟的2答案microdroplet用作polycondensation发生了的microreactor。根据TGA,XRD,红外,SEM和EA的结果,有好质量的PPTA通过这个新奇方法被获得,并且影响这个过程的很多个主要因素被调查为PPTA的准备决定最佳条件。而且,这个二阶段的polycondensation系统与常规解决方案polycondensation方法相比带给许多唯一的优点,包括使反应物离开氧和水的封上的反应环境,HCl到的容易的移动支持更少的精力花费了工具的反应,控制得好的温度和低粘性。
简介:Wereportanerbium-dopedfiberlaserpassivelyQ-switchedbyafew-layermolybdenumdisulfide(MoS2)saturableabsorber(SA).Thefew-layerMoS2isgrownbythechemicalvapordepositionmethodandtransferredontotheend-faceofafiberconnectortoformafiber-compatibleMoS2SA.Thelasercavityisconstructedbyusingathree-portopticalcirculatorandafiberBragggrating(FBG)asthetwoend-mirrors.StableQ-switchedpulsesareobtainedwithapulsedurationof1.92μsat1560.5nm.Byincreasingthepumppowerfrom42to204mW,thepulserepetitionratecanbewidelychangedfrom28.6to114.8kHz.PassiveQ-switchingoperationswithdiscretelasingwavelengthsrangingfrom1529.8to1570.1nmarealsoinvestigatedbyusingFBGswithdifferentcentralwavelengths.Thisworkdemonstratesthatfew-layerMoS2canserveasapromisingSAforwideband-tunableQ-switchinglaseroperation.
简介:Inthisstudy,nano-polyanlineandmanganeseoxidenanometertubularcomposites(nano-PANI@MnO2)werepreparedbyasurfaceinitiatedpolymerizationmethodandusedaselectrochemicalcapacitorelectrodematerials;andtheeffectofanilineamountonthemicrostructureandelectrochemicalperformancewasinvestigated.Themicrostructuresandsurfacemorphologiesofnano-PANI@MnO2werecharacterizedbyX-raydiffraction,scanningelectronmicroscopyandfouriertransformationinfraredspectroscope.Theelectrochemicalperformanceofthesecompositematerialswasperformedwithcyclicvoltammetry,charge–dischargetestandelectrochemicalimpedancespectroscopy,respectively.TheresultsdemonstratethatthefeedratioofanilinetoMnO2playedaveryimportantroleinconstructingthehierarchicallynano-structure,whichwould,hence,determinetheelectrochemicalperformanceofthematerials.UsingthetemplateassistedstrategyandcontrollingthefeedratioofanilinetoMnO2,thenanometertubularstructureofnanoPANI@MnO2wasobtained.Amaximumspecificcapacitanceof386F/gwasachievedinaqueous1mol/LNaNO3electrolytewiththepotentialrangefrom0to0.6V(vs.SCE).
简介:Li4Ti5O12(LTO)/carbonnanotubes(CNTs)compositematerialissynthesizedbasedonasolid-statemethodbysand-milling,spray-dryingandcalciningat8508CunderN2flow.TheLTO/CNTssampleswith1wt%and3wt%weightratioofCNTsadditionandthepristineLTOsampleareprepared.TherateperformanceandthethermalstabilityofthesesamplesareinvestigatedbasedonLiMn2O4(LMO)/LTOfull-cell.TheresultsshowthattheweightratioofCNTsadditionhasdistincteffectonLTOperformances.ThecompositematerialsofLTOcompositedCNTshavebetterperformanceathigh-rateduetotheintercalationenhancementbyconductivenetworkofCNTs.Atsecond,theoverchargingtemperatureresponseofthecell’ssurfacewith1wt%CNTsadditionisthelowest.Theparticlesizedistributionismeasuredandthemostuniformparticlesareobtainedwith1wt%CNTsaddition.ThistrendcouldexplainthatthemediumquantityofCNTsisoptimaltoimprovetheheatandmasstransferandpreventtheproblemsofcrystallitegrowinginterferenceandaggregationduringthecalcinationprocess.