学科分类
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61 个结果
  • 简介:Inthispaper,wereportedamultiwavelengthpassivelyQ-switchedYb3+:GdAl3(BO3)4solid-statelaserwithtopologicalinsulatorBi2Te3asasaturableabsorber(SA)forthefirsttime,tothebestofourknowledge.Bi2Te3nanosheetswerepreparedbythefacilesolvothermalmethod.TheinfluenceofthreeBi2Te3densitiesonthelaseroperationwascompared.Themaximumaverageoutputpowerwasupto57mWwithapulseenergyof511.7nJ.Theshortestpulsewidthwasmeasuredtobe370nswith110kHzpulserepetitionrateand40mWaveragepower.Thelaseroperatedatthreewavelengthssimultaneouslyat1043.7,1045.3,and1046.2nm,ofwhichthefrequencydifferenceswerewithintheterahertzwaveband.OurworksuggeststhatsolvothermalsynthesizedBi2Te3isapromisingSAforsimultaneouslymultiwavelengthlaseroperation.

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  • 简介:采用大涡模拟的方法计算了来流速度为0.6Ma的球/柱体附近的流场,并采用相屏法研究了该流场对激光传输的影响。结果表明:球头附近的流场引起的气动光学效应对传输到远场的激光光斑特性有较大影响,影响程度随激光传输方向而变化,并且激光发射孔径越大、激光波长越短,影响程度越大。

  • 标签: 激光传输 气动光学效应 大涡模拟
  • 简介:我们分类稳定的homotopy类型(n1)有2的维的polyhedra和3扭转释放的-connected,(n+k)为k的相同6。使用的技术是被Drozd给的矩阵问题(bimodule范畴)。

  • 标签: 多面体 分类 同伦类 同源性
  • 简介:Generally,ROSareregardedashostdefensemoleculesthatarereleasedbyneutrophilstodestroyexogenouspathogenssuchasbacteriaandtoactassecondarymessengersinsignaltransduction.However,increasedproductionofROSisalsoinvolvedininducingpathophysiologicalchangessuchasapoptosis,cellcycledisruption,andnecrosis.Forthisreason,inductionofROS-mediateddamageincancercellsbypharmacologicalagentsthateitherpromoteROSgenerationordisablethecellularantioxidantsystemisconsideredapotentialtherapeuticstrategyforpreferentiallykillingcancercells[1].

  • 标签: ROLE Redox STATUS
  • 简介:Pt/WO3/CnanocompositeswithparallelWO3nanorodsweresynthesizedandappliedasthecathodecatalystforprotonexchangemembranefuelcells(PEMFCs).Electrochemicalresultsandsinglecelltestsshowthatanenhancedactivityfortheoxygenreductionreaction(ORR)isobtainedforthePt/WO3/CcatalystcomparedwithPt/C.ThehighercatalyticactivitymightbeascribedtotheimprovedPtdispersionwithsmallerparticlesizes.ThePt/WO3/Ccatalystalsoexhibitsagoodelectrochemicalstabilityunderpotentialcycling.Thus,thePt/WO3/CcatalystcanbeusedasapotentialPEMFCcathodecatalyst.

  • 标签: 质子交换膜燃料电池 阴极催化剂 纳米复合材料 WO3 纳米棒 电化学稳定性
  • 简介:Theshapeofnanostructurehasimportanteffectsontheirproperties,thereforeinthisstudy,wehavepreparedandcharacterizedthreedifferentmorphologiesofWO3nanostructuresi.e.nanorod,nanosphereandnanoplateforsurveyingshapeeffectontheirphotocatalyticpropertiestowarddegradationofRhodamineB(RhB)dye.ObtainedresultsshowthatnanoplateWO3incomparisonwithothershasthebestphotocatalyticactivity.AccordingtoSEM,andphotocatalyticdegradationresults,thereasonforthisbehavioristhesharpedgesandcornersofWO3nanoplates.Becauseoftheirlowcoordinationnumber,atomslocatedintheedgesandcornersoftheWO3nanoplateshavemoreactivity,adsorbmoreRhBandthereforegivemorephotocatalyticactivitytotheWO3nanoplates.UsingofdifferentscavengersshowedthathydroxylradicalsaremainlyresponsibleforphotocatalyticactivityofWO3nanoplatesandnanospheresbutforWO3nanorods,superoxideradicalsarethemainphotocatalyticdegradationagents.

  • 标签: 光催化活性 纳米结构 光催化降解性能 形态 罗丹明B 形状效应
  • 简介:Grapheneanditsderivativeshaveattractedtremendousresearchinterestbecauseoftheiruniquecompositionandphysicochemicalproperties[1??3].However,thepotentialbiologicaltoxicityofGQDshasbecomeahealthriskbecauseoftheirinherentchemicalcompositionandnanoscaleproperties[4].Zebrafish(Daniorerio)isoneofthemostpromisinginvivomodelsystemsfortoxicitystudies[5].

  • 标签: TOXICITY GRAPHENE QUANTUM
  • 简介:AsimpleandefficientcascadeMichael/cyclizationreactionof3-aminoindolin-2-oneswithenones/enalswasidentifiedforthesynthesisofpotentiallybiologicallyactive3’,4’-dihydrospiro[pyrrol-3,2’-oxindoles],usingDBUasanefficientcatalystandethyleneglycolasanenvironmentallybenignsolvent.Morediverse3’,4’-dihydrospiro[pyrrol-3,2’-oxindoles]analoglibrarieswerepreparedingoodyields(upto97%).Thestructureof3’,4’-dihydrospiro[pyrrol-3,2’-oxindoles]wasconfirmedbymassspectrometryanalysis,NMRanalysisandsinglecrystalX-raydiffraction.Themainadvantagesofthismethodincludetheavailabilityofstartingmaterials,simpleexperimentaloperation,shortreactiontime,aswellashighyieldsobserved.

  • 标签: 环化反应 鞘氨醇 迈克尔 二氢 吲哚 烯酮
  • 简介:MalignanttumorsorcancershavebecomeoneofthemostfrequentcausesofdeathinChina;cancertherapiesareattractingmuchattention.Becauseofthenoninvasivenatureofradiationtherapy,lesserphysiologicalandpsychologicalburdenisplacedonpatientsthancomparedtothatresultingfromsurgicalorpharmaceuticaltreatments.Hadrontherapy(heavyiontherapyandprotontherapy)isconsideredsuperiorapproachforthetreatmentoftumorslocatedinhighlysensitivetissues(brain,neck,eyes),pediatriccancers,andalsotumorsthatareresistanttoradiotherapy.

  • 标签: NANOPARTICLES HADRON THERAPY
  • 简介:Wehavefoundthattheexcitedenergyfromthegroundstatewith1f7=2configurationtothefirstexcitedstatewith2p3=2configurationin37SisobviouslylowercomparedwiththatinnearbyN=21isotones35Si,39Arand41Ca(seeFig.1,Theinsertindicatestherelevantsingle-particleorbitsofprotonandneutron).ThisinterestingphenomenonmayresultfromthecollapseofN=28closure,whichgivesthesufficientvalencespaceforcollectivedeformationwhichcanbeenrevealedfromtheB(E2)value.Therefore,toobtaintheB(E2),weperformtheexperimentsformeasuringthelifetimeofthefirstexcitedstatein37S.

  • 标签: LIFETIME MEASUREMENT EXCITED
  • 简介:Thevisualsystemisvitaltohumanhealth,andtheeffectsofionizingradiationonvisionhavereceivedincreasingattention.Usingazebrafishmodel,thisstudywasdesignedtoinvestigatetheapoptosisineyesinducedbycarbonionirradiation.Zebrafishembryosat12hpost-fertilization(hpf)wereirradiatedusing12C6+ionbeamsatdosesof2,4and8Gy.

  • 标签: ZEBRAFISH EYES INDUCED
  • 简介:Intheprocessofoxidativephosphorylation,protonsarepumpedintotheintermembranespacetoestablishthemitochondrialmembranepotential(MMP).Relyingontheelectrochemicalgradient,protonscanreturntothematrixthroughtheATPsynthasecomplexwithATPgeneration.MitoQ,alipophiliccationdrug,canbebsorbedtotheinnermitochondrialmembranewiththecationicmoietystayingattheintermembranespace[1].

  • 标签: MITOQ Induces Non-functional
  • 简介:TheexistenceandorbitalinstabilityofstandingwavesforthegeneralizedthreedimensionalnonlocalnonlinearSchr¨odingerequationsisstudied.Bydefiningsomesuitablefunctionalsandaconstrainedvariationalproblem,wefirstestablishtheexistenceofstandingwaves,whichrelysontheinnerstructureoftheequationsunderconsiderationtoovercomethedrawbackthatnonlocaltermsviolatethespace-scaleinvariance.Wethenshowtheorbitalinstabilityofstandingwaves.Theargumentsdependupontheconservationlawsofthemassandoftheenergy.

  • 标签: 薛定谔方程组 不稳定性 非线性SCHRODINGER方程 局部非线性 轨道 三维