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简介：Wereportonatargetsystemsupportingautomatedpositioningofnano-targetswithaprecisionresolutionof4μminthreedimensions.Itreliesonaconfocaldistancesensorandamicroscope.Thesystemhasbeencommissionedtopositionnanometertargetswith1Hzrepetitionrate.Integratingourprototypeintothetable-topATLAS300TW-lasersystemattheLaboratoryforExtremePhotonicsinGarching,wedemonstratetheoperationofa0.5Hzlaser-drivenprotonsourcewithashot-to-shotvariationofthemaximumenergyabout27%foralevelofconfidenceof0.95.Thereasonoflasershootingexperimentsoperatedat0.5Hzratherthan1Hzisbecausethesynchronizationbetweenthenano-foiltargetpositioningsystemandthelasertriggerneedstoimprove.

简介：CarbondepositionduringmethanoltohydrocarbonsleadstothequickdeactivationofZSM-5catalystanditisoneofthemajorproblemsforthistechnology.DecreasingthecrystalsizeorintroducingmesoporesintoZSM-5zeolitescanimproveitsdiffusionpropertyanddecreasethecokeformation.Inthispaper,nano-sizedZSM-5zeolitewithintercrystallinemesoporescombiningthemesoporousandnanosizedstructurewasfabricated.Forcomparison,themesoporousZSM-5andnano-sizedZSM-5werealsoprepared.ThesecatalystsampleswerecharacterizedbyXRD,BET,NH3-TPD,TEM,Py-IRandTGtechniquesandusedontheconversionofmethanoltogasolineinafixed-bedreactoratT=405°C,WHSV=4.74h-1andP=1.0MPa.Itwasfoundthattheexternalsurfaceareaofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesreached104m2/g,largerthanthatofmesoporousZSM-5(66m2/g)andnanosizedZSM-5(76m2/g).Catalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporeswas93h,whichwasonlylongerthanthatofmesoporousZSM-5(86h),butshorterthanthatofnanosizedZSM-5(104h).Strongaciditypromotedthecokeformationandthusdecreasedthecatalyticlifetimeofthenano-sizedZSM-5zeolitewithintercrystallinemesoporesthoughitpresentedlargeexternalsurfacethatcouldimprovethediffusionproperty.Thespecialzeolitecatalystwasfurtherdealuminatedtodecreasethestrongacidity.Afterthis,itscokeformationratewasslowedandcatalyticlifetimewasprolongedto106hbecauseofthelargeexternalsurfaceareaanddecreasedweakacidity.Thisspecialstructuralzeoliteisapotentialcatalystformethanoltogasolinereaction.

简介：Owingtoitsthickness-modulateddirectenergybandgap,relativelystronglight–matterinteraction,anduniquenonlinearopticalresponseatalongwavelength,few-layerblackphosphorus,orphosphorene,becomesveryattractiveinultrafastphotonicsapplications.Herein,wesynthesizedagraphene/phosphorenenano-heterojunctionusingaliquidphase-strippingmethod.Tinylatticedistortionsingrapheneandphosphorenesuggesttheformationofanano-heterojunctionbetweengrapheneandphosphorenenanosheets.Inaddition,wesystematicallyinvestigatetheirnonlinearopticalresponsesatdifferentwavelengthregimes.Ourexperimentsindicatethatthecombinedadvantagesofultrafastrelaxation,broadbandresponseingraphene,andthestronglight–matterinteractioninphosphorenecanbecombinedtogetherbynano-heterojunction.Wehavefurtherfabricatedtwo-dimensional(2D)nano-heterojunctionbasedopticalsaturableabsorbersandintegratedthemintoanerbium-dopedfiberlasertodemonstratethegenerationofastableultrashortpulsedownto148fs.Ourresultsindicatethatagraphene/phosphorenenano-heterojunctioncanoperateasapromisingsaturableabsorberforultrafastlasersystemswithultrahighpulseenergyandultranarrowpulseduration.Webelievethisworkopensupanewapproachtodesigning2Dheterointerfacesforapplicationsinultrafastphotonicsandotherresearch.Thefabricationofa2Dnano-heterojunctionassembledfromstackingdifferent2Dmaterials,viathisfacileandscalablegrowthapproach,pavesthewayfortheformationandtuningofnew2Dmaterialswithdesirablephotonicpropertiesandapplications.

简介：BackgroundTheregulationoft-PAgeneistheessenceandcoreofthrombosis.Therefore,thepresentstudyaimedtopreparenanot-PAgenecoatedstentandtoobserveitseffectoncoronarystentthrombosisindogs.MethodsHighlyexpressedt-PAgeneplasmidwasconstructedandalbuminnanot-PAgenecoatingstentwasprepared.Themajorbranchvesselsofdogcoronaryarterywerepre-expandedwitha3.0mm×20balloonwith8-10atmosphericpressure.10dogsofthecontrolgroupwereimplantedwithbaremetalstent;while12dogsoftheexperimentalgroupwereimplantedwithnanot-PAgenecoatingstent.Bothgroupswerenotgivenanti-coagulationtreatments.Bloodsamplesweretakenfort-PAandD-dimerbeforetheoperation,at1,2,4and8weeksafteroperation.Pathologicalanalysisfoundthrombosisinthecavityandthehyperplasiaoftheintima.t-PAexpressionwasdetectedbyimmunohistochemicalindirectly,andthethicknessoftheintimaofthesectioncrosswasdirectlymeasuredbymorphometry.Liver,heart,kidneysandlungweretakenforpathologicalobservation.ResultsAllexperimentalanimalssurvivedatpostoperative8weeks.Vascularstentthrombosiswasseenin10casesofthecontrolgroupwiththethrombosisrateof100%;whilewasseenin2casesamong12casesoftheexperimentalgroupwiththethrombosisratewas16.67%(P=0.00087).Immunohistochemicalstainingshowedthatthepositivet-PAgenetransfectionoftheexperimentalgroupwasmainlydistributedonthesurfaceofhyperplasiaintima,andvascularwallt-PAexpressionofthecontrolgroupwasnegative.Positivet-PAsignalwasnotfoundintheliver,heart,kidneysandlung.ConclusionNanot-PAgenevectorcoatingstentcaneffectivelyexpresst-PAinvascularwallandeffectivelypreventsstentthrombosis.

简介：MonophasicCe~(3+)andPr~(3+)co-dopedyttriumaluminumgarnet(YAG:Ce~(3+),Pr~(3+))nanoparticleswithgooddispersityanduniformgrainsizesintherangeof50–80nmwerepreparedbyatwo-steproute,whichconsistedofamodifiedco-precipitationpreparationofmixedmetalhydroxidehydrateintermediatesatlowtemperatureofabout40oCandasubsequentcalcinationconversionofthesynthesizedintermediatestocrystallinenanoparticleproductsatabout1000oC.Theinfluencesofboththelanthanideion(Ce~(3+)andPr~(3+))dopingconcentrationanddifferentdoping(Ce~(3+)/Pr~(3+))ratioonthephotoluminescenceintensityweresystematicallyinvestigated.Thesynthesized(Ce_(0.6)Pr_(0.4))_(0.04)Y_(2.96)Al_5O_(12)nanoparticleswerenearsphericalnanoclusterswithgooddispersityanduniformsizesintherangeof50–80nmforabout85%oftheparticles.Thestrongestphotoluminescenceintensitywasobservedforthe(Ce_(0.6)Pr_(0.4))_(0.04)Y_(2.96)Al_5O_(12)nanoparticleproducts.