简介:Theadsorptionandelectronicpropertiesofisolatedcobaltphthalocyanine(CoPc)moleculeonanultrathinlayerofNaClhavebeeninvestigated.High-resolutionSTMimagesgiveadetailedpictureofthelowestunoccupiedmolecularorbital(LUMO)ofanisolatedCoPc.ItisshownthattheNaClultrathinlayerefficientlydecouplestheinteractionofthemoleculesfromtheunderneathmetalsubstrate,whichmakesitanidealsubstrateforstudyingthepropertiesofsinglemolecules.Moreover,strongdependenceoftheappearanceofthemoleculesonthesamplebiasintheregionofrelativelyhighbias(>3.1V)isascribedtotheimagepotentialstates(IPSs)ofNaCl/Cu(100),whichmayprovideuswithapossiblemethodtofabricatequantumstoragedevices.
简介:Continuoussiliconcarbidefiberreinforcedsiliconcarbide(SiCf/SiC)compositeshavebeenconsideredtobecandidatematerialsofhightemperaturestructuralapplicationinaerospace,energyconservationandpowergenerationduetotheexcellenthightemperaturemechanicalproperties,goodfractureresistance,corrosionresistanceandthermodynamicstability.Furthermore,duetothehighthermalstability,lowinducedradioactivity,quickdecayofactivityandlowafterheat,SiCf/SiCcompositeshavebeenrecognizedasthepromisingmaterialsoffissionandfuturefusionreactors.SiCf/SiCcompositesarecomposedofSiCfiberandSiCmarixmaterials.Radiationresistance,oxidationtolerance,fracturetoughnessandtensilestrengthofSiCfiberhaveadirectimpactontheSiCf/SiCcompositesperformance.
简介:基于计算机串口通信和功率型金属氧化物半导体场效应晶体管,设计研制了程控产生单次快前沿负高压脉冲的信号发生器。其性能指标为高压脉冲幅度一100~-1000V,脉冲宽度40ns~2μs,脉冲前沿随脉冲幅度和宽度变化,可小于30ns,输出负载为50Ω作为一种模拟源,该高压脉冲信号发生器已用于小功率气体放电管的高压保护特性实验研究中。