简介:MoS_2,MoSe_2andWSe_2thinflakeswerefabricatedbythestandardmicromechanicalcleavageprocedures.ThethicknessandtheopticalcontrastoftheatomicthindichalcogenideflakesonSiO_2/Sisubstratesweremeasuredbyatomicforcemicroscopy(AFM)andspectroscopicellipsometer.Arapidandnondestructivemethodbyusingreflectionspectrawasproposedtoidentifythelayernumberof2DlayeredtransitionmetaldichalcogenidesonSiO_2(275nm)/Sisubstrates.Thecontrastspectraof2DnanosheetswithdifferentlayernumbersareinagreementwiththeoreticalcalculationsbasedonFresnel'slaw,indicatingthatthismethodprovidesanunambiguousandnondestructivecontrastspectrafingerprintforidentifyingsingle-andfew-layeredtransitionmetaldichalcogenides.Theresultswillgreatlyhelpinfundamentalresearchandapplication.
简介:Inthepresentwork,anovelhybridcompositecomposedofTi-aluminidemulti-layeredpartandcontin-uous-SiCf-reinforcedTi-matrixpartusingavacuumhotpressing/hotisostaticpressure(VHP/HIP)sinteringprocesswassynthesized.Then,thedamagetolerancebehaviorofthishybridcompositewasstudiedbytensiletestsandinsituscanningelectronmicroscopy(SEM)three-pointbendingtests.Theresultsindicatethatthemechanicalpropertiesandcrackpropagationofthehybridcompositearestronglyinfluencedbytheextrinsictoughnessmecha-nism.Indetail,thecrackdeflectionofmulti-layeredcompositeandstrengtheningeffectofSiCf-reinforcedmatrixcompositeareobservedinthehybridcomposite.Owingtothestrengtheningeffectofcontinuous-SiCrre-inforcedTi-matrixpart,thetensilestrengthofhybridcompositeismuchhigherthanthatofneatTi-aluminidemulti-layeredcomposite.Furthermore,itisfoundthattheoptimaldamagetoleranceabilityisoptimizedwhenthenotchpositionislocatedattheTi-aluminidemulti-layeredpartduetothecrackdeflectionofmulti-layeredstructure.
简介:基于AB_5的氢存储薄电影(LaNi_(4.25)Al_(0.75)),由dc磁控管劈啪作响的扔的onCu底层在这研究被调查。X光检查衍射(XRD)表明层的微观结构在晶形。SEM和AFM分析证明这部电影看起来与近似在nmdiameter的15-40的众多的随机大小的毛孔相当不平。这部电影的结构的稳定性被DSC,XRD,andS他们,它显示这部电影在500K左右下面维持了它的结构的稳定性,和网络结构的联合分析检验在为30min在700K被加热以后在这部电影上被观察。这些电影的Electrochemicalhydrogen存储性质被模仿的电池测试调查。单人赛分层的LaNi_(4.25)Al_(0.75)大批拍摄类似于典型AB_5合金的展出电气化学的氢存储性质,这被发现,并且这部电影的最大的分泌物能力关于220mAh/g。在20个控告/解除周期以后,小塑造针的铝氧化物在电影表面的一些部分上被形成。