简介:Afacilecatalysis-freemethodwasutilizedtosynthesizefunctionalneodymiumhexaboride(NdB6)nanowiresofsinglecrystalusingNdpowdersandBCl3asstartingmaterials.TheXRDpatternconfirmedthatasinglephaseNdB6couldbeobtained.Raman-spectraelucidatedtheactivevibrationalmodesofthehexaborides.TheTEMimagesclearlyshowedthatthehexaboridesweresubmicroninsizewithacubicmorphology.Thefieldemissionoftheseone-dimensionalNdB6nanowiresshowedalowfieldemissionturn-on(5.55V/μmatacurrentdensityof10μA/cm2),andhighcurrentdensitywithafieldenhancementfactorof1037.TheemissioncurrentdensityandtheelectricfieldfollowedtheFowler-Nordheim(F-N)relationship.Thegoodperformanceforfieldemissionwasattributedtothesingle-crystallinestructureandthenanowiregeometry.
简介:这三个结构是英语中很常用的结构。这里简要叙述这些结构的用法。
简介:Inanother250millionyears,AmericanswillbeabletodrivetoAfrica.Bythattime,Earth'ssevencontinentswillhavemerged(?)intoonesupercontinent,predictsChristopherScotese,ageologistattheUniversityofTexasatArlington.Itwon'tbethefirsttimethecontinentshavegotten-together;aboutthesameamountoftime
简介:MAGINEbeingpro-motedtomanagingdi-rectorforyourcompanyinChina.Howwouldthatmakeyoufeel?Perplexed,pleased,excited,orperhapsamixofallofthesefeel-ings?Thispossibilitymightseemprettyremoteformostyoungexpats.ThatiswhyIamsharingthisstorytohelpyouprepareforthatmomentinthefuture.
简介:<正>PresidentXiJinpingputforwardtheterm"SilkRoadEconomicBelt"onSeptember7th,2013inKazakhstanwhenheproposedinhisspeech"toforgeclosereconomicties,deepencooperationandexpanddevelopmentspaceintheEurasianregion,weshouldtakeaninnovativeapproachandjointly