简介:Moleculardynamics(MD)simulationswereperformedtostretchtherectangulargraphenesheetsdopedwithsilicon,nitrogenorboronatoms.Young’smodulus,ultimatestress(strain)andenergyabsorptionweremeasuredforthegraphenesheetswiththedopingconcentration(DC)rangingfrom0to5%.Theemphasiswasplacedonthedistincteffectsofeachindividualdopantonthefundamentalmechanicalpropertiesofgraphene.TheresultsindicatedthatincorporatingthedopantsintographeneledtoanalmostlineardecreaseinYoung’smodulus.Monotonicreductionsinultimatestrength,ultimatestrainandenergyabsorptionwerealsoobserved.Suchdopingeffectswerefoundtobemostsignificantforsilicon,lesspronouncedforboron,andsmallornegligiblefornitrogen.Theoutputsprovideanimportantguidanceforthedevelopmentandoptimizationofnovelnanoscaledevices,andfacilitatethedevelopmentofgraphene-basedM/NEMS.
简介:LongtimebehaviorofdegenerateequationswiththenonlinearityofpolynomialgrowthofarbitraryorderonthewholespaceRNisconsidered.Byusing-trajectoriesmethods,weprovedthatweaksolutionsgeneratedbydegenerateequationspossessan(L2U(RN),L2loc(RN))-globalattractor.Moreover,theupperboundsoftheKolmogorovε-entropyforsuchglobalattractorarealsoobtained.
简介:NanofluidswerepreparedbydispersingCunanoparticles(~20nm)inn-tetradecanebyatwo-stepmethod.Theeffectivethermalconductivitywasmeasuredforvariousnanoparticlevolumefractions(0.0001-0.02)andtemperatures(306.22-452.66K).TheexperimentaldatacompareswellwiththeJangandChoimodel.Thethermalconductivityenhancementwaslowerabove391.06Kthanforthatbetween306.22and360.77K.Theinterfacialthermalresistanceincreasedwithincreasingtemperature.Theeffectivethermalconductivityenhancementwasgreaterthanthatobtainedwithamoreviscousfluidasthebasemediaat452.66KbecauseofnanoconvectioninducedbynanoparticleBrownianmotionathightemperature.
简介:Arylhalidesareakindofextremelyvaluablecompoundsusedintransition-metal-catalyzedcouplingreactions,aswellasimportantstructuremotifsinmanynaturalproductsandmanufactureddrugs[1,2].Theclassicalapproachforpreparationofhaloarenesiselectrophilicaromaticsubstitution(EAS)usingvarioushalogenatingreagentsoroxidativehalogenationswithhalogenatingreagentgeneratedinsitufromhalidesandoxidants,suchasperoxide,oxygenandmeta-cholorperoxybenzoicacid(mCPBA)[3,4].However,harshreactionconditionsarerequiredforhalogenationoflessactivearomatics.orthoMetalationfollowedbyhalogenquenchingisanotherapproachforhalogenationofaromatics[5].However,thereareobviousdrawbacksforthesemethods,suchaslowregioselectivity,harshconditionsandevendangerousprocedures.Therefore,thedevelopmentofanalternativeandpracticalwayremainschallengeinorganicsynthesis.
简介:LetL=L0+VbethehigherorderSchrdigertypeoperatorwhereL0isahomogeneousellipticoperatoroforder2mindivergenceformwithboundedcoefficientsandVisarealmeasurablefunctionasmultiplicationoperator(e.g.,including(-?)m+V(m∈N)asspecialexamples).Inthispaper,assumethatVsatisfiesastronglysubcriticalformconditionassociatedwithL0,theauthorsattempttoestablishatheoryofHardyspaceHpL(Rn)(0
简介:ThefirststarsintheearlyUniversewereformedabout400millionyearsafterthebigbang.VerificationoftheexistenceofthesestarsisimportantforourunderstandingoftheevolutionoftheUniverse[1].IthasbeenpredictedthatforPopulation-IIIstellarproductionyields,theabundancesofodd-Zelementsareremarkablydeficientcomparedtotheiradjacenteven-Zelements[2].Astronomersaresearchingforlong-lived,lowmassstarswiththeuniquenucleosyntheticpatternmatchingthepredictedyields[3].
简介:Anoveldiodestring-triggeredgated-PiNjunctiondevice,whichisfabricatedinastandard65-nmcomplementarymetal-oxidesemiconductor(CMOS)technology,isproposedinthispaper.Anembeddedgated-PiNjunctionstructureisemployedtoreducethediodestringleakagecurrentto13nA/μminatemperaturerangefrom25°Cto85°C.Toprovidetheeffectiveelectrostaticdischarge(ESD)protectioninmulti-voltagepowersupply,thetriggeringvoltageofthenoveldevicecanbeadjustedthroughredistributingparasiticresistanceinsteadofchangingthestackeddiodenumber.