简介:Basedonthesecond-ordermoments,thispaperderivesananalyticalexpressionoftheM2factoroffour-petalGaussianbeam.TheresultsshowthattheM2factorisonlydeterminedbythebeamordern.Thecorrespondingnumericalcalculationsarealsogiven.Asthebeamorderincreases,theaugmentofM2factorisdisciplinary.AstheexpressionofM2factorisexpressedinseriesformandbecomesmorecomplicated,anewconciseformulaofM2factorisalsopresentedbyusingcurvefittingofnumericalcalculations.When3≤n≤200,themaximumerrorrateoffittingformulawillnotexceed2.6%andtheaverageerrorrateis0.28%.Thisresearchishelpfultotheapplicationsoffour-petalGaussianbeam.
简介:MoleculardynamicssimulationsareperformedtostudythegrowthmechanismofCH4-CO2mixedhydrateinxCO2=75%,xCO2=50%,andxCO2=25%systemsatT=250K,255Kand260K,respectively.OursimulationresultsshowthatthegrowthrateofCH4-CO2mixedhydrateincreasesastheCO2concentrationintheinitialsolutionphaseincreasesandthetemperaturedecreases.Viahydrateformation,thecompositionofCO2inhydratephaseishigherthanthatininitialsolutionphaseandtheencagingcapacityofCO2inhydratesincreaseswiththedecreaseintemperature.ByanalysisofthecageoccupancyratioofCH4moleculesandCO2moleculesinlargecagestosmallcages,wefindthatCO2moleculesarepreferablyencagedintothelargecagesofthehydratecrystalascomparedwithCH4molecules.Interestingly,CH4moleculesandCO2moleculesfrequentlyreplacewitheachotherinsomeparticularcagesitesadjacenttohydrate/solutioninterfaceduringthecrystalgrowthprocess.Thesetwospeciesofguestmoleculeseventuallyacttostabilizethenewlyformedhydrates,withCO2moleculesoccupyinglargecagesandCH4moleculesoccupyingsmallcagesinhydrate.
简介:Receptor-ligandinteractionsinbloodflowarecrucialtoinitiatesuchbiologicalprocessesasinflammatorycascade,plateletthrombosis,aswellastumormetastasis.Tomediatecelladhesion,theinteractingreceptorsandligandsmustbeanchoredontotwoapposingsurfacesoftwocellsoracellandasubstratum,i.e.,two-dimensional(2D)binding,whichisdifferentfromthebindingofasolubleligandinfluidphasetoareceptor,i.e.,three-dimensional(3D)binding.Whilenumerousworkshavebeenfocusedon3Dkineticsofreceptor-ligandinteractionsintheimmunesystem,2Dkineticsanditsregulationshavebeenlessunderstood,sincenotheoreticalframeworkorexperimentalassayswereestablisheduntil1993.Notonlydoesthemolecularstructuredominate2Dbindingkinetics,buttheshearforceinbloodflowalsoregulatescelladhesionmediatedbyinteractingreceptorsandligands.Here,weprovideanoverviewofcurrentprogressin2Dbindingandregulations,mainlyfromourgroup.Relevantissuesoftheoreticalframeworks,experimentalmeasurements,kineticratesandbindingaffinities,andforceregulationsarediscussed.
简介:AtomicallythinMoS2filmshaveattractedsignificantattentionduetoexcellentelectricalandopticalproperties.Thedevelopmentofdeviceapplicationsdemandstheproductionoflarge-areathinfilmwhichisstillanobstacle.Inthisworkwedevelopedafacilemethodtodirectlygrowlarge-areaMoS2thinfilmonSiO2substrateviaambientpressurechemicalvapordepositionmethod.Thecharacterizationsbyspectroscopyandelectronmicroscopyrevealthattheas-grownMoS2filmismainlybilayerandtrilayerwithhighquality.Back-gatefield-effecttransistorbasedonsuchMoS2thinfilmshowscarriermobilityupto3.4cm2V-1s-1andon/offratioof105.Thelarge-areaatomicallythinMoS2preparedinthisworkhasthepotentialforwideoptoelectronicandphotonicdeviceapplications.
简介:SYNTHESISANDANTI-HUMANIMMUNODEFICIENCYVIRUS-1(HIV-1)ACTIVITYOF9-(2-PHOSPHONYLMETHOXYETHYL)ADENINE(1)ANDITSREGIOISOMER3-(2-PHO...
简介:Asynergyofcomputersimulations,analyticalformulations,andexperimentsprovesveryeffectiveinresearchanddevelopment.Usingnanorodgrowthasanexample,thisletterpresentsthesynergyofthethreecomplementaryapproachesinresearch,anddemonstratesitseffectiveness.Throughthissynergy,atheoreticalframeworkofnanorodgrowthemerges;throughthedirectionofthetheories,experimentalrealizationofsmallestwell-separatednanorodsbecomesreality;throughtherealizationofsuchnanorods,metallicglueinambientenvironmentsbecomestechnicalrealityandcommercialpossibility.