简介:ThechoicenumberofagraphG,denotedbyX1(G),istheminimumnumberksuchthatifalistofkcolorsisgiventoeachvertexofG,thereisavertexcoloringofGwhereeachvertexreceivesacolorfromitsownlistnomatterwhatthelistsare.Inthispaper,itisshowedthatX1(G)≤3foreachplanegraphofgirthnotlessthan4whichcontainsno6-,7-and9-cycles.
简介:Theabinitiomolecularorbitalmethodisemployedtostudytheenantioselectivereductionofacetophenonewithboranecatalyzedbythiszolidino[3,4-c]oxazaborolidine.Computationresultshowsthatthecontrollingstepforthereductionisthedecompositionofthecatalyst-alkoxyboraneadductandthereductionleadstoS-alcohols.ThetransitionatateofthehydridetransferfromtheboranemoietytothecarbonylcarbonofacetophenoneisatwistedchairstructurewithaB(2)-N(3)-BBH3-HBH3-CCo-OCO6-memberedring.
简介:Segmentationofthree-dimensional(3D)complicatedstructuresisofgreatimportanceformanyrealapplications.Inthisworkwecombinegraphcutminimizationmethodwithavariantofthelevelsetideafor3DsegmentationbasedontheMumford-Shahmodel.ComparedwiththetraditionalapproachforsolvingtheEuler-Lagrangeequationwedonotneedtosolveanypartialdifferentialequations.Instead,theminimumcutonaspecialdesignedgraphneedtobecomputed.Themethodistestedondatawithcomplicatedstructures.Itisratherstablewithrespecttoinitialvalueandthealgorithmisnearlyparameterfree.Experimentsshowthatitcansolvelargeproblemsmuchfasterthantraditionalapproaches.
简介:Duetolowactivationcharacteristics,desirablehigh-temperaturestrength,goodresistancetoradiationdamageandusablefabricationproperties,vanadium(V)alloysareattractivecandidatestructuralmaterialsforfusionreactors[1].Irradiationinducedhardening/embrittlementatlowtemperatureisamajorproblemforthematerialsapplicationinfusionreactor[2].Inthisstudy,H/Heionswithvariousenergieswereusedtoirradiateapurevanadium(V)andaValloy(V-4Ti)toobtainadamageplateaufromsamplesurfacetothedepthof1.5m,asshowninFig.1[3].Thedetailsofirradiationparameters(energies,fluences)forHandHeionsareshowninTable1.NanoindentationwasperformedtoinvestigatethehardeningbehaviorofV-4TialloyandpureVunderirradiation.
简介:BasedontheGrammianandPfaffianderivativeformulae,GrammianandPfaffiansolutionsareobtainedfora(3+1)-dimensionalgeneralizedshallowwaterequationintheHirotabilinearform.Moreover,aPfaffianextensionismadefortheequationbymeansofthePfaffianizationprocedure,theWronski-typeandGramm-typePfaffiansolutionsoftheresultingcoupledsystemarepresented.
简介:Photocatalyticwatersplittingandcarbondioxidereductionprovideuscleanandsustainableenergyresources.Thecarbondioxidereductionisalsotheredemptionofthegreenhouseeffect.MoS3/TiO2photocatalystsbasedonTiO2nanoplateshavebeensynthesizedviaahydrothermalacidificationrouteforwaterandcarbondioxidereductionreactions.ThisfacileapproachgenerateswelldispersedMoS3withlowcrystallinityonthesurfaceofTiO2nanoplates.Theas-synthesizedMoS3/TiO2photocatalystshowedconsiderableactivityforbothwaterreductionandcarbondioxidereduction.ThethermaltreatmenteffectsofTiO2,theloadingpercentageofMoS3andthecrystallinephaseofTiO2havebeeninvestigatedtowardsthephotocatalyticperformance.TiO2nanoplatesynthesizedthroughhydrothermalreactionwiththepresenceofHFacidisanidealsemiconductormaterialfortheloadingofMoS3forphotocatalyticwaterandcarbondioxidereductionsimultaneouslyinEDTAsacrificialsolution.
简介:AnovelmethodformodelingcellularmaterialsisproposedbasedonMATLABimageprocessingandsynchrotronX-raycomputedtomographyscanningtoobtainanaccuratecalculationresultofaluminumfoambasedonfiniteelementmodel.Themaximumentropyalgorithmisemployedtoobtainthebinarizationimage,andthemedianfilteringalgorithmisusedtoreducethenoiseafterbinarization.Theexternalcontourandinternalporesboundaryisextractedbythe"edge"functioninMATLAB,andthegeometricalmodelisreconstructed.Atwo-stepmeshalgorithmisadoptedtomeshthereconstructedgeometricalmodel.Accordingly,thefiniteelementmodelofaluminumfoamisestablishedbytheproposedmethodbasedonreconstructiongeometricalmodel.Thecompressionbehaviorofaluminumfoamisobtainedat25℃,100℃,200℃byABAQUS,andgoodagreementswithexperimentsareachievedbyapplyingthepresentreconstructionalgorithmandmodelingmethod.
简介:3-degree-of-freedom(3-DOF)的一个新分析模型旋转罗盘加速表系统由一个1-DOF驱动器和2-DOF感觉模式组成被介绍。模型构造微分方程由向量分析与系统的每DOF联系了的lumped。因此建立的联合微分方程是为他们在时间和频率领域的回答的解决的经分解。就这些频率反应方程而言,新奇设备设计概念被强迫感觉阶段到零导出,它导致在结构的频率之间的某个关系,从而在系统的表演上引起抑制效果的最小化。而且,现在的旋转罗盘加速表结构的可行性在他们的事件为旋转罗盘行动和线性加速的察觉用一个唯一的差别对待的计划被学习。这个计划把旋转罗盘加速表的提出的解决的短暂解决方案与同步解调和过滤的进程相结合,它导致同相并且系统输出的照部件发信号。这二个部件能在尖运动和线性加速的察觉被利用。获得的分析结果被模拟在MATLAB/Simulink环境验证,并且结果在对对方的优秀同意,这被发现。
简介:CuO/γ-Al2O3catalystswerepreparedbyplasmatreatmentandconventionalimpregnationmethods.Thecatalyticcombustionoftwokindsofvolatileorganiccompounds(VOCs),tolueneandbenzene,werecarriedoutovertheseCuO/γ-Al2O3catalysts.ThesurfacepropertiesofthesecatalystswerecharacterizedbyX-rayDiffraction(XRD)andScanningElectronMicroscopy(SEM).TheexperimentalresultsshowedthatincatalyticcombustiontheactivityoftheCuO/γ-Al2O3catalystpreparedviaplasmawasmuchhigherthanthatoftheCuO/γ-Al2O3catalystpreparedbyconventionalimpregnationmethod.XRDresultsshowedthatanenhanceddispersionhadbeenachievedwiththeplasmatreatment.SEMresultsindicatedthatthesizebecamemuchsmallerandthesurfacebecamemoreuniformwiththeplasmatreatment.
简介:WithintheframeworkoftheUsdpf(16)interactingbosonmodel(IBM),theeffectsofstrongcorrelationsofthedipole(p--boson)andtheoctupole(f--boson)degreeoffreedomonthepositive-paritystatesofeven-evennucleiinSU(3)limitarediscussed.Itisshownthatconfigurationsofanevennumberofmanyp-andf-bosonscannotonlybeincorporatedintotheusuallow-lyingcollectiverotationalbands,suchasthegroundstateband,β-andγ-vibrationalbands,butalsonaturallyformtheKπ=1+,3+rotationalbands,etc.TheseresultsaresimilartothatofUsdg(15)-IBMandinagreementwellwiththeexperimentaldataofthe17672Hf104nucleus.Besides,severalintrabandE2transitionprobabilitiesaregiven,whichareconsistentwiththatofUsd(6)-IBM.