学科分类
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30 个结果
  • 简介:对于Rn中充分光滑的凸体,通过欧式单位球面上的迷向测度,刻画了在T∈SL(n)下Mp(TK)和M*p(TK)的最小值问题.同时也得到了Mp(K)M*p(K)取得最小值的条件.

  • 标签: 极值问题 迷向测度 Mp(K)
  • 简介:InthispaperwestudythesolutionsandstabilityofthegeneralizedWilson’sfunctionalequation∫_Gf(xty)dμ(t)+∫_Gf(xtσ(y))dμ(t)=2f(x)g(y),x,y∈G,whereGisalocallycompactgroup,σisacontinuousinvolutionofGandμisanidempotentcomplexmeasurewithcompactsupportandwhichisσ-invariant.Weshowthat∫_Gg(xty)dμ(t)+∫_Gg(xtσ(y))dμ(t)=2g(x)g(y)iff≠0and∫_Gf(t.)dμ(t)≠0,where[∫_Gf(t.)dμ(t)](x)=∫_Gf(tx)dμ(t).WealsostudysomestabilitytheoremsofthatequationandweestablishthestabilityonnoncommutativegroupsoftheclassicalWilson’sfunctionalequationf(xy)+χ(y)f(xσ(y))=2f(x)g(y)x,y∈G,whereχisaunitarycharacterofG.

  • 标签: WILSON方程 稳定性定理 一般形式 FCG 泛函方程 局部紧群
  • 简介:TheConwaypotentialfunction(CPF)forcoloredlinksisaconvenientversionofthemultivariableAlexander–Conwaypolynomial.WegiveaskeincharacterizationofCPF,muchsimplerthantheonebyMurakami.Inparticular,Conway’s"smoothingofcrossings"isnotintheaxioms.Theproofusesareductionschemeinatwistedgroup-algebraP_nB_n,whereB_nisabraidgroupandP_nisadomainofmulti-variablerationalfractions.Theproofdoesnotusecomputeralgebratools.Aninterestingby-productisacharacterizationoftheAlexander–Conwaypolynomialofknots.

  • 标签: 势函数 Conway多项式 颜色 链接 计算机代数 CPF
  • 简介:Inordertodeepentheunderstandingoftherelationshipbetweenfundamentalproperties(including:microstructureandcomposition)andphotocatalyticperformance,fourbismuthatecompounds,including:LiBiO3,NaBiO3,KBiO3,andAgBiO3,areregardedasresearchexamplesinthepresentwork,becausetheyhaveparticularcrystalstructuresandsimilarcompositions.Usingdensityfunctionaltheorycalculations,theirstructural,electronic,andopticalpropertiesareinvestigatedandcomparedsystematically.Firstofall,thecalculatedresultsofcrystalstructuresandopticalpropertiesareinagreementwithavailablepublishedexperimentaldata.Basedonthecalculatedresults,itisfoundthatthetunneledorlayeredmicro-structuralpropertiesleadtothestrongerinteractionbetweenbismuthandoxygen,andtheweakerinteractionbetweenalkaline-earthmetaland[BiO6]octahedron,resultinginthefeatureofmulti-bandgapsinthecasesofLiBiO3,NaBiO3,andKBiO3.ThisconclusionissupportedbythecaseofAgBiO3,inwhichthefeatureofmulti-bandgapsdisappears,duetothestrongerinteractionbetweenthenoblemetaland[BiO6]octahedron.Thesepropertieshavesignificantadvantagesinthephotocatalyticperformance:absorbinglowenergyphotons,rapidlytransferringenergycarriers.Furthermore,thefeaturesofelectronicstructuresofbismuthatecompoundsarewellreflectedbytheabsorptionspectra,whichcouldbeconfirmedbyexperimentalmeasurementsinpractice.Combinedwiththecalculatedresults,itcouldbeconsideredthatthecrystalstructuresandcompositionsofthephotocatalystdeterminetheelectronicstructuresandopticalproperties,andsubsequentlydeterminethecorrespondingphotocatalyticperformance.Thus,anovelBi-basedphotocatalystdrivenbyvisible-lightcouldbedesignedbyutilizingspecificcompositionstoformfavorableelectronicstructuresorspecificmicro-structurestoformabeneficialchannelforenergycarriers.

  • 标签: 电子结构 光催化剂 光催化性能 弱相互作用 计算结果 NA
  • 简介:Theaimofthisexpositionistoprovideadetaileddescriptionoftheuseofcombinatorialalgebrainquantumfieldtheoryintheplanarsetting.ParticularemphasisisplacedontherelationsbetweendifferenttypesofplanarGreen'sfunctions.TheprimaryobjectisaHopfalgebrathatisnaturallydefinedonvariablesrepresentingnon-commutingsources,andwhosecoproductsplitsintotwohalf-coproducts.Thelattergiverisetothenotionofanunshuffiebialgebra.ThissettingallowsadescriptionoftherelationbetweenfullandconnectedplanarGreen'sfunctionstobegivenbysolvingasimplelinearfixedpointequation.Wealsoincludeabriefoutlineoftheconsequencesofourapproachintheframeworkofordinaryquantumfieldtheory.

  • 标签: PLANAR field theory Green's functions free
  • 简介:K-promotediron/carbonnanotubescomposite(i.e.,FeK-OX)waspreparedbyaredoxreactionbetweencarbonnanotubesandK_2FeO_4followedbythermaltreatmentsonapurposeastheFischer–Tropschcatalystforthedirectconversionofsyngastolowerolefins.ItscatalyticbehaviorswerecomparedwiththoseoftheothertwoFe-IMandFeK-IMcatalystspreparedbyimpregnationmethodfollowedbythermaltreatments.ThenovelFeK-OXcompositecatalystisfoundtoexhibithigherhydrocarbonselectivity,lowerolefinsselectivityandchaingrowthprobabilityaswellasbetterstability.ThecatalyststructureperformancerelationshiphasbeenestablishedusingmultipletechniquesincludingXRD,Raman,TEMandEDSelementalmapping.Inaddition,effectsofadditionalpotassiumintotheFeK-OXcompositecatalystontheFTOperformancewerealsoinvestigatedanddiscussed.Additionalpotassiumpromotersfurtherendowthecatalystswithhigheryieldoflowerolefins.Theseresultsdemonstratedthattheintroductionmethodofpromotersandironspeciesplaysacrucialroleinthedesignandfabricationofhighlyactive,selectiveandstableiron-basedcompositecatalystsfortheFTOreaction.

  • 标签: 碳纳米管复合材料 复合催化剂 低碳烯烃 合成制备 铁基 钾基
  • 简介:ThegatedielectricthicknessdecreasesdramaticallywiththecontinuousscalingofMOSdevices,whichhasseriousconsequencesontheleakagecurrentandthepowerconsumptionoftheSiO2-basedMOSdevices.Hafniumdioxide(HfO2),asakindofhigh-kmaterial,arerecognizedasalternativestoSiO2forfutureadvancedgatedevicesandspaceapplications[1].Radiation-inducedeffectsonconventionalSiO2dielectricshavebeeninvestigated.Now,anenormousamountofeffortwasrequiredtoadaptthenewhigh-ksystemsforradiationhardapplication.

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  • 简介:FranklandFürediin[1]conjecturedthatther-graphwithmedgesformedbytakingthefirstmsetsinthecolexorderingofN(r)hasthelargestLagrangianofallr-graphswithmedges.Denotethisr-graphbyCr,mandtheLagrangianofahypergraphbyλ(G).Inthispaper,wefirstshowthatif(3t-1)≤m<(3t),Gisaleft-compressed3-graphwithmedgesandonvertexset[t],thetriplewithminimumcolexorderinginGcis(t—2—i)(t—2)t,thenλ(G)≤λ(C3,m).Asanimplication,theconjectureofFranklandFiirediistruefor(3t)-6≤m≤(3t).

  • 标签: 猜想 超图 均匀 拉格朗日 顶点集 弗兰克
  • 简介:Inthispaper,anewclassofsolutionsofthevacuumEinstein'sfieldequationswithcosmologicalconstantisobtained.Thisclassofsolutionspossessesthenakedphysicalsingularity.ThenormoftheRiemanncurvaturetensorofthisclassofsolutionstakesinfinityatsomepointsandthesolutionsdonothaveanyeventhorizonaroundthesingularity.

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  • 简介:Compositesofcarbonaerogelandgraphiteoxide(GO)weresynthesizedusingaself-assemblymethodbasedondispersiveforces.Theirsurfacewasmodifiedbytreatmentinhydrogensulfideat650and800℃.Thesamplesobtainedwerecharacterizedbyadsorptionofnitrogen,TA-MS,XPS,potentiometrictitration,andHRTEMandtestedascatalystsforoxygenreductionreactions(ORR)inanalkalinemedium.Thesynergisticeffectofthecomposite(electricalconductivity,porosityandsurfacechemistry)leadstoagoodORRcatalyticactivity.Theonsetpotentialforthecompositeofcarbonaerogelheatedat800℃isshiftedtoamorepositivevalueandthenumberofelectrontransferwas2e-atthepotential0.68VversusRHEanditincreasedto4e-withanincreaseinthenegativevaluesofthepotential.Anexcellenttolerancetomethanolcrossoverwasalsorecorded.

  • 标签: 石墨复合材料 还原催化剂 碳气凝胶 氧化 氧还原反应 掺杂
  • 简介:Inordertoimprovethecarsalesservice4Sshopmanagementlevel,improvetheeconomicandsocialbenefitsofenterprises,incentivesareusedtoencouragetheirown4sshops.Inthispaper,throughouttherelatedanalysisofthequarterlyandannualawardsincentiveprograminlarge-scaledomesticautomobileenterprises,entropymethodwithMATLABsoftwareisappliedtoestablishthedimensionalfitfunction.Inthedataprocessing,themultiplelinearregressionfunctionintoLingosoftwareisemployedtogetthebestsolution;andClanguageisusedtorunthescreeningdataprogramthroughtheconsistencytestprograminthesensitivityanderroranalysis.Firstofall,considerthecompanytomaximizeprofitsandmaximizetheamountofcomplaintsinthestoretomaintainalowtarget;intermsofstaff,weshouldconsiderprovidingmoreincentivesforemployees;inthecustomer,theoverallsatisfaction,serviceAttitude,vehiclecleanlinessbasedshouldbeimproved.Andtwoprogramsforthemonthlyprofitandexcessprofitsofprogressiveincentivesshouldalsobeimproved.

  • 标签: ENTROPY Weight Method RELATED INDICATORS GRAY
  • 简介:目前,随着电动汽车的普及,物流企业逐渐重视电动汽车的应用。本文考虑到电动汽车在实际应用中的行驶里程、充电耗时以及配送时间等因素,研究含时间窗的电动汽车车辆路径问题,建立了相应的混合整数规划模型,然后改进分支定价算法以求得其最优解。改进的分支定价算法首先根据Dantzig-Wolfe分解原理将原问题分解为基于路径的主问题(MP)和求最短路径的子问题,然后用列生成和动态规划算法在主问题和子问题之间进行迭代以求得主问题线性松弛后的最优解,最后采用基于弧的分支策略求得其整数解。通过用改进的Solomon算例的实验数据,与CPLEX比较验证了模型和算法结果的准确性,并对该问题进行了灵敏度分析,证明了本文提出的算法具有一定的应用价值。

  • 标签: 车辆路径问题 分支定价算法 列生成算法 电动汽车 电量约束
  • 简介:Inthispaper,theauthorsstudytheCohen-Fischman-Westreich’sdoublecentralizertheoremfortriangularHopfalgebrasinthesettingofalmost-triangularHopfalgebras.

  • 标签: 三角Hopf代数 正定理 双中心