学科分类
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500 个结果
  • 简介:AgraphGiscalledchromatic-choosableifitschoicenumberisequaltoitschromaticnumber,namelych(G)=χ(G).Ohba’sconjecturestatesthateverygraphGwith2χ(G)+1orfewerverticesischromaticchoosable.ItisclearthatOhba’sconjectureistrueifandonlyifitistrueforcompletemultipartitegraphs.Recently,Kostochka,StiebitzandWoodallshowedthatOhba’sconjectureholdsforcompletemultipartitegraphswithpartitesizeatmostfive.Butthecompletemultipartitegraphswithnorestrictionontheirpartitesize,forwhichOhba’sconjecturehasbeenverifiedarenothingmorethanthegraphsKt+3,2*(k-t-1),1*tbyEnotomoetal.,andKt+2,3,2*(k-t-2),1*tfort≤4byShenetal..Inthispaper,usingtheconceptoff-choosable(orL0-size-choosable)ofgraphs,weshowthatOhba’sconjectureisalsotrueforthegraphsKt+2,3,2*(k-t-2),1*twhent≥5.Thus,Ohba’sconjectureistrueforgraphsKt+2,3,2*(k-t-2),1*tforallintegerst≥1.

  • 标签: 猜想 完全多部图 可选择 时间 KT 色数
  • 简介:令Vn=span{1,2,…,n},设函数f∈Lp[E,μ],1≤p<∞,在点p处定义一个最佳Lp逼近算子τ∫(p)。记Nf(p)=∥f-τ∫(p)∥p=inf/Q∈Vn∥f-Q∥po本文证明了Nf(p)/[μ(E)]l/p是p的单调增加且有界的函数。如果f∈L∞[E,μ],则存在τ∫(∞)∈Vn,使得∥f-τ∫(∞)∥∞=inf/Q∈Vn∥f-Q∥∞,并且给出了最佳逼近值。

  • 标签: 最佳逼近 证明方法 零测度 有限维线性空间 可测集 HOLDER
  • 简介:GivenacontinuousfunctionfdefinedontheunitcubeofRnandaconvexfunctiont,t(0)-0,t(x)>0,forx>0,weprovethatthesetofbestLt-approximationsbymonotonefunctionshasexactlyoneelementft,whichisalsoacontinuousfunction.Moreoverifthefamilyofconvexfunctions{t}t>0convergesuniformlyoncompactsetstoafunction0,thenthebestapproximationft→f0uniformly,ast→0,wherefoisthebestapproximationoffwithintheOrliczspaceL0Thebestapproxima-tions{ft}areobtainedaswellasminimizingintegralsortheLuxemburgnorm

  • 标签: 凝土 飞毛 几丁 去甲 可可 出工
  • 简介:让Sq-1,q≥2,联合起来的范围的表面在欧几里德几何学的spaceRq,f(x)∈Lp(Sq-1),f(x)≥0,f吗?0,1≤p≤+∞。然后,它在现在的纸被证明有顺序≤N和经常的C>的球形的泛音PN(x)0以便‖f-1/P_N‖L_p≤Cω(f,N~(-1))Lp,在哪儿ω(f,吗δ)Lp=sup_(0S_t(f,μ)='1/(|S~(q-2)|sin~(2λ)t)∫'连续性ofmoduli‖S_t(f)-f‖Lp>

  • 标签: 球面调和函数 近似值 倒数多项式 平移算子 EUCLIDEAN空间
  • 简介:证明了双诱导映射下L-Fuzzy子格群的像与逆像仍为L-Fuzzy子格群,基于L-Fuzzy集的层次结构特征,研究L-Fuzzy子格群的同态,给出了它们的性质.

  • 标签: L—Fuzzy子格群 双诱导映射 同态
  • 简介:ConsiderL2-projectionuhofuton-degreefiniteelementspaceonone-dimensionaluniformgrids.TwodifferentclassesoftheorthogonalexpansioninanelementforconstructingasuperclosetofunctionuhareproposedandthensuperconvergenceforbothuhandDuhareproved.Whennisoddandnoboundaryconditionsareprescribed,thenuhisofsuperconvergenceatn+1orderGausspointsGn+1ineachelement.Whennisevenandfunctionvaluesontheboundaryareprescribed,thenuhisofsuperconvergenceatn+1orderpointsZn+1ineachelement.Iftheotherboundaryconditionsaregiven,thentheconclusionsarevalidinallelementsthatitsdistancefromtheboundary≥ch|lnh|.Theaboveconclusionsarealsovalid.forn-dergreerectangularelementQ1(n).

  • 标签: Superconvegence L~2-projection FINITE elements.
  • 简介:Inthispaper,thenotionofL-Rcrossedcoproductisintroducedasaunifiedap-proachforsmashcoproducts,crossedcoproductsandL-RsmashcoproductsofHopfalgebras.AdualitytheoremforL-Rcrossedcoproductisproved.

  • 标签: HOPF ALGEBRA CROSSED COPRODUCT CLEFT coextension
  • 简介:AdsorptionpropertiesofL-histidineonactivecarbonwerestudiedinthepaper,whichareaffectedbythemainparameters,suchasthequantitypercentofactivecarbon,pHvalueofthesolution,thetimeofadsorptionequilibriumandadsorptiontemperature.TheresultsindicatethatadsorptionequilibriumtimeofL-hisonactivecarbonisabout80minutes.Withtheincreasingofthequantitypercentofactivecarbon,theadsorbanceofL-hisdecreasessharply,andincreaseslighterafterthat.Whenthequantitypercentofactivecarbonis10%,theadsorbancereachestheminimum.pHvalueofsolutionandextractiontemperaturehavegreataffectionontheadsorption.WhenthepHvalueishigherorlowerthanthepIofL-his,theadsorbanceissmall,evenzero.Itisproventhattheexperimentalequilibriumdatawhichareobtainedundertheconditionsof80℃andpH=1.0,arefittedwiththeFreundlichequation:q=2.5914c0.8097.TheresultscanprovidecertainreferencesinL-hisadsorptionprocessofindustrialoperation.

  • 标签: 吸附特征 L-组氨酸 活性碳 吸附平衡 氨基酸
  • 简介:AnewlayeredCu-basedoxychalcogenideBa3Fe2O5Cu2S2hasbeensynthesizedanditsmagneticandelectronicpropertieswererevealed.Ba3Fe2O5Cu2S2isbuiltupbyalternativelystacking[Cu2S2]2-layersandironperovskiteoxide[(FeO2)(BaO)(FeO2)]2-layersalongthecaxisthatareseparatedbybariumionswithFe3+fivefoldcoordinatedbyasquare-pyramidalarrangementofoxygen.Fromthebondvalencearguments,weinferredthatinlayeredCuCh-based(Ch=S,Se,Te)compoundsthe+3cationinperovskiteoxidesheetprefersasquarepyramidalsite,whilethelowervalencecationprefersthesquareplanarsites.Thestudiesonsusceptibility,transport,andopticalreflectivityindicatethatBa3Fe2O5Cu2S2isanantiferromagneticsemiconductorwithaNe′eltemperatureof121Kandanopticalbandgapof1.03eV.Themeasurementofheatcapacityfrom10Ktoroomtemperatureshowsnoanomalyat121K.TheDebyetemperatureisdeterminedtobe113K.TheoreticalcalculationsindicatethattheconductionbandminimumispredominantlycontributedbyO2pand3dstatesofFeionsthatantiferromagneticallyarrangedinFeO2layers.TheFe3dstatesarelocatedatlowerenergyandresultinanarrowbandgapincomparisonwiththatoftheisostructuralSr3Sc2O5Cu2S2.

  • 标签: 钙钛矿型氧化物 铁磁半导体 光学带隙 德拜温度 电子性质 阳离子
  • 简介:TheauthorfirstreviewstheclassicalKorninequalityanditsproof.FollowingrecentworksofS.Kesavan,P.Ciarlet,Jr.,andtheauthor,itisshownhowtheKorninequalitycanberecoveredbyanentirelydifferentproof.ThisnewproofhingesonappropriateweakversionsoftheclassicalPoincar'eandSaint-Venantlemma.Infine,bothproofsessentiallydependonacruciallemmaofJ.L.Lions,recalledatthebeginningofthispaper.

  • 标签: Korn不等式 证明 庞加莱 作者 引理
  • 简介:TheextendedcanonicalNoetheridentitiesandcanonicalfirstNoethertheoremderivedfromanextendedactioninphasespaceforasystemwithasingularLagrangianareformulated.UsingthesecanonicalNoetheridentities,itcanbeshownthattheconstraintmultipliersconnectedwiththefirst-classconstraintsmaynotbeindependent,soaquerytoaconjectureofDiracispresented.BasedonthesymmetrypropertiesoftheconstrainedHamiltoniansysteminphasespace,acounterexampletoaconjectureofDiracisgiventoshowthatDirac'sconjecturefailsinsuchasystem.WepresenthereadifferentwayratherthanCawley'sexamplesandother'sonesinthatthereisnolinearizationofconstraintsintheproblem.Thisexamplehasafeaturethatneithertheprimaryfirst-classconstraintsnorsecondaryfirst-classconstraintsaregeneratorsofthegaugetransformation.

  • 标签: 约束汉密尔顿函数 规范对称 迪拉克猜想 量子场论