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.
简介:<正>Foranoddfunctionf(x)definedonlyonafiniteinterval,thispaperdealswiththeexistenceofperiodicsolutionsandthenumberofsimpleperiodicsolutionsofthedifferentialdelayequation(DDE)(?)(t)=-f(x(t-1)).Byuseofthemethodofqualitativeanalysiscombinedwiththeconstructingofspecialsolutionsaseriesofinterestingresultsareobtainedontheseproblems.
简介:Inthiswork,webrieflydiscussanovelclassofmodifiedgravitylikef(T,TG)gravity.Inthisbackground,weassumethenewagegraphicversionofpilgrimdarkenergyandreconstructf(T,TG)modelsfortwospecificvaluesofs.Wealsodiscusstheequationofstateparameter,squaredspeedofsoundandwDE-wDEplaneforthesereconstructedf(T,TG)models.Theequationofstateparameterprovidesphantom-likebehavioroftheuniverse.ThewDE-wDEplanealsocorrespondstoΛCDMlimit,thawingandfreezingregionsforbothmodels.
简介:Theoneplusone(1+1)modeofhydrosilationreactionofladderlikecis-isotaticpolyallylsilsesquioxane(AllyI-T)andpolyhydrosilsesquioxane(H-T)usingdicyclopentadienylplatinumdichloride(Cp2PtCl2)asthecatalystleadstotheformationofanewpolyorganosiloxane(POS).ThepresenceofnanoscaletubularstructureintheproductPOSwaspreliminarilyprovedbyIR,1H-NMR,differentialscanningcalorimetry(DSC),X-raydiffraction(XRD),gelpermeationchromatography(GPC),atomicforcemicroscopy(AFM)andmolecularsimulation.
简介:T网孔是允许T连接的矩形的网孔的本地修正。在T网孔上的花键涉及许多领域,例如有限元素方法,CAGD等等。一个花键空格的尺寸是为花键的理论和应用程序的一个基本问题。然而,决定自从它,一个花键空格的尺寸重重地是困难的问题取决于分区的几何性质。在许多情况中,尺寸是不稳定的。在这份报纸,我们由使用变光滑的cofactor-conformality方法在T网孔上在花键空格的尺寸学习不稳定性。在有T周期的T网孔上的花键空格的修改尺寸公式也被介绍。而且,一些例子被给在一些特殊网孔上在花键空格的尺寸说明不稳定性。[从作者抽象]
简介:UsingthemethodofGirsanovtransformation,weestablishtheTalagrand'sT2-inequalityfordiffusiononthepathspaceC([0,N],R^d)withrespecttoauniformmetric,withtheconstantindependentofN.ThisimprovestheknownresultsfortheL2-metric.
简介:Inthispaper,weobtainaresultthatimprovestheresultsofGovilandNwaeze,QaziandtheclassicalresultofRivlin.
简介:我们为f(T)严肃理论在宇宙论的限制的精确上探索SandageLoeb(SL)测试的影响。因为它在远类星体的系列在Lyman-森林里测量redshift飘移,SL测试是对当前的宇宙论的观察的重要补充,盖住2z的redshift沙漠5。避免数据矛盾,当模仿30的基准的模型嘲笑SL测试数据,我们基于当前的联合观察数据使用最好合适的模型。我们确定为f(T)严肃理论的参数评价上的这些SL测试数据的影响。二个典型f(T)模型被考虑,幂定律模型f(T)PL和指数形式的模型f(T)终止。结果证明SL测试罐头有效地打破存在在在另外的宇宙论的观察的今日的事密度m和小瘤常数H0之间的强壮的退化。为考虑f(T)模型,SL测试的30年的观察能极其改进m和H0的限制精确,但是不能有效地改进模型参数的限制精确。
简介:目的:为使零件在设计阶段实现公差的自动分配,研究线轮廓度在计算机中的表达模型。创新点:1.提出一种新的构建线轮廓度公差T-Map图的方法;2.用运动学等效的方法表示理想轮廓公差域的允许偏差。方法:1.将零件轮廓分解成多段,然后分别为每段生成一个实体模型T-Map(图6和7);2.利用布尔交运算将所有分段T-Map合成一个完整线轮廓度的T-Map(图8);3.以弧形短槽为例,演示创建线轮廓度的方法步骤。结论:将弧形短槽轮廓分成多段,先实现每一段的T-Map,再利用布尔交实现整体线轮廓度公差的T-Map图,证明该方法在构建任意轮廓的线轮廓度公差上的有效性。
简介:WehavesynthesizedandinvestigatedphysicalpropertiesoftwonewquaternarycompoundsGd2CoAl4T2(T=Si,Ge)singlecrystals,whichareisostructuraltoTb2NiAl4Ge2andEr2CoAl4Ge2.Themostimportantstructuralfeatureofthesematerialsistheanti-CaF2-typeCoAl4T2slabs.Thesematerialsshowmetallicbehaviorbelow300Kandthereisalong-rangeantiferromagnetic(AFM)transitionappearingat20and27KforGdCoAl4Ge2andGd2CoAl4Si2,respectively.ResistivityandheatcapacitymeasurementsalsoconfirmthesebulkAFMtransitions.Furtheranalysisindicatesthatthislong-rangeantiferromagnetismshouldresultfromthemagneticinteractionbetweenlocalmomentsofGd^3+ions.
简介:本文用临界点理论中的能量最小原理得到了一类具(q(t),P(t))-Laplacian项的二阶非自治系统存在周期解的充分条件.
简介:Weintroducethecategoryoft-foldmoduleswhichisafullsubcategoryofgradedmodulesoveragradedalgebra.Weshowthatthissubcategoryandhencethesubcategoryoft-Koszulmodulesarebothclosedunderextensionsandcokernelsofmonomorphisms.Westudytheone-pointextensionalgebras,andanecessaryandsufficientconditionforsuchanalgebratobet-Koszulisgiven.Wealsoconsidertheconditionssuchthatthecategoryoft-Koszulmodulesandthecategoryofquadraticmodulescoincide.