简介:<正>ThispaperprovidesapolyhedraltheoryongraphsfromwhichthecriteriaofWhit-neyandMacLanefortheplanarityofgraphsareunified,andabriefproofoftheGausscrossingconjectureisobtained.
简介:Inthenormal-modetheoryofMorse,itgivesaseriesofnormalmodesasthesolutionofforcedvibrationinaroom.Butactuallythereisalwaysthedirectradiationbesidesthenormalmodeswhichrepresentthereverbrantsoundfieldonly.Thereasonisthatthenormalmodeswereassumedonlyinthesource,andnaturallynormalmodesonlyareobtainedinthesolution.Atheoryofdoublesourceisproposed,thatthesoundsourceisboththesourceofthedirectradiationasifinfreespacebeforetheboundarysurfaceswerereachedbythedirectradiation,andafterthefirstreflectionfromtheboundarysurfaces,thesourceofthereflectedwavelets,randomlydistributedbothinspaceanintimeontheboundarysurfacesthatbuildupthenormalmodesafterfurtherreflections.Thewaveequationisformedaccordingly,andthesolutionofthewaveequation,thesoundfieldinaroom,containsexplicitlyboththedirectradiationandthereverberantsoundformedofnormalmodes.Theapproximatemeansquaresoundpressureisfoundtobethedircetsounddeterminedbythesoundpowerofthesource,andreverberantsounddeterminedbythesoundpowerreducedbyafactorofπ/2,differentslightlyfromtheresultobtainedfromenergyconsideration,ifthesourceispuretone.Thereisessentiallynodifferenceforasourceofbandnoise.
简介:Anewformofdamagetheoryofmaterialsisproposed,thatisvalidforthecaseofnonconservativestresses.Thepartialentropy,strainandmicrostructureparametersaretakenasthestatevariables.Withoutassumingthefreeenergytobeastatefunction,thebasicgoverningequationsarederived.Accordingtothebalanceofreleasedanddissipatedenergy,thegeneralformofdamageevolutionequationisobtained.Further,assumingtheexistenceofindependentdamagemechanisms,thenormalityofdamageevolutionequationisproven.Thegeneralizeddamagevariablesaredis-cussed.Finally,someexamplesaregiventoshowtheapplicationsofthetheory.
简介:Inthispaper,weproposetheconceptofcohomologicaloperator.Concretely,wesuggestthecohomologicaldifferentialoperator,correlativecohomologicaldifferentialoperatorandextensivecohomologicaldifferentialoperatorandbringcovariantderivativeintotheextensivecohomologicaldifferentialoperator,WeconstructonetypeofnonlineardifferentialequationsbyextensivecohomologicaldifferentialoperatorandcomparetheobtainedresaleswiththeYang-Millsequation.
简介:Inthispaper,severalusuallyusedpolynomialinterpolationmethodsareexplainedinviewofvectorbasisanddimensioninlinearalgebratheory.Usingtransitionmatrixes,generalconversionformulabetweenthebasisfunctionsetsofthesepolynomialinterpolationmethodsaregiven.Anexamplealsoshowstheeffectivenessoftheresults.
简介:InthispapersomeequivalencedefinitionsaregivenfornativespaceswhichwereintroducedbyMadychandNelsonandhavebecomeinfluentialinthetheoryofradialbasisfunctions.Theabstractelementsinnativespacesareinterpreted.Moreover,WeinrichandIske'stheoriesareunified.
简介:在光线的基础功能的理论,数学家们把光线的基础功能的translates的线性联合用作interpolants。这些线性联合的集合是一个normed向量空格。这个空格能被完成并且变得一个Hilbert空格,叫了本国的空间,它在最后十年是很重要的。本国的空格然后包含不是光线的基础函数的线性联合的一些抽象元素。这些抽象元素的意思充分不被知道。这份报纸为这些元素论述一些解释。本国的空格被嵌进一些著名空格。例如,Sobolev空间被显示是一个本国的空格。因为许多微分方程在Sobolev空间有答案,我们能因此接近由光线的基础功能的线性联合的答案。而且,嵌进本国的空间L2()的著名问题被作者也解决。
简介:Inthispaper,anonlocaltheoryoffractureforbrittlematerialshasbeensystematicallydevel-oped,whichiscomposedofthenonlocalelasticstressfieldsofGriffithcracksofmode-Ⅰ,ⅡandⅢ,theasymptoticformsofthestressfieldsattheneighborhoodofthecracktips,andthemaximumtensilestresscriterionforbrittlefracture.Asanapplicationofthetheory,thefracturecriteriaofcracksofmode-Ⅰ,Ⅱ,ⅢandmixedmodeⅠ-Ⅱ,Ⅰ-Ⅲaregivenindetailandcomparedwithsomeexperimentaldataandthetheoreticalresultsofminimumstrainenergydensityfactor.
简介:LetXdenoteacomplexanalyticmanifold,andletAut(X)denotethespaceofinvertiblemapsofagerm(X,a)toagerm(X,b);thisspaceisobviouslyagroupoid;roughlyspeaking,a'Liegroupoid'isasubgroupoidofAut(X)definedbyasystemofpartialdifferentialequations.ToafoliationwithsingularitiesonXoneattachessuchagroupoid,e.g.thesmallestonewhoseLiealgebracontainsthevectorfieldstangenttothefoliation.Itiscalled'theGaloisgroupoidofthefoliation'.Someexamplesareconsidered,forinstancefoliationsofcodimensionone,andfoliationsdefinedbylineardifferentialequations;inthislastcaseonerecuperatestheusualdifferentialGaloisgroup.
简介:AimsandScope:NumericalMathematics:Theory,MethodsandApplications(NM-TMA)publisheshigh-qualityoriginalresearchpapersontheconstruction,analysisandapplicationofnumericalmethodsforsolvingscientificproblems.Importantresearchandexpositorypapersdevotedtothenumericalsolutionofmathematicalproblemsarisinginallareasofscience
简介:Onthebasisofthemedicalandmechanicalanalysisandexplanationsinthispaperthevisco-elasticsimplysupportedbeammodelisproposedtotreatthedisplacementwaveofthebloodvessels.Therelationshipsbetweenthedisplacementwaveandbloodvesselelasticityaswellastheviscousdissipationofthebloodandbloodvesselareobtained.ThecorrespondingrelationsofsuchkindsofpulsesinthetraditionalChinesemedicineassmoothpulse,surfacepulseanddeeppulsetothedisplacementwavesofbloodvesselsarealsofound.Thecomputationalresultsareingoodagreementwiththoseacquiredintheexperimentswithultrasonicwave.