简介:在这篇文章,我们在场有浸透的发生的一个肝炎B流行模型。确定、随机的系统的动态行为被学习。到这个目的,我们首先建立确定的模型的平衡的本地、全球的稳定性条件。由构造合适的随机的Lyapunov功能,第二,为肝炎B的各态历经的静止分发以及扑灭的存在的足够的条件被获得。
简介:LetB(E,F)bethesetofallboundedlinearoperatorsfromaBanachspaceEintoanotherBanachspaceF,B+(E,F)thesetofalldoublesplittingoperatorsinB(E,F)andGI(A)thesetofgeneralizedinversesofA2B+(E,F).InthispaperweintroduceanunboundeddomainW(A,A^+)inB(E,F)forA2B+(E,F)andA^+2GI(A),andprovideanecessaryandsufficientconditionforT2W(A,A^+).Thenseveralconditionsequivalenttothefollowingpropertyareproved:B=A^+(IF+(T??A)A^+)??1isthegeneralizedinverseofTwithR(B)=R(A^+)andN(B)=N(A^+),forT2W(A,A^+),whereIFistheidentityonF.Alsoweobtainthesmooth(C¥)diffeomorphismMA(A^+,T)fromW(A,A^+)ontoitselfwiththefixedpointA.LetS=fT2W(A,A^+):R(T)\N(A^+)=f0gg,M(X)=fT2B(E,F):TN(X)R(X)gforX2B(E,F)g,andF=fM(X):8X2B(E,F)g.UsingthediffeomorphismMA(A^+,T)weprovethefollowingtheorem:SisasmoothsubmanifoldinB(E,F)andtangenttoM(X)atanyX2S.ThetheoremexpandsthesmoothintegrabilityofFatAfromalocalneighborhooldatAtotheglobalunboundeddomainW(A,A^+).Itseemstobeusefulfordevelopingglobalanalysisandgeomatricalmethodindifferentialequations.
简介:TheintrinsicphysicalrelationshipofvorticitybetweenmodesAandBinthethree-dimensionalwaketransitionisinvestigated.Directnumericalsimulationsfortheflowpastasquare-sectioncylinderarecarriedoutatReynoldsnumbersof180and250,associatedwithmodesAandB,respectively.Basedontheanalysisofspacialdistributionsofvorticityinthenearwake,characteristicsoftheverticalvorticityinmodesAandBareidentified.Moreover,therelationshipofthreevorticitycomponentswithspecificsignsissummarizedintotwosignlaws,asintrinsicphysicalrelationshipsbetweentwoinstabilitymodes.Bythetheoryofvortex-inducedvortex,suchtwosignlawsconfirmthattherearetwoandonlytwokindsofvortex-sheddingpatternsinthenearwake,justcorrespondingtomodesAandB.Inbrief,alongthefreestreamdirection,modeAcanbedescribedbytheparallelsheddingverticalvorticeswiththesamesign,whilemodeBisdescribedbytheparallelsheddingstreamwisevorticeswiththesamesign.Finally,itisfoundoutthatthe-typevortexisabasickindofvortexstructureinbothmodesAandB.
简介:通过5-甲基-7-甲氧基异黄酮与盐酸羟胺的缩合制得中间产物4-苯基-5-(2-羟基-4-甲氧基-6-甲基苯基)异恶唑,然后经过光异构化反应合成了4-甲氧基-6-甲基-7a-苯基苯并吡喃并[2,3-b]氮丙啶-7-酮,并采用IR,NMR,HRMS和单晶X-衍射分析对其结构进行了表征.单晶X-衍射分析结果表明:标题化合物属于单斜晶系,空间群P2(1)/n.在其晶体结构中,存在着氢键及芳香堆积作用,这些作用将标题化合物分子组装成了三维网络结构.
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简介:Thispaperproposesandmakesastudyofanewmodel(calledthe3/2plusjumpsmodel)forVIXoptionpricing.Themodelallowsthemean-reversionspeedandvolatilityofvolatilitytobehighlysensitivetotheactuallevelofVIX.Inparticular,thepositivevolatilityskewisaddressedbythe3/2plusjumpsmodel.Dailycalibrationisusedtoprovethattheproposedmodelpreservesitsvalidityandreliabilityforbothin-sampleandout-of-sampletests.Theresultsshowthatthemodelsarecapableoffittingthemarketpricewhilegeneratingpositivevolatilityskew.