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简介：Thecurrentstructure-preservingtheory,includingthesymplecticmethodandthemultisymplecticmethod,paysmostattentionontheconservativepropertiesofthecontinuoussystemsbecausethattheconservativepropertiesoftheconservativesystemscanbeformulatedinthemathematicalform.But,thenonconservativecharacteristicsarethenatureofthesystemsexistinginengineering.Inthisletter,thestructure-preservingapproachfortheinfinitedimensionalnonconservativesystemsisproposedbasedonthegeneralizedmulti-symplecticmethodtobroadentheapplicationfieldsofthecurrentstructure-preservingidea.Inthenumericalexamples,twononconservativefactors,includingthestrongexcitationonthestringandtheimpactonthecantilever,areconsideredrespectively.Thevibrationsofthestringandthecantileverareinvestigatedbythestructure-preservingapproachandthegoodlong-timenumericalbehaviorsaswellasthehighnumericalprecisionofwhichareillustratedbythenumericalresultspresented.

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：在chiral媒介的电磁波繁殖被马方程和Drude-Born-Fedorov管理(组成)方程。这个问题被简化到一个二维的散布问题，并且被介绍二个透明边界条件在一个围住的领域提出。一与非局部的边界操作员的截断联系的posteriori错误估计被建立。基于posteriori错误控制，一个有限元素适应策略为计算衍射问题被介绍。截断参数突然地彻底地是坚定的posteriori错误估计。数字实验被包括说明我们的错误估计和建议适应算法的坚韧性和有效性。

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简介：Intheintroductionapreliminaryconsiderationofthesenseofconcepts“set”,“structure”,“system”,and“model”,aswellasoftheconnectionbetweenthemisproposedandonthebasisofitsresultsthetaskofinvestigationofabstractbasesofsystem(inparticularreconsiderationofconcept“abstractset”),ofabstractstructure,abstractsystemandofS-Modelisformulated.Thefirstsectionisdevotedtoformulationofanapproachtoconstructionofaggregatetheoryregardedasananalogofmoderateconstructivesettheory:therelations“inclusion”and“equivalence”betweenaggregatesandtheoperationsonaggregates“union”,“intersection,“difference”and“compliment”areintroduced.Definitionoftheconcept“a-system”aswellasofitsa-structureonthespaceofaggregatesisdefined.AspecialattentionisshowntosimilarityandessentialdifferencebetweenaggregatetheoryandsettheoryaswellastothefactthatthefamousparadoxesofCantorandRussellintheCantor’ssettheorytakenoplaceintheaggregatetheory.FurtheravariantofCantor’ssettheorycalledrestricteddiscretesettheoryisconsidered.Thesecondsectionisdevotedtoformulationofanapproachtoconstructionofalgebraofa-systems.Attheendtheconceptofsystemofsuccessivesystems(SSS),isintroduced.

简介：利用密度泛函理论（Densityfunctionaltheory，DFT）在B3LYP／6-311＋＋G（d，声）水平上研究了外电场（-15．43～15．43V／nm）对氟利昂F13（三氟氯甲烷，CRCl）分子物理和光谱特性的影响．计算结果表明，在C～Cl键连线z方向上，外电场从-15．43V／nm逐渐增加到15．43V／nm时，分子体系能量先增大后降低，偶极矩表现为先减小后增大，能隙ElG先增加后减小，C-Cl键键长逐渐增大，C-F键键长逐渐减小．外电场对CRCl分子红外振动光谱的频率和强度也有影响．进一步研究发现在外电场作用（O到15．43V／nm）逐渐增强下，CRCl分子的势能曲线束缚形态逐渐被解开，解离的势垒逐渐减小．在强度为15.43V／nm的电场作用下，CF3Cl分子将会发生C-C1键断裂而降解，该结果为对氟利昂进行外电场降解提供重要的参考依据．

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简介：本文的目的是研究如下非局部椭圆算子方程在Dirichlet边界条件下变号解的存在性{-Lku=f（x,u）inΩ,u=0,inR^n／Ω,其中Ω∈R^n（n≥2）是具有光滑边界的有界区域,非线性项f满足超线性以及次临界增长条件.利用变号临界点定理,证明了在更弱的条件下无穷多变号解的存在性.

简介：针对SINS/GNSS组合导航在GNSS信号异常时出现的系统滤波精度和稳定性下降的问题,提出一种基于EKF的自适应分类容错滤波算法。该算法通过比较系统残差协方差矩阵的实际值与理论值来检测GNSS信号是否存在异常,然后对异常信号进行分类,并对不同类别的异常信号使用不同的加权矩阵进行修正,以减弱异常值对系统滤波精度的影响,同时在滤波过程中加入UD分解,使系统滤波性能更稳定。仿真结果表明：该算法能够有效降低GNSS输出异常信号对SINS/GNSS组合导航带来的不利影响并提高系统稳定性;在GNSS信号出现异常情况下,其导航精度相比EKF至少提高95.6%,相比REKF和AEKF分别至少提高44.5%和24.6%。