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§1. IntroductionIn[1,2],AronsonandWeinbergerhavestudiedsystematiclythescalarnonlineardiffu-sionequationinonespacevariableut=uxx+φ(u),(1.1)whereu=u(x,t)andφ(u)isanonlinearfunction.Equation(1.1)arisesinseveralapplica-tions;See[1,2]and[3]forinformationa… 相似文献
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题目 已知当x∈[0,1]时,不等式x2cosθ-x(1-x)+(1-x)2sinθ>0恒成立,试求θ的取值范围.这是1999年全国高中数学联合竞赛试题第三题,下面给出一种有别于“标准答案”的简单解法.解 若对一切x∈[0,1],恒有f(x)=x2cosθ-x(1-x)+(1-x)2sinθ>0,则 sinθ=f(0)>0,cosθ=f(1)>0,∴ 2kπ<θ<2kπ+π2,k∈Z.(1)又 f(x)=(1+sinθ+cosθ)x2-(1+2sinθ)x+sinθ=(1+sinθ+cosθ)[… 相似文献
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§1. IntroductionIn1908,E.Landauintroducedthefollowingwellknownsequenceofoperators[1]Ln[f(t);x]=Kn∫1-1f(t)[1-(t-x)2]ndt, (1.1)where Kn=[∫1{-1(1-t2)ndt]-1~nπ (n→∞).(1.1)wasusedintheproofoftheWeierstrassTheorem.Sincethen,theapproximationprop-ert… 相似文献
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Thispaperiscontinuationsof[1],westilltousemarksandtermsin[1]andtheothertermsagreewith[2]and[3].LetEandFbetwoHausdorfftopologicalvectorspaces,XE,YFbetwononemptysets,FbethedualspaceofF,A:X→2YandB:Y→2Fbetwoset-valuedmapping,T:Y→Xbeinvertible.Inthisp… 相似文献
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笔者曾在文[1]中给出了△ABC中半角三角函数和式∑sinA2、∑cosA2、∑sinB2sinC2、∑cosB2cosC2及∑cosB-C2的用s、R、r表示的较强的下界.1999年5月,我们又获得∑cosB-C2的一个新的很强的下界及∑1cosB-C2的一个很强的下界.本文将阐述这些结果,并应用其给出了文[2]中Shc19的一个新证明(注:在文[3]中我们已给出Shc19的一个证明),解决了文[4]提出的猜想,即Cwx—161.本文记号约定:以a、b、c,s,R,r,wa、wb、wc,ha、… 相似文献
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书[1][2]收录了Wilkins的三个奇特结果:对任意△ABC(其内角A,B,C)有Ⅰ.sinAsinBsinC2≤293.仅当A=B=arccos133时取等号;Ⅱ.sinA2sinB2sinC≤154(213-5)·213+22,仅当A=B=a... 相似文献
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§1.IntroductionSupposeX1,X2,…,Xni.i.d~N(0,Ip).SetQ(u,ν)=∫∞-∞[I[ut]-Φ(t)][I[νt]-Φ(t)](φ(t))-1dt,whereΦ(t)andφ(t)are,respecti... 相似文献
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Lin Chunyan 《数学季刊》1998,(3)
§1. IntroductionandPreliminariesTheconsiderableprogresseshavebeenmadeinthetheoryofmatricesoverskewfieldssinceprofessorXieBandjiesimportantpaper[1]waspublished.Itiswellknownthatmatrixequationisoneofimportantcontentsofmatrixstudy.In[2-4],fivetypesofma… 相似文献
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1IntroductionForE-P-Dequationut+2btut-Δu=0(1)Ithasbenonehundredyearshistorysinceitwasstudied.Alotofresultshavebengottenin[1]... 相似文献
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关于格蕴涵代数的余元及结构 总被引:1,自引:0,他引:1
根据格蕴涵代数的性质,利用蕴涵滤子的概念,给出一种确定任意元素的余元的思路,指出在几种特殊的分配格上不能定义格蕴涵代数,给出几种格蕴涵代数的结构。 相似文献
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This paper introduced the concept of L-fuzzy sub lattice implication algebra and discussed its properties. Proved that the intersection set of a family of L-fuzzy sub lattice implication algebras is a L-fuzzy sub lattice implication algebra, that a L-fuzzy sub set of a lattice implication algebra is a L-fuzzy sub lattice implication algebra if and only if its every cut set is a sub lattice implication algebra, and that the image and original image of a L-fuzzy sub lattice implication algebra under a lattice implication homomorphism are both L-fuzzy sub lattice implication algebras. 相似文献
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OntheCharacteristicofProperLatticeImplicationAlgebras¥XuYang;QinKeyun(SouthwestJiaotongUniversity)(HenanNormalUniversity)Abst... 相似文献
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Lattice implication algebra is an algebraic structure that is established by combining lattice and implicative algebra. It originated from the study on lattice-valued logic. In this paper, we characterize two special classes of lattice implication algebra, namely, subdi-rectly irreducible and directly indecomposable lattice implication algebras. Some important results are obtained. 相似文献
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We define an ultra LI-ideal of a lattice implication algebra and give equivalent conditions for an LI-ideal to be ultra. We show that every subset of a lattice implication algebra which has the finite additive property can be extended to an ultra LI-ideal. 相似文献
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多值逻辑是人工智能中一个重要的研究方向。为了进一步深入研究多值逻辑,特别是真值基于格上的多值逻辑,文献「1」提出并提建立了格蕴涵代数这一逻辑代数结构,进而研究了对应的格值逻辑系统。本文则集中讨论了一类较特殊但也较广泛的格蕴涵代数,即内射的格蕴涵代数,深入探讨了这类代数和一些性质并给出了其特征结构的刻画。 相似文献
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In this paper,the concepts of product and factorization of lattice implication algebra areproposed,the relation between lattice implication product algebra and its factors and some properties oflattice implication product algebras are discussed. 相似文献