平面向量基本定理的应有举例

平面向量基本定理：如果e1，e2是同一平面内的两个不共线向量，那么对于该平面内的任一向量a，有且只有一对实数λ1,λ2，使n=λ1e1＋λ2e2．平面向量基本定理反映了在基底向量e1，e2确定的前提下，平面向量分解的存在性和唯一性．下面利用此定理证明三个著名的古典命题．     

向量最优化问题的Lagrange对偶与择一定理

本文讨论无限维向量最优化问题的Lagrange对偶与弱对偶，建立了若干鞍点定理与弱鞍点定理．作为研究对偶问题的工具，建立了一个新的择一定理．     

替换定理的另一证明方法

替换定理是向量空间中一个非常重要的定理，我们在教学中体会到，若能引导学生利用教材[1]6．1节引入的向量的矩阵记法，将6．3节里向量的线性相关性的一些概念与矩阵挂上钩来，如：所谓向量组{α1，α2，…，αr}可由向量组{β1，β2，…，β1}线性表示，即存在s×r阶矩阵A。     

平面向量基本定理的相关性质及应用

平面向量的基本定理是平面向量坐标表示的基础，说明了同一平面内任一向量都可以表示为两个不共线向量的线性组合．即：如果e1，e2是同一平面内的两个不共线向量，那么对于这一平面内的任一向量a.     

有序拓扑向量空间中的共鸣定理

本文研究有序拓扑向量空间中非线性映照的共鸣定理．对于取值于有序拓扑向量空间中的映照，利用序关系，引入了一类广泛的非线性映照．对于这类非线性映照，应用纲理论，并给出了关于点态序有界蕴涵一致序有界的共鸣定理．     

平面向量基本定理的一个推论的应用

平面向量是高中数学的一个重要考点．特别是对平面向量基本定理的应用更是常考的内容．但是,将平面向量中的平面向量基本定理加以推广,我们还可以得到如下命题：     

关于一类向量极值问题弱有效解的充分必要条件

本文研究带集合约束的向量极值问题。运用局部凸Hausdorff拓扑向量空间中广义次似凸映射的择一定理和其他一些结论，得到了关于集合约束向量极值问题弱有效解的几个充分必要条件．     

基底的选择

在平面向量中,有了共线向量定理和平面向量基本定理,平面内任一向量都可以通过选择一组基底向量来表示,这样,若所选择的两基向量的夹角及其模长都可知,则称这组基底为“已知基底”,那么涉及有关向量运算问题可以将所求向量转化到这组“已知基底”向量上解决,这样就形成向量问题解决的一个通法,在空间向量中这一方法同样是奏效的．     

Stampacchia向量均衡问题与向量相补问题

引进Stampacchia向量均衡问题与一种新的向量相补问题．用数值方法,得到它们的存在定理,并讨论Stampacchia广义向量变分不等式,向量隐相补问题与极小元问题的关系．     

三角形的余切定理及其应用

上述定理简洁工整，优美别致，与三角形的正弦定理极为类似，不妨称作三角形的余切定理． 该定理揭示了三角形中的角、面积及由边构成的向量之间的独特的数量关系，为我们编拟或解答当前中学数学的热点内容之一“向量”的试题，提供了更新的背景，带来了很大的方便．下面仅举几例，供大家参考．     

Φ-Conjugation and noneonvex optimization. a survey (part III)

In the present paper, which is part III of our review concerning the theory of Φ-conjugate functions, we consider Lagrangians, duality theorems are proved and the connection to saddle point theorems is shown. By a fundamental inequality, duality theorems are proved and the connection to saddle point theorems is shown. By a fundamental inequality, duality theorems can be obtained, where results are modified given in part I and part II of our paper.     

Applications of Michael's selection theorems to fixed point theory

Applying some of Ernest Michael's selection theorems, from recent fixed point theorems on u.s.c. multimaps, we deduce generalizations of the classical Bolzano theorem, several fixed point theorems on multimaps defined on almost convex sets, almost fixed point theorems, coincidence theorems, and collectively fixed point theorems. These results are related mainly to Michael maps, that is, l.s.c. multimaps having nonempty closed convex values.     

联合最佳逼近

本文研究了二元函数用紧Hausdorff空间上的连续函数集的联合逼近问题,建立了包括特征定理、唯一性定理、强唯一性定理和dela Vallée Poussin定理在内的Chebyshev逼近理论。给出了求解最佳逼近元的Remes型第一算法和两种一般的简化方法。     

The Study of KKM Theorems With Applications to Vector Equilibrium Problems and Implict Vector Variational Inequalities Problems

In this paper, we establish some equivalence relations between coincidence theorems and KKM-type theorems. We also obtain some new coincidence theorems and fixed point theorems. Applying the KKM-type theorems we obtain the existence theorems of generalized vector equilibrium problems. From these results, some existence theorems of generalized vector implicit variational inequality problems are established in this paper.     

拓扑空间中的KKM型定理和重合点定理

引入了一类新的有限连续空间(简称, $FC$-空间),并在$FC$-空间中证明了一些新的涉及容许类集值映射和具有紧局部交性质的KKM型定理和重合点定理.作为应用,在$FC$-空间中得到了一些新的不动点定理.这些结果统一和推广了近期文献在抽象凸空间中的一些重要结果.     

Perturbation theorems for estimating magnitudes of roots of polynomials

Two additional new theorems are posed and proven to estimate the magnitudes of roots of polynomials. Perturbation theory and the order of magnitude of terms are employed to develop the theorems. The theorems may be useful to estimate the order of magnitudes of the roots of a polynomial a priori before solving the equation. The theorems are developed for two special classes of polynomials of arbitrary order with their coefficients satisfying certain conditions. Numerical applications of the theorems are presented as examples. It is shown that the theorems produce good estimates for the magnitudes of roots.     

A duality approach to minimax results for quasi-saddle functions in finite dimensions

In this paper we show how saddle point theorems for a quasiconvex—quasiconcave function can be derived from duality theory. A symmetric duality framework that provides the machinery for deriving saddle point theorems is presented. Generating the theorems,via the framework, provides a deeper understanding of assumptions employed in existing theorems which do not utilize duality theory.     

Some New Types of KKM Theorem in H spaces with Applications

本文证明了Ｈ－空中的几个新型非空交定理．作为应用,文中得到了向量值极大极小定理和不动点定理,并研究了抽象经济平衡问题．     

Inverse and saturation theorems for radial basis function interpolation

While direct theorems for interpolation with radial basis functions are intensively investigated, little is known about inverse theorems so far. This paper deals with both inverse and saturation theorems. For an inverse theorem we especially show that a function that can be approximated sufficiently fast must belong to the native space of the basis function in use. In case of thin plate spline interpolation we also give certain saturation theorems.

     

FC-空间上的鞍点定理及应用

在不具有任何凸性结构和线性结构的有限连续空间(简称FC-空间)中给出了一个鞍点定理.并应用此定理,在很弱的条件下证明了一些非空交定理及截口定理,推广了近期文献中的一些相关的结果.