S6中具有常数K?hler角和常数曲率的极小曲面

本文给出了近Ｋ?ｈｌｅｒ球面Ｓ⁶中具有常数Ｋ?ｈｌｅｒ角和常数曲率的极小曲面的例子,同时证明了两个唯一性定理．     

基于坐标变换精确计算近奇异积分的双向sinh变换法

提出一种与坐标变换相结合的双向sinh变换方法用于精确计算近奇异积分.首先利用坐标变换法对近奇异积分进行双向分离,再针对分离出的两个方向的积分形式,根据复变函数极点理论,构造双向sinh变换.与传统结合环向变换和极坐标变换的单向sinh变换以及迭代sinh变换方法相比,双向sinh变换法的计算精度更高,并且最近点的位置...     

Synthesis and Crystal Structure of 2-Hydroxybenzoic Acid [1-（3,5-Dibromo-2-hydroxyphenyl）methylidene]hydrazide Methanol

A new Schiff base compound, 2-hydroxybenzoic acid [1-(3,5-dibromo-2-hydroxy- phenyl) methylidene]hydrazide methanol (C14H10Br2N2O3·CH3OH), has been synthesized by the condensation of equimolar 3,5-dibromosalicylaldehyde and 2-hydroxybenzoic acid hydrazide in a methanol solution. The compound was characterized by elemental analysis, IR spectra, and single- crystal X-ray diffraction. The compound consists of a Schiff base moiety 2-hydroxybenzoic acid [1-(3,5-dibromo-2-hydroxyphenyl)methylidene]hydrazide and a lattice methanol molecule. The crystal belongs to the monoclinic system, space group P21/n with a = 7.183(1), b = 15.673(2), c = 15.001(2) , β = 98.345(2)o, Z = 4, V = 1670.9(4) 3, Dc = 1.773 g/cm3, Mr = 446.10, λ(MoKα) = 0.71073 , μ = 4.872 mm-1, F(000) = 880, R = 0.0458 and wR = 0.0963. A total of 3445 unique reflections were collected, of which 2236 with I > 2σ(I) were observed. As expected, the molecule adopts a trans configuration about the C=N double bond. The two benzene rings are nearly coplanar (mean deviation from the combined plane is 0.061(4) ), with the dihedral angle of 7.9(3)o. The preliminary biological tests show that the compound has moderate antibacterial activities.     

重图的均匀边染色

图G的一个边染色称为是均匀的,如果对G的每个顶点v,与v关联的染任意两种颜色的边数至多相差一,我们给出了重图均匀边染色的一个充分条件。     

二维弹性问题边界元法中边界层效应问题的变换法

基于间接规则化边界积分方程,有效估计奇异边界积分,准确求得边界量,为场变量的计算奠定了基础。在计算场变量时,针对二维弹性力学边界元法中出现的几乎奇异积分,本文采用一类非线性变量替换法,有效地改善了被积函数的震荡特性,从而消除了核积分的几乎奇异性;在不增加计算量的情况下,极大地改进了几乎奇异积分计算的精度,成功地求解了弹性体近边界点上的力学参量,避免了边界层效应。此外,本文引入一种精确几何单元逼近,对于圆弧边界,这样的插值逼近几乎是精确的,提高了计算精度。数值算例表明,本文算法稳定,效率高,并可达到很高的计算精度,即使场点非常靠近边界,如场点到积分单元的距离小到纳米级,仍可避免边界层效应现象。     

刻划D-η-真预拟不变凸函数的新方法

The D-η-proper prequasi-invexity of vector-valued functions is characterized by means of (weak) nearly convexity and density of sets.Under weaker assumptions,some equivalent conditions for D-η-proper prequasi-invexity are derived.     

Infinite Dimensional Geometric Properties of Real Interpolation Spaces

Estimates for the moduli of noncompact convexity of l_p-sums and real interpolation spaces for finite families of spaces are given. It is proved that such an interpolation preserves nearly uniform convexity and property (β).     

Some Identities for Enumerators of Circulant Graphs

We establish analytically several new identities connecting enumerators of different types of circulant graphs mainly of prime, twice prime and prime-squared orders. In particular, it is shown that the half-sum of the number of undirected circulants and the number of undirected self-complementary circulants of prime order is equal to the number of directed self-complementary circulants of the same order. Several identities hold only for prime orders p such that (p + 1)/2 is also prime. Some conjectured generalizations and interpretations are discussed.     

集值优化问题的强有效解与Kuhn-Tucker鞍点

首先在局部凸Hausdorff拓扑向量空间中定义了集值优化问题的Kuhn-Tucker鞍点,在近似锥-次类凸集值映射下,讨论了集值优化问题的强有效解与Kuhn-Tucker鞍点之间的关系.     

Nearly Kähler 6-Manifolds with Reduced Holonomy

We consider a complete six-dimensional nearly Kählermanifold together with the first canonical Hermitian connection. We showthat if the holonomy of this connection is reducible, then the manifoldendowed with a modified metric and almost complex structure is aKählerian twistor space. This result was conjectured byReyes-Carrión.