二维对流扩散方程满足最大值原理的MMOCAA差分方法

Using FCT idea,the non-oscillation MMOCAA(The modified method of characteristics with adjusted advection) finite difference scheme satisfing the discrete maximum principle for convection-dominated diffusion equation in 2D is constructed.The scheme is free from oscillation,with which the problem is solved by the MMOCAA difference method based on 2-order Lag-range interpolation proposed by Jim.Douglas, Jr.(Numer.Math.,1999,83:353-369.). The error analysis of the new scheme and numerical example are given in the paper.The numerical example shows that the scheme has smaller numerical viscosity than the MMOCAA difference method based on bilineax Lagrange interpolation.     

Two Cu(Ⅱ) Complexes with Hydrolyzed Nicotinamide Ligand: Crystal Structures and Bioactivities

Two Cu(Ⅱ) complexes of [Cu(2,6-DPC)(Hnta)(H_2O)]·H_2O(2,6-DPC = 2,6-pyridinedicarboxylic-carboxylate, Hnta = nicotinic acid) and [Cu_2(2,4-D)_4(Hnta)_2](2,4-D = 2,4-dichlorophenoxyacetic-carboxylate) were synthesized and successfully obtained as single crystals in this paper. The supramolecular structures of the complexes from zero to three dimensions and the weak intermolecular force in the crystal were analyzed. The single-crystal structures of the complexes were further analyzed by Hirshfeld surface analysis. The competition capacity of the complexes about calf thymus DNA(ct-DNA) was also analyzed by fluorescence spectroscopy. The ability of complexes to cleave the plasmid DNA(pBR322-DNA) was determined by gel electrophoresis assay. And at last, the complexes' cytotoxic activities were reviewed for four kinds of cancer cell lines(HeLa, MCF-7, HepG, SKOV-3), showing that the coordination polymer has anti-tumor activity and cytotoxicity.     

武器系统中的图象处理与自动跟踪

很久以来,从第一次出现战争的时候起,胜利就属于自己不被发现,而又能发现敌人并精确进行武器瞄准的一方。如果试图说明过去几世纪中光学装置在探测和识别方面的惊人发展,那是会落空的。这种技术从20世纪开始才得到特别迅速的发展。但是,在第二次世界大战中及其以后,武器系统的逐步现代化又使我们清楚地看到单纯光学装置的局限性。一方面新     

非线性对流-扩散方程初边值问题的特征-差分解法

[1]讨论了线性方程c(x)((?u)/(?t))+b(x)(((?u)/(?x))-?/(?x))(a(x)(?u/?x))=f(x,t)初值问题的特征-有限元及特征-差分方法,[2]讨论了非线性方程 c(x)((?u)/(?t))+b(x,u)((?u)/(?x))-(?/(?x))(a(x,u)((?u)/(?x)))-f(x,u) (1.1)第一边值问题的特征-差分方法,并改善了[1]中某些重要结果。本文着重讨论非线性方程     

二维非线性对流-扩散方程的特征-差分解法

1.引言 近年来,求解对流-扩散方程的修正特征线法日渐被人们重视,已有不少人讨论了这一方法,如[1]-[5]。其中[1]和[2]是该领域的奠基性工作。[6]讨论了对流-扩散方程的特征-差分方法,改善并推广了[1]中某些重要结果。本文将讨论二维非线性对流-扩     

求解非线性对流-扩散问题的特征—差分法

近年来,已有不少文献讨论发展型方程的特征-有限元或特征-差分解法.在这一方向上,J.Douglas,Jr.及T.F Russell[1]是重要的工作,它讨论了一维对流-扩散方程C(x)?u/?t+b(x)?u/?x-?/?x(a(x)?u/?x)=f(x,t)的数值求解问题,建立了基于线性插值与基于二次插值的两种特征-差分格式,给出了误差分析,将前一种格式推广到     

非线性对流扩散方程的三层隐-显hp-局部间断Galerkin有限元方法

使用Arnold等人提出的求解椭圆方程的间断有限元的一般框架及新的处理非线性对流项的方法,得到了非线性对流扩散方程的三层隐-显hp-LDG方法的误差估计.对Burgers方程进行了数值计算,计算结果验证了文中得到的理论结果.     

O-(1-苯基-3-三苯锗基)正丁基硫代磷酸酯类化合物的合成

随着人们对倍半锗类化合物的合成和生物活性的深入研究，烷锗类和芳锗类化合物的生物活性也逐渐引起人们的重视。１９８７年，Ｋａｋｉｍｏｔｏ等发现３－三烷基（三芳基）锗基丙酸酯类化合物具有选择性酶分解抑制活性［１］。１９９４年，Ｘｉｅ等报道了三芳基锡基３－三...     

Quantum Chemical Study on the Reaction Mechanism of OBrO Radical with OH Radical

The reaction mechanism of OBrO with OH has been studied using the B3LYP/6-311 G(d,p) and the high-level electron-correlation CCSD(T)/6-311 G(d,p) at single-point. The results show that the title reaction could probably proceed by four possible schemes, generating HOBr O2, HBr O3, BrO HO2 and HOBrO2 products, respectively. The main channel is the one to yield HOBr O2. The whole reaction involves the formation of three-membered, four-membered and five-membered rings, followed by the complicated processes of association,H-shift, Br-shift and dissociation. All routes are exothermic.