非定常的热传导-对流问题的非线性Galerkin混合元法(Ⅲ):时间二阶精度的全离散格式

In this paper, a fully discrete format of nonlinear Galerkin mixed element method with two-step discretization of time for the non stationary conduction-convection problems is presented. The existence and the convergence of the fully discrete mixed element solution are shown. On the basis of [9] and [10], we have proved that the schemes have second-order convergence accuracy for the time discretization.     

A New Filled Function Method for Global Optimization

A novel filled function is suggested in this paper for identifying a global minimum point for a general class of nonlinear programming problems with a closed bounded domain. Theoretical and numerical properties of the proposed filled function are investigated and a solution algorithm is proposed. The implementation of the algorithm on several test problems is reported with satisfactory numerical results.     

二维平板光子晶体直波导的制备和光传输特性的测量

利用聚焦离子束刻蚀的方法在SOI(silicon on insulator)基片上制备了W3型二维光子晶体直波导.观察并测量了近红外激光通过光子晶体波导的散射图形和透过谱.实验结果说明，激光在有引入引出脊形波导的光子晶体直波导中具有很好的传输特性. 关键词： 光子晶体波导 光子带隙 脊型波导     

A note on uniformization of Riemann surfaces by Ricci flow

We clarify that the Ricci flow can be used to give an independent proof of the uniformization theorem of Riemann surfaces.

     

Difference in enzyme activity and conformation of glucose oxidase before and after purification

Enzyme activity of commercial glucose oxidase was enhanced after purification through a strong anionic exchange resin. In order to get a better insight into this phenomenon, surface pressure–area (π–A) isotherms and surface pressure–time (π–t) isotherms was used to study the interaction and the absorption at different pH values of the subphases between octadecylamine and glucose oxidase purified by a styrene system quaternary ammonium type strongly basic anionic exchange resin. Circular dichroism (CD), electrophoresis and enzyme activity measurements were conducted to study these phenomena. A preliminary hypothesis has been suggested to explain why the enzyme activity of purified glucose oxidase was higher than that of the commercial one.     

Elution Behaviour of Monocarboxylic Acids on a Cation-exchange Resin Column

The retention mechanism of monocarboxylic acids on a cation-exchange resin column was investigated. It was assumed that both Donnan membrane equilibrium and adsorption equilibrium were involved in the chromatographic process. On the basis of the proposed mechanism, an equation was derived for correlating distribution coefficient, Kd, dissociation constant, Aa, and adsorption equilibrium constant, K, of the analyzed acid. By this approach, retention data for some aliphatic acids under different operating conditions were predicted. Results are reasonably in agreement with experiment.     

测自来水的电阻率

研究性学习是新课程教学改革的核心，它既是一种教学活动形式，也是一种学习活动方式。研究性主题不同于一般教学中的课外活动，而是强调学生动手动脑的实践过程。在这一过程中，在教师的指导下，学生从自然现象、社会、生活中遇到的问题出发，提出问题，并应用已有的知识设法解决问题，从中主动获取新知识，达到培养学生提出和解决问题能力的目的。本着这一教学思想我们组织开展了一次研究性学习课，将学习课全程总结浓缩成文，仅以此供同仁商榷。     

A Facile Synthesis of Squamosamide Cyclic Analogs

A series of novel cyclic derivatives have been synthesized by utilizing a nickel powder mediated radical cyclization as the key step. The structures of the new compounds were confirmed by ^lH-NMR and MS.     

有限域上互反本原正规元的存在性

设q是素数方幂,n是正整数,Fqn是qn个元素的有限域．本文证明了:当正整数n≥32时,对任意的素数方幂q,存在Fqn中的本原元ξ满足ξ和ξ-1都是Fqn 在Fq上的正规元,也即{ξ,ξq,…,ξqn-1}和{ξ-1,ξ-q,…,ξ-qn-1)都构成Fqn在Fq 上的本原正规基．     

DEA评价与排序的新方法

文章简要回顾了 DEA(Data Envelopment Analysis)方法在先进制造技术 AMT(AdvancedManufacturing Technology)评价以及在其它领域中的研究、应用现状 ;分析了 DEA方法及其改进形式在决策单元有效性评价与排序中存在的问题 ,提出了解决这些问题的新方法