TAMB分光光度法测定微量铜的研究

本文研究了TAMB分光光度法测定微量铜的条件:条件宽容,方法简便用本法测定自来水及模拟橡胶填充剂“白炭黑”提取液中的微量铜,结果令人满意.     

λK n,n的P5-因子分解

给出了平衡完全二部多重图λKn,n存在P5-因子分解的充分必要条件为n=0（mod 40/d）,其中d=gcd（λ,8）。     

2-羟基-5-(4-磺酸基偶氮苯)-苯甲酸乙脂的合成

有机非线性光学材料的研究集中在有推拉电子结构(D-π-A)和分子内电荷转移的有机化合物，有机物的非线性光学效率应主要来自非定域的π电子，与无机非线性光学材料相比．具有较高的非线性系数和具有可设计、合成使材料多样化等诸多特点，偶氮化合物具有优良的光电性能。是一类很好的非线性光学生色基团．设计合成了具有D-π-A结构的偶氮化合物2-羟基5-(4-磺酸基偶氮苯)-苯甲酸乙脂。     

加密口令在ASP.NET中的实现

介绍MD5加密算法的基本原理.举例说明该算法在用ASP.NET开发WEB应用程序时,安全保护数据库中用户密码这一重要数据的方法.     

基于VB的一次性密码研究与实现

身份认证是网络安全技术的一个重要组成部分,它限制非法用户访问系统的资源。本文介绍密码技术的基本原理,详细讨论“一次性口令”认证技术的原理以及自己所设计的系统的实现过程。     

The effect of inquiry‐based learning on the achievement goal‐orientation of grade 10 physical sciences learners at township schools in South Africa

Due to apartheid policies, Black African learners in South Africa have been severely disadvantaged in school science. Despite policy changes to redress these historical imbalances, Black African learners continue to underperform in science. Previous research has identified motivation as a key factor that impacts performance. Achievement goal orientation is a construct of motivation that explains learning behaviour. In an attempt to address the problem of learner motivation, this study investigated the effect of inquiry‐based learning on the achievement goal‐orientation of grade 10 physical sciences learners at historically disadvantaged township schools in South Africa. In South Africa, the term “township” usually refers to under‐developed urban areas that were historically created for “non‐whites” during the apartheid era. The findings showed that the experiment group of learners who experienced inquiry‐based learning significantly gained in mastery goal orientation, while the control that were taught through a traditional direct didactic approach had an insignificant change in their mastery goal orientation. From these results, it can be concluded that inquiry‐based learning does support a mastery goal orientation in learners. This orientation is regarded as desirable because mastery approach goals could support positive outcomes in conceptual learning, leading to an improvement in science achievement of learners.     

统筹--老名词新观念

论文通过对我们党在不同时期的统筹问题的分析研究，既指出了过去对统筹问题上存在的认识上的片面性和实践中的误区，又阐明了我们党在新的历史时期对统筹问题的新的理论和认识上的发展。从而对统筹问题有了更深层次的理解和认识，有利于帮助人们加深对我们党新提出的“五个统筹”理论认识，增强人们在实践中贯彻执行“五个统筹”发展观的自觉性。     

Architecture Singularity Analysis of 4-U PS/U PU 5-DOF Parallel Mechanism

Architecture singularity of a parallel mechanism with five degrees of freedom (DOF) is analyzed. Such mechanism consists of a movable platform connected to the base by five active limbs. Four of them are identical 6-DOF limbs and the last one has the same DOF as the specified DOF of the movable platform. Based on the kinematics analysis, two categories of architecture singularities for such mechanism are proposed. Then the sufficient condition for each singularity is researched. Results show that the mechanism is singular when it employs each category of the proposed architecture, provided that it satisfies the corresponding sufficient condition. It can be concluded that the proposed two categories of architecture singularities should be avoided with the following dimension-al synthesis of such mechanism.     

正己烷在某些金属改性ZSM_5上的芳构化反应

本文对Ｎｉ，Ｃｕ，Ｚｎ三种金属改性的ＺＳＭ－５上正己烷的芳构化反应进行了探讨和比较，发现这些金属的引入在促进正己烷的芳构化性能方面既有共同点，也有某些差异，同时还研究了催化性能和酸性的关系，并就Ｂ酸和Ｌ酸中心的协同效应对芳构化的促进作用提出了看法。     

硅对原位反应自生Mg2Si/ZM5复合材料热处理态的组织和性能的影响

在真空感应炉中氩气保护下制备材料，用OM，SEM，EDAX及拉伸试验，探讨硅对原位反应自生Mg2Si，ZM5复合材料T6热处理后显微组织和性能的影响规律。结果表明，反应恭加物Si在ZM5合金中形成了高熔点、高硬度的Mg2Si强化相，时效处理可促进γ(Mg17Al12)相沿晶内连续析出，明显地提高了材料的室温与高温强度；且Mg2Si相的形貌亦随着硅含量的不同而变化；Mg2Si相是一种脆性相，使得该材料呈现出解理断裂，降低了材料的塑性。