概念内涵和外延关系的再认识

形式逻辑提出概念的内涵和外延之间具有反变关系,辩证逻辑则认为概念的内涵和外延之间还有正变关系."反变关系"、"正变关系"各有其应用的语境.在实践中,存在着在形式逻辑的框架下解释"正变关系"、"正变关系"的适用范围不确定以及不能用"反变关系"或"正变关系"解释的一些例外现象.为了正确认识概念内涵和外延的关系,需要对它们进行分析.     

福建省学生近视眼患病率的动态分析

应用可比性原则，将2000年与1995年的福建省汉族学生的近视检出率进行纵向对比，结果发现，福建省学生的近视发生率显著上升，造成这种现象的原因是学习任务繁重导致长时间、近距离用眼过度、班生数太多、课桌椅高差与学生坐高不符及每周体育锻炼不足。对此，学校、家长应引起高度的重视。     

Improper use of linear reasoning: An in-depth study of the nature and the irresistibility of secondary school students' errors

Several recent ascertaining studies revealed a deep-rooted and almost irresistible tendency among 12–16-year old students to improperly apply the linear or proportional model in word problems involving lengths, areas and volumes of similar plane figures and solids. While these previous studies showed to what extent students' improper use of linear reasoning is affected by different characteristics of the task, it remained largely unclear what aspects of their knowledge base are responsible for the occurrence and strength of this phenomenon and how these aspects relate to other more general misconceptions and buggy rules identified in the literature. This paper reports an in-depth investigation by means of individual semi-standardised interviews aimed at analysing the thinking process underlying students' improper linear reasoning and how this process is affected by their mathematical conceptions, beliefs and habits. During these interviews,students' solution processes were revealed through a number of well-specified questions by the interviewer with respect to one single non-linear application problem, as well as through their reactions to subsequent kinds of cognitive conflict. The interviews provided a lot of information about the actual process of problem solving from students falling into the ‘linearity trap’ and the mechanism behind it. Although some students seem to really ‘believe’ that quantities are always linked proportionally, their improper use of linearity often results from superficial and intuitive reasoning, influenced by specific mathematical conceptions, habits and beliefs leading to a deficient modelling process. This revised version was published online in July 2006 with corrections to the Cover Date.     

稀土氯化盐水溶液在293K时电导的研究

应用电导率仪在293K时测定了 4 种稀土氯化盐 ErCl3、DyCl3、NdCl3 和 YCl3 在极性水溶剂中的电导率,利用公式λ= (k液- k剂)×10-3c计算了稀土氯化盐在水中的摩尔电导率,并讨论了在293K时浓度对稀土氯化盐水溶液电导率和摩尔电导率的影响.     

浅谈乳化沥青混合料配合比设计

通过分析阳离子乳化沥青的特点及其拌制沥青混合料与热沥青拌制混合料的不同，阐述了修正的马歇尔稳定度试验的要点及乳化沥青混合料配合比设计方法。     

钢纤维体积率对中强混凝土性能的影响试验

通过对中强钢纤维混凝土进行试验，分析了钢纤维体积率与中强混凝土强度增幅之间的关系。试验结果表明，砂率不同，对混凝土的增强效果不同；随着钢纤维体积率的提高，中强混凝土抗压和抗拉强度都有不同程度的提高，抗拉强度则是大幅度提高。     

燕山大学数学教师发展规划初探

针对燕山大学目前教学师资短缺、同时既要提高数学科研水平，又要完成繁重的教学任务的现状，提出了燕山大学数学师资人员定额的、科学的、量化的、可持续发展的方案，从而在数学师资的引进、培养、发展规划等方面为学校及理学院提供了科学的理论依据。     

论连带债务

连带债务的法律规定起源于罗马法，连带债务能引起连带责任。连带债务多由法律规定。连带债务人履行了债务后，对其他债务人有求偿权。     

宽严相济：立足于有效性与法治国之间的刑事政策

正确理解宽严相济刑事司法基本政策,对刑事法治的发展和司法实践具有重大意义。同惩办与宽大相结合政策、“严打”政策相比较,宽严相济刑事政策在执行主体、对象和手段方面都发生了转变。宽严相济刑事政策的出发点是有效率、有效益地防止犯罪;目标是实现法治国原则;得以实现的具体原则是比例原则。宽严相济刑事政策是以人权保障为政策界限的。宽严相济刑事政策的实现,表现为刑事政策的法制化和刑事法的刑事政策化。     

极小相位差的测量

本文介绍了用理论推理和试验叙述用示波器可达到测量的极小相位差的方法。