中国耕地警戒值的测算与讨论

耕地安全是食物安全的基础，我国未来的耕地压力大，耕地保护是关键。耕地警戒值是影响政府土地管理部门加强耕地保护执法力度和老百姓建立耕地安全意识、参与性保护耕地的重要指标。近年来，人均耕地警戒值0.053hm²的引用对耕地安全意识的建立产生了很大影响，科学测算我国耕地警戒值具有紧迫性和现实意义。构建最小人均耕地面积的扩展模型S_min=MB∑ni=1βi·GiPi，建立饲料粮食消费量与肉蛋奶消费量、食品作物单产量与单产影响因素之间关系的5个线性回归方程，以及单产影响因素与时间关系等6个曲线估计方程，测量粮食、植物油、糖和蔬菜等食品作物单产量，计算2006年～2015年最小人均耕地面积并与相应年份实际人均耕地面积对比，确定2006年的最小人均耕地面积0.09035hm²和最小人均耕地面积总量1.18×10⁸hm²（17.7亿亩）分别为人均耕地警戒值和耕地总量警戒线。     

确定技术优先级的数学模型

国家就哪些技术应重点发展,哪些技术应限制发展作出正确决策,对于合理利用有限资源是至关重要的.本文基于对影响战略层次上的技术优先级的4个要素的分析,提出一种数学方法,可以有效地解决技术优先级的确定问题.本文采取的4个要素的度量方法,实质上是从定性思维向定量评估的合理转化.本方法既实用,又便于操作.     

Long-term retention of basic mathematical knowledge and skills with engineering students

This study focuses on the long-term retention of basic mathematical techniques in a first-year calculus course, involving a sample group of engineering students at the University of Pretoria. The study investigates which and how much of the basic mathematical knowledge and rote skills acquired in the first year of study is retained after a further two years of study. A quantitative and qualitative investigations show that, in general, there is a significant decline in performance over a two-year period. There are, however, areas in which students still performed reasonably well after the elapsed period or even showed improvement. The research is of diagnostic value in that it assists course designers in determining what basic mathematical skills and knowledge are retained after a period of two years in their teaching approach to and emphasis of different topics.     

高等数学教学与数学文化的传播

数学是一种文化,并且是现代文化的核,心.高等数学教育在传播数学知识的同时.更注重让学生感悟数学精神,理解数学思维,掌握数学思想方法,从而受到数学文化的熏陶,以提高数学文化素质.     

如何在数学教学中渗透数学建模思想

本文针对高职院校数学教学中的实际问题,结合自身的教学经验,从多个角度阐述了如何采取与学生认知一致的方式,将数学建模思想渗透到数学教学中。     

4级m序列发生器数学模型的仿真分析

对m 序列的数学模型进行了研究,探讨了实现m 序列的生成过程,设计了4 级移位寄存器的仿真模型,并运用SystemView 软件对其进行了仿真分析.结果表明,所设计的仿真模型的电路是合理的,结果与理论分析相符.     

论高等数学的有效教学策略

文章主要结合笔者的教学实践,从学习动机、教学目标、教学方法、数学思想方法等方面就大学课程中《高等数学》的有效教学进行一些探讨。     

试论数学基本活动经验

在数学学习过程中,数学活动主要有显性的操作活动、隐性的思维活动以及综合的实践活动等。数学活动属于思维活动,基本数学活动经验是重要的思维活动经验,主要包括抽象的经验、归纳的经验和演绎的经验。     

Examining the unique contributions and developmental stability of individual forms of relational reasoning to mathematical problem solving

Relational reasoning, a higher-order cognitive ability that identifies meaningful patterns among information streams, has been suggested to underlie STEM development. This study attempted to explore the potentially unique contributions of four forms of relational reasoning (i.e., analogy, anomaly, antinomy, and antithesis) to mathematical problem solving. Two separate samples, fifth graders (n = 254) and ninth graders (n = 198), were assessed on their mathematical problem solving ability and the different forms of relational reasoning ability. Linear regression analysis was conducted, with participants’ age, working memory, and spatial skills as covariates. The results showed that analogical and antithetical reasoning abilities uniquely predicted mathematical problem solving. This pattern demonstrated developmental stability across a four-year time frame. The findings clarify the unique significance of individual forms of relational reasoning to mathematical problem solving and call for a shift of research direction to reasoning abilities when exploring dissimilarity-based relations (opposites in particular).     

Subtraction by addition in children with mathematical learning disabilities

In the last decades, strategy variability and flexibility have become major aims in mathematics education. For children with mathematical learning disabilities (MLD) it is unclear whether the same goals can and should be set. Some researchers and policy makers advise to teach MLD children only one solution strategy, others advocate stimulating the flexible use of various strategies, as for typically developing children. To contribute to this debate, we compared the use of the subtraction by addition strategy to mentally solve two-digit subtractions in children with and without MLD. We used non-verbal research methods to infer strategy use patterns, and found that both groups of children switch between the traditionally taught direct subtraction strategy and subtraction by addition, based on the relative size of the subtrahend. These findings challenge typical special education classroom practices, which only focus on the routine mastery of the direct subtraction strategy.