关于一个几何命题证明的思考

数学学习的重要目的在于培养学生的数学思维能力,养成良好的数学思维品质。从不同的角度分析问题、解决问题是培养数学思维品质的一个好方法,对培养思维的灵活性、广阔性有重要意义。从3个角度出发,给出一个几何命题的证明方法。     

高师"初等几何研究"课程改革的实践与认识

针对基础教育改革的现实和高师"初等几何研究"课程存在的问题,就本课程的改革进行了探索.具体从课程体系方面:突出学生利用几何知识进行问题解决和几何建模的能力等;从教学内容方面:强调高初结合和对中学几何知识缺陷的补充等;从教学模式方面:高师数学课堂的"自主·合作·创造"模式三方面对改革的实践进行了总结.     

胶州湾地区近50年气候变化特征分析及未来趋势预估

利用胶州湾地区7个气象站点逐日气温和降水观测资料以及MIROC3.2_hires-RegCM3模式输出结果分析了胶州湾地区1959年-2008年气候变化特征以及2011年-2030年该地区的气候预估结果。研究表明：①近50a,胶州湾地区年平均气温升高了1.65℃,线性增温率为0.33℃/10a,高于同期全国平均增温速率...     

Sexual dimorphism in bone–muscle relationship in young adults

The purpose of this study was to analyse associations between lean soft tissue (LST), a surrogate of skeletal muscle mass and key fracture-related geometric characteristics of the proximal femur. Moreover, we examined the role that muscle played on the proximal femur geometry in response to physical activity (PA). Participants were 83 young adults. Leg LST (exposure) was assessed by dual energy X-ray absorptiometry (DXA). Proximal femur geometry was derived from a left hip DXA scan. Geometric variables (outcomes) included the femoral neck axis length (FNAL), the femoral neck width (FNW), the neck–shaft angle and FNW|FNAL (an index of robustness). PA was evaluated by accelerometry. Linear regression was used to analyse relationships. Additional exposure variables included body height and mass. In males, leg LST explained 17.4% of variation in FNAL (P < 0.001) and 15% in FNW (P = 0.015). In females, it explained 8.8% of the variance in FNAL (P = 0.020). Associations remained significant in males, but not in females, when vigorous PA was added to the models. These results suggest that public health approaches to promote PA may be particularly important in females since vigorous PA seems to convey advantages in femur geometry and consequently in bone strength.     

Knots in the Fourth Dimension

ABSTRACT

The article analyses a debate that preoccupied the Russian press in the winter of 1878/9. Writers, journalists and scientists discussed whether mathematics could explain spiritualist séance phenomena. At its core, this was an assessment of social change and a debate about the ambiguity of modern life. While spiritualists hoped to bridge the divide between science and religion, subjectivity and objectivity, their opponents feared that séance phenomena and modern mathematics undermined a rationalist world-view that was endowed with reliability and universal truth. That no agreement could be reached indicates that the post-reform public sphere had become truly pluralist and modern.     

"三线共点"的常用证明方法

从仿射几何学与射影几何学的基本方法出发,简述了"三线共点"问题的一些基本的证明方法.     

一类椭圆型方程组解的存在性

本文研究了一类依赖于正参数λ椭圆型方程组,利用变分方法得到方程组存在最小能量解且为正解。     

在解析几何教学中引入数学实验课的理论探讨

建构主义学习理论强调认知来源于学生对认知活动的自主参与,数学实验正是认知学习中可以替代具体活动的新技术。数学实验课对解析几何传统教学方式是一种有益的补充,该文将探讨如何把数学实验融入解析几何教学之中。     

平面图形几何性质计算方法研究

截面几何性质是结构设计中的重要数据,不同类型的截面形状采用的计算方法不同。着重介绍了一种基于AutoCAD的方法计算平面图形的面积、形心、惯性矩、惯性积等参数,通过与其它方法比较,显现出该方法具有简单、快速、准确和适用于各种平面图形的优点,是一种值得推广的方法。     

关于解析几何课程教学反思

本文就高等师范院校数学教育各专业解析几何教学的措施、内容、方法和手段等将如何改革进行了思考,提出了自己的看法。