关于在大学生中开展数学竞赛的思考

通过参加天津市大学生非数学专业数学竞赛,我校农科类学生培养了数学学习的兴趣,同时,竞赛也促进了数学教学质量的提高和数学课程改革的研究,提高了学生的数学素质。     

葡萄经济性状模糊综合评判

试验根据模糊数学基本原理 ,对重庆地区 12个中熟葡萄品种 (系 )的 14个经济性状进行了综合评判。结果表明 :巨峰 ,优选巨峰综合性状最好 ;红皇后 ,红伊豆 ,里扎马特综合性状次之 ,其余品种 (系 )较差。模糊数学综合评价的关键是评判模型的建立和权重的分配。     

水库渔业生产性能评价中的模糊综合评判方法

本文利用模糊数学中的综合评判原理,建立了水库渔业生产性能评价的一般方法和程序,本着说明方法的使用过程和作为应用的例证,对湖北省的若干个水库的渔业资源调查数据进行了实例分析。     

Achievement test scores in mathematics and science

Average achievement test scores of the nation's youth in mathematics and science have declined rather steadily since the early 1960's, and this decline is more marked in the higher grades. The average test scores in mathematics and science of high school seniors who have intended to go to college and major in those fields, however, have been quite stable. These findings may have implications for educational policy.     

以建构主义学习理论指导数学教学改革

主要阐述了按照建构主义学习理论,在数学课程的教学中,应如何发挥教师主导作用和学生主体作用,促使学生对知识的主动探索、主动发现和对所学知识意义的主动“建构“,以及“协作“学习和多媒体网络技术在数学教学中的重要作用,从而更好地培养当代社会所需求的人才.     

理想原木材积通式和缺陷原木模型与材积推导

本文采用截顶椭圆——幂曲线组合包络形成原木的数学模型,提出了以中间截面确定幂曲线次数和原木侧面曲线形式的方法,使原木解析模型的精度达到计算数学的要求精度,并提出原木材积计算的通式,使现行的几种原木材积公式仅是它的特例,使原木的数学描述理论向前推进了一步,在该式的基础上,本文又提出翘曲、弓形弯、尖削、偏心等缺陷原木的数学描述方法和材积计算公式。本文将为制材CAD、CAM和FMS提供新的理论基础,形成原木形状描述的新的理论体系。它将为下锯优化,B·O·F,微机控制下锯和最后实现下锯专家系统的工作,提供实测参数最少,精度满足设计要求的实用可靠的基础理论。     

板皮的数学模型和材积计算研究

以截顶椭圆一幂曲面原木数学模型为基础,分别以原木、板皮实测尺寸定义了板皮的数学模型和材积公式,将板皮的数学描述方法由平面简单近似描述,提高到空间解析精确的抽象定量描述。为板皮最佳裁边提供基础理论;为制材计算机辅助设计(CAD)、计算机辅助制造(CAM)和柔性制造(FMS)系统的软件编制提供理论基础。     

关于高等数学分层教学的思考

高等数学作为各级各类综合院校大学一年级的必修课程，由于其内容抽象，思维方式较以往思维方式的跨度较大等特征，使其成为很多刚刚步入大学校门学子学习的瓶颈。随着大学精英式教育向大众式教育的转化，高等数学的分层教学模式越来越多的为各级各类高校所接受。本文主要从高等数学教学的现状，分层教学的目标和意义以及注意的问题几个方面，阐述对高等数学分层教学模式的理性思考。     

The science of patterns

The rapid growth of computing and applications has helped cross-fertilize the mathematical sciences, yielding an unprecedented abundance of new methods, theories, and models. Examples from statistical science, core mathematics, and applied mathematics illustrate these changes, which have both broadened and enriched the relation between mathematics and science. No longer just the study of number and space, mathematical science has become the science of patterns, with theory built on relations among patterns and on applications derived from the fit between pattern and observation.     

园林景观数学评价研究

以济南植物园为研究对象,采用SD法进行数据采集,采用EXCEL、SAS软件等数学方法进行图示化分析、主成分分析和聚类分析,对其主要园林景点进行综合景观评价。结果显示:各样本在各项尺度上均存在区别于其他样本的自身特征,在各尺度上表现差异较大;不同的评价尺度对评价结果影响的重要性不同;各样本可根据尺度表现上的相似性进行归类。     

Surface molecules identify groups of growing axons

Studies on vertebrate and invertebrate species have established that, during development, axons have the ability to choose particular paths over others. The chemical basis of this pathfinding is not clear but biochemical differences between neurons have long been postulated to account for the specificity of neuronal connections. Such subtle molecular differences between different cells in a single tissue are difficult to study with standard biochemical techniques but hybridoma technology has offered a potential solution to this type of problem. This technique has made possible the production of monoclonal antibodies for identifying and characterizing a family of glycoproteins which are expressed on the surface of specific axon bundles during the development of the leech nervous system. The results show that groups of growing axons do indeed carry chemically distinct surface molecules.     

Social capital and the collective management of resources

The proposition that natural resources need protection from the destructive actions of people is widely accepted. Yet communities have shown in the past and increasingly today that they can collaborate for long-term resource management. The term social capital captures the idea that social bonds and norms are critical for sustainability. Where social capital is high in formalized groups, people have the confidence to invest in collective activities, knowing that others will do so too. Some 0.4 to 0.5 million groups have been established since the early 1990s for watershed, forest, irrigation, pest, wildlife, fishery, and microfinance management. These offer a route to sustainable management and governance of common resources.     

祁连山北坡青海云杉有关测树因子数学模型的初探

为了揭示祁连山北坡青海云杉的结构规律,探索该树种各测树因子之间内涵相关关系,对祁连山8个林场设置6株树样园295个,实测样木1695株,建立年龄,胸径、树高与各测树因子的数学模型11个,对科学经营祁连山水源林提供了一定依据,其目的是使祁连山水源林的经营管理逐渐走向科学化,不断提高和扩大森林的质量和数量,使其发挥愈来愈大的水源涵养效益。     

晋枣品种变异研究

对晋枣的12个无性系的16个性状进行了调查研究,根据其中4个数量性状,进行了聚类分析,将12个无性系分为3类,其中G2与其他无性系有明显差异.同时,利用POD同工酶技术,根据酶谱类型也将12个无性系分为3类.综合两种方法研究结果表明,晋枣品种内部存在一定程度的变异,同时可以确定G2是一个变异单株或同名异物品种.     

Reactions of oriented molecules

Beams of oriented molecules have been used to directly study geometrical requirements in chemical reactions. These studies have shown that reactivity is much greater in some orientations than others and demonstrated the existence of steric effects. For some reactions portions of the orientation results are in good accord with traditional views of steric hindrance, but for others it is clear that our chemical intuition needs recalibrating. Indeed, the information gained from simultaneously orienting the reactants and observing the scattering angle of the products may lead to new insights about the detailed mechanism of certain reactions. Further work must be done to extend the scope and detail of the studies described here. More detailed information is needed on the CH(3)I reaction and the CF(3)I reaction. The effects of alkyl groups of various sizes and alkali metals of various sizes are of interest. In addition, reactions where a long-lived complex is formed should be studied to see if orientation is important. Finally, it would be of interest to apply the technique to the sort of reactions that led to our interest in the first place: the S(N)2 displacements in alkyl halides where the fascinating Walden inversion occurs.     

数学建模思想渗透到数学教学中的地位与作用

大学数学教学中注重对数学建模思想的渗透，培养学生的创造性思维，提高学生的各种综合能力，已成为数学教学改革的一个重要课题。本文主要阐述了数学建模思想在数学教学中的地位与作用以及如何将数学建模思想渗透到数学教学中的方法。     

数学教学中德育话语的渗透

德育是人的终身教育,课堂中的德育话语交际效果对学生不同的学习阶段有着不同的影响,数学教学涉及更多的逻辑思维训练,但缺乏德育的意识形态,需要加强德育的话语渗透,帮助学生提高政治和道德的分析能力。本文分析了数学教学过程中德育渗透的必要性,建立数学课堂中德育话语的功能分析理论框架,从德育话语的内涵、教师的形象以及师生的关系、教师的德育话语表达技巧和组织能力三个方面探讨数学课堂教学中德育渗透的方法。     

高等数学教学方式改革探讨

高等数学在高等教育中占有重要的地位,随着社会的日新月异,高等数学亦随着高等教育的发展而需要改革.本文就高等数学的教学中,如何提高课堂效率和指导学生学习的问题提出了一点建议.     

外源DNA导入小麦后D0代的幼胚离体培养

对导入高粱、豌豆、长穗偃麦草等供体DNA后的10个春小麦组合进行了幼胚离体培养研究,结果表明,在胚龄为15 d左右,幼胚长1.5 mm左右时,剥取幼胚进行离体培养,愈伤组织诱导率平均为73.8%,绿苗诱导率平均为157.2%,幼胚平均直接成苗率为24.1%.经过离体培养挽救了为数不多的导入后代,并可进行加代培育,缩短了育种周期.     

从数学文化的角度谈高等数学的教学

为了促进非数学专业的高等数学教学,提高学生的数学素养,应在高等数学教学中融入数学文化教学.数学文化在教学中的实施,应强调点滴渗透的原则,通过较熟悉的知识内容剖析、典型例题的讲解、不同教学方法的运用、对数学美的认识、应用能力的培养等具体措施,使数学文化融入教学之中,有效地促进高等数学的教与学.