例谈小学生数学守恒观念的培养

守恒是皮亚杰儿童认知发展阶段论中的核心概念之一,是获得数和量概念的重要条件.发展和培养学生守恒观念,强化学生对数学知识本质的理解,达成知识的融会贯通,在现阶段教师应重视提高学生的数学素养.教师可从培养学生的数量守恒、长度守恒、面积守恒、体积守恒观念四个方面开展教学实践,培养数学守恒观念.     

计算教学中“守恒”思想的渗透

在计算教学中渗透“守恒”思想,让孩子们从观察、分析中得到一些不变的规律性的东西,有利于孩子们认识事物的本质,发展思维能力,提高教学效率。一、数的守恒数的守恒指的是一组物体的数目,不因其体积大小、排列形式等的改变而改变。可是四五岁的幼儿,在判断物体的数量时,往往受到物体大小或排列形式等的干扰,作出错误的判断。即便是相同个数的同一种物体,会误认为体积大的一组数量多,体积小的一组数量少;误认为排列得疏的一组数量多,排列得密的一组数量少。针对这种情况,如教学4的认识时,不妨选用4个大皮球、4个乒乓球作实物直观。先引导他们点数大皮球和乒乓球的个数,确认每一种球都有4个之后,便设问:“想想看,是4个大皮球个数多,还是4个乒乓球个数多?”旨在排除     

怎样教幼儿掌握10以内数的概念

形成幼儿10以内数的概念是幼儿园计算教学的主要内容。当幼儿学会了手口一致地点数物体的数量,会说出总数,按数取物,并在判断物体数量多少时不受物体的形状及排列形式的影响,即达到了数的守恒,这才算理解了数的实际意义,初步形成了数的概念。在此基础上,幼儿进一步掌握了数与数之间的关系和数群的结构,这时才可以说,幼儿已形成了10以内数的概念。     

4-5岁幼儿数量守恒概念发展的干预研究

数量守恒是幼儿数学认知发展中的重要概念。研究采用个别测查法与实验干预法,对30名尚未形成数量守恒概念的4-5岁幼儿进行三种不同方式的干预。结果表明,“正误反馈”、“正误反馈+幼儿对自我判断推理”和“正误反馈+幼儿对主试判断推理”等三种干预方法均可有效提升幼儿的数量守恒能力,后两种干预方法的效果显著好于第一种干预方法。     

10以内数的守恒

1．让幼儿在操作游戏中感知理解数的守恒。2．训练幼儿注意、观察、分析、判断等思维能力。     

守恒思想在核反应中的应用

守恒定律是自然界普遍成立的规律 ,守恒定律的本质是 :物体在发生变化或两物质在发生相互作用的过程中某些物理量的总量保持不变 .应用守恒定律不需要考虑物体间相互作用过程的细节 ,因此 ,解决问题时首先考虑应用有关的守恒定律 ,是物理学中一种有效的思维方法 .本文结合实例分类探析核反应中的守恒 .1　核反应中的守恒1 .1　电荷数、质量数守恒电荷数守恒和质量数守恒是原子核反应方程中的两个基本定律 ,也是解答这类题目的基本根据 .例 1 .( 2 0 0 0年全国高考题 )最近几年原子科学家在超重元素岛的探测方面取得重大进展 .1 996年科学家…     

系统的机械能守恒

单个物体的机械能守恒的问题很好掌握，而几个物体与地球、弹簧等组成的系统的机械能守恒的问题就比较难了，而且这也一直是近年来高考的重点和难点，在这种类型的问题中，尽管系统内单个的物体机械能并不守恒，但由几个物体组成的系统机械能却是守恒的．现将之归类分析如下——     

探析高中物理机械能守恒的解题策略

本文笔者试图从机械能守恒条件、单物体机械能守恒问题和多物体机械能守恒问题等三方面展开解题策略研究，以提升学生解决此类问题的能力.     

物体的惯性 惯性与守恒律

通过对不同的物体在不同的运动过程中都具有惯性的分析总结出“物体惯性是保持原状态不变的性质”；进一步阐明了“从每一种惯性都可以得到一表征物体运动状态的守恒律；反之，每一表征物体运动状态的守恒律也一定揭示出蕴含其中的一种惯性”这一客观道理。     

“系统”的机械能守恒

一个物体的机械能守恒很好掌握 ,而几个物体与地球、弹簧等组成的系统机械能守恒不仅较难 ,而且是近年来高考的重点和难点 .这种类型的问题尽管系统内单个的物体机械能并不守恒 ,而由几个物体组成的系统机械能却是守恒的 ,因为系统内物体之间的相互作用力是内力 .现归类分析如下 ,以供参考 .一、物体与物体直接接触【例 1】　如图 1所示 ,带有光滑的半径为R的 1 4圆弧轨道的滑块静止在光滑的水平面上 ,此滑块的质量为M ,一只质量为m的小球由静止从A点释放 ,当小球从滑块最低点B水平飞出时 ,滑块的反冲速度为多大 ?解析 :因为水平面光滑 ,…     

Nonverbal and Verbal Performance on a Number Conservation Problem and a Proposal about the Determinants of Nonconservation

This study compared the ease of verbal and nonverbal versions of a number conservation problem for 4and S‐year‐old children. The nonverbal task employed a ‘train‐transfer’ procedure in which children were first trained to a criterial level to make one response to stimulus pairs that contained two rows of the same number in one‐to‐one correspondence and a different response to stimulus pairs in which one of the rows was of greater or of lesser number than the other. Conservation performance was maintaining the learned response to the identical pair after one of its rows had been deformed. Taking both ages together the nonverbal task was the easier. However, children's justifications showed that verbal processes may have been responsible for both correct and incorrect performance in many cases. The data are interpreted as supporting the hypothesis that children interpret conservation terms perceptually when used by others in certain contexts in spite of what they know about the underlying fact of conservation.     

Impacts of the conservation education program in Serra Malagueta Natural Park,Cape Verde

Environmental and conservation education programs are commonly offered in the rapidly expanding network of protected areas in developing countries. There have been few evaluations of these programs and their impacts on participants. At Serra Malagueta Natural Park in Cape Verde, we assessed changes in environmental knowledge, opinions, and behaviors among visiting school children and a comparison group that did not visit the park. Participation in the park’s conservation education program has a positive impact on environmental knowledge after the visit. The program may also contribute to student knowledge by influencing classroom teaching in anticipation of the park visit.     

生态文明建设的内涵、意义及其路径

党的十七大报告提出了生态文明建设这一概念。生态文明建设就是端正人们对待自然环境的基本态度、理念、认识,并付诸开发与利用自然的实践的过程。它可以分为伦理层面、操作层面以及保障层面等三个层面。生态文明建设不仅丰富与发展了可持续发展理论以及和谐社会理论等,具有重要的理论意义,同时对我国社会经济发展具有着重要的实践意义。生态文明建设的路径有改革社会经济评价体系、改革政绩考核体系以及丰富环境管理手段等等。     

Exploring student ideas about biological variation

ABSTRACT

An understanding of biological variation is important for understanding ecological interactions, ecosystem function, and species’ response to environmental change. Biological variation is essential to species survival because natural selection acts upon the phenotypic variation within a population: the more varied the population’s genetic resources, the more likely that the population will persist into the future. We explored how students think about biological variation by evaluating written assessments and interviews of grades 6–16 students about starting a captive breeding programme for species conservation. We created a qualitative framework that describes levels of proficiency in student ideas about biological variation. Lower level responses reason about attributes related to an individual’s reproduction and survival rather than population-level variability. Student responses at a middle level of sophistication point to the importance of variation but do not link it mechanistically to species survival and resilience. We also describe alternative conceptions related to biological variation and natural selection which exist at all grade levels. Educators can use these findings to inform curriculum and instruction in terms of addressing important concept areas (e.g. variation at the population scale) and some common alternative conceptions that may impact an accurate understanding of natural selection and evolution.     

乌鲁木齐职业大学电力节能的探究

文章结合乌鲁木齐职业大学的实际情况,从学校用电能源浪费症状分析入手,找出系统电能使用效率低、用电设备复杂、电能质量差、节能意识低、管理不完善等问题,提出要合理设计,进一步改进供配电设施来降低损耗、采用节能产品和先进技术、加强制度建设和管理水平、养成良好的用电习惯等解决方法。     

不同封育时间蒙古栎林主要乔木种群分布格局的分析

应用理论拟合、聚集强度指数分析方法对不同封育时间蒙古栎林样地内的主要乔木种群进行研究，结果表明：蒙古栎、黄榆种群均为聚集型分布；蒙古栎和黄榆种群的聚集强度在不同封育时间内表现不同的变化．总体上看种群聚集强度均呈下降趋势．在封育初期，黄榆种群比蒙古栎种群的聚集强度更大，随着封育时间的延长，黄榆种群的聚集强度下降，呈扩散趋势．     

Nature is a nice place to save but I wouldn’t want to live there: environmental education and the ecotourist gaze

This article explores the role of ecotourism in the neoliberalisation of environmental education. The practice of ecotourism is informed by a particular ‘ecotourist gaze’ in terms of which the ‘education’ that providers characteristically offer is implicitly framed, embodying a culturally specific perspective in which western society is depicted as alienating and constraining and immersion in ‘wilderness’ is understood as a therapeutic escape from the reputed ills of industrial civilisation. While in the past, these educational aspects of ecotourism delivery have often contradicted the activity’s promotion as a quintessential neoliberal conservation mechanism, increasingly this education has become neoliberalised as well in its growing emphasis on the environment’s role as an instrumental provider of ‘ecosystem services’ for human benefit. In conclusion, this analysis calls for transcendence of these limitations in pursuit of a more inclusive environmental education encompassing diverse ethnic and socioeconomic dimensions of the human community.     

Perceptual,thematic and taxonomic relations in children’s mental representations: Responses to triads

Recent research into children’s conceptual representation-much of it based on the so-called ‘triads’ task-has created a number of issues such as the age at which children become capable of representation at the superordinate level; the relative prominence of taxonomic, perceptual or thematic relations as the basis of representation; and the range of categories to which these different representations apply at different ages. In the study reported in this paper we presented children of three different ages with three types of triads designed to assess children’s sensitivity to these different relations separately across ten common superordinate categories. The approach which allowed us to track preferences for perceptual, thematic and taxonomic relations simultaneously across the three age groups showed an increase in sensitivity to both thematic and taxonomic relations with age. We conclude by suggesting that these relations are part of a common representation based on patterns of covariation within (static taxonomic relations) and across (event relations) time.     

Children's learning preferences for the development of conservation education programs in Mexican communities

Learning theories are rarely considered in the design of conservation education programs in Mexico. However, if students are taught in a way in which they can easily relate, this could improve the educational experience through better attitudes toward the natural environment. The learning preferences of 354 Mexican children at the primary level were evaluated to identify the effect of context (rural or urban) and gender on learning preferences. Statistical differences related to the children's context and gender-associated context were found. The authors discuss different discourses of critical thinking and experiential education, the predominance of traditional education found in rural communities, and how conservation education could enrich these processes. Studying how children learn can provide valuable information for the development of effective conservation education programs, establishing a dialogue about learners' strengths and weaknesses, enhancing their participation, and empowering them to take action.     

The connotations of botho philosophy and its potential contribution towards environmental conservation: the case of Tlokoeng community in Lesotho

This paper explores innovative environmental education strategies to conserve biodiversity in a rural-based context, in Lesotho. A case study approach was employed to investigate the community’s conception of botho philosophy and how it might promote nature conservation. Focus Group Interviews were conducted with 105 participants. The responses were analyzed to determine the community’s emerging definition and conception of botho. The findings indicate features of botho that parallel the ones that are found in the literature. In addition, botho was described metaphysically as a holistic spiritualised worldview that is concerned with a harmonious co-existence with others, nature and the Creator and empirically, in terms of moral attributes that foster co-existence within the socio-economic and natural systems. It is illustrated that botho can contribute towards environmental education discourse and nature conservation and thus diversify the pre-dominantly Euro-centric knowledge landscape in Lesotho.