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1.
How to improve students' understanding of energy transformation and conservation remains one of the main challenges of energy teaching. To address this challenge, we developed a new teaching strategy suited to high school based on history and philosophy of science (HPS). It involves five key ingredients: study and reproduction of Joule's paddle-wheel experiment, introduction of Rankine's definition, study of a historical text of Joule, use of an “ID card of energy,” and early introduction and multiple application of the principle of energy conservation. This strategy was built and implemented in the frame of a collaborative and iterative work involving researchers and teachers. We examined the effects of this HPS-based teaching strategy on students' understanding of energy. We used a quantitative method based on pre- and post-tests (N = 95/87) completed by a qualitative analysis using both video recordings of classroom activities and videos produced by students during one of the teaching sequences. The outcomes show that the teaching strategy had an overall positive impact on students' learning of energy: in particular, Joule's paddle-wheel experiment seems to favor their understanding of the notion of energy transformation, while the early introduction and multiple application of the conservation principle appears as a relevant option to facilitate its mastering. This study illustrates how HPS might actually be introduced in classrooms and brings to light its usefulness for building new science teaching strategies.  相似文献   

2.
This paper is the first part of a three-part project ‘How the principle of energy conservation evolved between 1842 and 1870: the view of a participant’. This paper aims at showing how the new ideas of Mayer and Joule were received, what constituted the new theory in the period under study, and how it was supported experimentally. A connection was found between the new theory and thermodynamics which benefited both of them. Some considerations are offered about the desirability of taking a historical approach to teaching energy and its conservation.  相似文献   

3.
Learning about energy is recognized as an important objective of science teaching starting from the elementary school. This creates the need for teaching simplifications that compromise the abstract nature of this concept with students?? need for a satisfactory qualitative definition. Conventional teaching approaches have failed to respond to this need in a productive manner. In an attempt to maintain consistency with how energy is understood in physics, they tend to either provide abstract definitions or bypass the question what is energy?, which is vitally important to students. In this paper, we describe the epistemological barriers that are inherent in conventional attempts to introduce energy as a physical quantity and we suggest that shifting the discussion to a philosophically-oriented context could provide a means to address them in a productive manner. We propose a teaching approach, for students in the age range 11?C14, that introduces energy as an entity in a theoretical framework that is invented and gradually elaborated in an attempt to analyze the behavior of diverse physical systems, and especially the various changes they undergo, using a coherent perspective. This theoretical framework provides an epistemologically appropriate context that lends meaning to energy and its various features (i.e. transfer, form conversion, conservation and degradation). We argue that this philosophically informed teaching transformation provides a possible means to overcome the various shortcomings that typically characterize attempts to introduce and elaborate the construct of energy while at the same time it allows integrating, in a meaningful and coherent manner, learning objectives relevant to the understanding of the Nature of Science (NOS), which is recognized as a valuable component of learning in science. In this paper, we outline the rationale underlying this teaching approach and describe a proposed activity sequence that illustrates our proposal.  相似文献   

4.
The question of how to teach energy has been renewed by recent studies focusing on the learning and teaching progressions for this concept. In this context, one question has been, for the most part, overlooked: how should energy be defined throughout schooling? This paper addresses this question in three steps. We first identify and discuss two main approaches in physics concerning the definition of energy, one claiming there is no satisfactory definition and taking conservation as a fundamental property, and the other based on Rankine’s definition of energy as the capacity of a system to produce changes. We then present a study concerning how energy is actually defined throughout schooling in the case of France by analyzing national programs, physics textbooks, and the answers of teachers to a questionnaire. This study brings to light a consistency problem in the way energy is defined across school years: in primary school, an adapted version of Rankine’s definition is introduced and conservation is ignored; in high school, conservation is introduced and Rankine’s definition is ignored. Finally, we address this consistency problem by discussing possible teaching progressions. We argue in favor of the use of Rankine’s definition throughout schooling: at primary school, it is a possible substitute to students’ erroneous conceptions; at secondary school, it might help students become aware of the unifying role of energy and thereby overcome the compartmentalization problem.  相似文献   

5.
In this work an attempt is made to explore the possible value of using Thought Experiments (TEs) in teaching physics to upper secondary education students. Specifically, a qualitative research project is designed to investigate the extent to which the Thought Experiment (TE) called ‘Heisenberg’s Microscope’, as it has been transformed by Gamow for the public in his book Mr. Tompkins in Paperback, can function as a tool in the teaching of the ‘uncertainty principle’. The sample in the research consisted of 40 Greek students, in 11 groups of 3–4 students each. The findings of this study reveal that the use of this TE has positive results in teaching the uncertainty principle. Students, based on the TE, were able (i) to derive a formula of the uncertainty principle, (ii) to explain that the uncertainty principle is a general principle in nature and it is not a result of incompleteness of the experimental devices and (iii) to argue that it is impossible to determine the trajectory of a particle as a mathematical line.  相似文献   

6.
液压系统的节能设计已成为液压技术工作者所关注的重大课题.对液压传动的节能原理进行了阐述,介绍了节能液压元件、节能回路和节能液压系统的节能技术,为液压技术工作者更好地利用能源提供了参考.  相似文献   

7.
演示复合能源发电原理的科普教具针对传统演示说明多种能源发电技术及原理的教具使用不方便、直观性不理想等问题设计。演示复合能源发电原理的科普教具可以利用一套教具完成对包括太阳能、风能、温差能、水能等多种能源发电的原理及影响因素的演示说明,有利于不同能源发电技术的对比观察,有利于多种能源发电知识普及。  相似文献   

8.
介绍我们新开发的一个综合性实验,它主要包括拉力传感器、由LM331组成的V/F和F/V变换电路以及红外发射和接收装置等,以实现对弹簧振子加速度的红外遥测。利用计算机USB数据采集器进行数据采集和处理,包括计算弹簧振子的速度和位移、系统的弹性势能、重力势能、动能和总机械能,并绘制机械能变化曲线,由此验证了弹簧振子系统的机械能守恒。本实验项目在提高学生学习的主动性和创新能力方面取得了较好的效果。  相似文献   

9.
阐述了引入外势能质点系的"功能原理"和机械能守恒定律在一般情况下不成立,而且有悖常识,没有存在的必要;并进一步指出质点系的"功能原理"应改为质点系的机械能定理,质点系的机械能守恒定律是力学中的能量转化与守恒定律,是力学中一条独立定律,而不是"功能原理"的推论.  相似文献   

10.

In secondary education 'energy' is often introduced by distinguishing different 'forms of energy' for different phenomena. Of these forms of energy, only kinetic and potential energy are accepted in current science. The question has been raised whether all forms of energy should be eliminated from secondary school science curricula. As a contribution to this discussion we will first analyse the language used to introduce 'forms of energy' in order to determine possible inconsistencies and limitations of validity, judged from the viewpoint of thermodynamics. In Part II, the results of two teaching experiments at university level will be presented. In these experiments attempts are made to build on students 'forms of energy' language as well as to challenge its limitations. As a result of both parts, conclusions will be drawn as to whether 'forms of energy' can be accepted 'as an intermediary language' and changes to the usual teaching sequence will be proposed.  相似文献   

11.
This study diagnosed the understanding about energy and biological-context energy concepts held by 90 first-year South African university biology students. In particular, students’ explanations of energy in a biological context, how energy is involved in different biological situations and whether energy is present and what types of energy are involved in diagrams depicting biological phenomena were investigated. The pencil-and-paper diagnostic test, specifically designed for this study, was used to elicit students’ understanding using test items involving biological phenomena. The results showed that many students had problems in understanding energy and energy-related concepts in the following areas: First, the majority of the students provided definitions of energy rather than the explanations they were asked to provide, and the definition could have been rote-learned. Second, although nearly all students knew the energy conservation principle (energy cannot be created or destroyed), many of them were unable to apply this concept to biological contexts. Third, many students erroneously claimed that the energy for metabolism and life processes is made available during photosynthesis in plants, during digestion in animals or that this energy comes directly from the sun. Fourth, about two thirds of the students erroneously indicated that there is no energy involved/present in inanimate objects such as a statue. The implications for the teaching and learning of energy and its related concepts and recommendations for further research are discussed.  相似文献   

12.
Heine归结原理是函数极限的一个基本性质,它是沟通函数极限与数列极限的桥梁.利用这个原理,可以将许多函数极限问题归结为数列极限问题去解决,因此具有独特的重要性.本文结合自己多年的数学分析课程教学体会,通过研究式教学,引导学生发现了教材中Heine归结原理几个新的推广形式,以期与大家探讨.  相似文献   

13.
This paper discusses Ernst Mach’s interpretation of the principle of energy conservation (EC) in the context of the development of energy concepts and ideas about causality in nineteenth-century physics and theory of science. In doing this, it focuses on the close relationship between causality, energy conservation and space in Mach’s antireductionist view of science. Mach expounds his thesis about EC in his first historical-epistemological essay, Die Geschichte und die Wurzel des Satzes von der Erhaltung der Arbeit (1872): far from being a new principle, it is used from the early beginnings of mechanics independently from other principles; in fact, EC is a pre-mechanical principle which is generally applied in investigating nature: it is, indeed, nothing but a form of the principle of causality. The paper focuses on the scientific-historical premises and philosophical underpinnings of Mach’s thesis, beginning with the classic debate on the validity and limits of the notion of cause by Hume, Kant, and Helmholtz. Such reference also implies a discussion of the relationship between causality on the one hand and space and time on the other. This connection plays a major role for Mach, and in the final paragraphs its importance is argued in order to understand his antireductionist perspective, i.e. the rejection of any attempt to give an ultimate explanation of the world via reduction of nature to one fundamental set of phenomena.  相似文献   

14.
交流变频调速技术节能应用分析   总被引:1,自引:0,他引:1  
介绍了交流变频调速类型、基本原理和节能原理及分析,并在有关行业生产过程中,采用变频调速技术,实现节能、改善工艺、提高了产品质量,并阐述了变频调速技术(或装置)存在的优点,以及发展趋势.  相似文献   

15.
Energy is considered both a core idea and a crosscutting concept in science education. A thorough understanding of the energy concept is thought to help students learn about other (related) concepts within and across science subjects, thereby fostering scientific literacy. This study investigates students’ progression in understanding the energy concept in biological contexts at the transition from primary to lower secondary school by employing a quantitative, cross-sectional study in grades 3–6 (N?=?540) using complex multiple-choice items. Based on a model developed in a previous study, energy concepts were assessed along four aspects of energy: (1) forms and sources of energy, (2) transfer and transformation, (3) degradation and dissipation, and (4) energy conservation. Two parallel test forms (A and B) indicated energy concept scores to increase significantly by a factor of 2.3 (A)/1.7 (B) from grade 3 to grade 6. Students were observed to progress in their understanding of all four aspects of the concept and scored highest on items for energy forms. The lowest scores and the smallest gain across grades were found for energy conservation. Based on our results, we argue that despite numerous learning opportunities, students lack a more integrated understanding of energy at this stage, underlining the requirement of a more explicit approach to teaching energy to young learners. Likewise, more interdisciplinary links for energy learning between relevant contexts in each science discipline may enable older students to more efficiently use energy as a tool and crosscutting concept with which to analyze complex content.  相似文献   

16.
In the theory of heat of the first half of the nineteenth century, heat was a substance. Mayer and Joule contradicted this thesis but developed different concepts of heat. Heat was a force for Mayer and a motion for Joule. Both Mayer and Joule determined the mechanical equivalent of heat. This result was, however, justified in accordance with those concepts of heat. Mayer’s characterisation of force reappears in the very common textbook definition ‘energy cannot be created or destroyed but only transformed’ and his theory led to a phenomenological approach to energy. Joule and Thomson’s concept of heat led to a mechanistic approach to energy and to the common definition ‘energy is the capacity of doing work’. One and the same term ‘energy’ subsumed these two approaches. The problematic concept of energy, energy as a substance, appears then as a result of an eclectic development of the concept. Another approach, which appeared in the 1860s, is directly based on the mechanical equivalent of heat and can be characterized by the use of ‘principle of equivalence’ instead of ‘principle of energy conservation’. Unlike the others, this approach, which has been lost, poses no problems with the concept of energy. The problems with the energy concept as to the kind of phenomena dealt with in the present paper can, however, be overcome, as we shall see, in distinguishing between that which comes from experiments and that which is an interpretation of the experimental results within a conceptual framework.  相似文献   

17.
过控专业《节能技术》课程建设与教学实践   总被引:1,自引:0,他引:1  
本文论述了过程装备与控制工程专业开设<节能技术>课程的重要性和必要性,给出了该课程的教学内容和教学方法,并总结了两年的教学实践.  相似文献   

18.
Kuhn underlined the relevance of Galileo’s gestalt switch in the interpretation of a swinging body from constrained fall to time metre. But the new interpretation did not eliminate the older one. The constrained fall, both in the motion of pendulums and along inclined planes, led Galileo to the law of free fall. Experimenting with physical pendulums and assuming the impossibility of perpetual motion Huygens obtained a law of conservation of vis viva at specific positions, beautifully commented by Mach. Daniel Bernoulli generalised Huygens results introducing the concept of potential and the related independence of the ‘work’ done from the trajectories (paths) followed: vis viva conservation at specific positions is now linked with the potential. Feynman’s modern way of teaching the subject shows striking similarities with Bernoulli’s approach. A number of animations and simulations can help to visualise and teach some of the pendulum’s interpretations related to what we now see as instances of energy conservation.  相似文献   

19.
In this paper, we present the design, development, implementation and evaluation of educational software “Newton-3”, aiming at the learning of Newton’s Third Law by student-teachers who are not Physics majors. We describe the theoretical issues of our teaching approach and the various software tasks that we designed in order to promote students’ understanding. Specifically, the software is designed for the teaching of gravitational and electrostatic interactions between two distant bodies at rest. It is a web-based application and runs on a simple web browser with Macromedia Flash plug-in installed. The development of software and its integration into teaching–learning sequence is based on three main characteristics: the range of contexts in which the concept of force interaction applies, in the specification of the concept, and in an appropriate teaching learning environment (IDRF). We trialled the software on two groups of 8 primary school and 8 pre-school student-teachers, for 3 teaching periods, in the School of Education of our University. The research results indicate that the implementation was effective as the majority of the teacher-students improved their own knowledge concerning the existence and representation of gravitational and electrostatic interactions. An interesting result reveals that student-teachers have difficulty in perceiving the equality of magnitudes of action and reaction forces. This problem seems to be overcome after the teaching of the Inverse square law.  相似文献   

20.
从四个方面论述了古代教学原则:启发性原则;循序渐进原则;巩固性原则;因材施教原则.  相似文献   

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