Conceptual Problems in the Foundations of Mechanics     

Ricardo Lopes Coelho 《Science & Education》2012,21(9):1337-1356

There has been much research on principles and fundamental concepts of mechanics. Problems concerning the law of inertia, the concepts of force, fictitious force, weight, mass and the distinction between inertial and gravitational mass are addressed in the first part of the present paper. It is argued in the second that the law of inertia is the source of these problems. Consequences drawn from the law explain the metaphysical concept of force, the problematic concept of fictitious force, the nominal definition of weight and the difficulty with defining mass operationally. The core of this connection between the law and these consequences lies in the fact that acceleration is a sufficient condition for force. The experimental basis of the law in the course of its history shows, however, that the law presupposes acceleration necessarily whereas acceleration does not presuppose the law. Therefore, there is no inconvenience in taking acceleration independently of the law. This is enough to bypass those problems. Taking into account how force is measured by force meters and how mass is basically determined, by comparison with the standard mass, a minimal meaning for both concepts of force and mass is established. All this converges with several solutions proposed in the course of history and increases the communicability of mechanics, as outlined in the final part of this paper.  相似文献   

Karin Reich and Elena Roussanova: Carl Friedrich Gauss und Russland: Sein Briefwechsel mit in Russland wirkenden Wissenschaftlern     

Andre K. T. Assis 《Science & Education》2013,22(3):717-721

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The Evaluation of Modelling Competences: Difficulties and potentials for the learning of the sciences     

J. Bernardino Lopes 《International Journal of Science Education》2013,35(7):811-851

Modelling is an inherent process for the construction and use of science concepts that mobilize diverse specific competences. The aims of this work are to put forward a means of evaluating modelling competences that is relevant for physics teaching and science education research and to identify the potentials and constraints in the development of modelling competences. A written test, which embraces a wide range of modelling aspects in mechanics domain, was drawn up and validated, and a theoretically based evaluation methodology was specified. In the validation process, the test was given to 75 subjects distributed across seven levels of physics education. The answers were analysed and later cluster analysis was carried out in order to identify categories of answers among the diverse answers. The results indicate that the test identified and delimitated modelling competences. Some results are in agreement with those obtained through other research into this issue and other results better elucidate certain aspects of modelling. The way in which evaluation methodology can be used in other areas of physics is discussed, such as in research and in teaching. Also discussed is how the constraints and potentials identified in the development of modelling competences can be taken into account in teaching and learning sciences.  相似文献   

Robust asymptotic stability of interval fractional-order nonlinear systems with time-delay     

Penghua Li  Liping Chen  Ranchao Wu  J.A. Tenreiro Machado  António M. Lopes  Liguo Yuan 《Journal of The Franklin Institute》2018,355(15):7749-7763

This paper studies the global asymptotic stability of a class of interval fractional-order (FO) nonlinear systems with time-delay. First, a new lemma for the Caputo fractional derivative is presented. It extends the FO Lyapunov direct method allowing the stability analysis and synthesis of FO nonlinear systems with time-delay. Second, by employing FO Razumikhin theorem, a new delay-independent stability criterion, in the form of linear matrix inequality is established for ensuring that a system is globally asymptotically stable. It is shown that the new criterion is simple, easy to use and valid for the FO or integer-order interval neural networks with time-delay. Finally, the feasibility and effectiveness of the proposed scheme are tested with a numerical example.  相似文献   

Science Teacher Education in Brazil: 1950–2000     

Alberto Villani  Jesuina Lopes de Almeida Pacca  Denise de Freitas 《Science & Education》2009,18(1):125-148

This paper analyzes the most significant events occurring in Brazil’s educational, social and political areas over the last half century, viewed against a background of relevant worldwide events. The hypothesis presented here is that the relations between the country’s educational policies, the demands of the various segments of academia, and the public school system have always been strained. This strain has contributed positively to the evolution of academic knowledge and production, to the design of more modern curricular projects by institutional authorities, and to the initial recognition of the specific construction of school knowledge by the school system itself. However, the interaction of these major institutions lacks a crucial element—one that would lead to an effective change in the education of science teachers and produce a positive impact on Brazil’s schools—namely, the wholehearted participation of science teachers themselves. With this analysis, we intend to contribute by offering some perspectives and proposals for science teacher education in Brazil.  相似文献   

The One World, One Science Argument     

Kukla  Andre 《The British journal for the philosophy of science》2008,59(1):73-88

The one world, one science argument (so named by Rescher) isadvanced by Carl Sagan and others to support the thesis thatwe will be able to learn to converse with intelligent extraterrestrialsif and when we encounter them. The prima facie obstacle to extraterrestrialcommunication is that the aliens’ culture and geographyare bound to be so different from ours that we would find itextremely difficult, if not practically impossible, to finda common topic on which we can both converse. Sagan's rebuttalis that we will share mathematics and the laws of physics, thesebeing the same for all intelligent beings regardless of localcultural and geographical variations. I show that this argumentfails even if its contentious assumptions about science andthe world are granted—that is to say, it fails on uncontentiousgrounds.

1 OWOS

2 OWOS and Social Constructivism

3 OWOSand Conceptual Relativism

4 OWOS and the Selection Problem

5 The Fundamental Laws Solution

6 The Mathematics Solution

7 The Radio Solution

8 The Common Conditions Solution

9The Intractability of the Selection Problem

10 The Superfluityof OWOS

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THE EIGHTEEN‐MONTH EXPERIENCE OF THE NATIONAL EVALUATION COMMITTEE IN FRANCE     

Andre´ Staropoli 《Higher Education in Europe》1987,12(4):14-22

This article describes the origins of and the rationale for the creation of the French National Evaluation Committee, the niche which it fills within the context of French higher education, its make‐up, details of its first year of activity, its typical procedures for the evaluation of. a given institution and, in general terms, its evaluation criteria. An annex lists the current members of the Committee, the President of which is Laurent Schwartz, a member of the French Academy of Sciences.

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The Law of Inertia: How Understanding its History can Improve Physics Teaching     

Ricardo Lopes Coelho 《Science & Education》2007,16(9-10):955-974

The law of inertia is a problem in teaching due to the impossibility of showing the proposition experimentally. As we cannot do an experiment to verify the law, we cannot know if it is correct. On the other hand, we know that the science based upon it is successful. A study in the history of mechanics has shown that there are different foundations for the law but also that the law plays the same role in the science since Newton. To avoid a statement of which we cannot be sure, the present paper proposes to understand the law through its function in the theory. In this case, we do not have to say how a free body moves, but rather that the rectilinear and uniform motion is the motion of reference in Newtonian mechanics.  相似文献   

Cost‐effective teaching of radiology with preclinical anatomy          下载免费PDF全文

James S. Wilson  Jacqueline Alvarez  Bonnie C. Davis  Andre J. Duerinckx 《Anatomical sciences education》2018,11(2):196-206

Graduating physicians in all subspecialties have an increased need for competency in radiology, particularly since the use of diagnostic imaging continues to grow. To integrate the teaching of radiology with anatomy during the first year of medical school at Howard University, a novel approach was developed to overcome the limitations of resources including funding, faculty, and curricular time. The resulting program relies on self‐study and peer‐to‐peer interactions to develop proficiency at manipulating free versions of medical image viewer software (using the DICOM standard), identifying normal anatomy in medical images, and applying critical thinking skills to understand common clinical conditions. An effective collaborative relationship between a radiologist and anatomist was necessary to develop and implement the program of anatomic–radiographic instruction which consists of five tiers: (1) initial exposure to anatomy through dissection which provides a foundation of knowledge; (2) study of annotated radiographs from atlases; (3) a radiology quiz open to group discussions; (4) small group study of clinical cases with diagnostic images; and (5) radiographic tests. Students took all quizzes and tests by working from image datasets preloaded on their personal computers, mimicking the approach by which radiologists analyze medical images. In addition to stimulating student support of a new teaching initiative, the strengths of Howard's program are that it can be introduced into an existing preclinical curriculum in almost any medical school with minimal disruption, it requires few additional resources to implement and run, and its design is consistent with the principles of modern education theory. Anat Sci Educ 11: 196–206. © 2017 American Association of Anatomists.  相似文献   

Pavlovian appetitive discriminative conditioning inAplysia californica     

Ruth M. Colwill  Kevin Goodrum  Andre Martin 《Learning & behavior》1997,25(3):268-276

Three experiments demonstrated Pavlovian appetitive discrimination learning in the marine mollusc,Aplysia californica. In each experiment, subjects were exposed to two conditioned stimuli; one stimulus (CS+) was paired with food presentations and the other stimulus (CS?) was never followed by food. In Experiments 1 and 3 different chemosensory stimuli were used, and in Experiment 2 different tactile stimuli were used. For both types of conditioned stimuli, bite responses occurred significantly more often to the CS+ than to the CS?. Experiment 2 also showed thatAplysia could learn a reversal of this discrimination. Experiment 3 showed that nonreinforced presentations of CS+ resulted in a decline in the frequency of conditioned biting. The implications of these results for neurobiological analyses of learning are discussed.  相似文献