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171.
Some physicists have pointed out that we do not know what energy is. Many studies have shown that the concept of energy is a problem for teaching. A study of the history of the concept shows that the discoverers of energy did not find anything which is indestructible and transformable but rather that the concept of energy underwent a change of meaning and energy was considered a substance towards the end of the nineteenth century. In distinguishing between the treatment of phenomena and the theories carried out by Mayer and Joule, it can be concluded that they established equivalences between different domains, such as motion and heat, motion and electricity or position and motion. This complies with the interpretation presented in textbooks published about a century ago and enables us to overcome some difficulties with the concept of energy.
Ricardo Lopes CoelhoEmail:

Ricardo Lopes Coelho   has been a “professor auxiliar” at the Faculty of Sciences of the University of Lisbon, since 1997, and a “Privatdozent” at the Technical University of Berlin, since 2001. He studied piano, philosophy and physics in Portugal, did his PhD at the TU-Berlin, with a dissertation on Hertz’s Principles of Mechanics, and the Habilitation in History and Philosophy of exact Sciences, with a dissertation on the concept of force, at the same University. Among others, he published some writings concerning his main research interest, the understanding of scientific concepts and principles through its past and philosophy.  相似文献   
172.
Does technology require labour mobility to diffuse? To explore this, we use German social-security data and ask how plants that pioneer an industry in a location – and for which the local labour market offers no experienced workers – assemble their workforces. These pioneers use different recruiting strategies than plants elsewhere: they hire more workers from outside their industry and from outside their region, especially when workers come from closely related industries or are highly skilled. The importance of access to experienced workers is highlighted in the diffusion of industries from western Germany to the post-reunification economy of eastern German. While manufacturing employment declined in most advanced economies, eastern German regions managed to reindustrialise. The pioneers involved in this process relied heavily on expertise from western Germany: while establishing new manufacturing industries in the East, they sourced half of their experienced workers from the West.  相似文献   
173.
Research on students’ conceptions of learning is a growing and complex area of interest in the field of psychology of education. Even though much of the investigation addressed to explore conceptions of learning at the university level, still less research has considered how naïve (i.e. ‘learning as reduction of deficit knowledge through individual effort’) and sophisticated (i.e. ‘learning as opportunity and self-efficacy’) conceptions of learning are related to personal and contextual factors. This research investigated how gender, academic area, and level of study influence university students’ conceptions of learning. Three hundred forty-six university students participated in the study. They were either from humanities (240) or technical-scientific (106) areas of study and they were attending either a Bachelor (140) or Master’s degree (206) course. Conceptions of learning were explored using a self-report instrument (Learning Conceptions Questionnaire; LCQ). A MANOVA revealed that females show conceptions of learning more related to social and motivational aspects of learning with a greater personal involvement, compared with males. No typical pattern of conceptions of learning was found for humanities students or for technical-scientific students. Increasing with the level of study, students showed both naïve and sophisticated conceptions of learning increased, since both ‘learning as reduction of deficit knowledge through individual effort’ and ‘learning as opportunities and self-efficacy’ were more likely. Implications of these results and future lines of research will be discussed.  相似文献   
174.
The practice of integrated education for pupils with special needs has been attempted nationally in Portugal. This has prompted the development of area support teams across the country. Whilst this is a positive move, it has created a pressure for specialist training of teachers. This demand is yet to be fulfilled; an example of an inservice course is outlined in this report.  相似文献   
175.
Twenty-first century learners in post-secondary educational environments find themselves involved in online learning. Acquiring graduate degrees, especially for working professionals, has precipitated the need for effective, rigorous, relevant, and timely coursework online. Utilizing the qualitative research method of auto-ethnographic reporting, we explored one individual’s experience acquiring an online doctor of education degree from a research university in the state of Texas. The results indicated three major components: (1) personal: including but not limited to family, work, and cultural responsibilities; (2) coursework: including but not limited to rigor, relevance, requirements, collaboration, and personal contact with instructors; (3) writing of the record of study (ROS): including but not limited to the selection of the dissertation committee, formulation of the research topic, approval of topic, researching, writing, defending, and submitting the ROS. The implications on future program development are discussed, as well as an exploration of normative boundaries associated with online learning.  相似文献   
176.
Electronic government (e-Government) systems are becoming an essential strategic tool in the delivery of e-Government-to-Business services (e-G2B). The purpose of this research is to explore direct and indirect effects of trust in online services on the satisfaction of the e-Government service users and other perceptions such as e-G2B system effectiveness and the operational effectiveness of organizations. Based on a sample of e-G2B service users from Saudi Arabia, our preliminary findings suggest that the effects of trust on user satisfaction are mediated by e-G2B system effectiveness measures (e.g., System Quality, Service Quality, and Information Quality) and by operational effectiveness. In addition, we find that operational effectiveness and information quality are the most important drivers of user satisfaction. In contrast to previous research, our results show a negative relationship between trust in online services and service quality and suggest that this finding may have important implications for theory and practice.  相似文献   
177.
This paper describes implementation (fidelity, perceived acceptability) and tier 1 and Tier 2 outcomes of school‐wide positive behavior interventions and supports approach including mental health supports at Tier 2 in two K‐8 urban schools. Interventions for Tier 2 consisted of three manualized group cognitive behavioral therapy (GCBT) protocols for externalizing behavior problems, depression, and anxiety. Tier 1 and Tier 2 interventions were implemented with fidelity but program feasibility for Tier 2 was in question because school personnel needed a great deal of external support to implement the interventions. Tier 1 interventions were associated with a decrease in office discipline referrals. Students participating in GCBT showed a significant decrease in mental health diagnostic severity at posttreatment. A discussion of perceived and actual implementation barriers and how they were addressed is provided. Implications for practice in low‐income urban schools are discussed.  相似文献   
178.
179.
It began in 1869, and today we have 118 elements listed in the Periodic table, thanks to Mendeleev's work. Carbon, hydrogen, oxygen, and nitrogen are elements presented in many organic compounds. Some of them can exhibit photophysical and photochemical properties. Herein, we proposed an easy to make an experiment in chemistry classes to connect both subjects, periodic table and photochemistry, through periodic tables made of fluorescent jellies. A sheet of PET‐G was heated and put over the periodic table mold made in a 3D‐printing to produce the form used in this work. Quinine and vitamin B2, from tonic water and vitamin supplement, respectively, were the fluorescent compounds selected to be in the gelification process to give the jelly fluorescence. The light source was a black light lamp. This work allowed for the discussion of photophysics and photochemistry concepts, 3D‐printing process, gelification, and the International Year of the Periodic Table of Chemical Elements—IYPT2019—with undergraduate students without the use of expensive reagents or equipment.  相似文献   
180.
This study analysed the time course of the global metabolic acute response after resistance exercise (RE), with the use of proton nuclear magnetic resonance (1H NMR) spectroscopy. Ten young healthy males performed 4 sets of 10 repetitions at 70% of one-repetition maximum in the leg press and knee extension exercises and had the serum metabolome assessed at 5, 15, 30 and 60 min post-RE. Measurements were also performed 1 h earlier and immediately before the exercises, as an attempt to characterise each participant’s serum metabolome at rest. One-way ANOVA was applied and the significance level was set at P ≤ 0.05. RE promoted an increase in 2-hydroxybutyrate, 2-oxoisocaproate, 3-hydroxyisobutyrate, alanine, hypoxanthine, lactate, pyruvate and succinate concentrations. However, isoleucine, leucine, lysine, ornithine and valine had their concentrations decreased post-RE compared with at rest. This is the first study to show significant changes in serum concentration of metabolites such as 2-oxoisocaproate, 2-hydroxybutyrate, 3-hydroxyisobutyrate, lysine, hypoxanthine and pyruvate post-RE, attesting metabolomics as an interesting approach to advance in the understanding of global RE-induced metabolic changes. Moreover, the present data could influence the time point of blood collection in the future studies that aims to investigate metabolism and exercise.  相似文献   
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