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Educational research has shown that high school and university students also follow the Aristotelian idea about motion; for example, a continuous action of a force is necessary to keep an object in motion. The survey presented in this article aims at a deeper investigation of secondary education students' ideas about the forces involved in objects moving under the sole influence of gravity. The main objectives are: (1) to investigate other ideas or difficulties, which intervene and determine students' mental models about motion and force, and (2) to reveal how the students in the sample are grouped according to their alternative conceptions. Our study has been mainly determined by the revision in Science Curriculum established in Greece three years ago. A survey has been administered to a total of 146 students (15–16 years old) attending six typical public high schools in Greece. The results presented show that the traditional instruction is pertinent while the approaches of the New Physics Curriculum have not been effectively expanded to the schools. The majority of the students exhibited the idea that the original force is continuously exerted to the ball during its motion. On the other hand, multivariate analysis has identified three discernible groups of students which have exhibited a persistent and rather consistent approach: (1) An extended group of students having the above misconception, (2) a second group of students which, generally, responded correctly to the tasks, and (3) a third group of students, which ignored the presence of the gravitational force and/or believe that the action-reaction forces are both exerted to the ball during its motion. 相似文献
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Angeliki Mavropoulou Vassilis Barkoukis Styliani Douka Konstantinos Alexandris Dimitris Hatzimanouil 《The Journal of educational research》2019,112(2):223-233
Physical education in elementary education usually provides children’s first contact with sports. According to the trans-contextual model of motivation, physical education teachers can positively influence children’s beliefs toward and actual leisure time physical activity behavior. The aim of this study was to examine the effect of a dance-based physical education program on motivation regarding physical education lesson participation, as well as leisure time physical activity participation. The sample consisted of 252 pupils attending Grades 5 and 6 of elementary school (Mage?=?10.48 years, SD?=?0.50 years). Participants were randomly assigned into three groups. The first group attended a physical education lesson based on various forms of dance, the second one attended lessons with Greek traditional dances only, and the third group served as active control group that attended the typical curriculum. The intervention lasted six weeks. Before and after the intervention, students completed survey-based measures of motivational climate, motivational regulations in physical education and leisure time, enjoyment, attitudes, perceived behavioral control, subjective norms, and intentions toward leisure time physical activity. In support of the trans-contextual model, results showed that students in the dance intervention programs scored significantly higher in perceptions of motivational climate and beliefs toward leisure time physical activity. The findings of the study suggest that dancing lessons at school can bolster more positive attitudes and beliefs toward physical education and leisure time physical activity. 相似文献
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Farideh Fekrsanati Stefan Klein Jens Hildenhagen Klaus Dickmann Yiorgos Marakis Aleka Manousaki Vassilis Zafiropulos 《Journal of Cultural Heritage》2001,2(4):187
The application of lasers for the removal of superficial deposits from historic stained glass is a comparatively new field of scientific interest. Experimental studies concerning the behaviour of glass substrates and the corresponding superficial deposits towards different laser wavelengths were carried out. The experiments were performed using wavelengths of λ = 193 nm (ArF-Excimer), 308 nm (XeCl-Excimer), 355 nm (Nd:YAG third harmonic) and 1 064 nm (Nd:YAG fundamental) in comparison to λ = 248 nm (KrF-Excimer). This comparison is due to the fact that the present knowledge is based on the 248 nm wavelength. Specially prepared model glass samples representing the original fragments and samples of organic polymers (formerly used as a protective material for historic stained glasses) were used to study the effects of laser radiation and were subsequently characterised by optical microscopy. 相似文献
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Saraslanidis P Petridou A Bogdanis GC Galanis N Tsalis G Kellis S Mougios V 《Journal of sports sciences》2011,29(11):1167-1174
Repeated-sprint training often involves short sprints separated by inadequate recovery intervals. The effects of interval duration on metabolic and performance parameters are unclear. We compared the effects of two training programmes, differing in rest interval duration, on muscle (vastus lateralis) metabolism and sprint performance. Sixteen men trained three times a week for 8 weeks, each training session comprising 2-3 sets of two 80-m sprints. Sprints were separated by 10 s (n = 8) or 1 min (n = 8). Both training programmes improved performance in the 100-, 200-, and 300-m sprints, but the improvement was greater in the 10-s group during the final 100 m of the 200- and 300-m runs. Independent of interval duration, training mitigated the drop of muscle ATP after two 80-m sprints. The drop in phosphocreatine and the increases in glucose-6-phosphate and fructose-6-phosphate after two 80-m sprints were greater in the 10-s group. In conclusion, training with a limited number of repeated short sprints (≤10 s) may be more effective in improving speed maintenance in 200- and 300-m runs when performed with a 1:1 rather than a 1:6 exercise-to-rest ratio. This may be due to a greater activation of glycolysis caused, in part, by the limited resynthesis of phosphocreatine during the very short rest interval. 相似文献
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Maria Kallery Dimitris Psillos Vassilis Tselfes 《International Journal of Science Education》2013,35(9):1187-1204
This paper presents an epistemological analysis of typical didactical activities noted in early‐years science lessons, which was carried out in an attempt to diagnose the extent to which the teaching practices adopted by early‐years educators are successful in supporting young children’s understanding in science. The analysis of didactical activities used a framework that allowed us to discover whether they promoted desired connections between theoretical ideas, evidence and the material world. Theoretical ideas, evidence and the material world are entities internal to scientific inquiry and, in educational contexts, connections between them are considered essential in assisting the development of young children’s scientific thinking. The results indicated that in the early‐years science classroom scientific activity was mainly confined to the representational level. Intervention practices into the material world were limited, and were based on collected evidence. No interventions based on ideas were identified in the science lessons. Missing links between evidence and theory and between ideas and the material world suggest that the didactical activities analysed did not promote scientific understanding. 相似文献
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Athanasios Kabasakalis Stefanos Nikolaidis George Tsalis Kosmas Christoulas Vassilis Mougios 《Journal of sports sciences》2019,37(7):827-832
Irisin and redox status markers seem to share common pathways of exercise-induced upregulation. The aim of the present study was to assess the effects of sprint interval swimming exercise dose and sex on the circulating levels of irisin and redox status markers in adolescent swimmers. Sixteen male and 16 female adolescent swimmers completed two sets of 4 × 50 m maximal freestyle swimming with a send-off time of 90 s, separated by 10 min of passive recovery. Venous blood samples were obtained pre-exercise (Pre), after the first set (Post1) and after the second set (Post2). Males had higher irisin levels than females. Reduced glutathione (GSH, μmol g Hb?1) increased from 8.6 (2.2) [pooled males and females, mean (SD) throughout] at Pre to 9.4 (2.1) at Post1 and Post2. Total antioxidant capacity (μmol DPPH mL?1) increased from 0.89 (0.17) at Post1 to 0.94 (0.16) at Post2. 8-hydroxy-2´-deoxyguanosine (ng mL?1) increased from 20.9 (6.9) at Pre and 21.5 (7.1) at Post1 to 25.0 (10.9) at Post2. Overall, sprint interval swimming exercise induced small but potentially effective changes in the studied parameters. Exercise dose influenced the GSH and 8-OHdG responses, and sex affected irisin levels. 相似文献
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