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Romero-Maltrana Diego Benitez Federico Vera Francisco Rivera Rodrigo 《Research in Science Education》2019,49(6):1735-1757
Research in Science Education - There is an increasing demand in the field of science education for the incorporation of philosophical and sociological aspects that are related to the scientific... 相似文献
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Diego Giulliano Destro Christofaro Selma Maffei De Andrade Arthur Eumann Mesas Rômulo Araújo Fernandes José Cazuza Farias Júnior 《European Journal of Sport Science》2016,16(4):498-506
Objectives: To analyse the associations between high screen time and overweight, poor dietary habits and physical activity in adolescents according to sex. Methods: The study comprised 515 boys and 716 girls aged 14–17 years from Londrina, Brazil. Nutritional status (normal weight or overweight/obese) was assessed by calculating the body mass index. Eating habits and time spent in physical activity were reported using a questionnaire. The measurement of screen time considered the time spent watching television, using a computer and playing video games during a normal week. Associations between high screen time and dependent variables (nutritional status, eating habits and physical activity levels) were assessed by binary logistic regression, adjusted for sociodemographic and lifestyle variables. Results: Most adolescents (93.8% of boys and 87.2% of girls) spent more than 2 hours per day in screen-time activities. After adjustments, an increasing trend in the prevalence of overweight and physical inactivity with increasing time spent on screen activities was observed for both sexes. Screen times of >4 hours/day compared with <2 hours/day were associated with physical inactivity, low consumption of vegetables and high consumption of sweets only in girls and the consumption of soft drinks in both sexes. Conclusions: The frequency of overweight and physical inactivity increased with increasing screen time in a trending manner and independently of the main confounders. The relationship between high screen time and poor eating habits was particularly relevant for adolescent girls. 相似文献
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Alexis Patterson Diego Roman Michelle Friend Jonathan Osborne Brian Donovan 《International Journal of Science Education》2018,40(3):291-307
Reading is fundamental to science and not an adjunct to its practice. In other words, understanding the meaning of the various forms of written discourse employed in the creation, discussion, and communication of scientific knowledge is inherent to how science works. The language used in science, however, sets up a barrier, that in order to be overcome requires all students to have a clear understanding of the features of the multimodal informational texts employed in science and the strategies they can use to decode the scientific concepts communicated in informational texts. We argue that all teachers of science must develop a functional understanding of reading comprehension as part of their professional knowledge and skill. After describing our rationale for including knowledge about reading as a professional knowledge base every teacher of science should have, we outline the knowledge about language teachers must develop, the knowledge about the challenges that reading comprehension of science texts poses for students, and the knowledge about instructional strategies science teachers should know to support their students’ reading comprehension of science texts. Implications regarding the essential role that knowledge about reading should play in the preparation of science teachers are also discussed here. 相似文献
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Aldo Jonathan Muñoz-Vázquez Juan Diego Sánchez-Torres Salvador Gutiérrez-Alcalá Esteban Jiménez-Rodríguez Alexander G. Loukianov 《Journal of The Franklin Institute》2019,356(5):2709-2722
Robotic tasks are primarily defined to comply to spatial and time constraints, and in several of such tasks, it is required to track a nominal contour depending just on spatial coordinates, without involving the time variable in the definition of such a contour, in contrast to conventional trajectory tracking schemes. With the aim to satisfy the salient requirements of these robotic tasks, this paper presents an integrated robust controller. The contour is encoded by using a robust velocity field, such that, any particle immerse in such field converges in predefined-time to a predefined vicinity of the given contour. Then, a robust controller is proposed to enforce the velocity field, in turns, in predefined-time. In this sense, a predefined-time-precision contour tracking is assured, by considering a robust controller that does not assume the exact knowledge of the robot parameters for its real-time implementation. Numerical simulations are conducted to highlight the reliability of the proposed scheme. 相似文献
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Rodrigo P. Lemos Jonas A. Kunzler Diego F. Burgos B. Mário J. de Souza Hugo V. L. e Silva Yroá R. Ferreira Edna L. Flôres Oliver Sander 《Journal of The Franklin Institute》2019,356(6):3781-3796
SEAD method estimates the direction-of-arrival angles on an uniformly linear array based on the difference between the two largest singular values, what is called differential spectrum. Although it presented an outstanding performance, the ability to indicate the source positions was not elucidated yet. Inspired by the differential spectrum formulation we derived a total differential spectrum and found out that the matrix norm induced by the vector 2-norm of a modified spatial covariance matrix can be used to estimate the direction-of-arrival of multiple plane waves. Indeed we show that matrix norms are estimators and we propose their use instead of the singular value decomposition in SEAD-based methods. We present a general mathematical expression in order to explicit the operating principles of the proposed methods. Consequently, we were able to explain how the relation between the arriving and the search angles produces the larger peaks on the differential spectrum. To evaluate the important role played by matrix norms, a thousand experiments were carried out. They showed that the proposed approach proved to be as accurate as the previous SEAD-based methods, while providing a significant reduction on runtime. It also outperformed well-established methods like MODEX regarding the estimation error. 相似文献
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Danilo Bersani Pier Paolo Lottici Antonella Casoli Diego Cauzzi 《Journal of Cultural Heritage》2008,9(1):97-102
During the restoration plan of the famous painting “Madonna col Bambino e S. Giovannino” by Sandro Botticelli, located in the Museo Civico of Piacenza (Italy), a study on painting materials was carried out. The pigments, the binders and the materials used for the application of ground and priming layers were studied using micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry (GC/MS), optical and electronic microscopies. Gypsum and anhydrite were found in the ground layer, while carbon black and lead white were used in the priming layers. The precious pigments of the artist's palette and the binders used (egg and animal glue) were determined. 相似文献
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1984年乔丹领衔的黄金一代,开辟了90年代NBA众星捧月的大场面,马克利、奥拉朱旺、尤因、雷吉·米勒、超音速双怪以及犹他二老与篮球之神迈克尔·乔丹的轮番PK造就了美国职业篮球最辉煌的时代。1996年选秀大会又为联盟输送了科比·布莱恩特、阿伦·艾弗森、雷·阿伦这一批优质球星,加上1997年的邓肯和麦迪以及1995年的凯文·加内特,这一拨人是1998年乔丹退役之后NBA的中坚力量。 相似文献
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这个年代没有人会去深究上帝是否存在,也有人会不再认为他们读的圣经真的具有伟大的救赎之力能拯救世人脱离撒坦的阴暗。信仰在某种意义上。已经成为了一种纯粹供人们自我安慰的道德他律力量。所谓上帝的子民。在被消费主义日渐吞噬的现代社会浮沉之后,也不免会成为罪恶的祭品。 相似文献
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