TEACHERS’ MISCONCEPTIONS ABOUT THE EFFECTS OF ADDITION OF MORE REACTANTS OR PRODUCTS ON CHEMICAL EQUILIBRIUM     

Derek Cheung  Hong-jia Ma  Jie Yang 《International Journal of Science and Mathematics Education》2009,7(6):1111-1133

The importance of research on misconceptions about chemical equilibrium is well recognized by educators, but in the past, researchers’ interest has centered on student misconceptions and has neglected teacher misconceptions. Focusing on the effects of adding more reactants or products on chemical equilibrium, this article discusses the various misconceptions held by high school teachers. A misconception test was administered to two samples of chemistry teachers in Nanjing, China. Of the 109 teachers who participated in the test, only one understood that adding more CS₂ gas to the equilibrium system CS₂(g) + 4H₂(g) ⇌ CH₄(g) + 2H₂S(g) at constant pressure and temperature can shift the equilibrium to the reactant or product side, depending upon the amount of CS₂ in the initial equilibrium system. Most of the teachers relied on Le Chatelier’s principle and thus made erroneous predictions. The misconception test also revealed that those teachers who managed to compute equilibrium constants had a limited conceptual understanding of chemical equilibrium. Implications of these findings for teacher education and chemistry curriculum development are discussed.  相似文献   

Qualitative Differences Between Learning Environments Using Videos in Small Groups and Whole Class Discussions: A Preliminary Study in Physics     

Ashleigh Mayo  Manjula D. Sharma  Derek A. Muller 《Research in Science Education》2009,39(4):477-493

Interactivity, group learning and student engagement are accepted as key features of social constructivist learning theories. The challenge is to understand the interplay between such features in different learning environments. This study focused on the qualitative differences between two interventions—small-groups and whole-class discussions. In both interventions, three short video slices on the abstract topic ‘the physics of superconductivity’ were interspersed with the different discussion styles. The video slices are based on the Bruner stages. Twenty-nine first year university physics students completed a pre-test, underwent the intervention and completed a post-test. The remainder of the data were collected from student drawings, video recordings, observer notes and facilitator feedback. Results indicate that the use of the video slices in both interventions were successful in changing students’ understandings of superconductivity. However, the small groups treatment tended to facilitate questioning, meaning-making and subsequent changes of ideas more so than the whole class discussions. Implications for research and practice are discussed.  相似文献   

Futsal task constraints promote transfer of passing skill to soccer task constraints     

Luca Oppici  Derek Panchuk  Fabio Rubens Serpiello  Damian Farrow 《European Journal of Sport Science》2018,18(7):947-954

This study investigated how learning a passing skill with futsal or soccer task constraints influenced transfer to a new task. Futsal (n?=?24, 13.6?±?1.2 years old, 7.0?±?1.6 years of experience) and soccer (n?=?24, 13.6?±?1.2 years old, 6.8?±?1.2 years of experience) players performed two 5v5?+?goalkeeper modified games – a futsal-like task (small playing area with the futsal ball) and soccer-like task (large playing area with the soccer ball). Participants’ passing accuracy and their orientation of attention were assessed during the two tasks. The futsal group improved their passing accuracy (ES?=?0.75?±?0.61) from the futsal-like to the soccer-like task, and they were more accurate than soccer players (ES?=?2.98?±?2.96). Conversely, the soccer group’s passing accuracy remained stable across the two tasks (ES?=?0.10?±?0.52) and it was similar to the futsal group in the futsal-like task (ES?=?0.58?±?1.93). This indicates a higher magnitude of transfer (and adaptability) from performing passes in a small playing area with short time to act – futsal task constraints – to a larger playing area with longer time – soccer task constraints – than vice-versa. Furthermore, the futsal group showed a higher adaptation of attention orientation to the affordances that emerged with the soccer task constraints, which is suggested to be one of the main mechanisms promoting skill transfer. These results encourage soccer practitioners to introduce futsal task constraints to fast-track players’ ability to functionally adapt perception–action coupling.  相似文献   

“不是没有X”和“not without X”语义分析     

CHI Derek Asaba 《文学教育(上)》2018,(4)

双重否定是语言研究的一个重要范畴。双重否定是一种特殊的语法手段,是人们在否定的基础上通过二次否定的形式表达肯定的意思。在形式上,双重否定具有两个否定成分,但是在意义上却是肯定意义。不同语言表达双重否定的方式不一样。"不是没有X"和"not without X"是汉语和英语中的双重否定结构。这两个结构属于显性双重否定表达。本文通过对比以上两个结构的语义特点,分析这两者之间的共性及差异。  相似文献   

Fluid ingestion and exercise hyperthermia: Implications for performance,thermoregulation, metabolism and the development of fatigue     

Derek Kay  Frank E. Marino 《Journal of sports sciences》2013,31(2):71-82

The development of fatigue during exercise and the subsequent onset of exhaustion occur earlier in the heat than in cooler environments. The underlying mechanisms responsible for the premature development of fatigue in the heat have yet to be clearly identified. However, the proposed mechanisms include metabolic, cardiovascular and central nervous system perturbations, together with an elevated core temperature. Fluid ingestion is one of three strategies that have been shown to be successful in enhancing the performance of endurance exercise in the heat, with the other interventions being precooling and acclimatization. However, like the development of fatigue in the heat, the mechanisms by which fluid ingestion allows for improved exercise performance remain unclear. We propose that fluid ingestion enhances exercise performance in the heat by increasing the heat storage capacity of the body. We suggest that the thermoregulatory, metabolic and cardiovascular alterations that occur as a result of this increased heat storage capacity contribute to performance enhancement when fluid is ingested during exercise heat stress.  相似文献   

Effect of verbal instructions and image size on visual search strategies in basketball free throw shooting     

Saleh A. Al-Abood  Simon J. Bennett  Francisco Moreno Hernandez  Derek Ashford  Keith Davids 《Journal of sports sciences》2013,31(3):271-278

We assessed the effects on basketball free throw performance of two types of verbal directions with an external attentional focus. Novices ( n = 16) were pre-tested on free throw performance and assigned to two groups of similar ability ( n = 8 in each). Both groups received verbal instructions with an external focus on either movement dynamics (movement form) or movement effects (e.g. ball trajectory relative to basket). The participants also observed a skilled model performing the task on either a small or large screen monitor, to ascertain the effects of visual presentation mode on task performance. After observation of six videotaped trials, all participants were given a post-test. Visual search patterns were monitored during observation and cross-referenced with performance on the pre- and post-test. Group effects were noted for verbal instructions and image size on visual search strategies and free throw performance. The 'movement effects' group saw a significant improvement in outcome scores between the pre-test and post-test. These results supported evidence that this group spent more viewing time on information outside the body than the 'movement dynamics' group. Image size affected both groups equally with more fixations of shorter duration when viewing the small screen. The results support the benefits of instructions when observing a model with an external focus on movement effects, not dynamics.  相似文献   

The effect of biofeedback training on affective regulation and simulated car-racing performance: A multiple case study analysis     

William A. Edmonds  Gershon Tenenbaum  Derek T. Y. Mann  Michael Johnson  Akihito Kamata 《Journal of sports sciences》2013,31(7):761-773

Abstract

In this study, we wished to investigate the factors that determine the direction of the spin axis of a pitched baseball. Nineteen male baseball pitchers were recruited to pitch fastballs. The pitching motion was recorded with a three-dimensional motion analysis system (1000 Hz), and the orientations of the hand segment in a global coordinate system were calculated using Euler rotation angles. Reflective markers were attached to the ball, and the direction of the spin axis was calculated on the basis of their positional changes. The spin axis directions were significantly correlated with the orientations of the hand just before ball release. The ball is released from the fingertip and rotates on a plane that is formed by the palm and fingers; the spin axis of the ball is parallel to this plane. The lift force of the pitched baseball is largest when the angular and translational velocity vectors are mutually perpendicular. Furthermore, to increase the lift forces for the fastballs, the palm must face home plate.  相似文献   

Faith,Race, and LGB Affirmation: Experiences of African American Counselors‐in‐Training          下载免费PDF全文

Janeé R. Avent Harris  Derek L. Roberston  Brenda Jones  Ashley M. Prado 《Counselor Education & Supervision》2017,56(2):145-158

In this phenomenological study, the authors investigated the experiences of African American counselors‐in‐training, with roots in the Black church, as they navigated their faith and professional responsibilities to provide affirming services to lesbian, gay, and bisexual clients. Findings suggest attitudes toward lesbian, gay, and bisexual clients are intertwined with faith, race, and community allegiance.  相似文献   

A cross-national survey of cultural expectations and sex-role standards in reading     

John Downing  Carol A. Dwyer  Dina Feitelson  Mogens Jansen  Ritva Kemppainen  Hilkka-Liisa Matihaldi  David R. Reggi  Takahiko Sakamoto  Hugh Taylor  Derek V. Thackray  Douglas Thomson 《Journal of Research in Reading》1979,2(1):8-23

Cultural expectations and sex-role standards about reading in Canada, Denmark, England, Finland, Israel, Japan, and U.S.A. were investigated. A picture test showing various activities and objects including reading and books was administered in each country to six sub-samples that approximated to the levels: students in grades I, IV, VIII, and XII, college students, and adults. Subjects had to ascribe the activity or object as being appropriate for either a boy or a girl. The results were consistent with the hypothesis that cultural expectations and sex-role standards about reading are congruent within one country but that they differ between countries. In particular, boys in Canada and the U.S.A. rapidly learn to perceive reading as a feminine activity, whereas Danish and Japanese males at all ages consistently view reading as acceptable masculine behaviour.  相似文献   

Integrating Genomics Research throughout the Undergraduate Curriculum: A Collection of Inquiry-Based Genomics Lab Modules     

LM Banta  EJ Crespi  RH Nehm  JA Schwarz  S Singer  CA Manduca  EC Bush  E Collins  CM Constance  D Dean  D Esteban  S Fox  J McDaris  CA Paul  G Quinan  KM Raley-Susman  ML Smith  CS Wallace  GS Withers  L Caporale 《CBE life sciences education》2012,11(3):203-208

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