全球气候变化问题的视点:中国和美国

就中国在国际气候变化协议中的位置、中国怎样减少CO2排放、有关碳交易的制度建设、中国在国际碳交易市场中扮演的角色和气候变化协定中的重要性进行了探讨,介绍了美国正在运行的气候法案的主要内容,并提出了中国目前的气候政策和碳交易市场发展中存在的问题,在国际气候大环境中和美国进行了分析对比。     

Sex differences in the missing-letter effect: A question of reading or visual–spatial skills?

When readers must search for a target letter while reading a continuous text, they are more likely to miss targets in frequent function words than in less frequent content words. This missing-letter effect has been found across many languages, methodologies, and types of reading materials. Despite the ubiquity of the missing-letter effect, sex differences have been reported, but their pattern is conflicting and no clear interpretation has been offered so far. In two experiments, sex differences were examined in the letter search task, while also measuring spatial and reading skills. In both experiments, the missing-letter effect was found for both genders and a larger missing-letter effect was found for faster readers. It is concluded that when sex differences are observed in the missing-letter effect, they are likely due to reading speed and not to spatial skills as previously hypothesized. Results are interpreted in light of the Attentional Disengagement model of the missing-letter effect.     

A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords ??context-based??, ??contextual learning?? and ??chemistry education?? in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students?? attitudes and students?? understanding/cognition. Implications were investigated for practice in context-based chemistry studies, for future research in context-based chemistry studies, and for curriculum developers in context-based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students?? motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant structure of out-of-school learning, tough nature of some chemistry topics, and teacher anxiety of lower-ability students.     

Middle School Students’ Science Self-Efficacy and Its Sources: Examination of Gender Difference

The main purpose of the present study is to investigate middle school students?? science self-efficacy as well as its sources and outcomes as a function of gender. Bandura??s hypothesized sources of self-efficacy (i.e., mastery experience, vicarious experience, verbal persuasion, and emotional arousal) in addition to being inviting with self and inviting with others were examined as sources of self-efficacy, while cognitive and metacognitive strategy use was examined as an outcome of self-efficacy. A total of 1,932 students participated in the study and were administered self-report instruments. Results showed that the relationship between science self-efficacy and its proposed sources does not change as a function of gender. All proposed sources, except for vicarious experience, were found to be significantly related to students?? scientific self-efficacy. Moreover, girls were found to experience significantly more emotional arousal and to send positive messages to others more than boys. On the other hand, no gender difference was found concerning science self-efficacy and strategy use. The findings also revealed a positive association between science self-efficacy and strategy use. Overall, findings supported Bandura??s conception of self-efficacy and suggested invitations as additional sources of self-efficacy.     

Embedding Nature of Science in Teaching About Astronomy and Space

Science teachers need an adequate understanding of nature of science (NOS) and the ability to embed NOS in their teaching. This collective case study aims to explore in-service science teachers’ conceptions of NOS and the embeddedness of NOS in their teaching about astronomy and space. Three science teachers participated in this study. All participants attended the NOS workshop based on an explicit-reflective approach. They were asked to respond to the Myths of Science Questionnaire on three different occasions, i.e., at the beginning and the end of the NOS workshop and a semester after the workshop. Classroom observation, interviews after teaching, and a collection of related documents were also employed to collect data. The data were analyzed using a constant comparative method. The results revealed two important assertions. First, science teachers’ conceptions of NOS are stable and resistant to change. However, an explicit-reflective approach employed in the NOS workshop, to some extent, promoted science teachers’ understanding and reasoning about NOS. Second, science teachers’ conceptions of NOS are not directly related to their classroom practices. With different degrees of NOS understanding, all participants taught NOS implicitly and missed most of the opportunities to address aspects of NOS embedded in the topics they taught. The implications of these findings are also discussed.     

Conceptualizing climate change in the context of a climate system: implications for climate and environmental education

Today there is much interest in teaching secondary students about climate change. Much of this effort has focused directly on students’ understanding of climate change. We hypothesize, however, that in order for students to understand climate change they must first understand climate as a system and how changes to this system due to both natural and human influences result in climatic and environmental changes and feedbacks. The purpose of this article is to articulate a climate system framework for teaching about climate change and to stimulate discussion about what secondary students should know and understand about a climate system. We first provide an overview of the research on secondary students’ conceptions of climate and climate change. We then present a climate system framework for teaching about climate and climate change that builds on students’ conceptions and scientific perspectives. We conclude by articulating a draft conceptual progression based on students’ conceptions and our climate system framework as a means to inform curriculum development, instructional design, and future research in climate and environmental education.     

Executive functioning, metacognition, and self-perceived competence in elementary school children: an explorative study on their interrelations and their role for school achievement

In the present study, associations between executive functioning, metacognition, and self-perceived competence in the context of early academic outcomes were examined. A total of 209 children attending first grade were initially assessed in terms of their executive functioning and academic self-concept. One year later, children??s executive functioning, academic self-concept, metacognitive monitoring and control, as well as their achievement in mathematics and literacy were evaluated. Structural equation modeling revealed that executive functioning was significantly related to metacognitive control, both cross-sectionally and longitudinally, and that self-concept was substantially associated with metacognitive monitoring, both cross-sectionally and longitudinally. Individual differences in executive functioning and metacognitive control were significantly related to academic outcomes, with metacognitive control appearing to yield a more circumscribed influence on academic outcomes (only literacy) compared to executive functioning (literacy and mathematics).