大冶铜绿山矿给排水方案的优化设计

铜绿山矿长期沿用以尾矿库为汇的合流制排水系统,不利于尾矿库污水资源化,加剧了尾矿库安全和环境风险.为预防和缓解大冶湖流域日益突出的水环境污染问题,对铜绿山矿现有给排水系统进行了深入调查,并在水平衡测试的基础上,提出了"清污分流"、"分质处理"、"综合平衡"的优化设计方案,该方案只需另增一条排污管渠,具有技术经济可行性.环境效益对比数据表明:该优化设计方案水资源重复利用率提高了11.9%,尾矿库污水回用率提高到98.8%,实现了水资源的高效利用,选矿废水串联使用完全消纳,从源头上削减了废水及其有毒有害污染物的排放量,有利于铜绿山矿建设的可持续发展.     

混凝土结构空间多尺度相对湿度值

针对环境作用具有空间分布特性,借鉴空间多尺度环境作用模型框架（包括全局环境、地区环境、工程环境、构件表面环境、内部环境）及其数学模型,对相对湿度进行了空间多尺度研究：在分析空间各尺度上相对湿度的不同影响因素的基础上,由全局环境尺度开始,通过地区环境尺度、工程环境尺度以及构件表面环境尺度上环境因素的逐步调整,最终计算得到混凝土内部的相对湿度值。研究结果表明,采用＂常规统计模型＋空间残差＂的方法,可有效建立地区环境尺度上的相对湿度值与工程环境尺度上相对湿度值的定量关系;混凝土结构构件的表面相对湿度与表面温度有关;实际工程结构应考虑构件表面相对湿度与内部相对湿度之间的不同。     

成都市水资源及水环境 承载能力分析

本文在分析水资源和水环境承载能力定义及研究意义的基础上,分别利用三层次分析方法和基于一维水质模拟的纳污能力模型计算了成都市不同水平年的水资源与水环境承载能力,并对计算结果进行对比分析。结果显示现状条件下成都市的水环境承载能力对用水的限制更为严格,而未来水资源承载能力逐渐开始制约社会经济发展。为此,只有以水资源承载能力及水环境承载能力作为控制点,才能保障经济社会的可持续发展。     

Higher education scholars' participation and practices on Twitter

Scholars participate in online social networks for professional purposes. In such networks, learning takes the form of participation and identity formation through engagement in and contribution to networked practices. While current literature describes the possible benefits of online participation, empirical research on scholars' use of online social networks in the educational technology literature is negligible. The purpose of this paper is to understand scholars' naturalistic practices in social networks in general, and on Twitter in particular. Tweets from 45 scholars were analysed qualitatively to arrive at dominant themes describing online social network practice. Findings indicate that scholars participating on Twitter (1) shared information, resources, and media relating to their professional practice; (2) shared information about their classroom and their students; (3) requested assistance from and offered suggestions to others; (4) engaged in social commentary; (5) engaged in digital identity and impression management; (6) sought to network and make connections with others; and (7) highlighted their participation in online networks other than Twitter. These findings assist the field in understanding the emerging practice of scholarly participation in online networks.     

Pre-service teachers' perspectives of the diffusion of information and communications technologies (ICTs) and the effect of case-based discussions (CBDs)

This study investigates pre-service teachers' perspectives of the diffusion of information and communication technologies (ICTs) in elementary education and the effect of case-based discussions (CBDs). The sample consisted of 170 first-year pre-service teachers from elementary teacher education programs of the largest teacher education college in Turkey. The cases used in the study were obtained from a case repository at http://ornekolay.org, indexing teaching cases from elementary classrooms of the capital city of Turkey. The cases were mainly text-based and presented stories of elementary teachers' in-class usage of ICTs. A quasi-experimental pretest-posttest design was executed to test the effect of pre-service teachers' perspectives on ICTs diffusion in elementary teaching. Three scales were developed based on Rogers' Diffusion of Innovation Theory (2003) to measure pre-service teachers' preferred innovativeness, innovation perceptions, and innovation decisions in the use of ICTs. The results showed that pre-service teachers had pre-established perspectives, mainly positive, about the diffusion of ICTs in elementary teaching; their perceptions about innovativeness and relative advantage were the main indicators of persuasion and decision; and CBDs positively affected their perceptions such that their computer-related persuasion and decisions positively increased.     

The influence of student characteristics on the use of adaptive e-learning material

Adaptive e-learning materials can help teachers to educate heterogeneous student groups. This study provides empirical data about the way academic students differ in their learning when using adaptive e-learning materials. Ninety-four students participated in the study. We determined characteristics in a heterogeneous student group by collecting demographic data and measuring motivation and prior knowledge. We also measured the learning paths students followed and learning strategies they used when working with adaptive e-learning material in a molecular biology course. We then combined these data to study if and how student characteristics relate to the learning paths and strategies they used. We observed that students did follow different learning paths. Gender did not have an effect, but (mainly Dutch) BSc students differed from (international) MSc students in the intrinsic motivation they had and the learning paths and strategies they followed when using the adaptive e-learning material.     

Emerging university student experiences of learning technologies across the Asia Pacific

Three hundred students across eight countries and eleven higher education institutions in the Asia Pacific Region participated in two courses on climate change and disaster management that were supported by learning technologies: a satellite-enabled video-conferencing system and a learning management system. Evaluation of the student experience across the region proved a significant challenge, particularly the way the students conceived of the links between the technologies and their studies, and the way they approached the use of the technologies in connected and sometimes disconnected ways. This study examines the results of a quantitative investigation into the student experience and identifies key aspects of the structure of the variables used to evaluate the experience as well as identifying groups of students in the sample population who reported qualitatively different experiences. Significant outcomes reveal that cohesive conceptions of the learning technologies tend to be related to more effective ways of using both the video-conferencing and learning management systems, and that both at the level of variables, and at the level of groups of students, these experiences tend to be related to relatively higher outcomes. The results have important implications for both the design and teaching of technology-mediated courses and offer ideas for courses that combine systems such as learning management and video-conferencing.     

Influence of participation, facilitator styles, and metacognitive reflection on knowledge building in online university courses

Understanding how to foster knowledge building in online and blended learning environments is a key for computer-supported collaborative learning research. Knowledge building is a deeply constructivist pedagogy and kind of inquiry learning focused on theory building. A strong indicator of engagement in knowledge building activity is the socio-cognitive dynamic of epistemic agency, in which students exercise a higher level of agency for setting forth their ideas and negotiating fit with those of others rather than relying on their teacher. The purpose of this paper is to investigate the influence of (a) levels of participation, (b) facilitator styles and (c) metacognitive reflection on knowledge building in two blended, post-secondary education contexts. A study of a total of 67 undergraduate students suggest that high levels of participation, a supportive facilitator style, and ample opportunities for metacognitive reflection on the students’ own participation strategies are most conducive for fostering epistemic agency for knowledge building. Implications of these results for research and instructional design of online courses are discussed.     

Exploring students’ learning experience in an international online research seminar in the Synchronous Cyber Classroom

The development of computer-mediated communication enables teaching and learning to take place across geographical boundaries. An online synchronous learning environment with cyber face-to-face features affords students the sense of learning together online. This study reports a novel design of organizing a 16-week seminar for doctoral students across Canada, Italy, New Zealand, and Taiwan in the Synchronous Cyber Classroom, an online synchronous learning environment. Students’ learning experiences were explored from the perspective of students’ interactions with students, instructors, and the content, based on which the perception of being in a learning community was formed. This article reports how this international online research seminar was organized, how students’ learning experience was analyzed, and what we learned about students’ learning in this international online research seminar.