世界非燃料矿产资源的开发与环境保护

本文回顾了世界非燃料矿产资源开发的历史,阐述了矿产资源的开发与环境保护的关系。虽然非燃料矿产有巨大的消耗,但是世界储藏量所而有所增加。一方面是由于新矿脉的勘探、采矿和金属回收技术的提高、替代产品的不断涌现;更重要的是环境保护的需要和土地利用政策的改变限制了一些矿场的开采。在不同发达适度的国家情况有所不同,特别是不发达国家的经济发展与环境保护的矛盾仍很突出。     

The 2006 Bower Award for Achievement in Science, presented to Narain G. Hingorani

The scientific theme for the 2006 Bower Award for Achievement in Science was Electric Power Systems. The award was presented to Narain G. Hingorani for the conceptualization and pioneering advancement of Flexible AC Transmission Systems (FACTS) and Custom Power in electric power systems, and for outstanding technical contributions in High Voltage Direct Current (HVDC) technology. His contributions have enhanced the quality and security of the electric power system, and are expected to revolutionize future alternating current power transmission and distribution systems.     

Conceptual Mediation Program in Practice: Educational Outcomes from Two Sites

We report on two studies in which high school students who had been exposed to a cognitive training procedure known as the Conceptual Mediation Program (CMP) were compared to students who had not participated within the program. In the first study, based on data from two sites, it was found that 70 CMP students exhibited higher levels of school affect and strategy awareness than 103 comparable students not in the program. In the second study, based on retrospective data from one site, 53 students who had participated within CMP classes were found to exhibit higher levels of attainment on Year 12 South Australian public examination results (effect size of 1.04 on the aggregate). On the Year 12 examination results, the CMP students outperformed both the school and state norms.     

B/S模式程序中的分布式计算应用一例

B／S模式的应用程序主要是集中式计算和处理，本简要的以实例无纸化考试系统设计，说明了在B／S模式中采用分布式计算处理的一种思路。     

Computer use within a play-based early years curriculum

Early years curricula promote learning through play and in addition emphasise the development of computer literacy. Previous research, however, has described that teachers feel unprepared to integrate Information and Communication Technology (ICT) and play. Also, whereas research has suggested that effective computer use in the early years is associated with adult direction, further research suggests adult presence can inhibit play and reduce children's engagement. Focusing on 12 settings following the Welsh play-based Foundation Phase, this paper explores teachers' experiences of integrating computer use into classroom practice, children's levels of engagement with computer activities and how playful children perceive computer use to be. Teachers confidently delivered a variety of computing experiences. Children consistently rated these activities as play regardless of adult presence and demonstrated moderate to high levels of engagement. Findings and the features of observed practice are discussed in relation to the teachers' role as a play partner and the successful co-construction of the play-based curriculum.     

带干扰的离散时间的双险种风险模型

在我国保险公司的运营过程中,保费收入是主要收入来源,理赔则是主要的风险因素,保险公司的最基本经营目标就是提高它的赔付能力,确保稳定地运作.通过对破产概率及生存概率的研究,了解其相关制约因素.得出一些重要结论,从而科学地预测保险公司未来的收入,以及估计保险公司的概率等.     

Grade retention: Current decision‐making practices and involvement of school psychologists working in public schools

Research examining student outcomes (e.g., achievement, adjustment) after grade retention reveals that it does not result in long‐term improvements for students; however, grade retention continues to be used as an intervention. The purpose of this study was to examine retention decision‐making practices, as well as school psychologists' knowledge, beliefs, and opinions regarding retention. Actual and ideal roles of school psychologists in grade retention decisions were also examined. Participants included 250 school psychologists randomly selected from the membership of the National Association of School Psychologists. Results revealed that the decision to retain is a subjective one, typically made by a team. Responding school psychologists did not support retention and found the research moderately applicable to practice. However, most school psychologists indicated that they were not centrally involved in decision making. Findings also revealed a desire among school psychologists for increased involvement in developing and/or implementing programs aimed at improving performance and consulting on the effects of retention. © 2009 Wiley Periodicals, Inc.     

Large-scale academic achievement testing of deaf and hard-of-hearing students: past, present, and future

The first large-scale, nationwide academic achievement testing program using Stanford Achievement Test (Stanford) for deaf and hard-of-hearing children in the United States started in 1969. Over the past three decades, the Stanford has served as a benchmark in the field of deaf education for assessing student academic achievement. However, the validity and reliability of using the Stanford for this special student population still require extensive scrutiny. Recent shifts in educational policy environment, which require that schools enable all children to achieve proficiency through accountability testing, warrants a close examination of the adequacy and relevance of the current large-scale testing of deaf and hard-of-hearing students. This study has three objectives: (a) it will summarize the historical data over the last three decades to indicate trends in academic achievement for this special population, (b) it will analyze the current federal laws and regulations related to educational testing and special education, thereby identifying gaps between policy and practice in the field, especially identifying the limitations of current testing programs in assessing what deaf and hard-of-hearing students know, and (c) it will offer some insights and suggestions for future testing programs for deaf and hard-of-hearing students.     

An integrated and open-ended experiment

In this article we discuss an exciting experiment in non-linear dynamics. This provides an imaginative platform for bringing in chemical, physical, biological, mathematical and computational sciences together. There are implications for earth sciences as well. B M Deb is a theoretical chemist who has been designing experiments for chemistry teaching laboratories for more than thirty years. Mainak Sadhukhan, Sudarson Sekhar Sinha and Sucheta Sengupta were students of PBIR-Chemical Sciences. Ranjit Biswas is a physical chemist working on both theory and experiment in chemical dynamics.