氯化亚汞声光器件换能器五层结构设计

提出用环氧树脂聚合物作为缓冲层 ,设计氯化亚汞声光器件的换能器。从器件的布喇格带宽出发 ,设计了五层结构的换能器 ,计算了以Ag为电极 ,ln或pb粘接层时 ,其五层的各自厚度 ,并确保了换能器倍频程带宽     

我国优秀乒乓球人才流动特征分析

通过对新中国成立以来不同时期中国优秀乒乓球人才国内、国外流动方向、范围、规模等方面的研究,探究我国优秀乒乓球人才流动的特征与趋势,结果表明:(1)优秀乒乓球人才流动始终以垂直流动为主要方式;(2)优秀乒乓球人才在国内、国际流动的区域呈现出不均衡的分布趋势;(3)优秀乒乓球人才资源丰富与基层群众文化发展的急需相矛盾、脱节;(4)优秀乒乓球人才职业转换的跨度、范围增大,自主性流动趋势增强;(5)优秀乒乓球人才的流动促进r乒乓球运动全球化整体的发展与提高,推动了中国文化的繁荣与世界文化的全面交融.     

中国传媒产业市场结构、行为与绩效分析

据摩根斯坦利全球投资报告的统计分析,建立起世界级有竞争力的大企业,传媒业仅需要8年时间,远远快于医药业、银行、电力、能源等行业。可以说,传媒业已经成为继电子信息、制造业、烟草业之后我国排名第四的国家支柱产业,对其产业状况进     

Tennessee Promise: A Response to Organizational Change

Community colleges in Tennessee, either directly or indirectly, experienced unprecedented change as a result of Tennessee Promise. The present study explored how student support service administrators at three community colleges responded to organizational change as a result of the Tennessee Promise legislation. Investigators selected community colleges for the multi-site case study because the legislative impact would be actualized by the preparations made to serve incoming Promise recipients. The delivery of orientation services framed organizational change because the service staff facilitate connections and provide information to incoming students. Challenges like a shifting population, ill-equipped infrastructure, inadequate remediation support, heightened interest for social engagement opportunities, misinformation, and unmet fiscal needs left administrators seeking coherence through the change process. Investigators found community college administrators react to change similarly. Administrators acknowledged change as continuous, created a culture of innovation among stakeholders, and were not afraid to fail as responses to the organizational change phenomenon.     

The growing (but still limited) importance of evidence in education policy and practice

The last decade of education change has been characterized by the rise of evidence-based policy and practice agendas. Internationally, we are witnessing efforts to increase and incorporate research use in public services. This article examines efforts in education to address the research–practice gap through an emerging field we term knowledge mobilization (KM). We explore some of the controversy surrounding the use of ‘evidence’, outline national and international KM initiatives and consider some of the issues and challenges that arise from the increased interest in evidence and research use in education. We also assess the current state and desirable future directions of efforts to strengthen the role of research and evidence in education.     

Report on a Boston University Conference December 7–8, 2012 on How Can the History and Philosophy of Science Contribute to Contemporary US Science Teaching?

This is an editorial report on the outcomes of an international conference sponsored by a grant from the National Science Foundation (NSF) (REESE-1205273) to the School of Education at Boston University and the Center for Philosophy and History of Science at Boston University for a conference titled: How Can the History and Philosophy of Science Contribute to Contemporary US Science Teaching? The presentations of the conference speakers and the reports of the working groups are reviewed. Multiple themes emerged for K-16 education from the perspective of the history and philosophy of science. Key ones were that: students need to understand that central to science is argumentation, criticism, and analysis; students should be educated to appreciate science as part of our culture; students should be educated to be science literate; what is meant by the nature of science as discussed in much of the science education literature must be broadened to accommodate a science literacy that includes preparation for socioscientific issues; teaching for science literacy requires the development of new assessment tools; and, it is difficult to change what science teachers do in their classrooms. The principal conclusions drawn by the editors are that: to prepare students to be citizens in a participatory democracy, science education must be embedded in a liberal arts education; science teachers alone cannot be expected to prepare students to be scientifically literate; and, to educate students for scientific literacy will require a new curriculum that is coordinated across the humanities, history/social studies, and science classrooms.     

用于环路校准的延迟锁相环设计

延迟锁相环能够产生精确的延时而被广泛使用。本文介绍了一种适用于直接调制发射机锁相电路环路校准的延迟锁相环。电路采用TSMC 0.18μm CMOS工艺实现,参考频率为26 MHz。在3.3 V电源电压下的仿真结果显示:延迟锁相环锁定时间为520ns,锁定相位为2π,同时输出8路相位差为45o间隔的时钟。     

The role of special schools for children with profound and multiple learning difficulties: is segregation always best?

The education of young people with profound and multiple learning difficulties continues to raise challenges and controversies. In this article, Ben Simmons, an ESRC funded PhD student and research assistant, and Phil Bayliss, programme director for the masters degree in special education and disability, both based in the School of Education and Lifelong Learning at the University of Exeter, describe their research into provision for pupils with profound and multiple learning difficulties in a special school in the south west of England. Their work, based in an interpretivist, qualitative approach, set out to illuminate issues relating to the inclusion of pupils with profound and multiple learning difficulties. The findings presented here suggest that the school, in spite of its strong reputation, struggled significantly to provide appropriate learning experiences for pupils with profound and multiple learning difficulties. Ben Simmons and Phil Bayliss discuss the need for improved staff development opportunities focused on enhancing current levels of knowledge and skills. They conclude by calling for a reappraisal of the established view that special schools necessarily provide the best learning environment for pupils with profound and multiple learning difficulties.     

Governing software: networks,databases and algorithmic power in the digital governance of public education

This article examines the emergence of ‘digital governance’ in public education in England. Drawing on and combining concepts from software studies, policy and political studies, it identifies some specific approaches to digital governance facilitated by network-based communications and database-driven information processing software that are being discursively promoted in education by cross-sectoral intermediary organizations. Such intermediaries, including National Endowment for Science, Technology and the Arts, Demos, the Innovation Unit, the Education Foundation and the Nominet Trust, are increasingly seeking to participate in new digitally mediated forms of educational governance. Through their promotion of network-based pedagogies and database-driven analytics software, these organizations are seeking to delegate educational decision-making to socio-algorithmic forms of power that have the capacity to predict, govern and activate learners' capacities and subjectivities.