可编程控制器在温度控制上的应用

本文从可编程控制器在温度控制上应用的实例中,介绍了模拟量闭环控制系统和可编程控制器如何对模拟量进行闭环的PID调节,并给出了测温和电压自动控制的原理线路图.     

Resources for Science Learning: Tools,Tasks, and Environment

This article addresses the question of how science learning can be improved. It recognizes that, while learners themselves are responsible for their own learning, the quality of this learning is greatly influenced when appropriate resources are available to learners. These resources are provided through a partnership between teachers and learners. Three different types of resource are discussed. Tools, in the form of computer tools and conceptual tools, make tasks easier and allow learners to undertake tasks they would not otherwise be able to do. Tasks can facilitate effective learning by creating effective spaces for learners to work in, embodying key aspects of the disciplines of science, providing effective and authentic opportunities for learners to learn, and facilitating a dialogue between learners ideas and their experiences of the natural world. Environment – the ecology in which learning happens – provides three sources of information through the human, social, and conceptual worlds. When key aspects of these worlds are manifested in the environment, they scaffold the learning of science content, the nature of science, and the learning process itself, all of which are required for the deep understanding of science that constitutes improved science learning.     

试论非线性编辑系统的性能

非线性编辑系统是近年来比较流行的一种电视编辑系统 ,采用该系统编辑电视节目 ,电视信号基本没有损失。非线性编辑系统主要由计算机和编辑软件及外部设备来完成编辑工作的。作为电视工作者必须要掌握和了解非线性编辑系统的基本性能和特点 ,以及在电视节目制作中的实际应用     

转型期地方高校教育科研的任务与作用

经济社会大变革,给地方高校创造了良好的发展机遇,同时也带来了许多矛盾和问题。开展教育科研,是解决问题的重要手段和途径。为此,地方高校应进行办学指导思想、人才队伍建设、为区域经济社会服务、教育教学和培养模式的研究,为学校可持续发展提供理论支持和服务。     

数字电视机顶盒及其关键技术浅析

介绍了数字电视机顶盒的功能和基本工作原理，分析了其硬件和软件的关键技术，并阐述了其发展方向和前景．     

错误结果反馈对追踪任务学习迁移的影响

采用电脑追踪任务探讨错误结果反馈(KR)对运动技能学习迁移的影响.抽取在校大学生,随机分为正确KR组、错误KR组、混合KR组(组间性别均衡设计).在第1-3 d,3组受试者练习时分别获得正确的KR、错误的KR,或者获得25次正确KR后,再获得25次错误KR.正确的KR是每次追踪误差的毫秒数,错误的KR则是正确KR数值+10 mm.在第4 d,3组受试者分剐在无KR的条件下,用原任务进行保持测试10次,之后再操作两个迁移任务各10次.显示:KR在一致性时机任务和电脑追踪任务中的作用机理类似,当可以获得KR时,学习者将它作为觉察和纠正操作错误的信息源:错误KR会带来迁移测试绩效的偏差.提示:学习者形成自身觉察错误能力是运动技能学习的关键,实践工作者应根据运动情境的特点,合理地提供结果反馈,以促进运动技能的学习.     

Overload problem research on aperiodic real-time tasks

In this paper, a novel scheduling mechanism is proposed to handle the real-time overload problem by maximizing the cumulative values of three types of tasks: the soft, the hard and the imprecise tasks. The simulation results show that the performance of our presented mechanism in this paper is greatly improved, much better than that of the other three mechanisms: earliest deadline first (EDF), highest value first (HVF) and highest density first (HDF), under the same conditions of all nominal loads and task type proportions.     

关于普通高中大众化发展阶段的任务与办学模式的思考

普通高中教育的大众化发展阶段的任务与模式是:适当发展综合性高中,丰富高中阶段的办学模式;通过课程和教学管理制度改革促进普通高中的综合化发展,完善现有综合高中的个性试探、分流选择的功能;提升高考的多样性和灵活性,引导学生进行适性选择发展。     

Students’ fraction comparison strategies as a window into robust understanding and possible pointers for instruction

As part of individual interviews incorporating whole number and rational number tasks, 323 grade 6 children in Victoria, Australia were asked to nominate the larger of two fractions for eight pairs, giving reasons for their choice. All tasks were expected to be undertaken mentally. The relative difficulty of the pairs was found to be close to that predicted, with the exception of fractions with the same numerators and different denominators, which proved surprisingly difficult. Students who demonstrated the greatest success were likely to use benchmark (transitive) and residual thinking. It is hypothesised that the methods of these successful students could form the basis of instructional approaches which may yield the kind of connected understanding promoted in various curriculum documents and required for the development of proportional reasoning in later years.     

《机械制图与CAD技术》学习领域课程开发

以培养学生完成企业实际工作任务的综合职业能力为着眼点,依据工作任务设计学习情境、组织教学活动,开发项目任务式的识图绘图学习领域课程,达成本课程的教学目标。