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关键词： 空调系统   蓄冷   换热器  

摘要： 本文就蓄冷空调系统夜间蓄冷过程进行了分析计算。计算表明，蓄冷空调系统夜间蓄冷时间比蓄冷器的理论蓄冷时间要长，与蓄冷器性能、冷冻水流量、制冷机组的制冷量有直接关系。设计时，必须充分考虑蓄冷系统启动时的温度对蓄冷时间的影响，同时保证制冷机组的制冷量和冷冻水流量要与蓄冷器性能匹配。

关键词： decision analysis   forest planning   adaptive management   ecosystem management   national forests   analytical hierarchy process (AHP)  

摘要： Many authors have pointed out the need to firm up the 'fuzzy' ecosystem management paradigm and develop operationally practical processes to allow forest managers to accommodate more effectively the continuing rapid change in societal perspectives and goals. There are three spatial scales where clear, precise, practical ecosystem management processes are needed: the regional assessment scale, the forest-level scale, and the project-level scale. This paper proposes a practical decision analysis process for ecosystem management at the project-level scale. Goals are the focal point of management. To achieve them requires a formal, structured goal hierarchy, desired future conditions, several interesting alternatives, scenario analysis, and monitoring and evaluation of the results. The proposed process is firmly grounded in the body of theory and practice organized in the scientific literature under the heading of multi-objective decision analysis. An illustrative example of this decision analysis process is presented using the Bent Creek Experimental Forest of the Pisgah National Forest near Asheville, NC as a test case. Published by Elsevier Science B.V.

关键词： finite element system   structural modal reanalysis   topological modification   SENSITIVITY  

摘要： In this paper, a procedure for modal reanalysis of structures subjected to topological modifications is presented. The procedure is based on results of initial modal analysis of the original structure. The topological modifications include addition of joints, where the number of degrees of freedom (DOF) is increased. The method deals with the stiffness and mass matrices of structures directly, so it can be used with a general finite element system. It is shown that the proposed method is very effective, highly accurate and easy to implement on a computer. (C) 1999 Elsevier Science Ltd. All rights reserved.

关键词： 研究型   课程改革   创新能力   素质教育  

摘要： "小课题研究"校本课程是华东师大二附中自1996年以来进行的一项课程改革实验。实验旨在使学生通过自主进行的"小课题研究",得到科学研究的基本训练,培养其创新能力和其它相关素质。报告从分析该项实验对课程改革的意义入手,对"小课题研究"课程的特点、目标体系进行了概括,对研究的组织与实施过程作了介绍,并总结了该课程对学生发展的积极影响和课程实施的有益经验。

关键词： 东北电网   电压稳定   小阻抗支路   连续沓流法   功频静特性   静态电压稳定判据   大型电力系统  

摘要： 随着电力系统规模不断扩大,远距离送电的比例大大增加,人们对电能的要求和依赖越来越高,对电力系统的稳定性也提出了更高的要求.该文以东北电网电压稳定分析和调控科研项目为背景,对在该实际大型电力系统电压稳定性的研究过程中遇到的一些问题进行了深入地分析.内容涉及到改善连续潮流法的收剑性牧师高连续潮流法的计算速度的方法、计及功频静特性的连续潮流法算法研究、小阻抗支路潮流算法、实用静态电压稳定判据等方面内容.

关键词： 中国   工科   数学课程   教学经验交流会   CAI课件  

关键词： Key words: Disturbances – Human error – Manufacturing – Reliability – Systems analysis  

摘要： New demands on modern manufacturing systems, such as increased flexibility, higher quality standards, customer responsiveness, and higher innovative capacities, have emphasised the need for higher levels of overall system reliability. Within this context disturbances play a critical role, because of the effects they may have on production or on safety, which are both strong determinants of overall system performance. The main focus of this paper is the reliability of manufacturing personnel and the way in which this interrelates with overall system performance. A framework – Human Error and Disturbance Occurrence in Manufacturing Systems (HEDOMS) – integrates human reliability with overall system performance, relating human error with disturbance occurrence and handling. HEDOMS has been extended into a toolkit to enable the identification of potential for human error and disturbance occurrence in manufacturing systems, as well as the definition of suitable error reduction measures.

关键词： 《结构力学》课程   船舶结构力学   青年教师   学生动手能力   教学大纲   计算结构力学  

关键词： 学生能力   教学方法   教学过程   教学效果  

摘要： 本文以《作物营养诊断与施肥》教学方法改革为例，针对传统教学模式存在的问题，结合人才培养新要求和教学规律，以调动学生成为教学过程中最活跃的主体和培养学生运用知识的能力为目的，以启发式、参与式教学方法为主，建立和实践旨在培养学生动脑、动手、动笔、动口能力的教学方法体系。

关键词： 多媒体   VoD   综合业务网   资源预留协议  

摘要： 概述了资源预留协议ＲＳＶＰ的特点和工作原理。根据ＩＰ网上一个自行开发的基于ＲＳＶＰ的ＶｏＤ（ＶｉｄｅｏｏｎＤｅｍａｎｄ）实验系统．分析和研究了ＲＳＶＰ在实时传输系统中应用时的实际性能。获得了对建立该类系统具有一定指导意义的研究和实验结果。