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当前我国建筑正处于高速发展时期,并且在很长一段时期内仍会呈上升状态,也对很多相关产业的发展起到一定的推动作用。同时,也对供暖体制改革提出了更高更具体的要求。供暖建筑的室内温度是依据热舒适性、经济性及生产工艺等方面条件制定的,对各种建筑的室内温度都有具体的规划。在室内温度比规定的温度低的情况下,就无法满足热舒适性、生产工艺等方面的需求;在高于规定的温度时,虽然热舒适性得到满足,但耗热量却相应提高,非常不不利于建筑节能要求。对供暖方法与智能供暖温度控制器的选用提出了室温调节的方法和措施。 相似文献
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单户供暖系统本着简单、经济、易行的原则，一般采用热水作为热媒，即热水作为热暖，热水供暖按循环系统，本文主要介绍重力循环热水供暖，基工作原理：靠不同温度下，水的密度差为动力面进行系统循环，具体的循环过程为：在系统工作之前，先将系统充满冷水，水在锅炉中被加热后水混升高，密度减少 变轻， 相似文献
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低温热水地板辐射供暖以温度不高于60℃热水作为热媒,在加热管内循环流动,加热地板,通过地面以辐射和对流的传热方式向室内供热的供暖方式。从低温热水地板辐射采暖的定义,发展史,特点,影响低温热水地板辐射采暖效果的主要因素以及低温热水地板辐射供暖在现实生活中的应用等几个方面来阐述低温热水地板辐射采暖成为采暖方式可靠的选择。 相似文献
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强制循环热水供暖是指热水锅炉生产出的一定温度的热水,通过系统中安装的循环水泵推动作用,使一定流量的热水沿着各管网支线分别输入各热用户,以满足用户供热的需求。循环泵实际运行的状况将直接关系到供暖的质量的好坏以及能源的浪费与节约和供暖运行费用的高低。因此,循环水泵系统中有十分重要的地位。 相似文献
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强制循环热水供暖是指热水锅炉生产出的一定温度的热水，通过系统中安装的循环水泵推动作用，使一定流量的热水沿着各管网支线分别输入各热用户，以满足用户供热的需求。循环泵实际运行的状况将直接关系到供暖的质量的好坏以及能源的浪费与节约和供暖运行费用的高低。因此，循环水泵系统中有十分重要的地位。 相似文献
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北方冬季室内温度控制系统的设计 总被引：2，自引：0，他引：2
在冬季我国北方城市普遍采用集中供暖。然而由于传统的供暖设备没有配备自动化的温度调节装置,造成了供热效率低和能源的浪费。基于此,本文以单片机为核心设计了一套室内温度PID控制系统,并在MATLAB软件下进行了数值仿真计算。理论分析表明该系统具有节能环保、控制精度高、稳定性好等优点,具有一定的实用价值。 相似文献
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在介绍节能与住宅建筑能耗的基础上,根据供暖建筑的热舒适性及经济性,从合理选择冷热源系统,减少冷（热）媒介输送过程的能耗,合理选择采暖、通风与空调系统．应用废热及可再生能源等方面阐述了暖通系统的节能措施。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献