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Profibus通信稳定性分析及故障快速排查
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作者 黄玉合 李尧森 《中华纸业》 CAS 2019年第18期46-52,共7页
Profibus是工业控制领域中的主流现场总线标准,应用广泛且快速高效,但是故障率高,很难维护。本文介绍了Profibus现场总线概念,Profibus总线传输技术,Profibus网络拓扑方式,影响Profibus通信稳定性的几个主要因素以及Profibus网络检测办... Profibus是工业控制领域中的主流现场总线标准,应用广泛且快速高效,但是故障率高,很难维护。本文介绍了Profibus现场总线概念,Profibus总线传输技术,Profibus网络拓扑方式,影响Profibus通信稳定性的几个主要因素以及Profibus网络检测办法和通信故障的快速排查等六方面的内容。结合本厂Profibus通信应用的部分实例和部分成功案例,参考多年通信控制的现场维护经验,简要分析了影响Profibus通信稳定性的因素,并介绍了几种故障的快速排查方法。 展开更多
关键词 PROFIBUS 传输速率 中继器 OLM 终端电阻 三分网络法 网络法 补锅法 拔萝卜法
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Study on preparation of In_2O_3 superfine powder via polymer-network process 被引量:1
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作者 刘胜峰 赵国丹 +1 位作者 韩效钊 唐述培 《Journal of Southeast University(English Edition)》 EI CAS 2004年第2期212-215,共4页
Nanocrystalline,single-phase undoped In 2O 3 was prepared by a polymer-network synthesis technique with indium nitrate as the starting material;several methods such as X-ray diffractometry (XRD) and transmission ele... Nanocrystalline,single-phase undoped In 2O 3 was prepared by a polymer-network synthesis technique with indium nitrate as the starting material;several methods such as X-ray diffractometry (XRD) and transmission electron microscopy (TEM) were employed to obtain detailed information on the crystallography and microstructual appearance of In 2O 3 superfine powders. The influence of the concentration of starting solution,calcination temperature and time on the particle size was also that investigated by means of the XRD patterns. Results indicate that the obtained powders are mostly crystalline single phase with uniform size and also that the size of the products can be controlled under proper condition. 展开更多
关键词 indium trioxide nanoscale particle polymer-network method
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Structure of Chinese City Network as Driven by Technological Knowledge Flows 被引量:32
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作者 MA Haitao FANG Chuanglin +1 位作者 PANG Bo WANG Shaojian 《Chinese Geographical Science》 SCIE CSCD 2015年第4期498-510,共13页
Based on patent cooperation data,this study used a range of city network analysis approaches in order to explore the structure of the Chinese city network which is driven by technological knowledge flows.The results r... Based on patent cooperation data,this study used a range of city network analysis approaches in order to explore the structure of the Chinese city network which is driven by technological knowledge flows.The results revealed the spatial structure,composition structure,hierarchical structure,group structure,and control structure of Chinese city network,as well as its dynamic factors.The major findings are:1) the spatial pattern presents a diamond structure,in which Wuhan is the central city;2) although the invention patent knowledge network is the main part of the broader inter-city innovative cooperation network,it is weaker than the utility model patent;3) as the senior level cities,Beijing,Shanghai and the cities in the Zhujiang(Pearl) River Delta Region show a strong capability of both spreading and controlling technological knowledge;4) whilst a national technology alliance has preliminarily formed,regional alliances have not been adequately established;5) even though the cooperation level amongst weak connection cities is not high,such cities still play an important role in the network as a result of their location within ′structural holes′ in the network;and 6) the major driving forces facilitating inter-city technological cooperation are geographical proximity,hierarchical proximity and technological proximity. 展开更多
关键词 technological knowledge flows patent cooperation city networks network structure structure holes cohesive subgroup
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