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程控无油超高真空排气台的研制 被引量:3
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作者 米伦 李晓勇 +1 位作者 王远 李建 《真空与低温》 2005年第3期170-174,共5页
由外冷式吸附泵作为前级泵、溅射离子泵作为主抽真空泵构成无油超高真空系统,采用计算机控制技术,以真空度为工艺进程判据,对器件进行烘烤排气,实现电真空器件的真空排气工艺的自动控制。介绍了无油超高真空系统、控制系统、烘箱与热功... 由外冷式吸附泵作为前级泵、溅射离子泵作为主抽真空泵构成无油超高真空系统,采用计算机控制技术,以真空度为工艺进程判据,对器件进行烘烤排气,实现电真空器件的真空排气工艺的自动控制。介绍了无油超高真空系统、控制系统、烘箱与热功率以及软件的设计。排气台为多工位结构,具有气体质谱分析和充气功能;空载时极限真空度优于8×10-7Pa;烘箱烘烤温度为25~600℃,连续可调,恒温精度优于±1%;分析质量数为1~80。程控排气台设计合理,操作简便,计算机控制技术精细了工艺过程控制量,排除了人为因素,其性能稳定可靠,可满足使用要求。 展开更多
关键词 无油超高真空系统 真空度 程控工艺
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MACHINING-FEATURE BASED 3-AXIS AUTOMATIC NC PROGRAMMING FOR HIGH-SPEED MILLING 被引量:1
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作者 孙全平 汪通悦 +1 位作者 廖文和 何宁 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第2期150-156,共7页
Machining-features of the workplace are described by using of the object-oriented (O-O) technology. Geometrical machining-features are recognized in the given cut region by using the maximum membership priciple abou... Machining-features of the workplace are described by using of the object-oriented (O-O) technology. Geometrical machining-features are recognized in the given cut region by using the maximum membership priciple about the fuzzy set. Depending on the IF-THEN rule and the fuzzy matching method, the rough information of the machining-process for high-speed milling (HSM) is extracted based on the database of machining-process for HSM. The optimization model of machining-process scheme is established to obtain shorter cut time, lower cost or higher surface quality. It is helpful to form successful cases for HSM. NC programming for HSM is realized according to optimized machining-process data from HSM cases selected by the optimization model and the extracted information of machining-process. 展开更多
关键词 high-speed milling machining-feature) process-knowledge NC programming
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Research on Contract Management and Control in the Process of Project Cost
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作者 Lingtao BIAN 《International Journal of Technology Management》 2015年第5期44-46,共3页
In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management ... In the current economic situation, strengthening the contract management of the construction cost has a beautifully role. At the same time, according to construction project cost management, the scientific management of the contract, can promote the reasonable and balanced investment cost allocation in the quality and safety and other aspects of the project, so that the construction project can obtain higher added value, and to further promote China' s economic construction and accelerate the pace of the city. This paper first briefly elaborates our construction project cost of the contract management on the present situation, and some problems are analyzed and discussed, and then puts forward some suggestions on the measures and countermeasures for cost management of construction engineering contract. 展开更多
关键词 Construction project Cost management Contract management Problems and countermeasures
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A MEMS stronglink with multi-try function used for PC startup in authentication system
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作者 李胜勇 陈文元 +3 位作者 张卫平 肖奇军 谈顺毅 冯敏华 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期159-164,共6页
The stronglink with muhi-try function based on MEMS technology and the PC startup in authentication system have been designed and fabricated. The generation principle and structure of UQS code are introduced, which co... The stronglink with muhi-try function based on MEMS technology and the PC startup in authentication system have been designed and fabricated. The generation principle and structure of UQS code are introduced, which consists of two groups of metal counter-meshing gears, two pawl/ratchet mechanisms, two driving micromotors and two resetting micromotors. The energy-coupling element is a photoelectric sensor with a circular and notched plate. It is fabricated using the UV-LiGA process and precision mechanical engineering. The PC startup authentication system is controlled by BIOS program, which is written into the chip according with special format. The program in BIOS output signals controls the running of stronglink to finish the process of authentication. The device can run more than 10000 times before a stop. The driving voltage is 12 V, and the normal decoding time is 3 s. 展开更多
关键词 stronglink multi-try UQS AUTHENTICATION PC startup
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Controlling the Risk of Construction Delay in the Middle East: State-of-the-Art Review
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作者 Omayma Hashim Motaleb Mohammed Kishk 《Journal of Civil Engineering and Architecture》 2015年第5期506-516,共11页
The financial crisis in late 2008 arrested economic development in the construction sector in the Middle East, with the result that investors' confidence in the sector is severely depressed. Delays constitute one of ... The financial crisis in late 2008 arrested economic development in the construction sector in the Middle East, with the result that investors' confidence in the sector is severely depressed. Delays constitute one of the highest impediments to project success. In this respect, the traditional management is no longer sufficient for construction project success. The objective of this study is to conduct a literature review to identify additional effective measures for controlling the potential delays risks in construction projects in order to maximize the opportunities for success in those projects. Thirty-six scholarly articles published between 2000 and 2011 are reviewed to identify related MDRC (measures for delays risks control). This survey reveals that 60% of the studies are related to decision-making, performance, risk management variations and poor management knowledge of stakeholders and that 20% of these studies are undertaken in the Middle East. A further 25% of the studies are related to the lack of financial risk by stakeholders, and of these 14% are in the Middle East. A knowledge gap is identified in terms of project performance, stakeholder management and risk management, which are seen as significant measures of success in controlling project delay. 展开更多
关键词 Measures of delays risks control risk management project management STAKEHOLDERS Middle East.
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Modeling of Welding Process by Robotic Vision 被引量:1
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作者 Isak Karabegovic Samir Vojic Ermin Husak 《Journal of Mechanics Engineering and Automation》 2011年第2期135-138,共4页
Modeling of welding process by robotic vision is basically a theoretical problem, means mainly on physical problem, and also technological problem. To obtain a good model of welding process by robotic vision, theoreti... Modeling of welding process by robotic vision is basically a theoretical problem, means mainly on physical problem, and also technological problem. To obtain a good model of welding process by robotic vision, theoretical researches are required but also constant experimental researches of several welding processes. Until today researches of welding processes has been based on empirical and detailed experimentation. This paper presents welding process by robotic and automation points of view with application of new technologies. Welding robotic system has been designed with possibility to control and inspect this process. Parameters that should be controlled during the process have been identified to reach desired quality. Figure of control system of welding process by robotic vision is given in this paper. 展开更多
关键词 MODELING WELDING robotic vision control.
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