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41.
4102、4102A、4105接地电阻测试仪由日本共立KYORITSU制造,机器采用数字电路设计,操作时不受接地电压及辅助接地棒的接地电阻影响,并可直接读取接地电阻值等优点,普遍应用在地区及县气象站防雷检测工作中。本文主要介绍地阻仪检测方法和降低接地体电阻的一些方法。 相似文献
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针对地下水丰富的巨厚砂层工程特点,采用沉井、机械钻孔 钢筋笼 滤网定喷固结桩孔周围土体等护壁、降水方案进行人工挖孔桩补桩,成功地对某工程桩基缺陷进行了补救。 相似文献
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在汽车制造行业,其中的手动变速器设计与制造过程中,如果和自动化技术充分接轨,可以大大提高生产制造的效率。本文从自动化技术的基本概况出发,接着对自动化技术的发展前提和重要意义进行简要说明,然后对汽车手动变换器和自动化技术应用进行介绍,主要研究了汽车手动变速器在设计制造中自动化技术的具体应用,发现设计制造过程中高效利用自动化技术可以提高制造效率,降低制造成本。 相似文献
46.
某水泥厂建厂时,在原料上料系统流程上采用了传统的机旁手动操作方式。几年来,手动操作控制逐渐显露出很多弊端,于是将手动按钮启停控制更换为机旁优先的自动控制方式。详细介绍了自动控制方式的实施方案和控制原理,系统改造后,画面友好、操作简单、控制灵活,改造效果良好。 相似文献
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Xuesong Liu Burcu Akinci Mario Bergés James H. Garrett 《Advanced Engineering Informatics》2013,27(4):496-505
Heating, Ventilation and Air-Conditioning (HVAC) systems account for more than 15% of the total energy consumption in the US. In order to improve the energy efficiency of HVAC systems, researchers have developed hundreds of algorithms to automatically analyze their performance. However, the complex information, such as configurations of HVAC systems, layouts and materials of building elements and dynamic data from the control systems, required by these algorithms inhibits the process of deploying them in real-world facilities. To address this challenge, we envision a framework that automatically integrates the required information items and provides them to the performance analysis algorithms for HVAC systems. This paper presents an approach to identify and document the information requirements from the publications that describe these algorithms. We extend the Information Delivery Manual (IDM) approach so that the identified information requirements can be mapped to multiple information sources that use various formats and schemas. This paper presents the extensions to the IDM approach and the results of using it to identify information requirements for performance analysis algorithms of HVAC systems. 相似文献
48.
《Ergonomics》2012,55(11):1722-1732
The advantages and disadvantages of different methods of carrying objects on spine loading are still not fully understood. Previous studies have either examined the effects of carrying using physiological measures or examined isolated spine segments using biomechanical models. Additionally, most studies have been restricted to only a small number of carrying conditions. Very few studies have attempted to examine the various factors influencing spine loading together. To improve understanding of interacting factors on carrying, this study assessed the lumbar spine loads of 16 subjects as they assumed six styles of carrying at two weight levels and two activity levels (walking vs. standing). Concurrent with each trial, a subject-specific biomechanical model was used to assess spine forces over the full lumbar spine. Most carrying methods in the trials resulted in relatively low levels of spine loading. Anterior/posterior (A/P) shear loading was the only spine-loading dimension that reached biomechanically meaningful levels. Two carrying conditions, with bins carried in front of the body, significantly increased A/P shear compared with other carrying styles. This increase appeared to be due to the greater moment arms occurring in these conditions. Many of the other carrying styles produced A/P shears that were similar to those observed when carrying nothing at all. Of all the tasks, the backpack carry characteristically produced especially low spine loads. The findings of the study suggest that to achieve optimal carrying in terms of spine loading, loads should be positioned close to the body, even when carrying relatively light loads. 相似文献
49.
Environmental barrier coatings (EBCs) are proposed as an option to reduce the high temperature water vapour corrosion in gas turbines ceramic components made of Si3N4 or SiC/SiCf, which are projected to achieve further energy efficient gas turbines. These coating are commonly designed as multilayer systems firmly attached to the ceramic substrate with the aim of retarding or avoiding its degradation after exposure to environmental conditions close to those in gas turbines. Therefore, to fulfil this function crack formation/propagation in the coatings must be controlled. In present work, three types of environmental barrier coatings fabricated by air plasma spray and containing a Si layer attached to SiC substrate plus 2 to 5 layers of different mullite/Y2O3 stabilized–ZrO2 mixtures are examined. To determine the level of residual stresses in the as-sprayed coating/substrate systems a three dimensional finite element model is developed and also tested for same coatings but aged under, high temperature and rich water vapour atmosphere. The model calculates the zones of maximum tensile stresses in the coatings which agree with experimental observation identifying the type, number and location of cracks. This model could be extended to similar EBC systems, and more importantly, could be use as a powerful designing tool for these complex structures. 相似文献
50.
This paper aims to propose an accurate and quick assembly time estimation method using the modular arrangement of predetermined time standards in the product design stage. It describes a classification of 2382 assembly operations that are incurred in manually assembling consumer electronics such as air conditioners, washing machines and refrigerators, and a method of choosing representative motions comprising work elements by examining the frequency distribution of the assembly operation’s motions. It then presents criteria for assigning time values associated with the movement of the representative motions using the design factors employed in design for assembly and the layout factors of an assembly line. A case study then presents the practicality of the method, the statistical results of which indicate that the proposed method would be accurate enough for practical purposes. 相似文献