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31.
Simon-Cella高空作业车的自动调平机构 总被引:3,自引:0,他引:3
董大为 《筑路机械与施工机械化》2004,21(6):33-34
介绍了意大利Simon公司VTl65型高空作业车的主要技术参数、整体结构以及该车的一些主要特点,分析了电液自动调平机构的液压电子回路,为高性能高空作业车的研究设计提供了参考。 相似文献
32.
介绍T815-2型自卸车交流发电机原理,DLR-2P28V型电压调节器电路分析与常见故障检修。 相似文献
33.
ZHANG Hong-mei 《公路交通科技》2005,(Z2)
根据西部黄土高原区生态环境特征和西部交通建设的特点,提出公路交通建设中面临的主要生态问题,重点对西部交通建设中主要的生态环境问题进行了分析,在此基础上,建议在公路工程建设中应采取的生态环境保护措施。 相似文献
34.
简述小松、大宇等挖掘机电子控制系统、电子功率优化系统和工作模式控制系统,介绍自动怠速装置的原理及故障诊断,详细论述电子油门和发动机电子控制系统工作原理及故障诊断。 相似文献
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The role of residential self-selection has become a major subject in the debate over the relationships between the built environment and travel behavior. Numerous previous empirical studies on this subject have provided valuable insights into the associations between the built environment and travel behavior. However, the vast majority of the studies were conducted in North American and European cities; yet this research is still in its infancy in most developing countries, including China, where residential and transport choices are likely to be more constrained and travel-related attitudes quite different from those in the developed world. Using the data collected from 2038 residents currently living in TOD neighborhoods and non-TOD neighborhoods in Shanghai City, this paper aims to partly fill the gaps by investigating the causal relationship between the built environment and travel behavior in the Chinese context. More specifically, this paper employs Heckman’s sample selection model to examine the reduction impacts of TOD on personal vehicle kilometers traveled (VKT), controlling for self-selection. The results show that whilst the effects of residential self-selection are apparent; the built environment exhibits the most significant impacts on travel behavior, playing the dominant role. These findings produce a sound basis for local policymakers to better understand the nature and magnitude toward the impacts of the built environment on travel behavior. Providing the government department with reassurance that effective interventions and policies on land use aimed toward altering the built environment would actually lead to meaningful changes in travel behavior. 相似文献
38.
Environmental contours are often applied in probabilistic structural reliability analysis to identify extreme environmental conditions that may give rise to extreme loads and responses. They facilitate approximate long term analysis of critical structural responses in situations where computationally heavy and time-consuming response calculations makes full long-term analysis infeasible. The environmental contour method identifies extreme environmental conditions that are expected to give rise to extreme structural response of marine structures. The extreme responses can then be estimated by performing response calculations for environmental conditions along the contours.Response-based analysis is an alternative, where extreme value analysis is performed on the actual response rather than on the environmental conditions. For complex structures, this is often not practical due to computationally heavy response calculations. However, by establishing statistical emulators of the response, using machine learning techniques, one may obtain long time-series of the structural response and use this to estimate extreme responses.In this paper, various contour methods will be compared to response-based estimation of extreme vertical bending moment for a tanker. A response emulator based on Gaussian processes regression with adaptive sampling has been established based on response calculations from a hydrodynamic model. Long time-series of sea-state parameters such as significant wave height and wave period are used to construct N-year environmental contours and the extreme N-year response is estimated from numerical calculations for identified sea states. At the same time, the response emulator is applied on the time series to provide long time-series of structural response, in this case vertical bending moment of a tanker. Extreme value analysis is then performed directly on the responses to estimate the N-year extreme response. The results from either method will then be compared, and it is possible to evaluate the accuracy of the environmental contour method in estimating the response. Moreover, different contour methods will be compared. 相似文献
39.
陈勇 《浙江交通职业技术学院学报》2012,13(2):48-52
本文以基于工作过程系统化思想,对汽车车身修复技术课程进行了设计.阐述了本课程基于工作过程系统化的课程设计思路、学习情境设计、课程教学方法及考核方法设计. 相似文献
40.
This study intends to empirically verify Jacobs’ urban vitality theory, which was based on the observations of her New York City neighborhood in the mid-20th century. To examine the relationship between the residential built environment and walking activity, we used telephone survey data consisting of 1823 valid samples from across Seoul, a city characterized by a high population density and a well-established public transportation system. Respondents were asked questions about their residential location, their demographic and socioeconomic characteristics, and their walking activities. This study then used geographic information systems to measure objective indicators of built environment variables within 500-meter buffer areas based on the home addresses of the respondents. Then, this study constructed multilevel regression models with walking activity as the dependent variable. Our results indicated that walking activity is associated with Jacobs’ six conditions for urban vitality, including land use mix, density, block size, building age, accessibility, and border vacuums. 相似文献