共查询到13条相似文献,搜索用时 46 毫秒
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快开盲板一般由筒体、法兰、勾圈或卡箍、短节、安全连锁机构、开闭机构、转臂等部件构成。为了解决盲板开启困难、密封处渗漏等常见问题,从锁环式快开盲板的密封结构、工作原理和主要零部件作用入手,结合生产实际过程中典型案例,分析故障原因,提出解决措施,保障了站场安全平稳运行。 相似文献
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埋地管道铺建时预留的分支管道接口不合适,需要在管道带压正常运行的状态下进行开孔施工.介绍了埋地燃气管道带压开孔技术的专用设备组成、操作方法、步骤和技术要点.实践证明:这项带压开孔技术的应用会更加广泛. 相似文献
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以工作流技术为核心对企业节能减排项目管理系统进行建模,从而使项目管理的业务逻辑和具体功能独立开来,达到项目管理的统一、有序的管理,提高管理系统的兼容性和整体协作性,使系统的组织更顺畅,工作流程更灵活、适应性更强。采用快速开发平台技术,通过参数定制的方式进行开发,相较于传统的编程开发模式,通过对智能报表、数据维护、MVC业务控制和其他参数的管理,可以方便、快速、高质量地开发复杂的业务系统。 相似文献
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Sadayuki Yagi 《运输规划与技术》2013,36(5):589-612
Abstract An area pricing scheme for Jakarta, Indonesia, is currently under review as a transportation control measure along with the operation of new bus rapid transit (BRT) system. While this scheme may be effective for congestion reduction in the central business district (CBD), provision of alternative means of transportation for auto users that are ‘pushed-out’ is of great importance to obtain public acceptance. Hence, it is necessary to simulate simultaneously the area pricing scheme and the BRT development which may serve as an alternative for assumed ‘pushed-out’ auto users. Utilizing data from an opinion survey, this paper studies how BRT and auto ridership are likely to vary as a function of traveler and system attributes. Additionally, the study attempts to evaluate the way this new travel mode is distinguished from other existing conventional transportation alternatives in Jakarta. The survey data contains socioeconomic information of over 1000 respondents as well as details of to-work/school trips to the CBD including mode, travel cost, time, etc. Respondents were asked about their willingness to shift from their current mode to BRT to make the same travel for different BRT fare levels. Modeling efforts suggest that a mixed logit model performs better in explaining choice behavior. Therefore, this model was used for policy simulation. The simulation results brought about many implications as to the tested policies. While the developed models may be applied only to future BRT corridors in which the survey was conducted, they capture the key variables that are significant in explaining mode choice behavior and present great potential for practical use in policy simulation and analysis in a large metropolitan area of the developing world. 相似文献
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M. Estrada M. Roca-Riu H. Badia F. Robusté C.F. Daganzo 《Transportation Research Part A: Policy and Practice》2011,45(9):935-950
This paper presents and tests a method to design high-performance transit networks. The method produces conceptual plans for geometric idealizations of a particular city that are later adapted to the real conditions. These conceptual plans are generalizations of the hybrid network concept proposed in Daganzo (2010). The best plan for a specific application is chosen via optimization. The objective function is composed of analytic formulae for a concept’s agency cost and user level of service. These formulae include as parameters key demand-side attributes of the city, assumed to be rectangular, and supply-side attributes of the transit technology. They also include as decision variables the system’s line and stop spacings, the degree to which it focuses passenger trips on the city center, and the service headway. These decision variables are sufficient to define an idealized geometric layout of the system and an operating plan. This layout-operating plan is then used as a design target when developing the real, detailed master plan. Ultimately, the latter is simulated to obtain more accurate cost and level of service estimates.This process has been applied to design a high performance bus (HPB) network for Barcelona (Spain). The idealized solution for Barcelona includes 182 km of one-way infrastructure, uses 250 vehicles and costs 42,489 €/h to build and run. These figures only amount to about one third of the agency resources and cost currently used to provide bus service. A detailed design that resembles this target and conforms to the peculiarities of the city is also presented and simulated. The agency cost and user level of service metrics of the simulated system differ from those of the idealized model by less than 10%. Although the designed and simulated HPB systems provide sub-optimal spatial coverage because Barcelona lacks suitable streets, the level of service is good. Simulations suggest that if the proposed system was implemented side-by-side with the current one, it would capture most of the demand. 相似文献
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文章提出一个新的横张预应力混凝土梁桥建造工法,扩大了横张预应力混凝土的适用范围。该工法利用虚功原理和平衡构形概念,通过双榀对称侧立预制空心梁的方法,以接近普通钢筋混凝土的价值,可制作得预应力混凝土,进一步降低了预应力混凝土桥的建造难度,提高了施工的可靠性,具有一定的技术、经济和社会效益。 相似文献