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871.
文章针对高速磁浮车辆悬浮架装配关键技术展开研究,通过悬浮架的功能与技术以及各结构模块组成关系对悬浮架进行分析,确定装配工艺流程、工艺重点与难点,实现了装配的技术要求。  相似文献   
872.
山区铁路路堑边坡常出现滑塌现象,为保证铁路运营安全,需及时采取整治措施。本文以某铁路滑塌路堑边坡为例,根据现场调查、地质水文资料,结合数值模拟结果剖析路堑边坡稳定性及滑塌机制,并对引起边坡滑塌的因素制定针对性整治措施。结果表明:连续降雨以及长期排水不畅会导致地层性质减弱、滑动面下移,将诱发加固边坡发生二次滑塌;为减少对既有边坡防护的扰动破坏,对二次垮塌边坡挡护进行合理加固补强亦可满足边坡稳定要求。  相似文献   
873.
近年来有轨电车在国内迅猛发展,了解各地发展情况及问题是促进行业可持续发展的基本要求。中国有轨电车蓝皮书编写组展开全国调研并撰写了蓝皮书,报告研究并分析有轨电车的功能定位、项目审批、规划设计、设备、运营维保、立法和标准等关键技术和管理情况,指出我国有轨电车市场前景广阔、产业初步形成、创新技术得以应用的发展成就,但也存在审批制度不健全、法律法规及标准缺失、客流普遍偏低、运营人才及经验缺乏等风险。未来全行业应在法律及标准体系完善、规范PPP模式、提高技术国产化率等方面做出努力。  相似文献   
874.
A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is the use of alternative fuel vehicles (AFV). As global GHG emission standards have been in place for passenger cars for several years, infrastructure modelling for new AFV is an established topic. However, as the regulatory focus shifts towards heavy-duty vehicles (HDV), the market diffusion of AFV-HDV will increase as will planning the relevant AFV infrastructure for HDV. Existing modelling approaches need to be adapted, because the energy demand per individual refill increases significantly for HDV and there are regulatory as well as technical limitations for alternative fuel station (AFS) capacities at the same time. While the current research takes capacity restrictions for single stations into account, capacity limits for locations (i.e. nodes) – the places where refuelling stations are built such as highway entries, exits or intersections – are not yet considered. We extend existing models in this respect and introduce an optimal development for AFS considering (station) location capacity restrictions. The proposed method is applied to a case study of a potential fuel cell heavy-duty vehicle AFS network. We find that the location capacity limit has a major impact on the number of stations required, station utilization and station portfolio variety.  相似文献   
875.
随着高速列车运行速度的提高,采用包括风阻制动技术在内的组合制动方式以保证高速列车紧急制动时达到规定的制动距离成为热点研究方向。文章针对目前研发中的新型分布式风阻制动装置,采用计算流体力学(CFD)方法对安装风阻制动装置的列车进行了制动力计算,并将相关结果作为输入参数,评估不同布置工况下风阻制动装置对高速列车制动距离的影响。依据评估结果,确定了风阻制动装置的适用速度范围、使用特点及效果。  相似文献   
876.
Vehicle-to-vehicle communication systems allow vehicles to share state information with one another to improve safety and efficiency of transportation networks. One of the key applications of such a system is in the prediction and avoidance of collisions between vehicles. If a method to do this is to succeed it must be robust to measurement uncertainty and to loss of communication links. The method should also be general enough that it does not rely on constraints on vehicle motion for the accuracy of its predictions. It should work for all interactions between vehicles and not just a select subset. This paper presents a method to calculate Time to Collision for unconstrained vehicle motion. This metric is gated using a novel technique based on relative vehicle motion that we call “looming”. Finally, these ideas are integrated into a probabilistic framework that accounts for uncertainty in vehicle state and loss of vehicle-to-vehicle communication. Together this work represents a new way of considering vehicle collision estimation. These algorithms are validated on data collected from real world vehicle trials.  相似文献   
877.
This paper introduces a relocation model for free-floating Carsharing (FFCS) systems with conventional and electric vehicles (EVs). In case of imbalances caused by one-way trips, the approach recommends profit maximizing vehicle relocations. Unlike existing approaches, two types of relocations are distinguished: inter zone relocations moving vehicles between defined macroscopic zones of the operating area and intra zone relocations moving vehicles within such zones. Relocations are combined with the unplugging and recharging of EVs and the refueling of conventional vehicles. In addition, remaining pure service trips are suggested. A historical data analysis and zone categorization module enables the calculation of target vehicle distributions. Unlike existing approaches, macroscopic optimization steps are supplemented by microscopic rule-based steps. This enables relocation recommendations on the individual vehicle level with the exact GPS coordinates of the relocation end positions. The approach is practice-ready with low computational times even for large-scale scenarios.To assess the impact of relocations on the system’s operation, the model is applied to a FFCS system in Munich, Germany within three real world field tests. Test three shows the highest degree of automation and represents the final version of the model. Its evaluation shows very promising results. Most importantly, the profit is increased by 5.8% and the sales per vehicle by up to 10%. The mean idle time per trip end is decreased by 4%.  相似文献   
878.
通过对桥头跳车现象的产生机理及其危害的分析,结合实际工作经验,提出防治措施,并对此防治措施展开探讨。  相似文献   
879.
SPZ1100/40双线铁路箱梁造桥机的设计   总被引:2,自引:0,他引:2  
根据双线整孔简支箱梁节段预制拼装的施工要求,对造桥机的结构形式、梁段就位方式、走行方式、支承方式、下托梁和调位落架装置等进行了技术比较,确定了SPZ1100/40造桥机的总体构思。详细介绍了该机的构造和技术特点。实践证明,该机的设计和应用是成功的,为我国铁路简支梁向大跨方向的发展提供了先进的施工技术,具有广阔的应用前景。  相似文献   
880.
研究了化学成分、热处理工艺等因素对SiO_2-B_2O_3-Al_2O_3-MgO-K_2O-F系可加工玻璃陶瓷的组织和性能的影响。改变化学成分可影响玻化及结晶过程。结果表明,降低MgO、Al_2O_3的含量,可降低玻化温度;Al_2O_3强烈抑制失透;F对玻化过程的影响不大,但在晶化过程中起形核剂的作用。在结晶处理过程中,随着核化温度的升高,核化时同的延长,晶体的形核率增高,晶体的体积百分数增大。晶体的体积百分数越高,纵横比越大,玻璃陶瓷的可加工性越好。  相似文献   
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