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31.
悬挂式独轨列车转向架   总被引:3,自引:1,他引:2  
论述了一种悬挂式独轨列车转向架结构特征,对关键零部件如构架、驱动装置、牵引悬挂装置、走行轮和导向轮、车体与转向架之间的联接进行了介绍并进行了动力学性能分析,相关指标均满足要求。  相似文献   
32.
桥梁在地震中的碰撞反应不容忽视,文章综述了国内外桥梁地震碰撞的模拟方法以及各种形式桥梁结构的地震碰撞近期研究进展,归纳了桥梁碰撞的条件和影响因素,介绍了减轻桥梁结构地震碰撞方法和防落梁措施的主要研究成果,并对桥梁地震碰撞反应的进一步研究作了展望。  相似文献   
33.
Coastal and marine areas provide vital services to support the economic, cultural, recreational, and ecological needs of human communities, but sustaining these benefits necessitates a balance between growing and often competing uses and activities. Minimizing coastal zone conflict and reducing human-induced impacts to ecological resources requires access to consistent spatial information on the distribution and condition of marine resources. Seafloor mapping provides a detailed and reliable spatial template on the structure of the seafloor that has become a core data need for many resource management strategies. The absence of detailed maps of the seafloor hinders the effectiveness of priority setting in marine policy, regulatory processes, and marine stewardship. For large management areas, the relatively high cost of seafloor mapping and limited management budgets requires careful spatial prioritization. In order to address this problem, a consensus based approach, aided by decision-support tools, and participatory geographic information systems (GIS), was implemented in Long Island Sound to spatially prioritize locations, define additional data collection efforts needed, and identify products needed to inform decision-making. The methodology developed has utility for other states and regions in need of spatially prioritizing activities for coastal planning, and organizations charged with providing geospatial services to communities with broad informational needs.  相似文献   
34.
The noise induced by the fluctuant saturated steam flow under 250 °C in a stop-valve was numerically studied.The simulation was carried out using computational fluid dynamics(CFD) and ACTRAN.The acoustic field was investigated with Lighthill's acoustic analogy based on the properties of the flow field obtained using a large-eddy simulation that employs the LES-WALE dynamic model as the sub-grid-scale model.Firstly,the validation of mesh was well conducted,illustrating that two million elements were sufficient in this situation.Secondly,the treatment of the steam was deliberated,and conclusions indicate that when predicting the flow-induced noise of the stop-valve,the steam can be treated as incompressible gas at a low inlet velocity.Thirdly,the flow-induced noises under different inlet velocities were compared.The findings reveal it has remarkable influence on the flow-induced noises.Lastly,whether or not the heat preservation of the wall has influence on the noise was taken into account.The results show that heat preservation of the wall had little influence.  相似文献   
35.
The operating principle and specifications of a laser meter for measuring hydrosphere pressure variations are described in this article. The meter was designed to measure the hydrosphere pressure variations to a depth of 500 m within the frequency range of 0–1000 Hz at the level of background oscillations. Some results obtained using the apparatus under consideration when recording sea oscillations and waves of natural and artificial origin are presented.  相似文献   
36.
现有电动汽车底盘普遍为在传统汽车的基础上进行的改进,不能很好的适应电动汽车特有的结构,为更好的实现四轮转向的功能,重新设计了适合四轮转向电动汽车的车架。应用三维软件SolidWorks,通过整车虚拟装配确定了合理的四轮转向电动汽车的车架结构,进而建立了车架的三维模型。运用有限元分析理论,将模型导入Ansys Workbench软件后,建立了车架的有限元模型,对车架在弯曲和扭转工况下的静态结构性能进行了分析,得出相应工况下的应力和应变大小;还进行了模态分析,避免了共振。在满足强度和刚度的条件下对车架结构进行了改进,并通过焊接加工得到了适合四轮转向电动汽车的车架,对以后电动汽车底盘的改进设计提供了参考。  相似文献   
37.
杨璨  韩金刚  安鸿  肖维远  刘苹 《铁道车辆》2021,(1):97-101,109
货车空气制动系统因防尘不良导致内部清洁度差,影响制动系统性能。文章针对这一问题进行了防尘技术研究,通过调研和分析,识别出2个防尘不良点和8个污染物来源,针对防尘不良点及污染物进行了结构改进。改进后的货车制动系统防尘效果明显提升。  相似文献   
38.
“Big data” which admittedly means many things to many people is no longer confined to the realm of technology. Today it is a business imperative and is providing solutions to long-standing business challenges for banking and financial markets companies around the world. Financial services firms are leveraging big data to transform their processes, their organizations and the entire industry. Since 2012, the term “big data” has frequently been mentioned and used to describe and define the huge amount of data in the information explosive era and to name related technological development and innovation. As to the police work, the coming of big data era is not only a challenge but also an opportunity. Police agencies should go with the tide of development to start with such aspects as work thinking, top design, public information sharing and application and talent provision so as to promote the new development and progress of police work. This paper expounds the practical effect and significance of police big data application by cases happened in some areas.  相似文献   
39.
将模糊综合评判应用于鱼雷武器系统作战效能评估中,定量分析并处理评估中的模糊性问题。在建立评估指标体系的基础上,构建二级模糊综合评判模型,对指标进行综合评价,求出评价等级量化值。模型计算结果证明该方法具有较好的可行性。  相似文献   
40.
Travellers use the installations at multimodal areas to transfer from one mode of transport to another. In many cases these installations are called interchanges. This article characterises the users of transport interchanges to determine the fundamental attributes which they most value when they pass through the area. A Stated Choice survey is designed and administered and Mixed Logit models are estimated to calculate willingness to pay levels for three main attributes: transfer time, the quality of the available information and the services provided in the area. Travellers place most value on the quality of the information they receive and the available services rather than on transfer time, which contradicts the widely held opinion of experts in the field. This opens up new possibilities in the design of modern interchanges which should concentrate more on being welcoming areas with many information points rather than being based around minimising transfer times.  相似文献   
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