浅析城市道路设计中路线方案的比选——以兰州市南环路(西客站段)联通工程方案为例

城市道路建设过程中,存在各种不确定因素。当道路沿线构筑物较多、周边环境较为复杂时,需进行多方案的比选,在兼顾经济指标与技术指标的前提下确定切实可行的路线方案。结合兰州市南环路(西客站段)联通工程方案,总结了城市建设中路线方案比选的几点思考,供道路专业人员参考。     

路面沥青复合料基于孔隙水压力损坏的实验分析探究

集料-沥青界面强度实验,集料-沥青界面黏合机能影响要素分析,孔隙水压对沥青复合料的损坏原理。本研究经过界面拉拔实验,分析沥青老化、温度和水分等要素对集料-沥青界面黏合机能的影响,探讨车辆载荷作用下孔水压对集料-沥青黏合机能的影响及损坏原理,以为同类沥青复合料路面工程应用提供研究和技术参考。     

Using GPS-data to determine optimum electric vehicle ranges: A Michigan case study

Fuel-switching personal transportation from gasoline to electricity offers many advantages, including lower noise, zero local air pollution, and petroleum-independence. But alleviations of greenhouse gas (GHG) emissions are more nuanced, due to many factors, including the car’s battery range. We use GPS-based trip data to determine use type-specific, GHG-optimized ranges. The dataset comprises 412 cars and 384,869 individual trips in Ann Arbor, Michigan, USA. We use previously developed algorithms to determine driver types, such as using the car to commute or not. Calibrating an existing life cycle GHG model to a forecast, low-carbon grid for Ann Arbor, we find that the optimum range varies not only with the drive train architecture (plugin-hybrid versus battery-only) and charging technology (fast versus slow) but also with the driver type. Across the 108 scenarios we investigated, the range that yields lowest GHG varies from 65 km (55+ year old drivers, ultrafast charging, plugin-hybrid) to 158 km (16–34 year old drivers, overnight charging, battery-only). The optimum GHG reduction that electric cars offer – here conservatively measured versus gasoline-only hybrid cars – is fairly stable, between 29% (16–34 year old drivers, overnight charging, battery-only) and 46% (commuters, ultrafast charging, plugin-hybrid). The electrification of total distances is between 66% and 86%. However, if cars do not have the optimum range, these metrics drop substantially. We conclude that matching the range to drivers’ typical trip distances, charging technology, and drivetrain is a crucial pre-requisite for electric vehicles to achieve their highest potential to reduce GHG emissions in personal transportation.     

某48 m+80 m+48 m混凝土梁桥施工监控方法研究

结合工程实例,介绍了混凝土梁桥施工监控方法,并得出监控结论,有关经验可供相关专业人员参考。     

Experimental study on the width of the turbulent area around bridge pier

At present, the method of calculating the turbulent flow width around the bridge pier is not given in the "Standard for Inland River Navigation" (GB50139-2004) in China, and the bridge designer usually increases the bridge span in order to ensure the navigation safety, which increases both of the structural design difficulty and the project investments. Therefore, it is extremely essential to give a research on the turbulent flow width around the bridge pier. Through the experiments of the fixed bed and the mobile bed, the factors influencing the turbulent flow width around the bridge pier have been analyzed, such as the approaching flow speed, the water depth, the angles between the bridge pier and the flow direction, the sizes of bridge pier, the shapes of the bridge pier, and the scouring around the bridge pier, etc. Through applying the dimension analytic method to the measured data, the formula of calculating the turbulent flow width around the bridge pier is then inferred.     

舰船复合材料结构物应用工程技术特点及内涵分析

针对舰船平台技术所面临的发展需求与挑战,从总体平台特性、综合隐身以及综合保障技术发展需求的角度,简要分析开展舰船复合材料结构物应用工程的必要性和紧迫性.以西方国家潜艇应用为例,梳理国外舰船复合材料结构物应用发展思路,提出并阐明舰船功能复合材料结构物应用工程的3个"一体化"技术特点,着重探讨总体/结构设计技术的定义、内涵...     

摆盘发动机空间机构的震动力完全平衡研究

特种摆盘发动机在航空航天、武器系统等方面有着广泛的应用。从空间机构学理论出发,抽象出机构模型,利用空间机构的通路定理,分析摆盘发动机机构震动力完全平衡的可行性,并推导出该空间机构必须满足的平衡条件;结合发动机自身结构特点,研究震动力完全平衡时各构件的结构条件与配重条件;同时针对所给条件的不足之处提出进一步的分析研究方法,为发动机在结构设计与减振方面提供理论基础。     

基于OWA算子和语言OWA算子的舰船研制方案群决策

针对舰船研制方案存在的问题以及定量指标和定性指标的特点,提出一种基于OWA算子和语言OWA算子的综合多属性群决策方法,再结合效用函数来对其进行研究.将多位专家对研制方案的意见综合为专家组的一致意见,实现了舰船研制方案的评估.最后,通过实例说明该方法的有效性及合理性.     

五螺杆泵型线分析及改进

简缩了传统五螺杆泵齿型实用计算,并对型线改进进行探讨.给出提高五螺杆泵性价比的方案及计算实例,以供不同生产条件之参考.     

用人工神经网络预测沥青路面材料的回弹模量

将人工神经网络应用于沥青路面材料的回弹模量的预测 ,提出了一种有效的预测方法 ,并构造了预测回弹模量的神经网络模型 .预测结果表明 ,该模型具有较高的预测精度 ,为预测路面材料的回弹模量等力学指标提供了一种新的方法