电力推进科考船能效评估方法探索研究

以电力推进科考船为研究对象,分析了船舶能效管理计划(SEEMP)和智能船舶规范中货运船能效评估指标,结合科考船的实际情况,提出了适合电力推进科考船的能效评估指标,并通过实船能效计算验证指标的有效性,对电力推进科考船的能效评估进行了探索性研究,为后续研究提供参考。     

Shifting urban freight deliveries to the off-peak hours: a review of theory and practice

This paper presents a comprehensive review of the literature on off-peak hour deliveries (OPHD). The review identifies different approaches and policy levers used in the past, such as the laissez-faire approach, a road pricing approach, an incentives approach, and a regulatory approach. The paper also identifies different delivery reception schemes discussed in the literature. The authors complement the theory with a synthesis of pilot tests and the analysis of a set of interviews with practitioners (from the public sector and other organisations) in charge of OPHD programmes. The results from this review show the potential benefits that these programmes could bring about, the challenges faced in the early stages – along with potential solutions – and the significant progress that has been made in this domain in the last decade. According to the review, the results from the pilot tests tend to be positive, suggesting the importance of these programmes to reach more efficient and sustainable transportation systems.     

Operational profiles of ships in Norwegian waters: An activity-based approach to assess the benefits of hybrid and electric propulsion

Various regulations are imposed on shipping to increase energy efficiency and reduce environmental impacts. Alternative fuels and power systems are among the solutions for compliance with these regulations. The power system of a ship may not operate optimally because of the diversity of the operational profile during its lifetime. This article uses an activity-based approach and big data from the Automatic Identification System (AIS) to study the operational profiles of eight ship types operating in Norwegian waters around mainland Norway in 2016. The aim is to identify ship types that can benefit from electric and hybrid propulsion through analysis of their operational profiles. Close to shore, the operational profiles of various ship types are similar, and all ships spend a great proportion of their time with lower loads. As the distance from shore increases, the operational profiles of various ship types follow distinct trends. Among the considered ship types, reefers spend more operational time close to the diesel engine design condition. On the other hand, offshore and passenger ships show the most dynamic operational profiles and spend a large percentage of their operational time with a partial load, away from diesel engine design conditions. Such ships can benefit from hybridisation, diesel-electric propulsion, and other electric concepts, such as batteries and fuel cells. Another option is to downsize diesel engines for better operation while fuel cells and batteries supply peak and partial loads. Operational profiles are plotted and details of the approach are presented in the article.     

基于MCTS-HM的重型汽车多参数运行工况高效构建方法

提出了一种基于蒙特卡洛树搜索 （Monte Carlo Tree Search,MCTS） 和启发式方法 （Heuristic Method, HM）的多参数运行工况高效构建方法。根据工况质量要求,选取表征行驶工况特征的速度、加速度和坡度参数相关指标,设计工况的目标函数;改进多个启发式方法,确保被作用后的工况序列仍可满足行驶工况动态转移特性;采用MCTS选择更适合的启发式方法,进而高效地收敛至多参数目标行驶工况。基于重型汽车实际采集的试验数据,多次分析结果表明,生成的多参数行驶工况所有特征指标相对偏差均可保持在设定阈值以内,表明生成工况与原始数据特征具备一致性;相比于纯随机启发式方法,该方法能快速构建多参数期望运行工况。     

电动汽车制动能量回收系统评价方法研究

以电动汽车制动能量回收过程中不同能量间的传递关系为研究对象,提出了评价制动能量回收系统的测试方法和评价指标,搭建了电动汽车制动能量回收系统测试平台,并利用该平台对某电动汽车在NEDC工况下的制动能量回收效率进行了研究。试验结果表明,制动回收能量和回收率主要受制动能量回收控制策略、制动初速度和减速度的影响,当制动初速度低于控制策略中设定车速时系统将不进行能量回收;鉴于NEOC工况中制动初速度和减速度比较单一的情况,建议开发一种适用于电动汽车制动能量回收系统评价的工况。     

铝合金表面镍钼二元化学转化膜的制备及其耐腐蚀性

以NiSO4和Na2MoO4作为成膜主盐制备铝合金表面无铬的Ni-Mo二元化学转化膜,考察了溶液pH值、NiSO4浓度、Na2MoO4浓度、温度对Ni-Mo二元膜耐腐蚀性能的影响.耐腐蚀性试验、电化学分析和SEM表征结果表明：与空白铝合金试片、覆盖Ni一元膜的铝合金试片相比,覆盖Ni-Mo二元膜的铝合金具有更佳的耐腐蚀性能和更为平整的转化膜外观.     

基于改进ADC模型的某型两栖突击车作战效能评估

在传统ADC模型的基础上,通过分析对抗条件下战场环境的对抗效能及加入修正因子,提出一种改进的ADC模型,建立某型两栖突击车作战效能评估指标体系;通过利用计算机仿真生成实战环境下动态变量,计算平均效能值,使效能评估的结果更科学和符合实战的效果.     

高速公路限速设施对车辆燃油效率的影响研究

目前,为控制车速,我国在高速公路各路段设置了为数众多的限速设施,虽在一定程度上提高了道路交通安全,但对车辆的燃油效率和尾气排放却造成了不利的影响.为量化研究这一影响的程度,在对多条高速公路开展实地调研的基础上,分析了某一路段由于限速设施的存在而带来的车辆速度变化,继而运用车辆微观仿真软件TruckSim得到车辆在这一过程中的燃油消耗量;同时应用运行速度预测模型,计算假设限速设施不存在时车辆的行驶速度以及在这一预测车速下车辆通过同一路段的燃油消耗量,通过量化对比发现限速设施的存在成倍增加了燃油的消耗,这对控制尾气排放是极为不利的.最后提出在限速设施铺设前,应基于多种因素综合判断,全面考虑其可能带来的正负效应,真正做到科学、合理地使用限速设施.     

超静定土工格栅的强度特性测试研究

超静定土工格栅的测试在现行规范中难以找到明确的测试方法。为了对超静定土工格栅的强度力学性能进行测试研究,对超静定土工格栅采取了7种不同种方案的拉伸试验测试。试验结果表明：1超静定土工格栅的单向土工格栅多条受力时呈现出以上一级（少于此多条格栅一条的多条格栅）的单根格栅折算强度的大约90%增加;2建议现行相关规范中土工格栅单条法计算拉伸强度时试样最大拉力应乘以一折算系数,对于本实验中的超静定土工格栅,所乘折算系数取为10（1-0.9^N）,N为样品每米宽度上的肋数;3本研究中的超静定土工格栅的超静定作用使得单根格栅折算强度提高1.03%～14.06%,效果明显,建议更多超静定土工格栅的生产与应用。