电气化背景下电动汽车热管理技术的进步与展望

电动汽车热管理已成为保障车辆宽温域环境适应能力、电池热安全和乘员舱热舒适性等方面的关键技术,同时也对电动汽车的能耗,特别是高低温环境下的整车能耗有着显著影响。随着车辆电气化和智能化的快速发展,与传统汽车相比,电动汽车热管理技术和发展路线在动力系统、空调系统等子热力系统和整车层面都呈现出了明显的差异和巨大的进步。综述了国内外电动汽车热管理技术领域重要的研究进展,阐述了电池、电机、热泵空调等子系统和整车集成热管理系统的技术进步,总结了当前电动汽车热管理亟待突破的技术重点和未来发展趋势。     

基于模糊综合评判的鱼雷武器系统作战效能评估研究

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。     

Super-low-frequency laser instrument for measuring hydrosphere pressure variations

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.     

Optimizing bus-size and headway in transit networks

Optimization models for calculating the best size for passenger carrying vehicles in urban areas were popular during the 1980s. These studies were abandoned in the ‘90s concluding that it was more efficient to use smaller buses at higher frequencies. This article returns to this controversial question, starting from the point of view that any calculation of bus size can only be made after considering the demand for each of the routes on the system. Therefore, an optimization model for sizing the buses and setting frequencies on each route in the system is proposed in accordance with the premises detailed below. The proposed model is a bi-level optimization model with constraints on bus capacity. The model allows buses of different sizes to be assigned to public transport routes optimizing the headways on each route in accordance with observed levels of demand. At the upper level the model considers the optimization of the system’s social and operating costs, these are understood to be the sum of the user’s and operator’s costs. At the lower level there is an assignment model for public transport with constraints on vehicle capacity which balances the flows for bus sizes and headways at each iteration. By graphically representing the results of the model applied to a real case, a series of useful conclusions are reached for the management and planning of a fleet of public transport vehicles.     

长江中游熊城段水流特性研究*

针对长江中游熊城段碍航水流问题,采用数学模型对该河段水流特性进行研究。结果表明：因河道弯曲狭窄、洲滩不高,且受洞庭湖出流影响,熊城段水流三维特性明显,存在横流、环流、回流等多种水流结构,对船舶航行影响大;在干线来流量2.5万～3.0万m³/s且洞庭湖水位偏高时,易发生船舶事故,应提醒船舶谨慎航行。     

原材料对铁路扣件绝缘轨距块低温性能的影响研究

哈齐高速铁路穿越高寒地区,铁路扣件保持轨距的能力对于运营安全和运营成本非常重要。铁路扣件绝缘轨距块以玻璃纤维(33%含量)增强聚酰胺66体系(PA66-GF33体系)作为原材料,在原材料中添加增韧剂来改善绝缘轨距块低温下的力学性能。本文研究增韧剂(马来酸酐接枝三元乙丙橡胶)含量变化对PA66-GF33体系在常温下力学性能的影响,及其在-30℃和-50℃环境下缺口冲击强度的变化。研究结果表明:原材料中增韧剂含量由3%增加到12%时,缺口冲击强度增大,拉伸强度、弯曲强度和熔融指数降低,扫描电镜分析显示缺口冲击试验的样条断面由脆性断裂逐渐表现为韧性断裂;当增韧剂含量为6%时,PA66-GF33体系同时具有较好的低温韧性和优良的加工性能,选择增韧剂含量为6%的PA66-GF33体系作为绝缘轨距块原材料,采用注塑工艺制备的绝缘轨距块剖面无内部空隙,并且在-45℃环境下冲击强度试验合格。     

桥梁地震碰撞反应研究与发展

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。     

铁路货车空气制动系统防尘技术研究

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。     

Economic Dispatch of Islanded Microgrid Considering a Cooperative Strategy Between Diesel Generator and Battery Energy Storage System

For the impact of intermittent resources’ high penetration on the economic dispatch of islanded microgrid, a new economic dispatch method is presented to minimize the overall generating cost for islanded microgrid, considering a cooperative strategy between diesel generator (hereinafter referred to as DE) and battery energy storage system (BESS). The optimum economic operation range of DE and the optimal set-point between DE and BESS are presented in the cooperative dispatch strategy, in which BESS is used fully to enable DE in a lower cost and higher efficient way. The results are analyzed under various operation conditions and also prove the validity of the proposed method.     

悬挂式独轨列车转向架

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。