潜艇水下动力抗沉技术研究

潜艇水下动力抗沉技术是提高潜艇生命力的重要措施。阐述了国内外潜艇水下动力抗沉技术发展现状,重点探讨了高压气吹除技术的模型和肼吹除技术的原理,并且举例说明高压气吹除技术对潜艇水下动力抗沉具有良好的效果。最后与高压气吹除相比较,结论得出肼吹除技术也具有很好的应用前景。     

城市轨道交通通风空调设备选型附加系数探讨

已运行的轨道交通通风空调设备,由于选型存在不合理因素,有些不能较好地适应系统的实际需求,而设备选型附加系数取值的合理性是重要原因之一。先对现行设计规范、手册、技术措施、轨道交通工程设计技术要求对设备选型附加系数取值的规定进行了分析;然后对各种通风空调设备分析各参数需要修正的原因、各参数间相互关联对修正的影响;最后提出各类设备需要修正的主要参数及其附加系数的建议值。     

ATCEM: a synthetic model for evaluating air traffic complexity

Air traffic complexity, which measures the disorder of air traffic distribution, has become the critical indicator to reflect air traffic controller workload in air traffic management (ATM) system. However, it is hard to assess the system accurately because there are too many correlated factors, which make the air traffic complexity nonlinear. This paper presents an air traffic complexity evaluation model with integrated classification using computational intelligence (ATCEM). To avoid redundant factors, critical factors contributing to complexity are analyzed and selected from numerous factors in the ATCEM. Subsequently, to construct the mapping relationship between selected factors and air traffic complexity, an integrated classifier is built in ATCEM. With efficient training and learning based on aviation domain knowledge, the integrated classifier can effectively and stably reflect the mapping relationship between selected factors and the category of air traffic complexity to ensure the precision of the evaluation. Empirical studies using real data of the southwest airspace of China show that the ATCEM outperforms a number of state‐of‐the‐art models. Moreover, using the critical complexity factors selected in ATCEM, the air traffic complexity could be effectively estimated. Copyright © 2015 John Wiley & Sons, Ltd.     

海水源热泵技术在港口建设中的应用

结合海水源热泵在大连港的应用情况介绍其技术原理、设备选型及其与传统空调系统相比较的优越性。     

广州地铁车辆制动系统的特点分析

综述广州地铁1、2、3号线车辆制动方式、主要组成部件、作用原理及特点,着重介绍采用目前世界上最先进技术的3号线车辆制动系统,同时对供气系统也作了分析和说明。     

空调硬卧车内人体热舒适性研究

针对目前空调硬卧车内气流分布不均匀,不同铺位的乘客对车厢内的热舒适感差别较大这一现状,采用计算流体动力学对空调硬卧车内流场和温度场进行了数值模拟,研究了空调硬卧车内空气流动速度和温度分布规律及热舒适评价指标PMV和人体吹风感指标PD分布状况。研究结果对于改变目前车厢内上、中、下铺气流分布不均的现状,改善车厢内人体热舒适环境提供了理论依据。     

金属材料可焊性与机车空气管道材质选择

针对电力机车空气管道材质的选择问题,详细分析了一些常用同种金属材料和异种金属材料的可焊性,并根据应用经验提出选材参考对象。     

国产地铁车辆制动系统

介绍国产地铁车辆制动系统的主要性能及采用的德国克诺尔制动机公司生产的模拟式电控制动系统的主要组成部件及作用原理。其中,微处理制动控制与车轮滑行控制电子单元KBGM-P,以及制动控制单元BCU是该模拟式电控制动系统的核心控制部件。制动控制单元的所有部件集中地装在一个单独的具有气路的集成板上,结构紧凑,便于检修维护。     

新一代机车车辆制动装置

483型空气分配阀是前苏联研制的一种较先进的货运机车车辆用分配阀，在该分配阀的基础上，新研制出了483系列客运机车车辆用分配阀(包括电空制动机)，实现了客货机车车辆制动机在结构和原理上的最大限度地统一，并提高了旅客列车的制动性能。本文介绍了新研制的483系列分配阀的结构组成和性能特点。     

Development of a model for an air brake system with leaks and a scheme for the estimation of the steady-state pushrod stroke

Brake systems in trucks are crucial for ensuring the safety of vehicles and passengers on the roadways. Most trucks in the USA are equipped with S-cam drum brake systems and they are sensitive to maintenance. Brake deficiencies such as leaks and out-of-adjustment of the pushrod are a major cause of accidents involving trucks. Leaks in the air brake systems drastically affect braking performance by decreasing the maximum attainable braking pressure and also increasing the time required to attain the same, thereby resulting in longer stopping distances. Out-of-adjustment of the pushrod leads to loss of braking torque even if no leaks are present in the air brake system. In this paper, we present a mathematical model for an air brake system in the presence of leaks, with a view towards developing a diagnostic system for the air brake system based on the models. Additionally, we present a scheme that estimates the severity of leak in terms of the mass flow rate of air leaking from the air brake system to the atmosphere. This scheme can be implemented using a simple look-up table. We also present a steady-state pushrod stroke estimation scheme, based on brake chamber pressure measurements in the absence of any leaks in the air brake system.