驱逐舰烟气排放过程数值仿真及同模型试验比较研究(英文)

The exhaust smoke dispersion for a generic frigate is investigated numerically through the numerical solution of the governing fluid flow, energy, species and turbulence equations. The main objective of this work is to obtain the effects of the yaw angle, velocity ratio and buoyancy on the dispersion of the exhaust smoke. The numerical method is based on the fully conserved control-volume representation of the fully elliptic Navier-Stokes equations. Turbulence is modeled using a two-equation(k-ε) model. The flow visualization tests using a 1/100 scale model of the frigate in the wind tunnel were also carried out to determine the exhaust plume path and to validate the computational results. The results show that down wash phenomena occurs for the yaw angles between ψ =10° and 20°. The results with different exhaust gas temperatures show that the buoyancy effect increases with the increasing of the exhaust gas temperature. However, its effect on the plume rise is less significant in comparison with its momentum. A good agreement between the predictions and experiment results is obtained.     

路段环境交通容量优化模型与算法研究

在分析路段环境交通容量主要影响因素的基础上,探讨了路段的污染控制约束条件,以及通行能力约束条件,建立了通行能力和污染控制约束的环境交通容量优化模型,构建了基于增广拉格朗日松弛和辅助问题原则法的模型求解算法.实例结果表明,构建的算法能够快速有效地求解这类环境交通容量优化模型.     

浅议现代玻璃幕墙建筑光污染

着重探讨现代玻璃幕墙建筑构成光污染的成因，通过对玻璃幕墙建筑的光照分析，探讨解决光污染的有效方法和应采取的相应措施。     

破解难题 完善机制 做好我国海洋污染应急处置工作

文中重点就目前海洋污染事故存在的风险、交通运输部门针对船舶污染应急体系建设所做的工作、当前海洋污染事故应急瓜机制存在的问题以及对如何完善海洋污染事故应急反应机制等作思索和探讨。     

界面污染对沥青小梁疲劳性能的影响研究

为研究层间界面的污染情况对沥青铺面整体使用性能所产生的影响，采用由不同类型混合料复合而成的、含有层间界面的复合沥青小梁，进行抗剪强度试验和四点弯曲疲劳试验，以机油污染和黄土污染作为污染源，调整污染量，用于模拟施工过程中可能存在的污染情况，并对其在不同工况下的层间抗剪强度及整体疲劳寿命进行测定。试验结果表明：（1）就各类影响层间抗剪强度因素的敏感性而言，机油污染的敏感性要高于黄土污染；（2）同等试验条件下，随着污染量的增加，复合小梁的疲劳寿命显著减小，一定程度后逐渐趋于稳定；（3）在相同污染量工况下，机油对于层间粘结性能的影响要大于黄土污染对其产生的影响；（4）就弯曲劲度模量损失量而言，当污染量达到一定程度后，复合小梁的层间粘结性就会丧失。     

迈腾轿车加速不良故障检修

发动机加速不良的原因很多,既有油路方面的原因,也有电路方面的原因,还有进、排气系统方面的原因。本文主要以电控发动机工作原理和维修实例为依据,分析迈腾1.8 TSI手自一体轿车由于排气管堵塞造成加速不良的诊断思路、方法、步骤。     

汽油发动机尾气的售后治理措施

汽油发动机尾气主要成分是CO、HC、NOx等,汽车尾气的治理是一个系统工程,在汽车服务领域对尾气的治理一般形成了规律性的治理方案和措施,尾气诊断仪能够实时检测汽车的污染物排放数据,同时还引导一线维修人员有针对性的治理尾气,实现了售后领域的维修过程、维修质量一系列的如实记载和跟踪,对提升服务质量和企业内部员工的技术素质起到了很好的设备保证,从汽车售后领域控制了汽车污染物的排放。     

A ‘sustainability window’ of urban form

With global environmental change and the rise of global megacities, environmental and social externalities of urban systems, and especially of urban form, become increasingly prevalent. The question of optimal urban form has been debated and investigated by different disciplines in numerous contexts, including those of transport costs, land consumption and congestion. Here we elucidate theoretically how urban form and the urban transport system systematically modifies sustainability concerns, such as greenhouse gas emissions, local air pollution and congestion. We illustrate our analytical considerations with empirical analysis. Denser urban form would almost unambiguously mitigate climate change, but it would also lead to undesired effects, such as a higher proportion of urban dwellers affected by air pollution. Our study presents a ‘sustainability window’ by highlighting trade-offs between these sustainability concerns as a function of urban form. Only a combination of transportation policies, infrastructure investments and progressive public finance enables the development of cities that perform well in several sustainability dimensions. We estimate that a residential population density between 50 and 150 persons/ha and a modal share of environmental modes above at least 50% corresponds to the sustainability window of urban form. The parameters of the sustainability window of urban form is subject to policy changes and technological progress.     

船舶防污染作业等级评定量化研究

文章应用模糊数学评估方法,建立船舶防污染作业等级评定模型,为量化研究船舶防污染作业单位安全状况提供了具体的方法和依据。最后结合辖区实际进行了验证。     

水污染对飞机油液系统影响综述

通过论述油液系统中水污染的来源、特点、危害及水含量的主要测试方法,针对部队实际工作情况,提出几点预防和控制水污染的方法。