TOD 规划设计理论研究

轨道交通站点的主要职能之一是运输乘客,通过网络化建设推动人口的大量流动,同时也产生多空间尺度效应,公共交通导向开发(TOD)可以满足多元化的功能需求,激发影响区域的城市活力和协同公交都市的建设,理论和实践价值越发突出。然而目前的TOD相关研究成果主要基于单一尺度进行探讨,缺乏系统、多尺度、多维度的梳理。基于此,通过文献计量法分析TOD理论演进,研究新城市主义影响下的站点综合效应、精明增长影响下的站区集聚效应、多维度时代的站群结构效应,探明不同发展阶段TOD规划设计理论。对比中美语境下TOD概念差异,发现中国城市整体密度高、密度分布均质化、大城市通勤时距长、职住不匹配的问题突显。针对中国现在面临的问题,分别从站点、站区和站群尺度,提出TOD精细设计、协同规划、时空交互的开发建议和策略,希望对未来的TOD规划设计提供借鉴。     

一种用于船舶汽轮机的安全且经济的启动加速概念（英文）

This paper analyses the issue of accelerated start-up of a marine steam turbine, which is an important problem because the start-up of a steam machine involves the combustion of fuel that is not transformed into useful energy. To find novel technologies that offer improvements in this aspect is essential due to restrictions on reducing ship emissions. Thus, the shorter the start-up time, the better for the environment and economy. High-pressure(HP) part of the turbine originally located on the Q...     

耐碰撞车辆的撞击性能

对耐碰撞车辆列车的撞击性能作了分析研究,并编制了解析大型塑性变形的动力学模拟程序。对进一步改进耐碰撞车辆的设计进行了讨论。     

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交通流密度是衡量道路服务水平的指标之一. 当交通流中车辆长度和速度变化较大时,占有率则可以更好地反映交通流密度状况. 占有率的测定能够考虑到车辆的长度和速度变化,但是其值受到测量区域长度的影响,并且在混合交通情况下测量值缺乏准确性. 对于没有车道行驶规则的混合交通流,应当以整条路段为单位进行交通流分析. 因此本文提出了“区域占有率”的概念,且利用仿真技术验证其有效性. 对混合交通流条件下的占有率和区域占有率进行比较分析,区域占有率可以更合理地描述混合交通流的密度. 同时,得出混合交通条件下的区域占有率和交通流速度关系,证明了混合交通流条件下区域占有率提出的合理性和准确性.     

关于机械式增压器对商用车柴油机的适用性研究

用试验和数值分析方法,对1台商用车柴油机的增压系统进行了研究,该增压系统由1个机械式增压器和1个涡轮增压器组成。通过与涡轮增压器的组合,降低了系统中机械式增压器的机械损失。另外,发现优化的动力总成技术参数还可用于改善车辆的燃油经济性,同时,两级增压系统中的机械式增压器也提高了柴油机的低速扭矩。     

满足美国第2阶段第5级排放限值的Bluetec排放控制系统

近年来,柴油机在欧洲轻型车的市场份额持续增长,而北美市场的柴油机份额却仍很小.直至最近,柴油机仍可不使用活性的氮氧化物(NO<,x>)后处理系统,仅通过发动机机内优化措施就能满足欧洲和北美的NO<,x>排放限值要求.但美国于2007年引入第2阶段(Tier 2)第8级(Bin 8)和Tier2第5级(Bin 5)排放法...     

污垢组合对印度玛纳尔湾水域低碳钢腐蚀行为的影响研究(英文)

Corrosion behaviour and biofouling characteristics of mild steel in three different coastal locations in the Gulf of Mannar,India have been studied over a period of 24 months.Oyster fouling was predominant at Open sea-Tuticorin,while barnacle fouling was dominant at both Mandapam and Harbour-Tuticorin.The rate of corrosion for 24 months exposure period was highest at Mandapam,where fouling was minimal.The surface of the mild steel was characterized by etchings&crevices beneath the hard foulers attached on it,at all the test locations.The depth of crevice caused by hard foulers was higher at Open sea-Tuticorin followed by Harbour-Tuticorin and Mandapam.The loss in ultimate tensile strength was more in Open sea-Tuticorin than the other two locations.Corrosion behaviour of mild steel is discussed based on the variation in the biofouling assemblage at the three test locations.     

压缩天然气发动机用气门和气门座圈的开发

气门座圈和气门对内燃机的性能、排放和可靠性起着重要作用。这些零件失效会导致内燃机性能恶化。由于压缩天然气(CNG)发动机的燃烧环境干燥,工作温度较高,会对气门座圈和气门的寿命产生不利的影响。Greaves cotton公司开发了1台由柴油机改制的单缸水冷气道喷射CNG发动机。开发中遇到的主要挑战是气门座圈和气门的磨损。为了避免故障,在座圈材料适应性、座面锥角、座面宽度、气门头部刚度、座圈与气门的同轴度和气门落座速度几方面进行了设计改进。通过修改设计成功地解决了气门和气门座圈的磨损问题,并通过发动机台架试验和车辆试验得到了验证。     

Development of an Autonomous Flight Control System for Small Size Unmanned Helicopter Based on Dynamical Model

It is devoted to the development of an autonomous flight control system for small size unmanned helicopter based on dynamical model. At first, the mathematical model of a small size helicopter is described. After that simple but effective MTCV control algorithm was proposed. The whole flight control algorithm is composed of two parts: orientation controller based on the model for rotation dynamics and a robust position controller for a double integrator. The MTCV block is also used to achieve translation velocity control. To demonstrate the performance of the presented algorithm, simulation results and results achieved in real flight experiments were presented.