乙醇HCCI燃烧特性试验研究

文中对一台双缸四冲程自然吸气直喷柴油机上进行了乙醇的HCCI的试验,试验分析了过量空气系数和进气温度对乙醇均质压燃燃烧特性的影响。研究结果表明:发动机缸压和压力升高率峰值随着进气温度的上升而增加,并且峰值压力也会提前;过量空气系数的增大,缸压和压力升高率减小。与较小的过量空气系数相比,峰值压力的出现明显推迟。过量空气系数对压力升高率的影响较小,但对放热率的影响相当大。     

三电平PWM整流器半实物研究

本文基于三电平PWM整流器数学模型,采用状态反馈解耦后双闭环调节,辅以闭环观测器估计负载电流作前馈补偿的直接电流控制方案,同时通过辨识虚拟电网磁链,代替测量电网电压锁相作为控制中的定向矢量;针对三电平变换器中点电位平衡这一固有问题,采用准确解析计算使之平衡的零序电压分量,有效消除中点电位波动。最后搭建基于硬件在回路的半实物仿真实验装置,实现了低谐波双向能量传递,动静态性能良好,验证了控制策略的可行性和有效性。     

编队协同作战中的数据关联技术研究

介绍了编队协同作战系统及其功能,分析了该系统的关键技术之一—数据关联,分析了当前主要的数据关联算法,并指出了其未来发展趋势。     

基于CFD的某V型船用柴油机活塞环断裂故障研究

针对某船用12缸V型柴油机第2缸活塞环经常断裂的现象,应用CFD方法对其进行分析判断,结果表明:由于缸体水套中存在大范围的高温区和低流速区,活塞环处的热负荷及由温差产生的内部热应力增大,使活塞环发生断裂故障.通过对缸体水套进行结构改进,减小其最高温度及高温区域面积,可降低活塞环热负荷及应力,进而降低了活塞环断裂频率.     

铁路喷漆作业混苯治理措施的研究

铁路喷漆作业现场及喷漆作业过程中散发在空气中的有机废气［挥发的溶剂（酯、酮、醇类）及稀释剂（煤焦油类、苯、甲苯、二甲苯）］及固体漆雾粒子（树脂、颜染料）。依据国内外各行业喷漆技术发展的动向，找到了解决铁路机务段、车辆段及铁路工厂喷漆作业混苯物污染的控制手段。即：改革工艺采用新技术和新材料，实施上送风下排风空气幕及实施净化措施和加强个体防护的综合治理措施。     

集成化仿真系统在气制动TCS控制器开发中的应用

利用Simulink/xPC实时仿真软硬件环境,设计了集成化TCS仿真软硬件系统。建立了包括整车、动力传动系、制动器、轮胎、路面的动力学模型,应用离线仿真、快速原型仿真和ECU在环仿真等方法开发了气制动TCS控制器控制逻辑。经实车试验表明,系统能有效控制驱动轮的打滑趋势,提高汽车加速性能,改善发动机的工作条件。     

Sniffer原理解析及其WinPcap实现

在分析Sniffer工作原理的基础上,阐述了有关Sniffer设计的一般流程,并用VC＋＋结合WinPcap实现了Sniffer的主要功能.     

长江干线重点支流河口航标配布方案

长江干线重点支流河口航标配布缺乏统一配布原则和方法。采用分类研究的方法,根据河口地形及干线航道布置特点,将河口分为沿岸航道(或偏靠河口侧的河心航道)类、干线航道与支流河口间有一定距离类,确定不同类别河口航标配布所使用的航标种类,并分别根据标示支流河口位置、标示干支航道交汇点、标示干线航道与支流航道连接段航道界限与碍航物、提示支流河口信息的总体原则对不同类别的支流河口提出相应的航标配布方案,为类似工程提供参考。     

顶置凸轮轴配气机构有限元动力模型计算及试验研究

采用有限元动力模型，对顶置凸轮轴配气机构进行了动力分析计算，在已知凸轮升程数据的条件下，求出凸轮轴不同转速时的气门运动规律，配气机构各阶自振频率和振动振型，并研究了油温，油压及混入气泡量不同时，气门间隙液压调节器对配气机构运动特性的影响。     

Fluxes of biogenic carbon in the Southern Ocean: roles of large microphagous zooplankton

The Southern Ocean is an extreme environment, where waters are permanently cold, a seasonal ice cover extends over large areas, and the solar energy available for photosynthesis is severely restricted, either by vertical mixing to considerable depths or, especially south of the Antarctic Circle, by prolonged seasonal periods of low or no irradiance. Such conditions would normally lead to low productivity and a water column dominated by recycling processes involving microbial components of pelagic communities but this does not seem to be the case in the Southern Ocean, where there is efficient export to large apex predators and deep waters. This paper investigates the role of large microphagous zooplankton (salps, krill, and some large copepods) in the partitioning of biogenic carbon among the pools of short- and long-lived organic carbon and sequestered biogenic carbon. Large microphagous zooplankton are able to ingest microbial-sized particles and thus repackage small, non-sinking particles into both metazoan biomass and large, rapidly sinking faeces. Given the wide spatio-temporal extent of microbial trophic pathways in the Southern Ocean, large zooplankton that are omnivorous or able to ingest small food particles have a competitive advantage over herbivorous zooplankton. Krill efficiently transfer carbon to a wide array of apex predators and their faecal pellets are exported to depth during occasional brief sedimentation episodes in spring time. Salps may be a significant link towards some fish (directly) and other apex predators (indirectly) and, at some locations (especially in offshore waters) and time, they may account for most of the downward flux of biogenic carbon. Large copepods are a trophic link towards fish and at least one whale species, and their grazing activity generally impedes the export of organic particles to depth. As a result, biogenic carbon is channelled mainly towards apex predators and episodically into the deep ocean. Without these original interactions, Antarctic waters might well be dominated by microbial components and recycling processes instead of active export from the generally small primary producers towards large apex predators.