真空系统在船舶污水收集中的应用

介绍真空系统在船舶污水收集中的的工作机理,论述真空的产生、维系以及影响真空系统收集能力的因素,介绍真空管系及附件的设置原则。     

中小跨径钢与组合结构桥梁选型研究

综合考虑实际工程的建设需要,针对拆除重建引桥、净空受限拼宽桥、互通支线上跨桥几种典型的改扩建应用场景,分别从桥梁适用性、经济性、耐久性等方面对潜在的应用桥型进行方案比选,从而确定不同应用场景中合理的桥梁选型,对钢与组合结构桥梁在中小跨径建造和应用领域进行了有益的探索。     

3BO轴式米轨机车走行部曲线通过性能比较

提出了适用于曲线半径小、坡度大的山区米轨铁路的380轴式机车走行部的两种设计方案，并对这两种方案的结构以及直线、曲线通过性能作了分析和比较。认为这两种方案的转向架都能通过最小半径为62m的曲线，但方案二的结构性能及曲线通过性能都要优于方案一。     

MBR膜的特点及其在船舶生活污水处理中的应用研究

从MBR膜的微观结构特点、膜过滤的形式、船舶污水处理的环境条件及操作工况等方面对MBR膜开展研究。针对这些特点和膜在船舶生活污水处理中的应用,研究了膜污染控制和恢复的应对措施,为MBR在船舶生活污水处理中的应用,指明了重点研究方向。     

预制小箱梁常见裂缝分类和防治

该文针对现有预制小箱梁存在的常见裂缝进行了分类,并就如何在设计和施工中防治这类病害作了阐述。     

交通噪声环境影响及互动式规划环评的应对

交通噪声投诉已居各大城市居民投诉之首,但交通噪声污染治理仍处于"先污染后治理"的模式。合理的交通规划和城市土地使用规划是解决城市交通噪声污染问题的治本之道。然而目前城市规划的各个层次对交通噪声预防考虑不足。该文提出了与规划过程互动的规划环评程序和方法,以期得到噪声污染影响最小的城市规划用地布局方案和交通规划方案。     

隧道开挖中两种围护方式综合使用的探讨

该文以宁波火车南站地下车库连接隧道为例,探讨在复杂条件下隧道基坑围护设计碰到的一些问题及其对策,为同类问题提供参考。     

Model-based design of a variable nozzle turbocharger controller

Variable Nozzle Turbocharger (VNT) was invented to solve the problem of matching an ordinary turbocharger with an engine. VNT can harness exhaust energy more efficiently, enhance intake airflow response and reduce engine emissions, especially during transient operating conditions. The difficulty of VNT control lies in how to regulate the position of the nozzle at different engine working conditions. The control strategy designed in this study is a combination of a closed-loop feedback controller and an open-loop feed-forward controller. The gain-scheduled proportional-integral-derivative (PID) controller was implemented as the feedback controller to overcome the nonlinear characteristic. As it is difficult to tune the parameters of the gain-scheduled PID controller on an engine test bench, system identification was used to identify the plant model properties at different working points for a WP10 diesel engine on the test bench. The PID controller parameters were calculated based on the identified first-order-plus-dead-time (FOPDT) plant model. The joint simulation of the controller and the plant model was performed in Matlab/Simulink. The time-domain and frequency-domain performances of the entire system were evaluated. The designed VNT control system was verified with engine tests. The results indicated that the real boosting pressure traced the target boosting pressure well at different working conditions.     

基于FPGA的单片机端口扩展设计

针对单片机端口少的问题,应用FPGA对单片机进行端口扩展。FPGA端口数量巨大,片上资源丰富,可以方便灵活的对单片机端口进行各种形式的扩展。而且FPGA的再开发能力很强,可以根据实际应用的需要,和单片组成更加强大的系统。     

不完全信息下的CGF主体决策行为及模型研究

着重分析了决策的风险特性,建立了CGF主体的决策行为模型。分析加入感知行为后对决策行为复杂性的影响;提出了一种不确定型决策方法用于处理不完全感知信息对决策行为的影响;最后用示例说明了该方法的有效性。