国产摩托车欧Ⅲ排放解决方案及催化净化技术的应用

控制摩托车排气污染是一项系统工程,必须遵循先机内、后机外,内外协调的方针。无论是采用化油器还是电喷发动机,要满足欧Ⅲ排放标准,催化净化是最有效的技术手段。在对化油器优化的同时进行二次补气和催化转化是一种成本低、见效快的达标方案,而电控燃油喷射与三元催化净化则是满足欧Ⅲ及未来更严格排放标准的必然方向。     

大跨度提篮式钢管砼拱桥主拱肋砼灌注旋工技术

某跨海大桥设计为主跨270m的中承提篮式铜管砼拱桥,主拱肋的砼灌注是拱肋合拢后的又一关键工序,本文介绍了主拱肋砼灌注施工方案、施工工艺以及质量检测方法.     

S^2 BHCA Multiple AUVs cooperation oriented control architecture

Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill ＆ simulation based hybrid control architecture （S^2BHCA） as the controller＇s design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S^2BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the ＂skill＂. The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three ＂skills＂ for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S^2BHCA.     

驾驶员手伸及界面与驾驶室尺寸综合因子G

驾驶员手伸及界面与驾驶员的手伸、能力及驾驶室内部尺寸有关。驾驶员手伸及能力的统计性可通过身材百分位和男女比来反映。而驾驶室内部尺寸对手伸及界面的影响应以多元统计分析理论加以分析。本文介绍如何利用因子分析法来求取对手伸及界面具有综合影响的驾驶室尺寸综合因子G。     

人工责任成本的管理与控制

目前铁路工程建设施工中人工责任成本的控制是企业成本管理与控制的难点。此文从实际工作出发，介绍了人工责任管理与控制在实际工作中的一些措施、做法和心得。     

A second order volume of fluid （VOF） scheme for numerical simulation of 2-D breaking waves

Among all environmental forces acting on ocean structures and marine vessels, those resulting from wave impacts are likely to yield the highest loads. Being highly nonlinear, transient and complex, a theoretical analysis of their impact would be impossible without numerical simulations. In this paper, a pressure-split two-stage numerical algorithm is proposed based on Volume Of Fluid (VOF) methodology. The algorithm is characterized by introduction of two pressures at each half and full cycle time step, and thus it is a second-order accurate algorithm in time. A simplified second-order Godunov-type solver is used for the continuity equations. The method is applied to simulation of breaking waves in a 2-D water tank, and a qualitative comparison with experimental photo observations is made. Quite consistent results are observed between simulations and experiments. Commercially available software and Boundary Integral Method (BIM) have also been used to simulate the same problem. The results from present code and BIM are in good agreement with respect to breaking location and timing, while the results obtained from the commercial software which is only first-order accurate in time has clearly showed a temporal and spatial lag, verifying the need to use a higher order numerical scheme.     

Experimental study on the width of the turbulent area around bridge pier

At present, the method of calculating the turbulent flow width around the bridge pier is not given in the "Standard for Inland River Navigation" (GB50139-2004) in China, and the bridge designer usually increases the bridge span in order to ensure the navigation safety, which increases both of the structural design difficulty and the project investments. Therefore, it is extremely essential to give a research on the turbulent flow width around the bridge pier. Through the experiments of the fixed bed and the mobile bed, the factors influencing the turbulent flow width around the bridge pier have been analyzed, such as the approaching flow speed, the water depth, the angles between the bridge pier and the flow direction, the sizes of bridge pier, the shapes of the bridge pier, and the scouring around the bridge pier, etc. Through applying the dimension analytic method to the measured data, the formula of calculating the turbulent flow width around the bridge pier is then inferred.     

Mixed analysis of shell and solid elements using the overlaying mesh method

 This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate the effectiveness of the method. Received: August 6, 2002 / Accepted: November 25, 2002 Address correspondence to: S. Nakasumi (sumi@nasl.t.u-tokyo.ac.jp) Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:219–224; and 190:655–662)     

Dynamic Simulation of a Smart Crank and Slider Mechanism

In this paper, a smart crank and slider mechanism is analyzed mostly from a dynamic view. By means of dynamic explicit finite element method, 3D nonlinear structure is simulated. It is proved that the mechanism can effectively accomplish smart movement prescribed. And in order to ensure reciprocal movement with higher frequency, measures should be taken to avoid over heating of parts. Compared with internal energy, kinetic energy of total rigid body is dominating, and Y direction equivalent rigid velocity is much higher than X direction velocity. Equivalent rigid velocity of all parts is consistent with respective movement condition. For both energy and velocity, slider effect is dominating. Three direction equivalent inertia force oscillates. Force amplitude in Y -direction is comparitively the greatest.     

小型程控交换机话费信息自动采集系统的设计

老式交换机是靠连接交换机并口的打印机来收集话费信息的,然后由人工根据打出的话费信息进行分类汇总。该系统利用一台联网计算机的并行接口和增加的辅控电路,通过运行在计算机中的采集程序来仿真交换机的打印机,实现话费信息的自动采集和分类,并以文件的形式写入服务器,提供给结帐程序使用。