Pressure-Based Approach to Estimating the Injection Start and End in Single and Split Common Rail Injection Processes

The deep understanding on sand and sand dunes scale can be useful to reveal the formation mechanism of the sandstorm for early sandstorm forecast. The current sandstorm observation methods are mainly based on conventional meteorological station and satellites remote sensing, which are difficult to acquire sand scale information. A wireless sensing network is implemented in the hinterland of desert, which includes ad hoc network, sensor, global positioning system (GPS) and system integration technology. The wireless network is a three-layer architecture and daisy chain topology network, which consists of control station, master robots and slave robots. Every three robots including one master robot and its two slave robots forms an ad hoc network. Master robots directly communicate with radio base station. Information will be sent to remote information center. Data sensing system including different kinds of sensors and desert robots is developed. A desert robot is designed and implemented as unmanned probing movable nodes and sensors’ carrier. A new optical fiber sensor is exploited to measure vibration of sand in particular. The whole system, which is delivered to the testing field in hinterland of desert (25 km far from base station), has been proved efficient for data acquisition.     

铅酸蓄电池密度测量传感器研究

研究船用铅酸蓄电池电解液密度测量方法,分析了力学密度传感器、振动管式密度传感器、声学量密度传感器、光学量密度传感器等测量方法的优缺点。     

GIS-aided prediction for sea-ice distribution

A method of applying the geographic information system (GIS) to predict sea-ice distribution is proposed. The prediction computations are performed using the distributed mass/discrete floe (DMDF) model. The GIS is used to prepare the initial data for the DMDF model, and to display the simulation results together with a digital map and observational data for evaluation and further use. Two areas in the Arctic Ocean were selected to test the computations in this study. The results of the case studies show that this method can help with (1) free-area and free-scale prediction fitting for various purposes, (2) a high-resolution output to provide more detailed data, and (3) a reasonable combination of different data sets to make the best use of the information obtained. The results also suggest that the DMDF model is a good simulation of the ice motion not only for large-scale but also for local-scale predictions. Received: March 19, 2002 / Accepted: June 20, 2002 Acknowledgments. This study was financially supported by the Japan Science and Technology Corporation. The SSM/I sea-ice data were obtained from the EOSDIS NSIDC Distributed Active Archive Center (NSIDC DAAC), University of Colorado at Boulder. The authors thank the persons concerned. Address correspondence to: H. Yamaguchi (yama@fluidlab.naoe.t.u-tokyo.ac.jp)     

汽车后门柱拉延工艺及模具设计

介绍了凌河牌汽车驾驶室后门柱拉延工艺及模具设计过程。根据工件在拉延过程中材料变形，流动特点，该设计从工艺和模具结构两方面采取了模拟，并采用了较为新颖的内一外双边结构，有效地解决了拉裂和起皱问题，提高了产品质量。     

颈动脉粥样硬化病变的彩色多普勒检查

本文报告用彩色多普勒检测151例颈动脉粥样硬化病变和34例正常人。结果表明颈动脉分叉处是粥样硬化斑块多发部位(62.3%),声像图显示斑块有3种类型(扁平斑、软斑、硬斑)。本组中有6例颈内动脉腔明显狭窄(腔径减少45%以上),狭窄部位显示有镶嵌血流。频谱多普勒分析显示收缩期峰值流速增高和频谱增宽。2例颈内动脉完全阻塞,彩色多普勒显示颈内动脉内无彩色血流。这种方法可用于颈动脉粥样硬化的早期诊断,也对缺血性脑病的预防具有价值。     

聊天室在网络课程交互中的应用探究

随着网络教育应用的普及,为学习者寻求各种支持的探索,也在不断的深入。交互手段为学习信息的交流提供了强有力的支持,本文从寻求交互支持的依据出发,然后阐述了聊天室的功能特点,最后又详细论述分析了聊天室在网络学习环境中应用的可行性。     

船舶碰撞案例库研究与应用

建立规范化和信息化表示的船舶碰撞案例库,以适应船舶避碰理论研究、避碰决策研究、避碰仿真研究、培养船舶驾驶人员以及海事审判等多方面的应用,具有重要理论和现实意义。本文基于多功能应用的船舶碰撞案例的规范化、信息化表示进行研究,设计实现了船舶碰撞案例库,并案例库的应用进行了研究。     

T7型检衡车使用、维护及检定情况概述

目前在铁路上广泛使用的有T6D,T6F,T7等型号的检衡车,而T7型检衡车在静态轨道衡计量检定工作中得到广泛应用,本文从影响检衡车标称值的角度浅谈其复现性和使用维护应该注意的事项。     

某城市中心开敞式膜结构屋盖的风荷载试验研究

以郑州大上海步行街中心广场膜结构屋盖为工程背景,进行了刚性模型的同步测压试验。详细研究了该屋盖的平均风荷载和脉动风荷载的分布特征、上下表面对应点风压的相关性、以及围护结构设计和承重结构设计的风荷载。结果表明:该屋盖表面的风压以负压为主,脉动成份很大;上下表面对应点风压的相关系数绝大部分为正值;采用规范方法的结果进行围护结构设计偏于不安全,应采用概率统计方法的结果。     

旋挖钻孔灌注桩的技术经济优势

介绍了旋挖钻机的性能和成孔工艺，分析了与传统的钻孔工艺在设备性能、成孔工艺方面的技术经济优势。此文结合工程实例分析了旋挖钻机的成本情况，近似计算了旋挖钻机的施工机械台班单价。