桥梁0#、1#块施工技术探析

大跨度连续刚构桥0#块施工既是桥梁施工中的关键环节,也是施工难点之一.结合某预应力桥梁施工情况,对桥梁0#块的施工技术进行总结,可供今后类似工程的施工参考借鉴.     

Profile-speed data-based models to estimate operating speeds for urban residential streets with a 30 km/h speed limit

A speed limit of 30 kilometres per hour (km/h) has been widely introduced for urban residential streets to ensure traffic safety and allow these streets to fulfil other intended functions. However, excessive speeds on these roads are very common, causing traffic safety problems and threatening the liveability of neighbourhoods. An effective and active way to deal with speeding is the application of a performance-based design approach, as mentioned in previous research. In a performance-based design approach, street geometrics and roadside elements are selected based on their influence on the desired driving speeds. The relationship between driving speeds and street features therefore needs to be determined. Although several studies have developed operating speed models for urban streets, all of these models were calibrated based on data for streets with speed limits of more than 30 km/h. The present research is designed to investigate the influence of various roadway and roadside characteristics on operating speeds on urban tangent street sections with a 30 km/h speed limit using profile-speed data. A simultaneous equation regression with a three-stage-least-square (3SLS) estimator was used for the modelling effort. The driving speed models developed in this study incorporate several street design factors, which provide helpful information for urban planners and street designers to cope with speeding issues on residential streets.     

基于Web2．0的高校图书馆个性化信息服务

摘要本文从Web2．0的涵义与特征、高校图书馆用户个性化信息服务的特点和Web2．0技术在高校图书馆个性化服务中的应用等三个方面论述基于Web2．0的高校图书馆个性化信息服务。     

An innovative method for the analysis of vehicle movements in roundabouts based on image processing

The objective of this paper is to propose a method, based on the image processing of field survey data, to analyze vehicles movements into roundabouts. This research study consisted of three stages: a field survey to collect vehicular flow images captured by video cameras, the processing of these images using a proprietary software (VeTRA—Vehicle Tracking for Roundabout Analysis), and finally, the analysis of the collected data. The main feature of the software is that it allows the automatic computation of the main variables necessary to rank and evaluate a generic roundabout: the entry/exit (E/E) matrix with classification of vehicles (e.g., heavy, light, and motorbikes), vehicle trajectories, and vehicular speed diagrams along the paths inside the roundabout. The processing system is robust enough to withstand classic problems affecting image processing such as variable wind conditions, cloud cover, shadows, and obstructions. Calibration and error evaluation have been deduced from data collected by a high precision Real Time Kinematic GPS video recording system mounted on a probe vehicle. Data of E/E matrices generated by VeTRA are compared with those manually counted on the corresponding video images. A case study of an existing roundabout is featured in the paper. The results indicate that the software has a high capability of generating the E/E matrix. The analysis of vehicular trajectories with both the plot of curvature diagrams and the corresponding speed diagrams enable the evaluation of driver behavior relative to the geometric shape of the roundabout. Copyright © 2011 John Wiley & Sons, Ltd.     

论致病性大肠杆菌(EPEC)的致病机理

由于分子和细胞生物学方法的出现,对EPEC的致病机理有了更好的了解,EPEC侵入体外培养的组织细胞,但是一般认为这不会发生在体内主要是由一种超微损伤介导的,细菌通过这种超微损伤从而与原生质膜紧密接触,导致肠刷状缘局部破坏和原生质膜变形。     

CRH2型200 km/h动车组

介绍CRH2型200km／h动车组的主要技术参数，阐述了车体、转向架、牵引系统、网络控制系统、辅助电源系统、制动系统、空调系统及车内装饰等的基本特点。     

基于μC/OS-Ⅱ的热泵热水器控制器设计

热泵热水器是节能环保型产品,智能热泵控制器可自动控制热泵机组安全、稳定地运行.本文介绍了热泵热水器的工作原理并分析热泵热水机组的控制要求,研制成功由ADμc834单片机与三星S3C44B0组成的双核热泵控制器,详细叙述了ADμc834核采集控制装置的设计方法,介绍了基于μC/OS-Ⅱ与μC/GUI的ARM7核图形操作终端的软硬件平台.     

哈大线电气化铁道远动系统简介

介绍了哈尔滨大连电气化铁道所引进德国的S.P.I.D.E.R.远动系统用于对供电系统的控制、监督、采集和分析数据,并提供一个建立网络控制应用的操作平台。系统的引进为我国电气化铁道远动控制提供了可借鉴的经验。     

基于ARM的嵌入式虚拟示波器系统的设计

基于ARM技术，以S3C44BOX为CPU，在uClinux基础上，通过USB设备来连接装有Labview的PC机，设计了一种嵌入式虚拟示波器系统．uClinux是一种运行于没有MMU的嵌入式微处理器的Linux衍生操作系统，实现了多任务运行．介绍了虚拟示波器的概念及Labview的特点和工作过程．