北京市动态交通信息服务系统建设及制约因素

为探讨当前我国动态交通信息服务的制约因素和发展方向,在北京市实际研究和建设经验的基础上,结合采集交通信息准确性验证、交通信息发布内容以及标准化和产业化建设这三个制约动态交通信息服务发展的因素,分别阐述其发展现状及存在的问题,重点提出浮动车数据验证方法及北京市部分验证结论、动态交通信息发布内容基本原则和发展思路、标准化和产业化建设的机制,为我国动态交通信息采集、处理、发布技术的研发和信息服务系统的建设提供参考。     

Operational Analysis on Beijing Road Network during the Olympic Games

Monitoring and analyzing performances of urban road traffic is a crucial work to ensure traffic operation well during the Olympic Games in Beijing and evaluate the effects of traffic demand management strategies and measures. In this paper, as the basis for performance analysis, a traffic congestion evaluation index system which consists of comprehensive and characteristic indices is introduced. Beijing floating car system is also used to collect real-time data of urban road traffic. In addition, expressways, arterial roads, some of the secondary roads and branch roads over the area within the 5th ring road are selected as the evaluation objects. Moreover, urban traffic operation performances are compared among pre-Olympics, during the Olympic Games and during the Paralympics Games from the aspects of the intensity, duration, extension of traffic congestion, the distribution of recurrent bottlenecks and average speed. It is concluded that the urban traffic is in the level of “smooth” during the Olympic Games and the Paralympics Games comparing with the “moderate-congested” status before the Olympic Games. The vehicle speeds of urban traffic network increase obviously under the Olympic traffic demand management strategies and measures.     

ADENO-ASSOCIATED VIRUS INTRODUCED INTEGRATION AND EXPRESSION OF FOREIGN GENES IN PC12 CELLS

The ability to induce the expression of targetgenes in neurons is a goal of molecular neurobiolo-gy up to now. A variety of means including lipo-somes and recombinant retrovirus vectors and re-combinant adenovirus vectors have been used to ac-coplish this goal. Each method has some specificdisadvantages['J. None can provide reliable andcontinuouk gene expression in neurons of the cen-tral nervous system.Vectors derived from adeno--associaed virus(AAV ) have the potential to stably transducem…     

A HISTOPATHOLOGIC IMMUNOHISTOCHEMICAL AND ULTRASTRUCTURAL STUDY OF RABBIT CORNEA AFTER EXCIMER LASER PHOTOREFRACTIVE KERATECTOMY

In excimer laser photorefractive keratectomy(PRK), the central part of the Bowman's mem-brane and superficial stroma is ablated after re-moval of the corneal epithelium. Clinical studiesshowed that the results of PRK for myopia of up to--6 diopters are satisfactory[' 'J. However, deeperresearch is needed, especially the healing processfollowing PRK,which is different from the woundhealing mechanism after conventional occularsurgery['.'J. Corneal haze and myopic regression arethe 2 main co…     

EFFECT OF THE TOTAL SAPONIN OF DIPSACUS ASPER ON INTRACELLULAR FREE CALCIUM CONCENTRATION IN THE CELLULAR MODEL OF ALZHEIMER‘S DISEASE-SCANNING CONFOCAL MICROSCOPY

ＡｌｔｈｏｕｇｈｔｈｅＡｌｚｈｅｉｍｅｒ’ｓｄｉｓｅａｓｅ(ＡＤ)ｗａｓｄｉｓ ｃｏｖｅｒｅｄｂｙＡｌｏｉｓＡｌｚｈｅｉｍｅｒ ,ａＧｅｒｍａｎｎｅｕｒｏｐａｔｈｏｌｏ ｇｉｓｔ,ｉｎｅａｒｌｙ 2 0ｃｅｎｔｕｒｙ ,ｉｔｄｉｄｎｏｔｇａｉｎｍｕｃｈｐｕｂｌｉｃａｔｔｅｎｔｉｏｎｕｎｔｉｌｔｈｅｌａｓｔｔｗｏｄｅｃａｄｅｓ .Ａｓｔｈｅｌｉｆｅｓｐａｎｏｆｈｕｍａｎｂｅｉｎｇｓｐｒｏｌｏｎｇｓ ,ｔｈｅｎｕｍｂｅｒｏｆｐｅｒｓｏｎｓｗｉｔｈＡＤｈａｓａｌｓｏｉｎｃｒｅａｓｅｄ .Ｂｅｓｉｄｅｓｃａｎｃｅｒａｎｄ…     

驻车制动系统设计缺陷浅析

驻车制动系统是在车辆气压制动系统中配置的储能弹簧制动气室及相关控制阀类,其对于提高车辆的安全性能具有良好的作用:     

宇通客车气压ABS原理及检测

介绍宇通客车气压ABS的组成,每个元件的功能、测试方法以及ABS的闪码诊断程序和故障码含义.     

天津港CAD数据向GIS数据迁移解决方案探讨

为适应天津港GIS系统建设需求,将传统的CAD数据转换为GIS格式的数据已经成为必需.而由于长期的绘图手段和绘图习惯,CAD数据存在着点、线不合规范,面不闭合,层与层内的图形混乱等现象,使CAD数据与GIS数据的结构存在很大差异,不能将CAD数据完整地向GIS数据迁移.在分析目前CAD数据到GIS数据迁移中存在问题的基础上,深入探讨天津港基础地形图数据转移为GIS数据的逻辑结构、分层设计和属性设计等解决方法.     

大数据技术在智能交通管理中的运用

在交通管理中,海量的数据为智能化的交通管理提供了决策支持。文章就大数据与智能交通的情况进行了概述,分析了大数据时代智能交通的发展趋势以及大数据技术在智能交通管理中的应用特性与优势意义,并在确保数据安全性、技术多样性、结果优质性的基础上对大数据技术在智能交通管理中的运用进行了探索。     

发动机曲轴多级橡胶阻尼式扭转减振器的设计

介绍了发动机曲轴系统中应用的多级橡胶阻尼式减振器的结构,提出了各级减振器设计参数的优化方法。计算结果表明,多级扭转减振器可以较好地控制发动机曲轴的扭振。