快乐的钥匙

著名专栏作家哈理斯(Sydney Harries)和朋友在报摊上买报纸,那朋友礼貌地对报贩说了声:"谢谢!"但报贩却板着脸,没发一言。"这家伙态度很差,是不是?"他们继续前行时,哈理斯问道。"他每天晚上都是这样的。"朋友说。"那么你为什么还是对他那么客气?"哈理斯问他。朋友答道:"为什么我要让他决定我的行为?"     

丰田1JZ-GE电喷发动机实验台的研究

丰田1JZ—GE电喷发动机实验台，可在不同的工作状态下对发动机进行测试，实时监控其工作性能，能够满足理论教学和实训教学的需要。     

无线浅层地震仪实现方法及其在隧道工程中的应用

文章以虚拟仪器技术和高速无线传输技术(Wi-Fi)为主线,论述了无线浅层地震仪设计原理与实现方法;提出针对不同的探测对象,无线浅层地震仪只要改变其信号传感器和应用软件就可以实现多种功能,同时还可以在不方便或无法进行布线的测量中使用,增强其使用的灵活性和方便性;并结合隧道工程应用实例,对其先进性和实用性进行了充分验证。     

城市商业步行街服务水平评价体系研究

从量化的角度对城市商业步行街的服务水平进行分析。以西安市2条典型商业步行街为例,对断面情况、行人特性、障碍物、步行街相关设施以及其它影响因素进行问卷调查,借助SPSS软件筛选出主要影响因素,建立商业步行街服务水平评价模型,并通过模型对商业街服务水平进行计算,模型的计算结果与实际调研结果相吻合。     

框架桥顶进施工中主体结构状态控制措施

介绍了辽阳市新华街下穿既有沈大铁路立交框架桥顶进施工中,对主体结构的启动、就位、方向和高程等四种状态控制的目的和方法。利用这些方法,对主体结构顶进状态进行了控制,防止了抬头、扎头现象及方向出现偏差,高质量地完成了框架桥的施工任务,各项偏差指标均满足验收规范的要求。     

Numerical method on load sharing problem of thick laminate joints

Accurately and efficiently predicting the load sharing of multi~bolt thick laminate joints is necessary to quicken the optimization of the large-scale structures over various design variables, and a two-dimensional （2D） finite element method （FEM） is introduced to meet such a demand. The deformation contributions of the joint zone are analyzed and calculated separately, including the shearing deformation of the fasteners shank, the bending deformation of the fasteners shank, and the bearing deformation of the fasteners and joint plates. These deformations are all transferred and incorporated into the components of the fastener＇s flexibility. In the 2D finite element model, the flexibilities of the beam elements and bush elements are used to simulate different components of the fastener＇s flexibility. The parameters of the beam elements which include the bending moment of inertia and intersection area, and the parameters of the bush elements which include the stiffness in different directions, are all obtained through equalizing the fasteners flexibilities. In addition, the secondary bending effect introduced by the single-lap joints is also taken into account to verify the flexibilities of the fasteners in practical application. The proposed FEM is testified to be more accurate than the traditional 2D FEMs and more efficient than the three-dimensional （3D） FEM in solving load sharing problem of multi-bolt single-lap thick laminate joints. With the increase of joint plates＇ thickness, the advantages of the proposed method tend to be more obvious. The proposed 2D FEM is an effective tool for designing bolted joints in large-scale composite structures.     

城市道路分隔绿化带对交通安全影响的分析

城市道路分隔绿化带起到分隔车道以及美化环境等作用,但不当的绿化带设置也给交通安全带来了显著的影响.首先,基于对南京市主城区道路分隔绿化带的实地调查,总结并分析了几类道路分隔绿化带对交通安全的影响;然后,通过对绿化带开口处的视距分析,参照相关规范要求,对分隔绿化带的几何尺寸进行了重新设计,得出了保证行车视距的安全绿化带设计参数并进行了三维模拟验证;最后,在眩光问题上,对现有的关于绿化带防眩高度的理论与算法进行了修正和简化,得出了新的防眩计算公式.该成果有助于城市道路分隔绿化带的合理设计与调整,也将有助于城市道路分隔绿化带相关规范标准的修订.