浅析钢桥梁安装方法

随着我国经济的快速发展,交通运输量的迅速增长,城市市政基础设施路桥工程建设规模越来越大。由于钢箱形梁制作、安装快速方便的特点,近年来钢结构桥梁工程越来越受到大家的重视,并逐步取代砼结构桥梁,引领桥梁建设新时代。在金融危机下,国家计划投入4万亿用于基础建设和拉动内需。中国的公路、铁路、城市轨道交通建设等迎来快速发展的黄金周期,我国的桥梁建设也将进入高速发展的最好时期。文章介绍了上海市浦东段市政工程钢结构桥梁的拼装、吊装、组装、焊接工程特点和难点,以及钢结构桥梁安装施工过程和施工人员如何成功的应对了钢结构方面的技术难题,同时在此过程中,创造了城市独有的高架桥钢结构组合吊装新工艺。     

旋转机械转子-机匣系统碰摩的随机响应

针对仅考虑具有质量偏心的旋转机械Jeffcott转子-机匣系统碰摩模型的动力学方程,进行了转子-机匣系统碰摩的随机响应研究·应用Kronecker代数、矩阵微分理论、向量值和矩阵值函数的二阶矩技术、矩阵摄动理论和概率统计方法系统地研究了转子-机匣系统碰摩的随机响应问题,推导出了一般的数学表达式,给出了数值分析解·分析了把转轴刚度和阻尼、定子刚度和阻尼、偏心距和定子径向刚度作为随机参数的随机系统的响应·分析表明,该转子系统在初始阶段振动强烈,响应幅值超过转子和定子之间的间隙,会发生碰摩现象·     

大跨预应力混凝土箱梁桥收缩徐变效应

随着大跨预应力混凝土粱桥的迅速发展。桥梁收缩和徐变影响的分析和计算成为结构设计人员越来越关心的问题,因此徐变计算理论和方法得到了不断发展．综述了徐变的各种分析方法,采用积分退化核方法对大跨预应力混凝土连续刚构蟹进行了计算,得出了一些有意义的结论,可供桥梁设计参考．     

Taming theory with thought experiments: Understanding and scientific progress

I claim that one way thought experiments contribute to scientific progress is by increasing scientific understanding. Understanding does not have a currently accepted characterization in the philosophical literature, but I argue that we already have ways to test for it. For instance, current pedagogical practice often requires that students demonstrate being in either or both of the following two states: 1) Having grasped the meaning of some relevant theory, concept, law or model, 2) Being able to apply that theory, concept, law or model fruitfully to new instances. Three thought experiments are presented which have been important historically in helping us pass these tests, and two others that cause us to fail. Then I use this operationalization of understanding to clarify the relationships between scientific thought experiments, the understanding they produce, and the progress they enable. I conclude that while no specific instance of understanding (thus conceived) is necessary for scientific progress, understanding in general is.     

Packaging Radium,Selling Science: Boxes,Bottles and Other Mundane Things in the World of Science

This article discusses the intersection of science and culture in the marketplace and explores the ways in which radium quack and medicinal products were packaged and labelled in the early twentieth century US. Although there is an interesting growing body of literature by art historians on package design, historians of science and medicine have paid little to no attention to the ways scientific and medical objects that were turned into commodities were packaged and commercialized. Thinking about packages not as mere containers but as multifunctional tools adds to historical accounts of science as a sociocultural enterprise and reminds us that science has always been part of consumer culture. This paper suggests that far from being receptacles that preserve their content and facilitate their transportation, bottles and boxes that contained radium products functioned as commercial and epistemic devices. It was the 1906 Pure Food and Drug Act that enforced such functions. Packages worked as commercial devices in the sense that they were used to boost sales. In addition, ‘epistemic’ points to the fact that the package is an artefact that ascribes meaning to and shapes its content while at the same time working as a device for distinguishing between patent and orthodox medicines.     

土-箱基-框架结构动力相互作用体系试验研究

通过对1/2大比例模型的试验与仿真分析,研究了结构-箱基础-土体系的动力反应.将实测基频结果与基于刚性地基的仿真分析结果对比,发现实测结果小于有限元结果;但将实测基频结果与考虑相互作用的仿真分析结果对比,发现实测结果与仿真分析结果吻合,这说明土-箱基础-结构相互作用改变了结构体系的动力特性,使结构体系的自振周期延长,同时也验证了仿真分析的有效性.     

钻孔施工对孔侧箱涵的影响及测斜结果分析

分析了钻孔施工对孔壁土体和地下箱涵不利影响的几点原因,介绍了测斜监测在钻孔施工中的使用,以此监测地下箱涵的安全性,以及通过分析监测成果,提出了道路施工中对地下管线不利影响有参考价值的结论。     

意识形态批评分析——以《阿甘正传》为例

意识形态批评产生于20世纪60年代,是最重要也是最具活力的电影批评理论,对于揭示由大众文化所负载的新主流意识形态的建构过程,保持着现实的活力。影视文学的意识形态批评受益于路易·皮埃尔·阿尔都塞的意识形态国家机器理论。《阿甘正传》这部既在美国国内又在世界上引起轰动的影片正好是进行意识形态批评的恰当文本。从意识形态批评理论的角度对《阿甘正传》进行分析,可知该影片反映了两种意识形态,一是种族问题及和解;二是性别、文化间的冲突与和解。     

浅谈建设工程安全监理工作要点

从事故多发的环节出发,全面阐述了安全监理工作的相关要点,包括安全监理的必要性、监理依据、监理程序、监理内容等.     

锅炉防焦箱鼓包原因的分析

本文对一起锅炉的防焦箱鼓包事故进行了原因分析,同时提出了一些的建议与改进措施。