系杆拱桥拱肋现浇施工支架设计及内力验算

文章结合黎湛铁路河湛段新增二线工程平坡仔中桥项目的施工实践,阐述了下承式钢筋混凝土系杆拱桥的拱肋现浇施工支架的设计,并进行了受力验算,以期对其他类似工程的施工提供借鉴。     

宽体车车架结构分析与整车性能验证

本次研发的宽体车总质量为40t,是在总质量60t级平台产品的基础上向下衍生而来的。应用三维造型软件建立了矿用自卸车实体几何模型,并对关键结构——车架给出了应力分析时的模型简化方法,根据整车的装配关系和车架的受力特点确定了车架强度有限元分析的边界条件,在此基础上建立了包括车桥、悬挂和车厢在内的整车有限元模型,依据矿用车的典型受力重点选取满载静止或平稳行驶、扭转组合和侧倾举升作业作为分析工况,应用ANSYS软件求解得到各工况下车架的应力大小和应力分布规律。为验证整车的性能,在华润水泥南宁公司矿山对样车进行了为期3个月的性能试验,并对该矿车进行了全面检验,为下一步优化设计提供依据。     

地铁车站节点换乘主体结构设计的思考

本文以地铁车站主体结构T型换乘节点为例,通过建立板壳整体模型计算受力分析,指出节点换乘部分结构设计时所应注意的特点,并提出自己的一些观点。     

浅析发展钢结构住宅的必要性

钢结构住宅是一种新型的结构体系,其无论在主体承重方面、墙体方面和楼板方面与传统住宅结构体系相比,都有着巨大的变化;同时,钢结构住宅在施工方面、设计使用方面、经济效益方面、产业化和可持续发展方面、住宅的可变性等方面与传统住宅相比,也有着巨大的发展优势;因此,钢结构住宅势必成为住宅业发展的主流方向。     

新型外包型钢与粘钢综合加固法

由于业主对建筑结构使用功能的需求,往往在剪力墙开设新的洞口,开洞后将大大降低剪力墙的抗剪能力,对于新建工程可以对剪力墙洞口部位进行增加暗柱、暗梁或加强钢筋来补强剪力墙的抗剪能力。而对于剪力墙开洞改造工程来说,开洞后因无法增加暗梁、暗柱对剪力墙提高承载能力。因此,在开洞后就必须进行加固,现就对传统的加固方法进行分析,并根据实际施工情况提出新的方法。     

Blocked-Error-R 2: A Conceptually Improved Definition of the Proportion of Explained Variance in Models Containing Loops or Correlated Residuals

Bentler and Raykov (2000, Journal of Applied Psychology 85: 125–131), and Jöreskog (1999a, http://www.ssicentral.com/lisrel/column3.htm, 1999b http://www.ssicentral. com/lisrel/column5.htm) proposed procedures for calculating R ² for dependent variables involved in loops or possessing correlated errors. This article demonstrates that Bentler and Raykov’s procedure can not be routinely interpreted as a “proportion” of explained variance, while Jöreskog’s reduced-form calculation is unnecessarily restrictive. The new blocked-error-R ² (beR ²) uses a minimal hypothetical causal intervention to resolve the variance-partitioning ambiguities created by loops and correlated errors. Hayduk (1996) discussed how stabilising feedback models – models capable of counteracting external perturbations – can result in an acceptable error variance which exceeds the variance of the dependent variable to which that error is attached. For variables included within loops, whether stabilising or not, beR ² provides the same value as Hayduk’s (1996) loop-adjusted-R ². For variables not involved in loops and not displaying correlated residuals, beR ² reports the same value as the traditional regression R ². Thus, beR ² provides a conceptualisation of the proportion of explained variance that spans both recursive and nonrecursive structural equation models. A procedure for calculating beR ² in any SEM program is provided.     

Integrating decomposition approaches for the analysis of temporal changes in economic structure: an application to Chicago's economy from 1980 to 2000

This paper presents an attempt to integrate two flow decomposition methods to analyse temporal changes in a region's economic structure. The two methods of structural analysis are push–pull decomposition analysis and structural Q-analysis. Push–pull analysis presents a quasi-optimization decomposition of a set of matrices with actual intersectoral economic flows into a weighted set of matrices, while structural Q-analysis provides a form in which the structure of these decomposed flows can be considered. The paper provides an expository application to Chicago's economic structure over the period of 1980 to 2000, to reveal a complementary perspective of hollowing-out the production process in the Chicago economy that was identified in previous studies.     

钢铁厂行车上电子秤传感器安装的改进及其设计与计算

文章针对钢铁厂和铸造厂吊运钢（铁）水的起重机（行车）上的电子秤存在容易失灵的问题进行了实地观察分析,并提出了切实有效的改进措施。     

断面法储量计算在某金矿的应用分析

文章以断面法在胶东某金矿的应用为例,对断面法计算储量进行了详细的介绍。实例说明断面法是一种应用比较方便的储量计算方法,也能保证计算精度。分析总结断面法的优缺点,并从理论上分析了储量计算误差来源及储量计算的精度。     

基于VBA的土地勘测定界信息系统开发

本文利用VBA语言对Auto CAD进行二次开发,定制了菜单栏、工具栏、线型库及符号库;生成技术报告等勘测定界信息系统的主要功能。