Locally one-dimensional-alternating segment explicit–implicit and locally one-dimensional-alternating segment Crank–Nicolson methods for two-dimension parabolic equations

In the paper two new locally one-dimensional alternating segment schemes for solving the 2-D parabolic problems are developed. The parabolic problems can be solved efficiently over decomposed sub-domains. Two schemes are proved to be unconditionally stable and numerical experiments show the validity of the schemes.     

Closed form solution for predicting the horizontal capacity of masonry portal frames through limit analysis and comparison with experimental test results

The paper deals with the problem of evaluating the in-plane seismic capacity of unreinforced masonry portal frame, which can be considered the basic structural element in historical buildings. In particular, the Limit Analysis approach is used to provide simplified “closed form” expressions of the horizontal collapse multiplier, also taking into account the eventual contribution of steel tie rods. Both sliding shear and shear diagonal cracking are also considered in order to take into account the shear failure modes of the pier walls.The proposed formulations have been used for performing an extensive parametric analysis, with the aim of studying the effect of both geometry and vertical/horizontal loading distributions on the portal horizontal strength. Furthermore, the influence of the steel tie-rods has been addressed in order to understand their effectiveness on the portal seismic capacity.A comparison with the results of experimental tests on full-scale portal frames is also provided in terms of in-plane collapse multiplier and failure mechanism aimed to validate the proposed “closed form” expressions.Major outcome of this study is a simple rule of thumb, which can be used for the straightforward assessment of the horizontal strength of simple masonry structures, and for verifying the results of more complex structural analyses such as the nonlinear static analysis.     

空间H形梁柱节点的节点域滞回性能试验研究

为研究空间效应对节点域滞回性能及稳定性的影响，设计了4个不同构造的空间H形梁柱节点试件，于柱端施加恒定轴向荷载，于柱弱轴平面梁端施加恒定反对称荷载，于柱强轴平面梁端施加反对称往复荷载。试验及分析结果表明：基于平面梁柱节点试验提出的考虑竖向连接板对提高节点域稳定性的推荐公式仍适用；柱弱轴平面不平衡弯矩通过竖向连接板及横向加劲肋传递至柱翼缘，当该荷载不致引起节点域周边构件过早屈服时，若传力路径连续，节点域不直接抵抗该荷载作用；在本试验的柱弱轴平面荷载应力水平下，构造设计合理的空间试件节点域的承载力、变形能力、稳定性、耗能能力均不低于相应的平面试件。     

制药企业在2010版药品GMP实施过程中召回管理现状与常见问题分析

总结制药企业在2010版药品GMP实施过程中召回管理的现状,并分析存在问题,包括对产品召回持消极态度,召回管理方面培训不到位,操作规程缺乏可操作性,有效性评估不足等。建议制药企业必须重视产品召回的管理,严格按照2010版药品GMP的要求积极建立召回系统。     

关于农林生物质直燃发电项目的现状、问题及建议

在国家利好政策的引导下,我国生物质直燃发电快速发展,但同时暴露了布局不合理、收储运成本高等问题。文章主要介绍我国生物质直燃发电现状、直面的问题,并提出相关对策建议。     

加压反应-自热浓缩工艺在粉状磷酸一铵生产中的应用

介绍甘肃瓮福化工有限责任公司粉状磷酸一铵装置采用加压反应-自热浓缩技术生产的工艺流程,并针对浓缩系统运行初期存在Ⅰ效下行换热器堵塞的问题,对Ⅰ效浓缩系统二次蒸汽的管路与设备等进行改造。改造后Ⅰ效浓缩系统的温度提高,换热器的结垢堵塞速度减缓,在有效利用反应热的同时延长了装置的运行周期。     

浅析门式钢架结构在池窑拉丝厂中的应用

介绍了门式钢架结构的力学原理和结构组成,分析了门式钢架结构的特点、优势及建筑布置要点,结合具体工程案例重点对门式钢架与网架结构经济性能方案进行了比较和探究,并展望门式钢架结构的发展趋势.     

商用车车架阴极电泳涂料的选型

以商用车车架阳极电泳切换为阴极电泳时电泳涂料的选型为例,详细介绍了阴极电泳涂料的选型过程、选型时所做的试验项目以及对比结果,为同行业其他厂家在进行电泳涂料选型时提供参考。     

浅谈玻璃总包项目现场安全管理

通过对目前国内玻璃总包项目现场存在的管理问题进行分析,并进一步提出项目现场安全管理对策,以达到降低安全事故率、提升安全管理水平的目的。     

三塔精馏工艺应用总结

针对200kt/a焦炉气制甲醇装置三塔精馏系统原始开车初期出现的诸多问题,采取相应的处理措施及优化操作后,效果良好。