预防液化石油气储罐应力腐蚀的初探

液化石油气储罐在工业和人民生活中有着广泛的应用,探讨液化石油气中所含H2S腐蚀介质对储罐的应力腐蚀及预防措施显得非常重要。     

水泥混凝土路面早期裂缝成因分析及防治对策

水泥混凝土路面是目前我国一种主要的高等级路面。但因为原材料、混凝土配合比、施工等因素的影响,水泥混凝土路面早期易产生裂缝。文章深入分析了水泥混凝土路面出现早期裂缝的主要原因,提出了防治早期裂缝的对策。     

钢筋混凝土现浇楼板裂缝成因分析及防治措施

文章对某工业厂房现浇楼板产生裂缝进行调查,分析了裂缝的特征和产生的原因,介绍了防治裂缝的措施以及修补裂缝的方法。     

矿区铁路钢筋混凝土桥梁裂缝成因及整治

平顶山矿区铁路线上有几十座钢筋混凝土桥梁，在使用过程中由于多种原因产生了各种裂缝，通过不同整治方法处理后，延长了桥梁的使用寿命，提高了桥梁的承载力。     

φ127×9．19mmG105钻杆NC50内螺纹接头直角台肩根部裂纹原因分析

对某井在钻进期间发生的钻杆断裂事故进行了详细调查研究.对裂纹的钻杆样品断口进行了观分析和微观分析,对断裂钻杆材料的化学成分、机械性能和金相组织进行了全面试验分析。最终结合钻杆使用情况和试验分析结果对钻杆接头断裂和裂纹的原因进行了全面分析讨论，认为钻杆接头断裂和裂纹原因是该部位结构尺寸不合理，应力集中严重所致。     

框架填充墙裂缝原因分析及预防

文章分析了加气块填充墙裂缝的开裂成因,并提出了相应的预防措施。     

基于某办公楼的混凝土结构裂缝研究

钢筋混凝土作为一种脆性材料,由于其早期强度较低,因此,在施工过程中极其容易出现裂缝等缺陷,从而对建筑结构的整体性和耐久性产生很大的影响。目前在工程界最普遍关注的问题就是如何更好的预防钢筋混凝土裂缝的产生以有效保证施工工程的质量。     

Shrinkage Estimation Strategies in Generalised Ridge Regression Models: Low/High-Dimension Regime

In this study, we suggest pretest and shrinkage methods based on the generalised ridge regression estimation that is suitable for both multicollinear and high-dimensional problems. We review and develop theoretical results for some of the shrinkage estimators. The relative performance of the shrinkage estimators to some penalty methods is compared and assessed by both simulation and real-data analysis. We show that the suggested methods can be accounted as good competitors to regularisation techniques, by means of a mean squared error of estimation and prediction error. A thorough comparison of pretest and shrinkage estimators based on the maximum likelihood method to the penalty methods. In this paper, we extend the comparison outlined in his work using the least squares method for the generalised ridge regression.     

Varying Coefficient Regression Models: A Review and New Developments

Varying coefficient regression models are known to be very useful tools for analysing the relation between a response and a group of covariates. Their structure and interpretability are similar to those for the traditional linear regression model, but they are more flexible because of the infinite dimensionality of the corresponding parameter spaces. The aims of this paper are to give an overview on the existing methodological and theoretical developments for varying coefficient models and to discuss their extensions with some new developments. The new developments enable us to use different amount of smoothing for estimating different component functions in the models. They are for a flexible form of varying coefficient models that requires smoothing across different covariates' spaces and are based on the smooth backfitting technique that is admitted as a powerful technique for fitting structural regression models and is also known to free us from the curse of dimensionality.     

PC小箱梁开裂机理有限元仿真分析

以福建省某30米跨径预制小箱梁桥为依托实例,利用Midas Fea土木专用非线性软件对PC小箱梁在施工期间预应力的偏位及预应力偏位与超张拉综合作用是否会导致箱梁底板产生纵向裂缝进行了仿真分析计算,通过对不同预应力偏位程度及超张拉多种分析工况的计算结果分析比较,研究PC小箱梁开裂原因,为PC小箱梁混凝土防裂提供理论依据。