聚乙烯管材的国内外发展及应用

介绍国内外PE管材的现状和发展前景、以及管材专用料的生产、研究情况     

Reliability evaluation and optimisation of imperfect inspections for a component with multi-defects

In this paper, a model is developed to evaluate the reliability and optimise the inspection schedule for a multi-defect component. The model uses a non-homogeneous Poisson process (NHPP) method in conjunction with a delay time approach. The inspections are designed to detect any defects in the component, however it can be imperfect. The defect is a definable state before a functional failure happens to the component. Occurrences of defects are assumed to follow an NHPP and a defect will be minimally repaired if it is identified during an inspection. It is shown that the failures occurring in an interval of inspection will also follow an NHPP. The situation of imperfect inspections and non-constant inspection intervals are considered. An algorithm is presented to optimise the intervals of inspections in order to maximise the reliability of the component, and the properties of the algorithm are shown. A numerical example with parametric study is given to show the performance of the model and the algorithm.     

复合多功能通风管道的性能及在空调系统中的应用

详细介绍了复合多功能通风管道的各种性能,并与薄钢板通风管道作了比较,指出了其在空调系系统中的推广应用具有广阔的发展前景。     

雏议造价监理工程师在工程建设中的作用

分析了造价监理工程师如何在在施工前期的招投标、施工组织方案技术经济评价和工程施工阶段的签证、索赔、进度款控制等方面对造价进行合理确定和有效控制。     

立式罐冷却管喷水孔堵塞的原因及解决办法

在油库检查中发现,立式罐冷却喷水环管的喷水孔经常堵塞,堵塞的主要原因是水中含有杂质,喷水环管上没有装放空阀,喷水环管内壁有毛刺和喷水孔易锈蚀。根据堵塞原因找出对应的解决办法,并进一步说明了采用膜式喷头的好处。     

邯钢西区煤气管网改造及效果分析

介绍了邯钢为减少煤气放散，节约能源，采用环网供应混合煤气的有效方法。提高了供气可靠性，取得了很好的经济效益。     

企业供应物资入库质量验收问题的探讨

剖析了企业供应工作中存在的物资入库质量验收问题及存在的原因，提出了搞好企业物资供应管理，加强物资质量验收的对策。     

Rail defects: an overview

For about 150 years, the steel rail has been at the very heart of the world's railway systems. The rail works in a harsh environment and, as part of the track structure, it has little redundancy; thus, its failure may lead to catastrophic derailment of vehicles, the consequences of which can include death, injury, costs and loss of public confidence. These can have devastating and long‐lasting effects on the industry. Despite the advances being made in railway permanent way engineering, inspection and rail‐making technology, continually increasing service demands have resulted in rail failure continuing to be a substantial economic burden and a threat to the safe operation of virtually every railway in the world. This paper presents an overview of rail defects and their consequences from the earliest days of railways to the present day.     

热焊弯管用钢板工艺探讨

在统计分析、正交多项式回归和模拟试验的基础上，建立了高精度的屈强比预报模型，并运用多元函数极值原理，求导极值点及相应的工艺参数，为优化工艺制度，提高热焊弯管用钢(L360-WG系列)性能合格率提供了定量依据。     

可编程控制器在水压实验机上的应用及设计

可编程控制器在恶劣环境下比继电器，接触器安全，可靠，耐用，以水压试验机编程控制器程序控制为例。阐述了液压，气动。电气联合作用下系统的可编程控制设计方法以及防干扰措施。