Behavior of 316L stainless steel containing corrosion pits under cyclic loading

The environmental performance of 316L grade stainless steel, in the form of tensile specimens containing a single corrosion pit with various aspect ratios, under cyclic loading in aerated chloride solutions is investigated in this study. Results from environmental tests were compared and contrasted with those obtained using finite element analysis (FEA). Fractography of the failed specimens obtained from experiments revealed that fatigue crack initiation took place at the base of the shallow pit. The crack initiation shifted towards the shoulder and the mouth of the pit for pits of increasing depth. This process is well predicted by FEA, as the strain contour maps show that strain is the highest around the centric strip of the pit. However, for shallow pits, local strain is uniformly distributed around that strip but begins to concentrate more towards the shoulder and the mouth region for increasingly deep pits.     

The concept of smartness in cyber–physical systems and connection to urban environment

The next-generation systems are expected to be largely cyber–physical systems (CPSs) that autonomously control physical processes, through sensors and actuators typically in real-time feedback and cooperative control loops distributed among physical and cyber environments. The rapid technological advancements enhance the smartness of these CPSs, pushing their boundaries of performance and efficiency by embedding new information and communication technologies. However, to what extent CPSs should be smarter so that they do not compromise safety and security of safety critical systems? is an open research question. Towards this goal, the purpose of this study is to establish a grounded theory to analyse what makes these systems smart? and eventually, how to find a balance between smartness and safety risks? In this precinct, this article aims to develop a conceptual framework, define the dimensions and derive the characteristics that make CPSs smart. The proposed approach combines an automated informetric and systematic analysis of literature pertinent to the topic of smartness across anthropology, science, engineering and technology. The analysis of a case study building and the discussions presented herein support the connection between the existing understanding of CPSs and smartness offered by the building design approach in urban environment.     

矿用无人卡车国内外研究现状及关键技术

分析了国内外露天矿山用卡车无人驾驶技术发展现状,详细介绍了露天矿山卡车无人驾驶关键技术;通过分析对比前装线控和后装线控两种技术路线的优缺点以及超声波雷达、毫米波雷达、激光雷达、4D光场智能感知系统、红外传感器、视觉传感器等环境感知技术的优缺点;提出多传感器高度融合将是露天矿山卡车实现全天候环境感知的发展方向。通过分析对比惯性导航系统、GNSS差分定位技术、车联网定位技术、电子地图定位技术、视觉传感器等定位导航技术的差异,指出多定位技术融合是露天矿山无人驾驶卡车定位方式的必然选择。结合露天煤矿的生产实际,提出将现有的无人驾驶各种技术算法与露天矿山标准作业流程有机融合是实现卡车无人驾驶的必由之路。最后指出无人驾驶卡车应用5G技术是露天矿山安全生产的关键和核心,是无人驾驶的必备技术。     

高盐高有机制药废水污泥电渗透高干脱水

为研究高盐高有机制药废水污泥的电渗透脱水效果，深入认识化学污泥的电脱水过程，本文采用电渗透高干脱水技术对经抽滤脱水的高盐高有机制药废水化学污泥进行深度脱水，考察了泥饼初始pH的改变对污泥电渗透高干脱水过程中阴阳极污泥的含水率、电流、电导率、pH、zeta电位与能耗的影响，验证了对高盐高有机制药废水污泥实行电渗透高干脱水的可行性，解析了化学污泥电渗透脱水过程的机制。结果表明，泥饼pH为2、3、4时，zeta电位为正值，电渗流反向流动，无法脱水；pH增至5时，zeta电位为负值，电渗流从阴极脱除，污泥含水率从53.2%降至44.8%，脱水效果最好；但pH增至6时，脱水量有所降低。污泥电导率随pH的增加而降低。pH为5时初始电流最大。脱水15min时，即污泥含水率降至45.5%时，能源利用率最高。     

现场总线漫谈

从现场总线多标准的现状出发，阐述了控制对象多样性与技术多样性之间的必然联系，通过对目前现场总线与传统DCS应用现状的分析，对现场总线的发展和应用前景进行了展望。     

FF现场总线的网段负载能力的设计及计算

从生产安全运行的管理要求；电压压降和电流的限制及信号的衰减；网络运行时间的要求；系统设计的影响；备用能力的考虑等各个方面，结合上海赛科聚苯乙烯项目的具体设计，分析隔爆条件下FF现场总线的H1网段负载能力的设计，以供大家探讨。     

墙体裂缝的成因及防治

介绍了墙体裂缝的种类，从地基不均匀下沉、温度变化等方面分析了引起墙体裂缝的原因，介绍了墙体裂缝的预防措施和治理措施，以有效控制墙体裂缝的危害程度。     

双排桩门架—锚杆新型组合支护体系的应用研究

本文分析了双排桩门架支护结构的受力机理。针对工程实际进行变形分析,提出增设锚杆形成锚杆———双排桩门架式组合支护体系的方法,并与监测数据对比、验证。     

对CFG桩质量缺陷的探讨

根据具体工程的概况及水文地质条件，分析了CFG桩在地下水位出现大面积缩颈现象和复合地基载荷试验达不到设计要求的原因，并介绍了地基补强措施，以满足工程质量的要求。     

控制爆破在复杂基坑开挖中的应用

在紧邻厂房中控室的基坑开挖中，根据复杂环境条件与施工要求，采用浅孔微差爆破并通过选取合理开沟掏槽位置来控制最小抵抗线方向以及控制一次最大起爆药量等措施，达到了控制飞石、降低爆破地震的效果，保证了爆破质量与爆破安全，提高了施工效率。