大气环境污染对文物古迹的影响

国内外多年的研究结果表明,大气环境污染是造成文物古迹损害的重要因素。其中影响最大的是降尘、酸雨、二氧化硫、二氧化氮、二氧化碳和臭氧等。该文根据近年来关于大气环境污染的报导,着重论述了尘埃对文物损害的机理和现象,酸雨对文物的腐蚀过程和反应机理,以及SO₂,NO₂,CO₂和O3等气态污染物使无机质文物老化、生锈,有机质文物脱色、褪色的原因。      

模拟海洋全浸区环境下A517海工钢的腐蚀机理研究

目的 探究 A517 海工钢在海洋全浸区环境下的腐蚀机理。方法 通过模拟海洋全浸区腐蚀环境,利用失重法、SEM、EDS、XRD、电化学等测试技术,分析A517钢的腐蚀行为历程,并探讨其在全浸区的腐蚀机理。结果A517钢在厚度方向上的最大电位差为 13 mV,小于发生电偶腐蚀的最小电位差50mV,说明材料在厚度方向上的腐蚀敏感性一致。随浸泡时间的延长,腐蚀质量损失量逐渐增加,平均腐蚀速率先降低、后升高、最后趋于稳定,腐蚀速率约为 0.127 mm/a。结论 腐蚀动力初期主要是由溶解氧的极限扩散控制,后期则是腐蚀产物的氧化还原电荷转移控制。腐蚀首先在 Al₂O₃、MgO 等夹杂物处萌生扩展,腐蚀产物出现明显的分层现象,外锈层主要是疏松易脱落的γ-FeOOH,内锈层主要是致密均匀的 Fe₃O₄,同时锈层中还检测到了β-FeOOH和α-FeOOH的存在。锈层中存在大量微裂纹,削弱了产物膜的保护作用,促进了腐蚀的进行。     

硬膜缓蚀剂对钛合金紧固件电偶腐蚀的防护作用研究

目的 研究YTF-3硬膜缓蚀剂对由TC4螺栓、不锈钢螺母、7050铝合金及TC4钛合金夹层板组成的组件电偶腐蚀的影响作用。方法 利用硬膜缓蚀剂对钛合金紧固件和夹层板进行整体腐蚀防护处理,并通过盐雾加速腐蚀试验。将齿轮槽螺栓与无耳托板自锁螺母安装连接后,进行自然环境加速腐蚀试验,腐蚀后对螺栓螺母以及夹层板的腐蚀情况进行拍照检查,采用图像处理方式对腐蚀情况进行评价,并通过室温拉伸试验对钛合金螺栓腐蚀前后的力学性能情况进行对比分析。结果 经过腐蚀试验后,TC4螺栓和铝合金组件刷涂缓蚀剂区域比未刷涂缓蚀剂区域的平均腐蚀面积要小。不锈钢螺母与TC4钛合金组件刷涂缓蚀剂区域出现明显褶皱和破损现象。对比了试验前后钛合金螺栓的最大拉断载荷,发现降幅仅为0.5%。结论 铝合金夹层板会遭受电偶腐蚀,而YTF-3缓蚀剂可以有效隔绝腐蚀介质渗入固定间隙,大幅缓解电偶腐蚀,而钛合金螺栓在加速腐蚀试验中并未发生明显的腐蚀,并且力学性能无明显改变。     

Internal corrosion hazard assessment of oil & gas pipelines using Bayesian belief network model

A substantial amount of oil & gas products are transported and distributed via pipelines, which can stretch for thousands of kilometers. In British Columbia (BC), Canada, alone there are over 40,000 km of pipelines currently being operated. Because of the adverse environmental impact, public outrage and significant financial losses, the integrity of the pipelines is essential. More than 37 pipe failures per year occur in BC causing liquid spills and gas releases, damaging both property and environment. BC oil & gas commission (BCOGS) has indicated metal loss due to internal corrosion as one of the primary causes of these failures. Therefore, it is of a paramount importance to timely identify pipelines subjected to severe internal corrosion in order to improve corrosion mitigation and pipeline maintenance strategies, thus minimizing the likelihood of failure. To accomplish this task, this paper presents a Bayesian belief network (BBN)-based probabilistic internal corrosion hazard assessment approach for oil & gas pipelines. A cause-effect BBN model has been developed by considering various information, such as analytical corrosion models, expert knowledge and published literature. Multiple corrosion models and failure pressure models have been incorporated into a single flexible network to estimate corrosion defects and associated probability of failure (PoF). This paper also explores the influence of fluid composition and operating conditions on the corrosion rate and PoF. To demonstrate the application of the BBN model, a case study of the Northeastern BC oil & gas pipeline infrastructure is presented. Based on the pipeline's mechanical characteristics and operating conditions, spatial and probabilistic distributions of corrosion defect and PoF have been obtained and visualized with the aid of the Geographic Information System (GIS). The developed BBN model can identify vulnerable pipeline sections and rank them accordingly to enhance the informed decision-making process.     

锅炉运行中的腐蚀原因分析及处理对策

就锅炉水侧金属壁上产生锈泡的主要原因进行了分析,并提出了相应的处理对策及煮锅的操作过程和方法。     

高盐量循环水的缓蚀试验研究

矿井酸性水中和后循环应用的主要问题是高盐量造成的腐蚀问题。通过对高盐量循环水的腐蚀试验,得出腐蚀速度CR与总盐量、时间的相互关系,通过对缓蚀剂的筛选试验,得出SEH+SPZ缓蚀配方,并确定其应用条件。该研究为缺水的盐碱地区矿业用水提供了有益的途径和借鉴。     

我国多功能水处理剂的研究现状

综述了我国多功能水处理剂的现状，通过分析相关资料，说明了多功能水处理剂的研究重点及方向是进一步提高产品的质量、开发新品种。     

碱性电池中无汞添加剂的研究

为了寻找碱性电池中取代汞的缓蚀剂，通过腐蚀实验、极化曲线的测量，研究了单质金属Ｉｎ、Ｂｉ和有机物添加剂—硫脲、聚乙二醇和ＣＴＭＢ的联合作用。利用恒电位控制电沉积的方法，研究了这些有机物添加剂对碱液中锌枝晶生长的抑制作用。实验结果表明，在锌粉中加入单质金属—Ｉｎ、Ｂｉ，可以提高锌在碱液中的析氢超电势，减缓锌的腐蚀速度［１，２］。实验结果还证明，Ｉｎ、Ｂｉ和ＣＴＭＢ联合作用，对锌电极的缓蚀效果非常明显，而且，对抑制锌枝晶的生长和防止锌电极的变形也有显著作用。因此，本文认为，这几种添加剂联合使用很有可能成为碱性电池中取代汞的缓蚀剂     

Inhibition of nitrification in soil by metal diethyldithiocarbamates

IntroductionNitrificationisaprocessinwhichammoniumformofnitrogenisconvertedintonitrateform .Nitrogenuseefficiencyintermsofplantuptakeisgenerallylowandvariesgreatlyunderdifferentsoilandcroppingconditions.MostfertilizerNappliedtosoilsisintheformofammonium orammoniumproducingcompoundssuchasurea,andisusuallyoxidizedrapidlytonitratebynitrifyingmicroorganismsinsoils.Applicationofnitrogenfertilizersmorethanoptimumlevelsleadstolownitrogenrecoveriesandgreaternitrogenaccumulationinthesoilprofile .Theac…     

中小型反渗透系统处理高硬度水操作参数的优化

中小规模反渗透(RO)系统处理高硬度水时往往采用投加阻垢剂、降低回收率来减少碳酸钙在膜上结垢的风险,该系统操作参数主要是阻垢剂投加量和系统回收率。目前许多反渗透系统是凭借经验或生产厂家的建议来确定这2个参数,缺少科学、快速的求解方法。就这2个参数的确定提出了便捷办法。