瞬变电磁法金属管道腐蚀检测理论初探

对应用瞬变电磁法进行金属管道腐蚀检测作了理论上的初步研究,首先将实际问题简化为等效柱体的全空间问题,然后利用柱体在谐变场中的响应公式,由正余弦变换实现了频率域正演到时间域的转换,最后通过对模拟结果的分析,提出了简洁而又有效的评价管道质量的方法。经由中国冶金地质勘查工程总局地球物理勘查院的施工实验,进一步验证了方法的可行性。     

An Experimental Study of Mixture Corrosion Effects of Carbonate Rocks in the Transitional Zone of Littoral Karst Areas

The mechanism for development of littoral karst differs from that of inland karst, and the mixture corrosion effects are one of the most important factors that control the development of littoral karst. Through seven groups of static experiments carried out in a closed CO2-H2O system, basic conclusions can be drawn as follows: (1) the basic law of corrosion process in a transitional zone of seawater-freshwater in littoral karst areas is identical with that in the fresh water, i.e., the lithologic characteristics and rock structure are the main factors which control the development of littoral karst; (2) the mixture corrosion rate of the carbonate rock in the above transitional zone is faster than that in fresh water or seawater; (3) the mechanism for development of carbonate rocks differs at various pressures of CO2 in a transitional zone in littoral karst areas.     

新疆康萨依水库坝址区水文地质问题

康萨依坝址区地下水对普通水泥具硫酸盐型强腐蚀,本文分析了地下水中腐蚀性介质(SO2-4)的来源,预测了水库蓄水后地下水化学成份的变化,并对各水工建筑物区地下水的腐蚀性进行评价。     

我国西南岩溶地区土地石漠化研究

在西南地区分布着以贵州为中心的、面积约54万km^2的碳酸盐岩山区，它是我国喀斯特地貌最发育的地区。同时也是石漠化最严重的地区。石漠化的产生与发展既有自然方面的原因，又有人为方面的原因，究其根本原因，是其岩溶生态系统中土壤这个关键因子的脆弱性所致。文章试图从土壤这个角度来全新阐述石漠化的成因及防治对策     

冻结管对人工冻结构件加筋作用的试验研究及数值模拟

为研究冻结管对人工冻结构件的加筋作用,通过淤泥质粘土人工冻结梁构件三点弯试验,获得了各级载荷下构件的位移值,并运用MARC软件中的加筋单元进行了对应的有限元计算. 根据对冻土梁加筋与否,构件特定力学响应的比较分析,揭示了考虑土层冻结构件中冻结管的加筋作用对于增加冻结构件强度,减小变形量及对提高人工冻结支护工程经济效益的重要作用. 同时,通过物理试验和数值模拟试验的对比,验证了应用MARC软件进行类似计算的可靠性.     

CHARACTERISTICS OF THE OXYGEN REDUCTIONIN ATMOSPHERIC CORROSION

ImODUcrlONArnaorandnowincreasinglyimPoftantprobleminthemanyyearsinvestigationsofabosphericcormsionofmetaIsandalloyisthatthecormsionrmctionunderathineleCtrolytelayerchangessigwhcanhywithdrying.Tornashov(l966)reportedthatthecorm-sionrateisinfluentalbytheelamlytelayerthwhnessandiscontrolledbythedtheion-lndtingcurrentofoxygenreduCtionreig.l)whentheel~lytefilmisthickerthanthediffUSionlayerthickness.ThereforetherateisnotaffededbytheelCCtrolyteFilmthwh-nessforthecaseofaverythickFilm,e.g.regionI…     

预应力锚固工程中测试技术的现状与发展趋势

预应力锚杆（索）由于具有主动加固、深层加固、布置灵活、施工快速、对岩(土)体扰动小、经济性好等显著特点,因此在桥梁、边坡、基坑、隧道、大坝加固、结构抗浮和抗倾、地质灾害治理等工程中得到了广泛的应用。总结了预应力锚固工程中常用测试方法与仪器的发展现状和存在的问题,指出了预应力锚固工程测试技术的研究与发展方向。     

埕岛油田的腐蚀现状与防腐蚀技术

从埕岛海洋腐蚀环境入手 ,介绍了埕岛海上平台和海管的腐蚀现状所采用的防腐技术。提出了今后油田的防腐措施     

Zn-Al合金镀层低铬钝化膜的组成和耐蚀性

目前，在中国采用热浸镀Zn及其合金一直是防止钢材在自然环境中腐蚀的最经济有效的方法，为了提高镀层的防腐和涂装性能，往往在其表面进行钝化处理。传统的镀锌层钝化处理工艺均采用高浓度的铬酸盐溶液， 这对环境污染和人体的危害较严重。随着环境保护问题日益引起人们的重视，在传统的高铬钝化基础上，低浓度铬酸盐钝化开始步入实用性阶段(吴双成，1996；卢燕平等，1995)。但是，目前低铬钝化研究主要集中于热浸镀Zn或电镀Zn镀层，而合金镀层由于化学稳定性高，与铬酸溶液自发反应能力差，无法采用常规的低铬钝化方法处理，有关这方面的报道目前尚少。王洪仁(1998)对Zn-Al合金镀层的低铬钝化处理进行了有益的探索，获得了一个优化的低铬钝化配方和稳定的钝化工艺，并成功地应用于热浸镀Zn-Al合金镀层的表面防锈处理；实验证明，海水在模拟浸泡6个月后，钝化处理Zn-Al合金镀层的腐蚀失重比未钝化样品降低65.9%，表明低铬酸盐钝化使Zn-Al合金镀层的耐海水腐蚀性能得到显著提高(Li Y et al.，2001)。本文作者在前人基础上对Zn-Al合金镀层低铬钝化膜的组成和耐盐雾腐蚀性进行了研究，并初步探讨了钝化膜的形成过程及其耐蚀机理。对Zn-Al合金镀层低铬钝化处理技术的研究，不仅大大降低了对环境的污染和人体的危害，也是在低铬钝化研究方面的重大突破，具有十分重要的意义和实际应用价值。     

Artificial neural networks and their application to assessment of ultimate strength of plates with pitting corrosion

The potential for the structural capability degrading effects of both corrosion and fatigue induced cracks are of profound importance and must be both fully understood and reflected in vessel's inspection and maintenance programme. Corrosion has been studied and quantified by many researchers, however its effect on structural integrity is still subject to uncertainty, particularly with regards to localized corrosion. The present study is focused on assessing the effects of localized pitting corrosion on the ultimate strength of unstiffened plates. Over 265 non-linear finite-element analyses of panels with various locations and sizes of pitting corrosion have been carried out. The results indicate that the length, breadth and depth of pit corrosion have weakening effects on the ultimate strength of the plates while plate slenderness has only marginal effect on strength reduction. Transverse location of pit corrosion is also an important factor determining the amount of strength reduction. When corrosion spreads transversely on both edges, it has the most deteriorating effect on strength. In addition, artificial neural network (ANN) method is applied to derive a formula to predict ultimate strength reduction of locally corroded plates. It is found out that the proposed formulae can accurately predict the ultimate strength of locally corroded plates under uniaxial in-plane compression.