污染大气中浑仪,简仪的带锈防护

浑仪、简仪（以下简称两仪）在高PH、大气污染和日晒雨淋环境中的腐蚀是一种动态加速腐蚀过程。采用合成的双唑胺铜缓蚀剂和有机硅改性的甲基丙烯酸树脂,并分别复配成协同缓蚀剂群和含有增效稳定剂的封护剂。采用这两种材料和脱水后再防护的工艺,使带锈防护后的浑仪、简仪的腐蚀低于无污染大气中的速率。用电化学方法评价了防护技术的可行性,根据腐蚀与人工老化试验结果讨论了防护材料性能与腐蚀环境和带锈防护的关系,采用XPS分析方法探索了双唑胺比BTA更适用于两仪防护的原因。     

五种含氯铜合金腐蚀产物的拉曼光谱及扫描电镜的分析研究

为深入研究五种含氯铜合金腐蚀产物(氯铜矿、斜氯铜矿、羟氯铜矿、氯磷钠铜石和铜氯矾)的拉曼光谱图,进一步补充金属锈蚀物的拉曼光谱库,采集不同考古来源的铜合金上腐蚀产物的拉曼光谱,并结合扫描电镜观察了腐蚀产物的形貌特征。研究结果表明,氯铜矿、斜氯铜矿和羟氯铜矿3个同分异构体的拉曼光谱并不相同:氯铜矿和斜氯铜矿较为常见,且经常混合在一起;羟氯铜矿不稳定,非常少见,一般与其他两种混合在一起。扫描电镜观察氯铜矿主要为粒状形貌,同时也发现有葡萄状、皮壳状、钟乳状等形貌;羟氯铜矿因少见,目前只观察到板状形貌。氯磷钠铜石腐蚀产物较厚且疏松柔软,常发现于干旱地区有动物或人遗骸墓葬的出土器物上,扫描电镜观察呈花瓣形状的蓓蕾形貌。铜氯矾更为少见,笔者目前只在2件器物上发现。同时对5种腐蚀产物的形成原因进行了讨论。     

宝鸡眉县出土27件窑藏青铜器锈蚀特征及成分的分析研究

为了研究刚出土的青铜器在新的环境中的发展变化情况,在宝鸡眉县27件国宝级西周窖藏青铜器出土一年半后,对这批器物出土前后的锈蚀类型及特征进行了分析和描述,并对每一器物的锈蚀产物进行了系统检测分析。结果显示,这批青铜器腐蚀类型主要为封闭环境中的大气腐蚀,主要产物为碳酸盐和氧化物。但同时在其中一个器物上发现了氯化物类有害锈成分,分析认为,出土前后环境的变化是有害锈得以产生和发展的根本原因。     

Hydrothermal dolomitization,mixing corrosion and deep burial porosity formation: numerical results from 1‐D reactive transport models

Major corrosion has been found at depth in carbonate hydrocarbon reservoirs from different geologic provinces. Fluid inclusion microthermometry and stable isotopic compositions of carbonate cements, predating major corrosion, constrain the interpretation of the evolution of parental fluids during progressive burial and prior to the major corrosion event. Post‐major corrosion mineral paragenesis includes pyrite (‐marcasite), anhydrite, kaolinite (dickite) and fluorite. Although the post‐corrosion mineral paragenesis represents minor volumes of rock, it may provide valuable insights into the post‐corrosion brine chemistry. Using reactive transport numerical models, the roles of cooling and/or mixing of brines on corrosion have been evaluated as controls for dolomitization, deep burial corrosion and precipitation of the post‐corrosion mineral paragenesis. Modelling results show that cooling of deep‐seated fluids moving upward along a fracture may cause minor calcite dissolution and porosity generation. Significant dolomitization along a fracture zone and nearby host‐rock only occurs when deep‐seated fluids have high salinities (4 mol Cl kg^?1 of solution) and Darcian flow rates are relatively high (1 m³ m^?2 year^?1). Only minor volumes of quartz and fluorite precipitate in the newly formed porosity. Moreover, modelling results cannot reproduce the authigenic precipitation of kaolinite (dickite at high temperatures) by cooling. As an alternative to cooling as a cause of corrosion, mixing between two brines of different compositions and salinities is represented by two main cases. One case consists of the flow up along a fracture of deep‐seated fluids with higher salinities than the fluid in the wall rock. Dolomite does not precipitate at a fracture zone. Nevertheless, minor volumes of dolomite are formed away from the fracture. The post‐corrosion mineral paragenesis can be partly reproduced, and the results are comparable to those obtained from cooling calculations. Minor volumes of quartz and fluorite are formed, and kaolinite‐dickite does not precipitate. The major outputs of this scenario are calcite dissolution and slight net increase in porosity. A second case corresponds to the mixing of low salinity deep‐seated fluids, flowing up along fractures, with high salinity brines within the wall rock. Calculations predict major dissolution of calcite and precipitation of dolomite. The post‐corrosion mineral paragenesis can be reproduced. High volumes of quartz, fluorite and kaolinite‐dickite precipitate and may even completely occlude newly formed porosity.     

A Minimum-Impact Method for Measuring Corrosion Rate of Steel-Hulled Shipwrecks in Seawater

Current research on USS Arizona is focused on a minimum-impact technique for calculating corrosion rate of the battleship's steel hull by analysing physical and chemical properties of marine encrustation covering the exposed hull. An equation is derived that allows concretion thickness, density, and total iron content to be used to calculate corrosion rate of steel hull plate.
© 2006 The Authors     

青铜文物缓蚀剂效率及封护剂抗腐蚀能力的比较研究

为评价青铜文物缓蚀剂效率及封护剂抗腐蚀能力进行了两项电化学实验。一是利用直流腐蚀的极化电阻法对缓蚀效率评价,二是应用恒电位交流阻抗法对涂层的抗腐蚀效率评价。实验表明,复合缓蚀剂的缓蚀效率优于单一缓蚀剂如AMT、BTA,在模拟中性土壤介质的水溶液中各自缓蚀效率分别为88.7%、94.6%,两者组成复合缓蚀剂后其缓蚀效率高达98.8%,这是发挥其缓蚀剂各组分的协同效应的结果。应用恒电位交流阻抗实验,可以更好地理解附着有封护层时复杂的腐蚀过程。结果表明,石蜡涂层样品的Nyquist谱图出现扩散过程引起的阻抗特征;聚乙烯醇缩丁醛涂层、Paraloid B72涂层、空白样(缓蚀层BTA)三种样品Nyquist谱图均是由于涂层微孔引起的阻抗特征,在同一浓度下其抗腐蚀性能排序呈依次递减趋势。     

河南三门峡虢国墓出土西周——春秋时期费昂斯珠的分析研究

河南三门峡虢国墓是西周晚期至春秋初期的大型邦国墓地,其中M2009的六璜组玉佩上使用了费昂斯珠,作为人工制品的费昂斯珠,其材料组成和工艺特点显示了古代科技水平,利用科学分析揭示其科学价值很有意义。本研究运用扫描电子显微镜(SEM-EDX)、激光拉曼光谱(Raman)分析了四件三门峡虢国墓M2009出土的费昂斯珠的微观结构和成分。研究发现,四件费昂斯珠采用直接施釉法,釉层使用了铜离子着色,可能使用了含氯和铜的矿物。费昂斯珠的内外表层还发现了羟基磷灰石和朱砂,来自于墓主遗骸和墓葬环境。     

Management of Historic Shipwrecks Through a Combination of Significance and Conservation Assessments

Abstract

Corrosion modelling of decay rates of the iron wrecks in Port Phillip Bay, Victoria, has enabled an estimation of the speed at which the historic resource of iron shipwrecks is disappearing. Use of the significance ranking of the iron wrecks, based on the Australian National Standards for significance assessment, provides a useful guide to decision-making, but decisions based solely on these criteria can lead to less than optimal results. From the corrosion rates and the amount of residual metal thickness in structural elements it is possible to determine a conservation ranking that is based on the need for intervention and the chances of being successful in stabilizing the wrecks. The arithmetic product of the significance and conservation rankings defines the treatment score or ranking which forms the basis for rational decision making about deployment of resources.     

The effect of soil conditions on the long-term corrosion of buried tin-bronzes and copper

The object of this work was to relate the corrosion of tin-bronzes to the chemical condition of the soil in which they have been buried, most of them since the Bronze Age. Naturally, it was not easy to obtain recent hoards with their related soils, and considerable reliance had to be placed on recorded finds by taking recent soil samples from sites on which hoards were found over a hundred years earlier. Even so, with the exception of peat, a reasonable relationship appears to exist between the pH of the soil and the state of the metal. Acid soils are aggressive to metals and alkaline soils are benign. In no cases were sulphate reducing bacteria active in promoting corrosion. In the main, peat and peaty soils were benign in spite of their acidity, probably due to the protective action of polyphenols.     

秦陵出土青铜水禽锈体组织结构的初步分析

本研究旨在研究秦始皇帝陵园出土彩绘青铜水禽锈体的结构形貌及其形成原因。采用扫描电镜能谱(SEMEDS)、X射线荧光光谱(XRF)、金相显微分析和离子色谱分析(IC)等多种分析手段,对青铜水禽锈体的组织结构及其埋藏土壤进行了分析检测。结果表明:高湿、火烧、人为破坏的特殊埋藏环境是该批青铜水禽严重矿化的主要原因,而有些矿化严重的部分为稳定的粉状锈蚀物,并非传统意义上的“有害锈”;从组织的微观腐蚀特征来看,铸态枝晶结构的样品α相优先腐蚀;而铸后受热组织则呈晶间腐蚀的特点,腐蚀由晶粒间界向晶粒发展;锈体层状结构的产生与Cu₂O溶解产生空隙,并在合适的环境条件下生成了孔雀石有关。