天然氧化铜矿与铜制品腐蚀产物区别的探讨

在一些新石器时代的遗址中经常会出现一些铜渣、小块孔雀石等与炼铜有关的遗物。为探究这些孔雀石到底是天然的氧化铜矿还是铜制品的腐蚀产物,本工作对天然氧化铜矿和青铜器腐蚀产物进行岩相分析和元素成分分析。结果表明,天然氧化铜矿大都具有一些特殊的结构构造,而在铜制品的腐蚀产物中却很难发现这些结构构造;同时,二者在元素成分上也有显著不同,Bi、Sb、As、Fe、Mo、Co、Mn等微量元素可以作为区分天然氧化铜矿和青铜器腐蚀产物的一个判别标志。结合岩相分析和成分分析,可以确定一个遗址出土的孔雀石或蓝铜矿是天然氧化铜矿还是铜制品的腐蚀产物;同时,可进一步判断是红铜的腐蚀产物还是青铜的。这一结论对探讨铜冶金的起源有重要意义。     

青铜器锈蚀结构组成及形态的比较研究

采用X射线衍射(XRD)、扫描电镜(SEM)、X射线电子能谱(EDS)和金相显微镜(OM)等方法,分析比较了染有“粉状锈”与未染“粉状锈”的典型青铜残片的锈蚀产物的矿物组成、腐蚀层分层结构及金相组织。结果发现,未染有“粉状锈”的青铜样品腐蚀层一般分为二层,外层是二价铜化合物,合金组织中未见α (α δ)组织,锈蚀产物中不含碱式氯化铜;而染有“粉状锈”的青铜样品都含有碱式氯化铜,其断面腐蚀层分三至四层,且每层锈体的结构和元素组成各不相同,在靠近合金基体层的锈层中发现了大量的CuCl存在。结果表明,青铜文物表面锈蚀覆盖层的致密性、空气中的湿度及锈层中CuCl层状分布的存在,是青铜器表面“粉状锈”形成和发展的根本原因。     

应用电位活化理论研究青铜器的腐蚀与保护

应用电位活化理论分析和阐述了青铜器腐蚀的观点和防护理念。对青铜器腐蚀的全过程提出了致密膜保护期、保护膜破坏局部腐蚀期和小孔腐蚀粉状锈加速期三个阶段的看法。用高效钝化保护剂对处于不同腐蚀阶段的青铜器保护膜进行修复和改性 ,结果表明 ,理论腐蚀电阻RC 从 10 5Ω提高到 10 7Ω ,并具有可间断涂覆、可回复的特点 ,可应用于青铜文物的保护试验。     

Investigating archaeological site formation processes on the battleship USS Arizona using finite element analysis

Scientists from the National Institute of Standards and Technology (NIST) worked in a collaborative partnership with archaeologists from the National Park Service's (NPS) Submerged Resources Center (SRC) to develop a finite element model (FEM) of the battleship USS Arizona. An FEM is a computer-based engineering model that calculates theoretical stresses, propagation of force, and shape changes to a structure under loads using thousands or even millions of individual elements whose individual responses are well understood. NIST researchers created an FEM of an 80 ft. (25 m) midships section of the Arizona site to analyze archaeological site formation processes on the sunken battleship, in particular to determine the current condition of the wreck and predict its future strength and structural integrity as it continues to corrode. The NIST's FEM study is one aspect of a larger project under the direction of the NPS, the USS Arizona Preservation Project, whose goal is to determine the nature and rate of corrosion affecting USS Arizona, and to model its long-term structural deterioration. The FEM incorporates findings from other key components of the USS Arizona Preservation Project, such as steel hull corrosion rates, structural surveys of the vessel, sediment compaction studies, and analysis of the concretion that covers the ship's hull, into a single tool that is being used to predict how the wreck will degrade in the future.     

Numerical Investigation of Residual Strength and Energy Dissipation Capacities of Corroded Bridge Members Under Earthquake Loading

Recent damage examples of aged steel bridge infrastructures around the world are so alarming. They intensified the importance of careful evaluation of existing structures for the feasibility of current usage and to ensure public safety. Corrosion and fatigue cracking may be the two most important types of damages in aging structures. Furthermore, recent earthquakes demonstrated potential seismic vulnerability of some types of steel bridges. Corrosion and its effects can trigger the damages caused by earthquakes, and it will be vital to understand the behavior of existing steel bridges which are corroding for decades in future severe seismic events as well. This article comprises the results of nonlinear FEM analysis of many actual corroded plates with different corrosion conditions and proposes a simple and reliable methodology to estimate remaining seismic strength and energy dissipation capacities by measuring only the minimum thickness of a corroded surface, which can be used to make rational decisions about the maintenance management plan of steel infrastructures.     

考古发现所见两汉琥珀印探述

琥珀制品在两汉时期风靡一时,琥珀印在琥珀制品中颇具特色。本文在对中国境内考古发现所见两汉琥珀印资料收集与整理的基础上,对其出土地域、自身特征、出土位置及伴出物品等问题进行了探讨。研究表明出土琥珀印的墓葬等级较高,且出土位置特殊,并伴随有水晶、玛瑙、海蓝宝等贵重宝石。这些宝石的产地可能源自南亚或东南亚地区,而这类随葬品在两汉墓葬中的流行亦体现了当时物质交流的成果。     

X射线显微CT成像技术在金属文物制作工艺研究与腐蚀状态评估中的应用

金属腐蚀过程不仅受环境等外部因素的影响,制作工艺、合金组成及缺陷等内部因素同样起着重要作用。为实现金属文物制作工艺和内部腐蚀状态的可视化研究,运用X射线显微CT对铜镜文物碎片以及出土、海洋出水铁质文物样品进行扫描探测,并结合X射线荧光、X射线衍射等检测手段,开展金属文物材质、工艺及矿化程度的综合分析。结果表明,在显微CT影像重建基础上,通过设定不同的阈值,可实现文物内部缺陷、腐蚀矿化程度等内部信息的测量统计。该方法可为金属文物材质、制作工艺研究和腐蚀状态评估提供无损的研究手段。     

旅游产品交换过程中的价格与价值关系探讨

旅游产品的随意涨价,让很多游客感到头痛和不爽,然而业界还在蠢蠢欲动,继续运筹涨价。旅游产品的价格问题实际上关系到一重大的理论问题:由什么来衡量旅游产品价值量。旅游产品在其实现过程中没有物质性的产品传递过程,因此用"商品的价值量取决于社会必要劳动时间,商品按照价值相等的原则互相交换。价格围绕价值上下波动",已经明显解释不通了。感受才是决定旅游产品是否有价值的关键因素。旅游过程中旅游者所获得的感受越深,旅游产品的价值越大,因此它遵循刘氏"发汗定律"。也就是感受的程度是决定价格高低的直接因素。但是感受是一种纯粹的主观心理体验,它是人类社会经济文化背景的直接反映,也是人类文明的区域再现。     

深圳发展会展旅游的探析

会展旅游已成为当今世界旅游业发展的一个重要方向。它不仅可以促进城市经济发展,而且能够提升城市国内、国际形象,是城市旅游业发展的重要方式。本文论述了深圳发展会展旅游的优越条件和存在的问题,并提出几点建议和对策。     

Space, culture and economy—a question of practice

This article addresses the current debate within geography and other circles studying urban and regional development of the relationship between culture and economy. It revolves around two arguments. First, that the relationship should be seen not only as a question of epochal change, of de-differentiation and culturalisation of the economy; it should be considered as an analytical rather than a historical question. Second, it is argued that a theoretical articulation may be gainfully employed starting from the level of social ontology-particularly an ontology of practice. These arguments are developed starting from a critical discussion of two dominant bodies of thought about the relationship, following which, a demonstration of the inseparability of practice and meaning is used to conduct a theoretical re-articulation of culture and economy. Finally, the spatiality of the culture economy relation is considered, displacing the emphasis from connectivity in bounded regions towards joint involvement in the production of space on different scales.