A truly refractory crucible from fourth millennium Tepe Hissar, Northeast Iran

From the Early Chalcolithic to the Late Iron Age, melting and smelting crucibles were usually made from non-refractory ceramic fabrics, which required heating of the charge from within the crucible to avoid collapsing the ceramic itself. In this paper, an unusual melting crucible from Northeast Iran, radiocarbon-dated to the Late Chalcolithic (ca. 3600 BCE), will be presented that significantly changes our understanding of the development of technical ceramics in Southwest Asia. This crucible, made of a highly refractory talc-based ceramic held together by an outer layer of traditional non-refractory ceramic, is to our knowledge unprecedented at such an early date. As will be argued, this ancient crucible was heated from the exterior or from below and not from the interior. This method of firing, combined with the highly-specialized construction technique, makes this crucible so far unique in prehistoric metallurgy, and forces us to re-examine traditional models for the development of technical ceramics and metallurgical practices in the Old World.     

Transient fluid flow in and around a fault

We present the results of simple numerical experiments in which we study the evolution with time of fluid flow around and within a permeable fault embedded in a less permeable porous medium. Fluid movement is driven by an imposed vertical pressure gradient. The results show that fluid flow is controlled by two timescales: τ_f = Sl²/κ_F and τ_F = Sl²/κ_M, where S is the specific storage of the porous material, l the length of the fault, and κ_M and κ_F are the hydraulic conductivities of the porous material and the fault, respectively. Fluid flow and the associated fluid pressure field evolve through three temporal stages: an early phase [t < τ_f] during which the initial fluid pressure gradient within the fault is relaxed; a second transient stage [τ_f < t < τ_F] when fluid is rapidly expelled at one end of the fault and extracted from the surrounding rocks at the other end leading to a reduction in the pressure gradient in the intact rock; a third phase [t < τ_F] characterized by a steady‐state flow. From the numerical experiments we derive an expression for the steady‐state maximum fluid velocity in the fault and the values of the two timescales, τ_f and τ_F. A comparison indicates excellent agreement of our results with existing asymptotic solutions. For km‐scale faults, the model results suggest that steady‐state is unlikely to be reached over geological timescales. Thus, the current use of parameters such as the focusing ratio defined under the assumption of steady‐state conditions should be reconsidered.     

汶川地震可移动文物震害研究

为探索汶川地震作用下以浮放为主的可移动文物的震害及防震措施,通过震后勘查,讨论了汶川地震造成的可移动文物的典型震害症状。从博物馆、陈列台、文物本身等三个方面,分析了可移动文物的主要震害原因和传统的防震措施的不足之处,对国内外可移动文物的先进防震技术进行了探讨,研究了其防震机理。基于国内外可移动文物防震经验,对我国可移动文物提出了防震建议。研究结果表明:汶川地震造成可移动文物震害除了地震本身因素外,文物防震措施不足是一个重要原因;为保证可移动文物的防震性能,首先应规范博物馆建筑抗震设计,其次考虑陈列台隔震技术应用,最后再考虑可移动文物与陈列台之间的可靠连接;采取先进的隔震技术对可移动文物的防震具有促进作用。     

“Mycenaean” political domination of Knossos following the Late Minoan IB destructions on Crete: negative evidence from strontium isotope ratio analysis (Sr/Sr)

Strontium isotope ratio analysis of human dental enamel and bone is applied to investigate a highly debated question of population movement and cultural discontinuity in Prehistoric Aegean Archaeology. The Late Minoan IB (ca. 1490/1470 BC) destructions on Crete are succeeded by cultural upheaval. The novel cultural features that appear at Knossos (Crete) in this period have forerunners in the Mainland. In Cretan context, the Linear B writing system, the funerary architecture and burial practices of the Mainland style are interpreted as evidence of an actual “Mycenaean” long-term settlement and political domination of Knossos. Human skeletal material from tombs that are associated with non-locals from the Mainland based upon the material culture is analysed to measure ⁸⁷Sr/⁸⁶Sr. The results of the analysis show that all the examined individuals from the Knossos tombs were born locally.     

在硫代硫酸钠—醋酸铅双组分体系中黄铜器表面着色的动力学研究

通过调整流代硫酸钠一醋酸铅双组分试液的不同浓度比以及控制着色温度、试液酸度和着色时间,确定黄铜试样表面着以不同颜色的条件。用x射线衍射方法测定不同颜色表面膜的成分,并对膜形成的动力学进行了探讨．为研究黄铜着色提供了一种新的方法。     

Comparison of rapid preparation methods for Pb isotope analysis of high-Pb ceramic glazes: A case study of late medieval Besztercebánya/Banská Bystrica-type stove tiles

This study identified the provenance of Pb flux used in the production of the glaze of unique, high-quality late medieval stove tiles from the northern part of the Carpathian Basin, and elaborated and evaluated a fast preparation process to measure Pb isotope ratios in high-Pb glazes. We compared three different methods of preparation. Method 1 consisted of the dissolution of bulk chips of glaze, dilution of the solution and mass spectrometric analysis without Pb purification. Method 2 collected the Pb from the surface of the glaze with acid-impregnated swabs, subsequent dilution and direct analysis of the sample solution. Method 3 used solutions from method 1, extraction of Pb by ion-exchange chromatography and analysis of the purified Pb. Each preparation method produced a similar Pb isotope ratio. The majority of the Pb isotope ratios fall into one group and indicate that lead imported from the Krakow–Silesia mining region was mainly used for production of the glazes of the stove tiles made by different workshops.     

拱桥与我国古代力学

本文探讨了古代拱桥实物所体现的力学水平,并以拱桥源流为线索,结合有关文献和记载,分析了古代拱桥及相关力学的发展状况。结果表明,拱桥诸多方面符合近代力学原理,具有独特的计算方法,经历了一个春秋战国酝酿、秦汉产生、隋唐成熟、宋元发展完善、明清继承普及的过程。     

Pb and Sr Isotopes and the Provenance of the Painting Materials of Cornelius Krieghoff in 19th‐Century Canada

Radiogenic lead and strontium isotope data are presented for lead‐ and calcium carbonate/barium sulphate‐containing paint and ground samples from 15 paintings, executed between 1844 and 1871, by 19th‐century Canadian artist Cornelius Krieghoff. Like many artists of this era, Krieghoff used lead‐based pigments such as lead white, chrome yellow and Naples yellow, and extenders such as calcium carbonate and barium sulphate. The lead isotope analyses of the majority of these pigments are consistent with the isotopic compositions of lead mined from European lead deposits in England and/or Germany. However, three samples from Krieghoff's early career yield lead isotope compositions that are much more radiogenic than European sources. The lead isotope compositions of these three samples are consistent with the addition of a more radiogenic lead component that is similar to the lead derived from North American lead deposits in Missouri and Illinois (Mississippi Valley Pb–Zn type deposits). The strontium isotope compositions of the extenders suggest that the raw materials for calcium carbonate or barium sulphate extenders were largely derived from Palaeozoic to modern‐day marine environments. This study shows that pigments manufactured from North American lead were being incorporated into Canadian paintings as early as 1844.     

基于铅同位素比值的古代矿料混合模型分析法

为深入研究古代青铜器示踪矿料来源中矿料混合问题,通过铅同位素研究数据构建矿料混合模型,从理论上探讨满足条件的青铜器数据样本其矿料混合的情况。基于模型,通过对铅同位素数据的处理,不仅能够匹配相应的矿料混合模式,而且可为器物分类提供依据。此外,还可计算出相应的铜料中表观含铅量,为相关研究提供参考依据。     

Lead isotope analysis of intra‐skeletal variation in a 19th century mental asylum cemetery: diagenesis versus migration

Living bone sequesters environmental lead (Pb) from both inhalation and ingestion, providing a record of Pb exposure over a lifetime. Questions about the effects of diagenesis and how to remove them have hampered most isotopic and elemental determinations. As a result, researchers often restrict their analyses to tooth enamel, despite its limitations. We report Pb isotopes in teeth and bones in a frontier population of 15 individuals from a late 19th century mental hospital graveyard in Pueblo, Colorado, a town active at that time in the smelting of ores. Analysis of lead isotopes sequestered in healing bone from rib fractures gives an isotopic fingerprint from the last few months of individual's lives. When bone tissues or teeth from different stages of life are analysed, life history trajectories such as migration routes can be developed which are partially self‐correcting for diagenesis. Copyright © 2005 John Wiley & Sons, Ltd.