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51.
This study presents an integrated archaeobotanical analysis of human impact at the Dutch Neolithic wetland site the Hazendonk (4000–1800 cal BC). The analysis included pollen, non-pollen palynomorphs and macroremains from on-site sample columns and macroremains and wood from refuse layers. The various remains provide evidence of disturbance of both dryland and wetland vegetation, information on crop cultivation and food plants, and indications of selection of wood for artefacts. The integrated approach provides results that would not have been obtained by the analysis of one of the sources alone.  相似文献   
52.
This study investigated wet charred wood excavated at an archaic cemetery in Corfu, Greece, dating from 6th century B.C. The preservation condition of the material was evaluated based on its physicochemical properties and micromorphology in comparison to modern combusted wood. Charring temperature of the material was estimated by Electron Spin Resonance (ESR). Results indicated a severe degree of decay, resulting not only from charring. Conservation treatments involved spraying, as the material readily collapsed during immersion.  相似文献   
53.
This paper presents the results of the analysis carried out on a polychrome wood mask from Papua New Guinea during conservation work at Pigorini Museum's restoration laboratory. The significance of this study is that no prior work has characterized the painting materials of Papua New Guinea masks both with spectroscopic and internal microstratigraphic analysis. In fact, these objects were studied especially from an anthropological or conservative point of view and the wood was wrongly defined by its visual appearance. Microstratigraphic and spectroscopic investigations discovered a refined execution technique that up to now has not been demonstrated. The stratigraphy of the painted layers demonstrates a deep knowledge of the materials and of the application techniques on the part of the Papua New Guinea people, together with the ability to foresee the aesthetic result for the artefact. The analysis of the constitutive materials and of the stylistic features supplied valid results in favour of provenance of the mask from Papua New Guinea.  相似文献   
54.
Abstract

The peat moors of lowland Somerset contain a wealth of waterlogged archaeological sites, including some of the most significant prehistoric monuments in the country. There has been a long history of attempts to preserve archaeological sites in situ and monitoring of the burial environment began in 1982. The monitoring has become more complex over time, but the results suggest the same continuing problem of a drop in the water table over the summer months across the whole landscape. With the sole exception of the portion of the Neolithic Sweet Track that benefits from an irrigation system, all the other known sites remain at risk of gradual destruction. The solutions must be found on a landscape scale using agri-environment payments to secure sustainable management of the peat resource. Unfortunately, short-term changes to these payments and long-term changes to the climate are likely to worsen the situation and eventually to require a more drastic solution to the problem. Evidence has been generated to support an ecosystems approach to sustainable peatland management.  相似文献   
55.
Quantitative eco-anatomical analyses were carried out on charred wood from modern olive trees (Olea europaea L.) in order to quantify influence of irrigation on wood characters and to detect irrigated olive specimens among charcoal assemblages dating back to the Middle Ages.  相似文献   
56.
At the bottom of a well on a medieval farm on the Danish island of Amager, archaeologists found a planking clamp dated by dendrochronology to 1405 AD. 1 The clamp is of great importance: very few examples have been found or recognised in Northern Europe to date, and this is the best preserved, and thus provides data about its shape and use; and the size of boat it was used in the construction of. It is discussed whether the clamp was used exclusively for boatbuilding or whether it might also have been used in other crafts. It is suggested that copies of the Tårnby planking clamp might be used in future experimental boatbuilding projects.
© 2004 The Nautical Archaeology Society  相似文献   
57.
一种饱水木质文物含水率无损检测方法的研究   总被引:1,自引:0,他引:1  
含水率是评估饱水木质文物糟朽程度最常用的物理参数之一。目前含水率检测常用方法有烘干法、电阻法、近红外光谱法等,但这些方法或属于破坏性分析,或检测范围不适用。为寻找一种适用于饱水木质文物含水率的无损检测方法,基于饱水木材组成理论模型,建立了含水率与湿态密度、灰分含量三者之间关系,进而提出一种检测含水率的便捷方法——溶液密度法。采用上述方法对天长、淮北等地出土饱水木质样品含水率进行测试,并与烘干法测得标准值进行验证。结果发现两者数据较为接近,相对误差在10%以内,证明了该方法的可靠性。进一步研究发现,样品越糟朽,使用该方法获取的数据与标准值之间相对误差越小。说明该方法更适用于糟朽饱水木材含水率的检测。  相似文献   
58.
文中采用扫描电镜(SEM)和透射电镜(TEM)对海门口遗址饱水古木进行降解机理分析。结果表明:古木细胞次生壁收缩严重并与胞间层分离;胞间层保存较完好,呈连续网状。说明古木纤维素和半纤维素降解相对严重,木质素降解相对较轻。古木主要是受细菌降解,通过SEM和TEM均可见明显的细菌腐朽特征。细菌首先侵入细胞腔,再通过S3层侵入细胞壁内部。细胞壁内由于降解而产生的空隙在几十到几百纳米之间。饱水古木也受到了一定程度的真菌降解,但这类真菌主要降解古木内淀粉等物质,对细胞壁物质降解能力差,主要是使古木变色。  相似文献   
59.
为了更好地保护古建筑,采取静力试验方法,以故宫太和殿二层平身科、柱头科、角科斗拱为对象,研究了竖向荷载作用下斗拱的受力性能。基于上述3种斗拱构造特征,制作了1∶2比例模型,进行了竖向加载试验,讨论了不同斗拱在荷载作用下的破坏形式、内力及变形特征,归纳了斗拱的竖向刚度计算模型。结果表明:竖向荷载作用下,太和殿二层斗拱的坐斗及与之相交的头翘、正心瓜拱容易产生破坏,且模型倒置时下层构件受力要小于上层构件。对于不同斗拱而言,斗拱极限承载力:平身科角科柱头科;斗拱变形及残余变形量:柱头科角科平身科;斗拱延性:角科柱头科平身科。竖向荷载作用下,太和殿二层斗拱的竖向刚度计算模型可简化为三折线段形式。  相似文献   
60.
Here we present a database of responses by South African agate and chalcedony to heat treatment. This will assist analyses of heated stone tools not only in South African archaeological sites, but wherever heated agate and chalcedony pieces were knapped. The minerals are abundant worldwide. To replicate potential heating methods during the Stone Age we placed some minerals in a wood fire, some under coals, and others were buried in sediments beneath fires. Thermal responses include lustrous flaked surfaces, pot lid fractures, semi-circular internal fractures, rough internal surfaces, and crazing. Aerobic heating is implied by pot lid fractures. To explain the thermal responses we analyzed the minerals using X-ray fluorescence, Raman spectroscopy, and carbon and sulfur analyses. Our chalcedony contains more water and impurities than agate, making it more vulnerable to thermal damage. Our method of combining field experiments with chemical analyses has global applications even though we expect that mineral components of agate and chalcedony will vary slightly in different parts of the world.  相似文献   
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