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31.
宝鸡益门出土玉器分析研究 总被引:1,自引:0,他引:1
使用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)对陕西宝鸡益门出土的玉器残块的显微结构、元素和物相组成进行了分析研究。结果表明,益门二号墓出土玉器分析样品属单斜闪石类型中的透闪石系,其透闪石含量在85%以上。出土玉器样品应归属为青玉种类,玉料较好,属中上水平的玉料。根据我国玉器文化的历史和和田玉的矿物特征,益门二号墓出土玉器分析样品类似于和田玉矿物。 相似文献
32.
J. A. J. Gowlett 《Journal of World Prehistory》1987,1(2):127-170
Accelerator mass spectrometry (AMS) allows radiocarbon dating to be carried out by direct counting of14C atoms, rather than the conventional counting of radioactive disintegrations. The result is that samples up to 1000 times smaller can be handled. The approach was tested in principle by 1977 and for archaeological operation by 1983. More than 2000 samples per year are now being dated worldwide. The machines can now operate to about ± 80 years or better. Dates older than 40,000 years have not yet been achieved, but the ability to use small samples has already had considerable impact on dating the period 10,000–30,000 years ago. Bone is an ideal material for the new technique, since amino acids can normally be isolated and purified from gram-size samples. Studies of the origins of domestication are aided by the dating of individual grains and seeds. Because small samples can be mobile in the soil, careful sample selection strategies and procedures are required. The full impact of the technique can be assessed only through the rapid and comprehensive publication of archaeological results. 相似文献
33.
为了预防性保护和修复秦俑,必须掌握秦俑残片显微结构及其烧制环境、破损方式,从而为改善秦俑修复工艺、筛选修复材料提供基础,运用偏光显微镜对秦兵马俑残片中的一些矿物质(石英、长石、云母等)颗粒的分布形态和含量来分析陶土的成分结构、制作工艺、烧成气氛及原料来源等信息。结果表明,秦俑陶片主要成分为少量砂屑及大量粘土,而粘土为岩土矿风化的产物,秦俑残片裂痕较多的部位风化、酥粉痕迹明显。秦俑制作工艺以模为主,模、塑结合,并在粘土中添加了细砂,多于还原气氛中烧制而成。 相似文献
34.
Ancient decorated potteries from Susa (Mesopotamia) dating from 4200 to 3700 bc , were studied in order to determine the origin and the nature of the raw materials used, and to identify the technological processes applied to make the ceramic bodies and their decorations. Bulk compositions were determined by particle induced X‐ray emission (PIXE), while the microstructure and the mineralogical phases were studied using scanning electron microscopy (SEM), energy dispersive X‐ray analyses (EDX) and X‐ray powder diffraction (XRD). The results showed that the raw materials used to elaborate these potteries were similar for all the ceramic bodies (carbonates and iron and magnesium‐rich clays containing sand), and for all the decorations (iron oxides, silica, potassic and alumina sources). The variations of coloration of the ceramics and of their decorations were due to different firing temperatures. The ranges of firing temperatures used by potters were evaluated on the basis of mineral stability domains. 相似文献
35.
Wei She M. R. Jones Yunsheng Zhang Xing Shi 《International Journal of Architectural Heritage》2015,9(7):775-793
The Hui-style residence is an important architectural heritage of China. The hollow wall structures are widely used to build its exterior wall system. However, the thermal performance of the hollow wall is no longer able to meet the new energy-saving and environmental requirement. This article describes a laboratory study of the development of foamed mortar (FM), with the potential for use in thermal upgrading of the Hui-style hollow wall system without dramatically changing its traditional structure. The key early age, physical, mechanical and thermal properties were systematically measured. Two extended models were respectively developed to calculate compressive strength and thermal conductivity, as a function of porosity. Environment chamber test was also employed to investigate the effectiveness of this novel thermal upgrading approach and the results show that filling the voids with FM can effectively improve the overall thermal resistance of the hollow wall system by 44%, which is almost equal to the overall thermal resistance when using the more expensive commercial inorganic stucco system. In addition, the combination of these two methods yielded an overall thermal resistance of 0.701 m2·K/W, which is even higher than 0.67 m2·K/W for the code required in the hot summer/cold winter climate zone. 相似文献
36.
37.
P. Valério A. M. M. Soares M. F. Araújo R. J. C. Silva L. Baptista 《Archaeometry》2016,58(6):1003-1023
In the Iberian Peninsula, the copper metallurgy from the Chalcolithic to the Middle Bronze Age (MBA) was mostly characterized by low arsenic contents. A collection of 53 MBA artefacts from southern Portugal was analysed by micro‐EDXRF, optical microscopy, SEM–EDS and Vickers to investigate the metal composition and manufacture. No technological distinction was found between artefacts from domestic and funerary contexts, which were radiocarbon‐dated to 2000–1500 cal bc . The arsenic contents of almost 100 MBA artefacts from this region, including the above‐mentioned set, have a Gaussian distribution with a high average (3.9 wt% As). Possible explanations are discussed for this distinctive metallurgy at the south‐western end of the Iberian Peninsula. 相似文献
38.
Characterization of a Historical Cannonball from the Fortress of San Juan De Ulúa Exposed to a Marine Environment 下载免费PDF全文
M. Hernandez M. Hernandez‐Escampa C. Abreu J. Uruchurtu M. Bethencourt A. Covelo 《Archaeometry》2016,58(4):610-623
Metallurgical analyses and chemical characterizations were carried out on historical cannonballs from the Fortress of San Juan de Ulúa, Veracruz, México. Cannonballs dating from the 18th and 19th centuries share metallurgical characteristics similar to those of material coming from a shipment of ammunition found in the wreck of a sunken French ship from the battle of Trafalgar. The analyses show that the base material is grey cast iron with a carbon equivalent of 4.94 and a ferritic–perlitic matrix, in which the high phosphorus content has led to the formation of iron phosphide compounds in conjunction with a homogeneous distribution of carbon graphite flakes of Type C. In addition, corrosion products from samples revealed the presence of various crystalline iron compounds (X‐ray diffraction), mostly highly chlorinated iron compounds identified as akaganeite. X‐ray fluorescence identified various characteristics of the corrosion products as a function of the sampling depth. FT–IR spectroscopy revealed that the main difference between the corrosion products (internal and external) is determined by the number of organic species. Differential scanning calorimetry corroborated that these corrosion products are thermally stable compounds at elevated temperatures. 相似文献
39.
This paper explores the effectiveness of policies ‘in’ attracting the foreign research and development (R&D) of multinational enterprises (MNEs) to specific countries in Europe. We develop a macroeconomic investigation covering 29 European countries during the period between 1990 and 2012 in order to address: (a) whether the provision of direct financial support for business R&D is effective for the attraction of foreign R&D; (b) whether direct support is more effective than indirect support for this purpose and (c) whether the link between direct financial support for business R&D and the foreign R&D of MNEs is conditioned by the context within which the support is provided. The results of the analysis show that, first, the provision of direct financial support is generally effective for the attraction of foreign R&D by MNEs. Second, direct support for business R&D is more effective for this purpose than indirect support. Third, the provision of direct financial support for business R&D yields greater returns in contexts that are more socio-economically suitable for knowledge-intensive, innovative activity. 相似文献
40.
Erena Le Heron 《Geographical Research》2019,57(2):215-229
In 2004, a controversy arose in Aotearoa New Zealand's coal mining sector that involved Powelliphanta augusta, a species of land snail. This paper considers that controversy in terms of emergent assemblages involving the snail, the mining industry, the Department of Conservation, political action by environmental non‐government organisations, and public expressions of environmental and other values. Three sets of relations embedded in those assemblages are examined—those related to positioning and organising nature; values, politics, and power relations; and human and non‐human materialities. Those relations illuminate how a protracted controversy and its objects form a “social test bed” for contested views in legislation and guidelines dealing with economy, conservation, and restoration. To assess the dynamics, complexities, and contingencies of such relations, attention is paid to the controversy's detailed time line and legal framing, as well as to ontological shifts of snail and habitat and snail metrics. This analytical focus highlights the shifting quality of ideas about how the snail and its habitat are understood as entangled in fraught and mutating strategies of translocation that are played out in a particular regulatory setting. It also provides insights into international geographical efforts to re‐shape environmental governance and management. 相似文献