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21.
Determining the behavior of a structure estimated by means of finite elements analysis requires not only an in-depth knowledge of its geometry and dynamic properties but also an experimental validation to corroborate the adequacy of the characteristics of the structure. Most of the current structural identification techniques are based on linear methods that call for many measurement points and/or a relative simple structure. Complex structures are somewhat still an unexplored field due to the difficulties with the finite element method and the experimental corroboration of its results. This study presents the use of particle motion computation applied to each structural vibration mode to improve the identification of its dynamic properties, and its application to the Gothic Cathedral of Palma de Majorca (Spain).  相似文献   
22.
M. Niwa  Y. Mizuochi  A. Tanase 《Geofluids》2015,15(3):387-409
In some cases, water–rock interactions in fault zones can affect radionuclide migration. Here, we analyzed the chemical compositions of well‐exposed fault rocks from the strike‐slip Atera Fault, Central Japan, in order to understand the variability and behavior of major and selected trace elements. The fault zone has a 1.2‐m‐wide, smectite‐rich fault core and paired damage zones that developed within welded tuff on one side of the core and within granite on the other side. The 30‐cm‐wide, kaolinite‐rich fault gouge is developed in granite cataclasite, and it shows indications of the latest fault activity, while the 1.2‐m‐wide fault core appears to be older. Hydrogen and oxygen isotope ratios in the clay‐rich fault gouges, and carbon and oxygen isotope ratios in carbonates indicate that the two major clay‐rich zones formed in bedrock near the surface, consistent with observed deformation structures. Based on chemical analyses, we identified (1) a slight depletion in SiO2, Na2O, K2O, and light rare earth elements at the edges of the 1.2‐m‐wide fault core, (2) a clear depletion in SiO2, Na2O, K2O, and all rare earth elements except Eu in the 30‐cm‐wide fault gouge, and (3) an increase in CaO, MnO, and heavy rare earth elements across the entire 1.2‐m‐wide fault core. Findings (1) and (2) reflect water–rock interactions in the 1.2‐m‐wide fault core and in the 30‐cm‐wide fault gouge that resulted in the formation of smectite and kaolinite. Finding (3) reflects carbonate precipitation caused by the addition of basalt fragments from a nearby site to the 1.2‐m‐wide fault core during faulting, and subsequent sorption reactions of heavy rare earth elements via processes such as complexation with the carbonates.  相似文献   
23.
Lead isotope data, together with an evaluation of previously published results for the chemical composition of Omani ores and copper‐base artefacts are used to define a material signature of Omani copper. Absent from our group of Bronze Age metal (Umm an Nar and Wadi Suq periods) are the signature of ores from Masirah Island and also from the vast deposits in north Oman inland from Suhar. Contemporaneous copper from Bahrain and from Tell Abraq on the Gulf coast is consistent in its material signature with Omani copper; a derivation from Omani ores of this copper is highly likely. A few exceptions at Tell Abraq point to Faynan/Timna in the southern Levant as a possible source region. Among Mesopotamian artefacts the signature of Omani copper is encountered during all cultural periods from Uruk at the end of the fourth millennium BC to Akkadian 1000 years later. Oman/Magan appears to have been particularly important during Early Dynastic III and Akkadian when about half of the copper in circulation bears the Omani signature.  相似文献   
24.
Tang sancai is one of the most important types of Chinese ceramics. To determine the provenance of Tang sancai is important to study ancient trade and other issues. In this paper we compare ICP-MS trace elements and TIMS Sr–Nd isotopes of visibly similar Tang sancai from two major production centres Gongxian and Yaozhou. The variation in contents/ratios of many of >40 trace elements is small for samples from Gongxian, yet is considerably bigger for that from Yaozhou. However, the variation in 87Sr/86Sr and 143Nd/144Nd isotopic ratios is very small for samples from both places. Gongxian and Yaozhou samples have distinctive Sr–Nd isotopic and trace element features despite their similarity in major elements, and these analysis data can be interpreted with geochemistry, indicating that Sr and Nd isotopes have great potential in ceramic provenance studies. The distinct characterisation of these samples provides valuable criteria for identifying provenance of Tang sancai of uncertain origin. Two modern fakes are also analysed, and they can as well be distinguished from antique Tang sancai using above criteria.  相似文献   
25.
Bone chemistry paleodietary studies are emerging as important research areas in archaeology, biological anthropology, and paleontology. With appropriate controls, the inorganic and organic chemical composition of bones and teeth can provide information about past diet and habitat use. Chemical signatures are used to address individual dietary variability in early hominid fossils, paleontological remains, and more recent human and faunal populations.  相似文献   
26.
包头市城市生态支持系统可持续发展的限制因子探讨   总被引:5,自引:0,他引:5  
宁小莉  秦树辉  包玉海 《人文地理》2005,20(6):102-105,82
本文在了解包头市自然环境与社会经济状况的基础上,采用了静态与动态相结合的方法,运用层次分析法从支持水平、协调性、发展能力三个方面构建指标体系,建立研究模型,定性与定量相结合,对包头市的城市生态支持系统自1992年-2001年十年以来的发展轨迹进行了全面深入的研究分析与评价,得出包头市"城市生态支持系统支持水平较低"的结论,在此基础上提出了包头市城市生态支持系统的主要限制因子。目的在于通过对包头市城市生态支持系统的综合水平的分析与评价,正确认识城市发展中存在的问题,提高城市生态支持系统的结构、功能,提高限制因子容量,推动包头市城市生态支持系统的建设,促进城市健康发展。  相似文献   
27.
孙丽华 《人文地理》1995,10(4):56-60
作为亚太地区组成部分的东北亚地区,主要包括中国东北、俄罗斯远东地区、朝鲜、韩国、日本和蒙古。这六个国家(地区)相互毗邻,联系密切,而且交通方便,运输距离短。  相似文献   
28.
We present the results of geochemical analysis of silver coinage issued by Rome and dated between the fourth and second century BCE, which are complemented by data of coinage issued by Carthage, the Brettii, and the Greek colony of Emporion. Each of these minting authorities represents one of the major parties involved in the struggle for hegemony in the fourth to second centuries BCE Western Mediterranean region. This study retraces how the metal supply shifts in response to the transforming power relations and how this change is related to Rome's rise to the virtually uncontested ruler of the region.  相似文献   
29.
This study presents the results of compositional and lead isotopic analysis of coinage issued by the Greek colonies of Syracuse, Metapontum, Taras and Thurium in the fifth to third centuries bce . The data suggest that each colony in Magna Graecia, regardless of its motherland roots and despite ongoing conflicts between the cities, had access to the same silver, and that this supply was stable overall throughout their period of minting and issuing coinage. The paper retraces the silver sources of the colonies and points out a potential supply route for the metal. It includes a method development for a multi-standard quantification approach for laser ablation-inductively coupled-mass spectrometry (LA-ICP-MS) analysis of silver.  相似文献   
30.
本文以形制最具代表性的陶鬲为切入点,对罗山天湖商代墓葬出土陶器文化因素构成和墓葬葬俗进行了分析,认为罗山天湖商代墓葬与晚商殷墟类型存在明显差异,而这种差异也正是晚商中心文化势力衰落的一个表现形式。  相似文献   
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