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31.
Jelmer W. Eerkens Gry H. Barfod Kevin J. Vaughn P. Ryan Williams Charles E. Lesher 《Archaeological and Anthropological Sciences》2014,6(3):241-254
The Nasca culture of the south coast of Peru developed during the first millennium ad and is known internationally for its elaborately decorated polychrome pots. Despite decades of iconographic analysis, little is known about the more technological aspects of Nasca pigment production and application. We present results from a pilot study on iron isotopes as a potential line of inquiry into the differences between red and black pigments in Nasca pigments. As well, we conduct a small firing experiment to examine potential changes in isotope composition. Our analyses show three significant results. First, firing does not change the isotopic ratios of Fe in pigments. Second, red and black pigments show differences in their iron isotope composition, which relate to differences in the minerals used to make the different colors. Third, naturally available hematite samples show greater isotopic variation than pigment samples, suggesting that people selected a limited range of iron oxides to produce pigments. 相似文献
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Justin C. Williams 《Geographical analysis》2002,34(4):330-349
The land acquisition problem is a spatial partitioning problem that involves selecting multiple parcels to be acquired for a particular land use. Three selection criteria are considered: total cost, total area, and spatial contiguity. Achieving contiguity or connectivity has been problematic in previous exact methods for land acquisition. Here we present a new zero‐one programming model that enforces necessary and sufficient conditions for achieving contiguity in discrete cell landscapes, independent of other spatial attributes such as compactness. Computational experience with several demonstration problems is reported, and results and extensions are discussed. 相似文献
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This article examines how the British government has responded to Zimbabwe’s ongoing crisis. This case raises several wider issues for British foreign policy, most notably the question of how much leverage London can exercise on the international scene in general, and over relatively small and weak states like Zimbabwe in particular. Zimbabwe’s crisis also raises profound questions about the appropriate balance between bilateral and multilateral policies, and between engaging in public criticism and conducting so–called ‘quiet diplomacy’. While bilateralism clearly has not worked, multilateralism has revealed its own frustrations, especially given the reluctance of many African elites within a number of organizations to criticize President Mugabe’s policies. This reluctance threatens to unravel the British Labour government’s stated objectives in Africa while at the same time raising important doubts over the credibility of the New Partnership for Africa’s Development (NEPAD), and whether an ‘Africa moment’ can be discerned in the manner articulated by prime minister Tony Blair. 相似文献
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Michael Williams 《Journal of Historical Geography》1983,9(1):1-28
Many historical geographers would claim Sauer to be one of them. Yet, with the exception of his Foreword to historical geography (1941) he made no major declaration of his interest in the sub-discipline. This paper attempts to examine Sauer's attitude to the time element in geography through a close appraisal of his published work but particularly through his hitherto unpublished correspondence. It soon becomes evident that Sauer changed his ideas during his long working life, and that it is difficult to disentangle Sauer's philosophy about the time element in geography from his philosophy about life, particularly within university circles in the United States, and within American society in general. Sauer's comment to a student in 1936 that historical geography “is of course the apple of my eye” would seem to be demonstrated amply, but that historical geography was not a conventional methodology so much as a flexible metaphor to encompass the study of man on earth through time. It was also the vehicle for some of his prime concerns; scholarship, independent thought, opposition to bureaucracy, concern for human values and environmental quality, and deep distaste for the technological and scientific “fix”, particularly the solutions offered by the social sciences. It might repay contemporary historical geographers to take a close look at Sauer's academic and intellectual values. 相似文献
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