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11.
J.M.P. Cabral M.A. Gouveia A.M. Alarcão J. Alarcao 《Journal of archaeological science》1983,10(1):61-70
The concentrations of two major elements and thirteen trace elements in 73 selected sherds of fine grey ware from the Iron Age and Roman period, excavated at Conimbriga, Santa Olaia and Tavarede, Portugal, were determined by instrumental neutron activation analysis. These concentrations were used to calculate distance matrices which were then subjected to cluster analysis employing SAHN and k-means methods, as well as to principal components analysis, to group the sherds according to the overall similarity of their compositional characteristics. The results showed that equivalent groupings appeared regardless of the taxonomic method used. Two major clusters were recognized corresponding to two different sites, namely Conimbriga and Santa Olaia, suggesting that the ceramics from these sites were made locally. No significant differences in compositional patterns were observed between iron age and roman sherds from Conimbriga. 相似文献
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A problem which has arisen in discussions of an elm-disease explanation for the Neolithic elm decline has been the lack of fossil records of Scolytus scolytus (F.) (elm bark beetle), which is the main carrier of the fungus which causes the present epidemic of Dutch Elm Disease. Now, the discovery of wing cases of two individuals from elm decline deposits at Hampstead Heath, London, proves that the beetle was present in Britain during this episode. The deposits in which it occurs are described, and the various implications for elm disease causing, aiding or at least occurring during this stage of the early Neolithic are discussed. 相似文献
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Susan R. Brooker-Gross 《Journal of Historical Geography》1981,7(2):167-179
News wire services were established in the United States in the mid-nineteenth century to gather and distribute news for local newspapers, using the new technology of the telegraph. With that early beginning in the era of electronic communication, the expansion of news wire services spans the change from a society of local communities to a more nationally integrated society. This paper assesses the importanceof changes in the medium's spatial organization which promoted national culture. The first wire services were local, ad hoc groups, organized to achieve greater efficiency in news-gathering. Formal services were first organized on a local basis, but in 1848 they began to sell news to the major urbanized portions of the United States. As the nation grew, the desire for greater efficiency conflicted with the desire for greater autonomy. Regional wire services persisted from the 1860s to the 1880s but after the 1880s, a tenuous national organization was achieved, cementing itself into a national system after the turn of the century. Efficiency in news collection was the primary reason for the increasing scale of news collecting groups. Each step toward larger spatial coverage, fed the growth of a complex interdependent urban system. 相似文献
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