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911.
Lead isotope analyses have been undertaken on a group of Islamic lead‐glazed pottery artefacts from Fustat, Egypt, spanning the period from the eighth to the 14th century ad , that had previously been the subject of a comprehensive typological, chronological, petrographic and technological study. Comparison of the lead isotope ratios for the glazes with those for lead ores from Egypt, Iran, Tunisia, Anatolia, Greece, Sardinia and Spain provided information on the possible sources of the lead used in the production of the glazes. The results show that the lead used in glaze production by the Islamic potters at Fustat was most probably obtained from distant ore sources in Iran or Tunisia, Sardinia, Spain and the Taurus Mountains. Different ore sources were favoured in different periods and, to a limited extent, for different types of pottery, but at no time did the Fustat potters use the potentially more accessible Egyptian ore sources. 相似文献
912.
Peter M. Atkinson Sally E. German David A. Sear Michael J. Clark 《Geographical analysis》2003,35(1):58-82
The relations between riverbank erosion and geomorphological variables that are thought to control or influence erosion are commonly modelled using regression. For a given river, a single regression model might befitted to data on erosion and its geomorphological controls obtained along the river's length. However, it is likely that the influence of some variables may vary with geographical location (i.e., distance upstream). For this reason, the spatially stationary regression model should be replaced with a non‐stationary equivalent. Geographically weighted regression (GWR) is a suitable choice. In this paper, GWR is extended to predict the binary presence or absence of erosion via the logistic model. This extended model was applied to data obtained from historical archives and a spatially intensive field survey of a length of 42 km of the Afon Dyfi in West Wales. The model parameters and the residual deviance of the model varied greatly with distance upstream. The practical implication of the result is that different management practices should be implemented at different locations along the river. Thus, the approach presented allowed inference of spatially varying management practice as a consequence of spatially varying geomorphological process. 相似文献
913.
914.
In this paper we present data to demonstrate the applicability of laser‐ablation MC–ICP–MS isotope analysis to archaeological artefacts, in this case Roman silver coins. The technique requires no chemical preparation, does minimal damage to the sample and yields external reproducibility that is better than conventional TIMS analysis; 207Pb/206Pb =±0.015% 2σ in comparison with 207Pb/206Pb =±0.04% 2σ, respectively. We show that Pb isotope compositions give isotope fingerprints to mints despite the likely reworking of the metal during coin production. 相似文献
915.
Urban Growth in the 1990s: Is City Living Back? 总被引:3,自引:0,他引:3
The 1990s were an unusually good decade for the largest American cities and, in particular, for the cities of the Midwest. However, fundamentally urban growth in the 1990s looked extremely similar to urban growth during prior post–war decades. The growth of cities was determined by three main trends: (1) cities with strong human capital bases grew faster than cities without skills, (2) people moved to warmer, drier places, and (3) cities built around the automobile replaced cities that rely on public transportation. Although the negative impact of population density diminished slightly in the 1990s, there is no real evidence for a return to large, dense cities. 相似文献
916.
Robert M Vanderbeck 《对极》2003,35(2):363-384
This paper provides an analysis of media discourse surrounding the arrest, trial, and conviction of Norfolk farmer Tony Martin for the murder of 16-year old Fred Barras, a Traveller from Newark, Nottinghamshire. The paper argues that discourses about Travellers (re)constructed in the media during the Martin affair showed evidence of both older, stereotypical representations of Travellers and newer ways of locating them in relation to contemporary societal anxieties about "dangerous youth", the "underclass", and "social exclusion". The coverage was often emblematic of political discourses in Britain, which too often emphasise the moral failings of the "excluded" without any significant discussion of the sources of inequalities. 相似文献
917.
Richard M. Fried 《外交史》2003,27(5):741-745
Book reviewed:
Kathryn S. Olmsted. Red Spy Queen: A Biography of Elizabeth Bentley. 相似文献
Kathryn S. Olmsted. Red Spy Queen: A Biography of Elizabeth Bentley. 相似文献
918.
919.
Here we report δ13C and δ15N measurements of serial sections of human deciduous and permanent tooth dentine from archaeological samples taken from the medieval village site of Wharram Percy, Yorkshire, UK. We found a pattern of enrichment, for both δ13C and δ15N, where the tooth crown was greater than the cervical part of the root, which in turn was greater than the apical portion of the root and the associated rib collagen values. This pattern reflects a decrease in the consumption of isotopically enriched breast milk and the introduction of less enriched weaning foods in the diet. The (mean±SD) difference between the deciduous second molar crowns and corresponding rib samples from the same individuals after 2 years of age was 1.2±0.4‰ for δ13C and 3.2±0.8‰ for δ15N. The δ15N values are as predicted, but as there were no C4plants at Wharram Percy, this 1.2‰ enrichment in δ13C represents clear evidence of a carbon trophic level effect in collagen from breastfeeding infants. Carbon and nitrogen results also show that the infant diet among those who died in infancy did not differ from those who survived into childhood. This study demonstrates the promise of using dentine serial sections to study the temporal relationships of breastfeeding, weaning, and dietary patterns of single individuals. 相似文献
920.
Y. M. Lam O. M. Pearson Curtis W. Marean Xingbin Chen 《Journal of archaeological science》2003,30(12):1701-1708
Accurate bone density data are essential for assessing the influence of destructive processes in archaeological faunal assemblages. Unfortunately, the diversity of methods employed by different researchers to derive density values has resulted in recent confusion. Two recent publications in this journal [J Archaeol Sci 29 (2002) 883; J Archaeol Sci 29 (2002) 979] exemplify this state of misunderstanding. Both studies argued that the role of bone density in shaping archaeological faunal assemblages has been largely overrated, but both based their conclusions on density values that were inaccurately derived. The former employed a method of calculating bone density that has been largely discredited over the past decade [J Archaeol Sci 29 (2002) 883]. Within a larger discussion of zooarchaeological methodology, the latter provided an assessment of the current state of bone density research that inappropriately characterized the discrepancies between available sets of density data as a reflection of the differences between two technologies—photon densitometry and computed tomography [J Archaeol Sci 29 (2002) 979]. The actual dichotomy exists—irrespective of the technology employed—between studies that account for variation in the shape of bone cross-sections and those that do not. The different sets of density data currently available to zooarchaeologists vary tremendously in their accuracy. We review and evaluate the different techniques employed in the research of bone density patterns of mammalian fauna. Computed tomography produces the most accurate density data. For elements without medullary cavities, photon densitometry may provide density values of similar accuracy but only if a method of cross-sectional shape-adjustment is applied. 相似文献