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81.
This paper describes the use of electron spin resonance spectroscopy to estimate the degree of heating of quartzite cobbles from hearths on the floor of the archaeological remains of an eighteenth-century Dutch colonial slave lodge. A novel technique based on the comparison of line intensities for the E’and O-2 centres in quartz distinguished successfully between cobbles which had been heated to estimated temperatures ranging from 300 °C to 450° C and controls from an adjacent stream bed. This inexpensive and simple technique could be applied to a wide range of archaeological problems involving the thermal history of objects consisting of or containing quartz. 相似文献
82.
The levels of ten elements (phosphorus, calcium, magnesium, strontium, barium, potassium, sodium, zinc, iron, and aluminium) have been measured in the femurs and humeri of laboratory rats grown on test diets as a model for palaeodietary studies of excavated human skeletons. High levels of dietary fibre correlate with lower Ca and higher Sr and Ba in the bone. High values of the dietary Sr/Ca ratio correlate with high Sr levels in the bone. High levels of dietary protein correlate with lower Sr and higher Zn. High values of the ratio Ba/Ca and lower levels of Fe correlate with higher levels of Ba. Because bone levels typically are controlled by several dietary components, variation of the levels of a given element in the diet does not necessarily translate into analogous variations in bone. Only K and Fe in bone correlate highly with their levels in diet. The failure of bone Sr, Ba, and Zn to correlate positively with dietary levels is fully explicable in terms of their interdependence on other dietary components, such as Ca, P, Fe, protein, and fibre. 相似文献
83.
John B. Parr 《Journal of regional science》1993,33(2):167-186
ABSTRACT. A multi-plant producer has sole access to a region, and each of the plants processes a raw material which is drawn from its own exclusive supply area. Under these conditions what spatial structure of production (in terms of plant scale, plant frequency, supply-area size and supply-area shape) will enable region-wide or multi-plant profit to be maximized? The form of this optimal structure is shown to vary with prevailing level of price, which is exogenously determined. 相似文献
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In skeletons excavated from Woodland sites, copper and barium levels are found to have been contaminated by influx from the soil environment. Electron microprobe scans for both elements show build-up along the outer surface of femur cross sections. Elemental levels for Cu and Ba are lower in the femur or fibula than in the more porous rib. The distribution of Cu in the immediately surrounding soil is highly anisotropic. These observations indicate that Cu and Ba should not be used for dietary inferences about ancient populations without independent evidence that diagenesis is not important. 相似文献
87.
Particle induced X-ray emission (PIXE) has been used in analysis of ink and paper of the 42-line Bible and other early printed works. Results are reported and their significance discussed. 相似文献
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Karen B. Wiley 《政策研究杂志》1984,13(2):434-438
Books reviewed in this articles:
Laura M. Lake, Environmental Regulation; The Political Effects of Implementation
R. Shep Melnick, Regulation and the Courts; The Case of the Clean Air Act
Lettie M. Wenner, The Environmental Decade in Court 相似文献
Laura M. Lake, Environmental Regulation; The Political Effects of Implementation
R. Shep Melnick, Regulation and the Courts; The Case of the Clean Air Act
Lettie M. Wenner, The Environmental Decade in Court 相似文献