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991.
In order to ascertain whether the technology of Etruscan bucchero was similar everywhere or showed local variation, a comparative study was carried out on 23 samples of bucchero from different sites. The use of carbon dust as a black pigment in this type of pottery was confirmed in all samples, while the hypothesis of the addition of MnO2 as a colouring was disproved. Further information on the nature of the basic constituents of Etruscan bucchero was also provided. 相似文献
992.
Of twelve elements analyzed in a series of bovid teeth from the Olduvai Gorge, uranium is the only element which varies appreciably with the ages of the samples. Uranium concentrations increase at first, then decrease with increasing age, and therefore cannot be used by themselves to obtain absolute or even relative ages of the samples. A model accounting for the behaviour of uranium is proposed in which uranium is absorbed in the samples during the decay of organic material and is lost after this decay ceases. If one accounts for uranium losses, the concentrations of uranium and its decay products may be used to accurately date skeletal material from the Olduvai gorge. 相似文献
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John E. Tunbridge 《The Canadian geographer》1986,30(2):146-154
The inner city contains a variety of activities that may be broadly categorized as warehouse functions. They include wholesaling, storage, and related functions of a commercial, public, or institutional nature - a miscellaneous assortment that forms a rather nebulous 'grey zone' between the more fully researched components of the urban economy, notably retailing, offices, and manufacturing. These miscellaneous warehouse functions have been primarily identified with the margins of the central business district (cbd), and particularly with the 'zone of discard,' the area of delapidation away from which the cbd core has traditionally migrated.1 Such functions share fundamental characteristics: they are space-consuming, typically truck-dependent, concerned with market proximity, but relatively unconcerned with appearances. 相似文献
1000.
This third list of accelerator dates includes material dated in the same period as datelist 2 (Gillespi?et al. 1985) and subsequently. The dates have been achieved by the same methods as described there. 相似文献