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61.
A group of Roman glass objects from the Bocholtz burial in the SW of Limburg (The Netherlands) was found to have been subject to varying degrees of degradation. Many of the 25 colourless glass objects were fragmented to pieces <0.1 cm (“sugared”), whereas the three transparent blue-green glass objects were in near-pristine state. Analyses using SEM, XRF and EDS revealed that the fragmentation was the direct result of the intense leaching of Na2O from the glass structure and its replacement with water. The resulting gel layers with low-Na2O contents and large amounts of water are sensitive to cracking when they dry out. Thin-walled glass appears to be less sensitive to cracking from the resulting stress than thick-walled glass. Local differences in the moisture regime during burial also influence the severity of the glass degradation. Glass with low concentrations of CaO seems to be the most sensitive to this form of degradation. The typical blue-green Roman glass is less sensitive as it generally has considerably higher concentrations of CaO. 相似文献
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Christopher van der Krogt 《The Journal of religious history》1998,22(3):320-335
The Catholic campaign against contraception in New Zealand during the 1930s is usually interpreted from the perspective of the promoters of birth control, who accused the church of exercising undue influence over the Labour government (1935–49). This paper argues that while Catholics were the most outspoken opponents of contraception, their opposition to the dissemination of birth control information and contraceptive devices was shared with other influential groups, notably the Protestant churches, the medical profession, journalists, and politicians. It was the combined strength of these conservative interests, not pressure from Catholics alone, which discouraged the Labour government from establishing birth control clinics. Catholics and many other New Zealanders feared that increased access to contraceptives would reduce the birth rate, leaving New Zealand vulnerable to non-British migration or even invasion. There was also widespread concern that the promotion of birth control would encourage sexual promiscuity. Since Catholics sought a compete ban on artificial contraception, however, they were unable to cooperate with non-Catholics who, accepting the restrained use of contraceptives, sought only to limit their availability. Catholic influence reinforced the efforts of other conservative interests but was not strong enough to secure legislation reflecting distinctively Catholic principles. 相似文献
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Producer Services, Economic Geography, and Services Tradability 总被引:3,自引:0,他引:3
We investigate how the incorporation of producer services linkages affects the outcome of an economic geography model. We specify the production of manufactures such that a variety of producer services is needed to transform tradable unfinished goods into final consumption goods. We find that service linkages promote the concentration of economic activity in a single region, but whether full concentration is achieved depends on the costs and mode of services trade. Applying the model to a multiregion world shows that incorporating producer services may also give rise to regions that specialize in different economic activities. 相似文献
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Martin van Gelderen 《History of European Ideas》2011,37(2):154-159
Through a discussion of Hugo Grotius’ conception of just war, this essay shows that within his critique of liberalism, Schmitt clashed with the very intellectual tradition he claimed to represent. Both historically and philosophically Schmitt's concept of the Ius Publicum Europaeum was a mirage. Indeed, his concept of the political was a rejection of the moral and civil philosophy that sees politics as the world of active citizens and commonwealths arguing with each other about fundamental questions of justice and equity. 相似文献
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The present paper explores the potentials of trace elements in human dental enamel to indicate mobility and to detect the presence of individuals who had migrated into a community after childhood. Three Pre-Hispanic samples of infants from the Yucatán peninsula were chosen, one from the northern coast (Xcambó), one from the coast of the Gulf of Mexico (Campeche) and the last one from the tropical inland rain forest (Calakmul). Infants’ first permanent molars are the term of reference because infants were very likely born in the same place where they died and therefore are supposed to represent the local geo-chemical environment. Their chemical signature was then compared to the one of the adults from the site of Xcambó. The elemental composition was recorded by means of laser ablation-time of flight-ICP-MS. Sr and Ba (and secondly Mg and I) discriminate well the three infant samples. All the Early Classic adults from Xcambó fall within the range of variation of the site’s infants, while 25% of the Late Classic adults fall outside the range in agreement with archaeological, bioarcheological, and isotopic evidence. LA-ICP-Ms analyses of trace elements in archaeological samples can be an important analytical tool to detect foreigners in local populations. The selection of infants as reference values helps reduce the limits faced by trace element analyses in past human populations studies. 相似文献