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31.
浑仪、简仪(以下简称两仪)在高PH、大气污染和日晒雨淋环境中的腐蚀是一种动态加速腐蚀过程。采用合成的双唑胺铜缓蚀剂和有机硅改性的甲基丙烯酸树脂,并分别复配成协同缓蚀剂群和含有增效稳定剂的封护剂。采用这两种材料和脱水后再防护的工艺,使带锈防护后的浑仪、简仪的腐蚀低于无污染大气中的速率。用电化学方法评价了防护技术的可行性,根据腐蚀与人工老化试验结果讨论了防护材料性能与腐蚀环境和带锈防护的关系,采用XPS分析方法探索了双唑胺比BTA更适用于两仪防护的原因。 相似文献
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Stephen J. Shennan 《Journal of World Prehistory》1993,7(2):121-161
The chronology of the period is briefly considered in the light of the dendrochronological results which have appeared in recent years. Patterns of settlement history in different parts of the area are then examined, and it is suggested that in some of them the late fourth millennium was a period of population decline which was not reversed until the Early Bronze Age, 1000 years later. Detailed information about specific local occupation patterns is provided by recent work on the circum-Alpine lake villages. Changes in cultural patterns during the period, especially the appearance of the Corded Ware, are discussed and explanations of them reviewed. It is argued that changing patterns of gender relations were a major feature of the period, linked to processes which eventually led to the development of small-scale chiefdoms. The development of copper and bronze metallurgy and its connection to these processes are discussed. 相似文献
34.
曾中懋 《文物保护与考古科学》1993,5(2):36-40
高颐阙是东汉晚期的红色砂岩的建筑物。位于四川省雅安市。阙檐东面残缺.导致日晒雨淋加剧,苔藓丛生,从而引起严重风化。为此,对残损阙檐进行了修复。根据高颐阙的结构.雅安市的气候特征及阙石的化学组成和物理性质.讨论了薄片检查和 X 衍射分析的结果、修复残缺阙檐的理论基础以及计算、修复的程序和效果。 相似文献
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Jen Jack Gieseking 《The Canadian geographer》2018,62(1):55-66
In the last decade, conversations around queering of GIScience emerged. Drawing on literature from feminist and queer critical GIS, with special attention to the under‐examined political economy of GIS, I suggest that the critical project of queering all of GIS, both GIScience and GISystems, requires not just recognition of the labour and lives of queers and research in geographies of sexualities. Based upon a queer feminist political economic critique and evidenced in my teaching critical GIS at two elite liberal arts colleges, I argue that the “status quo” between ESRI and geography as a field must be interrupted. Extending a critical GIS focus beyond data structures and data ethics, I argue that geographic researchers and instructors have a responsibility in queering our choice and production of software, algorithms, and code alike. I call this production and choice of democratic, accessible, and useful software by, for, and about the needs of its users, good enough software. 相似文献
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Kate Stevens 《The Journal of Pacific history》2018,53(4):478-501
ABSTRACTEarly colonial officials and other newcomers frequently lamented the poor copra production in Wallis and Futuna, positioning the continued consumption of coconuts by Islanders as a waste. This article explores the contested uses of coconuts and the divergent visions of the islands’ landscape and future held by Islanders, officials, missionaries and traders during opening decades of French colony rule. In particular, a variety of incidents in the 1920s – from an indigenous co-operative to French expulsions – highlight the centrality of the emergent copra trade to the social and political status of these different groups. More broadly, however, the article demonstrates the failure of elites – both indigenous and newcomer – to substantially increase copra exports prior to the Depression in 1930, indicative of the limits of their ability to demand labour and transform the lifeways of the wider population. 相似文献
39.
ABSTRACTDuring a survey conducted by the authors in the eastern part of al-?arrah in Jordan in 2017,1 a number of new Safaitic and Nabataean texts were found. Some of them mention events dated during the reigns of ?r?t and rb?l, others refer to the revolt of dm?y. Other Safaitic texts contain references to the Nabataeans. Three Nabataean graffiti were also found and are presented here. These sixteen new texts constitute a remarkable addition to the corpus of Safaitic and Nabatean texts found in this region. 相似文献
40.
Van Nguyen-Marshall 《War & society》2018,37(3):206-222
During the Easter Offensive hundreds of Republic of Vietnam soldiers and civilians were killed while fleeing Qu?ng Tr? city along Highway One, earning this stretch of the road the name ‘the Highway of Horrors’ [??i L? Kinh Hoàng]. This article examines this understudied event and the efforts of ordinary people, particularly the staff of the daily newspaper Sóng Th?n, to collect and bury the corpses left on the highway. In focusing on this humanitarian endeavour, it highlights the spiritual consequences of mass death, people’s agency in countering the violence of the Vietnam War, and the dynamism of South Vietnam’s civil society. 相似文献