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土遗址和壁画遗址可溶盐主要为NaCl和Na_2SO_4,其中Na_2SO_4是破坏程度最严重的盐。一般认为,硫酸钠只有在温度、湿度变化时才不稳定,才发生得失结晶水引起的晶型及体积变化。为研究土质文物盐害的形成机制及内在原因,调研了全国几处典型土遗址和壁画遗址的盐害状况并取样分析。分析发现:1)土遗址和壁画遗址中硫酸钠的形貌、结构是动态变化的(无论在任何极端干燥环境甚至真空条件下);2)环境因素如温度、相对湿度的变化只是加剧上述变化进程。硫酸钠结晶析出时,其体积膨胀约4倍。这一系列的过程,深刻影响着硫酸钠的相变复杂性和对依存土质文物本体的破坏性。本工作从微观和宏观两个层面探讨了这些发现,并通过不同盐分(不同浓度氯化钠、硫酸钠)侵蚀破坏模拟试验、不同温度条件下模拟试验、不同相对湿度下模拟试验,从宏观层面印证了上述微观机制在土遗址和壁画遗址本体的外在表现。本研究发现土遗址中硫酸钠的形貌、结构是动态变化的,该工作弥补了以往研究和认识上的局限。本研究将对阻止、延缓及预测土质文物盐害的发生、发展提供科学参考。 相似文献
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《馆藏文物防震规范》WW/T 0069-2015,基于馆藏文物防震安全提出馆舍、展陈和文物全系统防震安全理念、设计方法和具体措施。本研究针对馆藏文物防震设计方法、适用范围、展柜及文物安全性判别等关键技术问题展开研究。首先,提出了\"地震波+馆舍+展柜+文物\"的全过程全系统防震设计理念;其次,针对浮放展柜及文物,进行地震作用下安全性分析研究;第三,与Getty博物馆研究成果对比,验证本研究理论的正确性与可靠性。分析得出:文物防震安全与文物高宽比、支撑接触面摩擦系数、安放处加速度峰值等因素有关;引入了抗滑动安全系数和抗倾覆安全系数进行设计,可充分保证文物安全性。 相似文献
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生态旅游在中国：研究回顾与本质回归 总被引：6，自引：0，他引：6
利用文献法对中国生态旅游的研究历程进行回顾与反思,指出存在的概念、方法和功效问题,并对生态旅游系统的核心予以理论梳理,认为统筹生物多样性和旅游生产力、实施平衡管理是中国生态旅游健康发展的必然选择,生态旅游研究需要强调科学性,重视形态——功能关系分析,探索和发展实地观察方法和实验方法。 相似文献
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本文对敦煌写卷《诸杂推五姓阴阳等宅图经》中涉及“五姓”分类的两个写卷,即P．2615a、P．2632v中出现的“五姓”作了校勘;并在茅甘和陈于柱先生录文的基础上,对部分有疑义的姓氏作了考释。 相似文献
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对宋钱版别的分类与定名,当推日本《古泉大全·丙集》、《符合泉志》及《新定北宋符合泉志》三书。日本钱币界历经两个世纪,几代人的辛勤耕耘,基本奠定了对中国宋钱研究的基础。但在至道元宝的整理与分类上,我们时常会遇到挑选的至道元宝如按书中所示无法归类与区分的困惑。分析其原因有二。一是近年来宋代窖藏钱币的大量发现,极大地丰富了宋钱的版别;二是上述之书由于时代与所见钱币有限,又以形制作为版别区分的主线所致,如将至道元宝分为“细缘”、“阔缘”及“中缘昂元”,而阔缘钱币经磨损边缘被误认为“中缘”或“细缘”的情况时有所见… 相似文献
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What is disclosed in the questioning of the human being in post‐humanism? Addressing this question in congruence with Heidegger's questioning of being in Being and Time, we end up with two discoveries: first, that the characteristic of Dasein, as the being of the questioning, already carries the same implications as the post‐human figure, and second, that questioning in this sense is indicative of the effort of realizing anew scientific space for conceptualizing the human being as non‐substantialist. Conceived of in this way, however, post‐humanism is a result of a very human effort indeed. 相似文献
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Cai, C.-y. & Wang, B., 2013. The oldest silken fungus beetle from the Early Cretaceous of southern China (Coleoptera: Cryptophagidae: Atomariinae). Alcheringa 37, 1–4. ISSN 0311-5518Atomaria cretacea sp. nov., a new silken fungus beetle, is described and figured based on an impression fossil from the Lower Cretaceous Shixi Formation at a locality near Qingxi Town, Jiangxi Province, southern China. The new species can be referred to the extant family Cryptophagidae as supported by the tiny body size, the clubbed antenna with dilated antennomere 1, closely spaced antennal insertions, and abdominal ventrite 1 being longer than the remaining ventrites. It is placed in the extant subfamily Atomariinae based on the presence of a frontoclypeal suture and the absence of gular sutures; and tentatively in Atomaria based on its body size, sub-parallel body shape, and the presence of a frontoclypeal suture.Chen-Yang Cai [caichenyang1988@163.com], Bo Wang [savantwang@gmail.com], State Key Laboratory of Palaeobiology and Stratigraphy; Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China. Received 11.11.2012; revised 26.1.2013; accepted 31.1.2013. 相似文献
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Working from previously unknown sources in Danish archives, this article establishes for the first time the important role that the island of St Croix played in the Lincoln administration's considerations on colonizing African Americans abroad. This article argues that U.S. Secretary of State William H. Seward, commonly viewed as an anti-colonizationist, was at least a mild proponent of colonization in its earliest stages. The article demonstrates further that in the summer of 1862, the St Croix colonization project was an important stepping stone in the Lincoln administration's legal justification for emancipation, and that it was recognized as such by high-ranking Confederates. The negotiations failed for reasons that had little to do with Lincoln or his opinion on the matter. Rather, the plan fell through because the Danes slowly turned against it for economic and political reasons. The substantial conclusion of this article is that, contrary to earlier perceptions in the historiography, African American colonization during the Civil War was not led and directed entirely from Washington. Rather, in this case, the Danish minister proposed a colonization plan and then worked with the U.S. Government to attempt to see it through. 相似文献