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51.
Michele Finelli 《Journal of Modern Italian Studies》2013,18(4):486-491
Abstract The essay examines the reasons for the difficult ‘reception’ of Mazzini's image in Italy. With particular reference to themes dear to Mazzini, like the role of public monuments and publications, the author explains why Mazzini's image has had a precarious hold on the collective memory of the Italian people. He goes on to offer a brief overview of the revival of Mazzinian scholarship in the last 15 years (1993–2008), underscoring how the renewed interest is related to the ongoing European and global debate on the meaning of democracy. The author concludes with a list of titles appearing since 1993 that suggest new approaches to the study of Mazzini, and that will be of use to scholars and students. 相似文献
52.
介绍了石质文物的加固原则和化学加固材料的种类、特点及应用情况,并对研究前景进行了展望 相似文献
53.
一类潜在的石质文物表面防护材料:仿生无机材料 总被引:5,自引:0,他引:5
仿生技术已经越来越广泛地应用于各个领域 ,包括生物医学材料、纳米材料、薄膜材料和多孔材料等等。在一些石质文物表面发现了一种以草酸钙为主要成分的致密的生物矿化膜 ,以及一种磷酸钙类薄膜 ,使人们看到了仿生技术在文物保护领域的应用前景。本文指出了目前石质文物保护材料的不足之处 ,介绍了一些仿生无机材料的优点和合成方法 ,探讨了这些新材料在文物保护方面应用的可能性。 相似文献
54.
Earlier views saw West Africa as culturally stagnant through much of the Holocene until stimulus or intervention from north of the Sahara transformed Iron Age societies. Evidence accumulating over the past 15 years suggests that stone-using societies from 10,000 to 3000 B.P. were far more diverse than previously thought. Against an increasingly detailed record of Holocene climate change, the complexity of local adaptation and change is becoming better understood. Although a strong case currently exists for the introduction of copper and iron to West Africa from the north in the mid-first millennium B.C., the subsequent development of metallurgy was strongly innovative in different parts of the subcontinent. Soon after the advent of metals, a dramatic increase in archaeological evidence for social stratification and hierarchical political structures indicates the emergence of societies markedly more complex than anything currently documented in the Late Stone Age. The best-documented examples come from the Middle Niger region and the Nigerian forest. In these areas, earlier diffusionist models in which complexity originated outside West Africa have yielded to evidence that indigenous processes were instrumental in this transformation. Trade, ideology, climate shifts, and indirect influences from North Africa, including the introduction of the domesticated horse to the Sahelian grasslands, are identified as factors essential to an understanding of these processes. 相似文献
55.
J. Desmond Clark 《Journal of World Prehistory》1988,2(3):235-305
The history of research into the Middle Stone Age of East Africa and the present state of knowledge of this time period is examined for the region as a whole, with special reference to paleoenvironments. The known MSA sites and occurrences are discussed region by region and attempts are made to fit them into a more precise chronological framework and to assess their cultural affinities. The conclusion is reached that the Middle Stone Age lasted for some 150,000 years but considerably more systematic and in-depth research is needed into this time period, which is now perceived as of great significance since it appears to span the time of the evolution of anatomically Modern humans in the continent, perhaps in East Africa. 相似文献
56.
为研究制作保护石质文物的加固材料,采用溶胶-凝胶法,以两种有机硅材料(正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES))为共同前驱体,少量正辛胺为催化剂,聚二甲基硅氧烷(PDMS)(方法 1)或硅烷偶联剂KH-570(方法 2)为有机改性剂,制备了有机-无机复合疏水型Si O2涂层。通过红外光谱(FT-IR)、扫描电镜(SEM)和水接触角(WCA)来表征在砖块表面形成的SiO_2膜层化学组成、表面形貌以及疏水性能,然后再通过测试砖块加固前后外观、吸水性能和孔隙率的变化来验证实际加固效果。结果表明,两种方法均可以制备骨架带-CH3基团的SiO_2溶胶。采用方法 1(添加前驱体质量10%的PDMS)或者方法 2(MTES/TEOS质量比为2),加固后的砖块对水接触角均超过140°,毛细吸水率降低到未处理时的1%~2%,并且砖块的色差和光泽度改变较小。通过耐候性能测试表明,方法 2的保护效果相对较好,说明用此种方法合成的疏水性二氧化硅涂层可以作为砖块加固材料。 相似文献
57.
石质文物破坏问题不仅在于人为破坏和表面污染,更多来自自然因素对文物的破坏,例如,日晒雨淋、风沙吹蚀、地表水的冲刷、地震、地下水的侵蚀溶蚀。为对第六批全国重点文物保护单位阳华岩摩崖石刻露天石质文物病害进行探查,采用无损探测的地面核磁共振方法和探地雷达方法,直接找水的地面核磁共振方法成功探测出摩崖石刻依附岩体地层含水分布状况。探地雷达方法探测出依附岩山体内岩溶、裂隙的发育状况。两种方法探测结果发现,石刻依附岩体内岩溶、裂隙发育,部分区域岩溶裂隙带已成为地下水汇聚场所或流通通道,对阳华岩摩崖石刻构成了极为严峻的侵蚀威胁。两种方法解释结果互为验证,研究结果为阳华岩摩崖石刻的病害治理和保护提供了宝贵的基础资料。 相似文献
58.
Raman spectroscopy and scanning electron microscopy confirm ochre residues on 71 000‐year‐old bifacial tools from Sibudu,South Africa
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Micro‐residue analysis of stone tools is generally performed with optical light microscopy and the visual observations are then compared with experimental, replicated pieces. This paper complements such archaeological research by providing physico‐chemical evidence. Raman spectroscopy and scanning electron microscopy have been used to confirm the presence of hematite on red‐stained medial and proximal parts of 71 000‐year‐old Still Bay bifacial tools from Sibudu Cave. Our results confirm the conclusion from optical light microscopy that the tools were hafted with an ochre‐loaded adhesive. However, we point to some instances when hematite residues are incidental or may be inclusions in the rock used to make the stone tools. 相似文献
59.
Peter J. Mitchell 《African Archaeological Review》1996,13(1):35-76
The spatiotemporal distribution of seashells and ostrich eggshell in the Later Stone Age of southeastern southern Africa is used to infer several areas of social interaction. The inferred patterns are supported by comparisons with preferences for lithic raw materials and the distribution of bifacial stone arrows. Plusiers zones de l'interaction sociale sont déduites des distributions chronologiques et spatiales de la coquillage et de la coquille de'autruche de l'Age de la Pierre Récent au sud- est de l'Afrique australe. Ces distributions sont soutenues des préférences pour des matières premières lithiques et de la distribution des flèches bifaciales de la pierre.
Provincial names and boundaries are as given on May 1, 1994 相似文献
60.
为明晰明代石拱桥的结构性能,并提出适宜的加固修缮方法,以典型的明代石拱桥永昌桥为例进行研究。首先对其进行精确测绘,获得其准确可靠的几何信息;然后对其建筑形制、构造工艺及残损状况进行研究,为结构性能分析提供依据;接着利用ANSYS软件建立永昌桥主体结构的有限元模型,进行包括荷载影响分析、重要度分析和裂缝分析的结构性能研究;最后基于现状分析和结构性能研究,通过对比拱背套钢筋混凝土拱加固法和拱背粘贴碳纤维布加固法对石拱桥的结构性能的影响,提出了明代石拱桥永昌桥的加固修缮方法。研究成果可为同类型石拱桥的加固修缮提供参考。 相似文献