Assembling dams in Ghana: A genealogical inquiry into the fluidity of hydropolitics

The paper offers a geographical interpretation of the evolving technical, political, and economic intricacy of large dams. It incorporates existing hydropolitical scholarship and the notion of the Chinese Water Machine to reframe dams as assemblages built by specific political, financial and technical processes in particular socioenvironmental regions. The paper examines the continuity of hydropolitical relationships through a genealogical inquiry into the formulation and materialisation of Ghana's three dams: the Akosombo and Kpong dams built during the Cold War, backed by Western lenders and engineering companies; and the Bui dam commissioned in the 2010s, with support from China. Based on fieldwork in Ghana and China, as well as documentary evidence, the paper argues that the thinking, planning and building of dams interconnect the host regime and external techno-financial actors with their floating political-economic interests, but in a durable way. Sometimes, even if little concrete is actually poured, the symbolic power of dams endures, transforms, and at certain times and places expands, through events and discourses of national and international interest groups pursuing their own purposes, albeit with the replacement of influential individuals and powerful institutions, and regardless of the involvement of Western, Chinese and/or other actors. Ruptures exist but do not necessarily break the continuity of dam assemblages. The emergence of an opposition assemblage that battles against dams is a more recent complexity.     

聚醋酸乙烯酯乳液的表征、性能及其在彩绘类文物保护中的应用

聚醋酸乙烯酯(PVAc)乳液是常见的彩绘类文物保护材料。采用激光粒度仪、热重/差热分析、红外光谱、X-射线衍射、扫描电镜、透射电镜等表征了PVAc乳液的粒径以及胶膜的热稳定性、结构和形貌;采用粘度计、表面张力仪、pH计、电导率仪等研究了乳液浓度与其粘度、表面张力、pH、电导率的关系;通过冻融、室温-高温放置、离心分离研究了乳液的稳定性;同时用PVAc乳液对模拟起甲和酥碱的壁画进行了修复。结果表明,PVAc乳液粒径呈双峰分布,小粒子的平均粒径为380 nm,大粒子的平均粒径为5.85μm;乳液胶膜为非结晶物质,胶膜热重的最终质量残留为1.54%,335℃出现放热峰。PVAc乳液的电导率随浓度的增大而增大,pH随浓度的增大而下降;相同温度下表面张力随浓度的增大而基本呈现低浓度下降,高浓度上升的趋势。相同浓度下,表面张力随温度升高而无显著变化,表明PVAc乳液的表面张力受温度变化影响不大。相同温度下,乳液粘度随浓度的增大而增大;相同浓度下,乳液的粘度随温度的升高而降低。冻融、离心分离和不同温度下静置发现,该乳液出现分层。用该乳液对模拟起甲和酥碱壁画修复后,再分别老化20个循环和12个循环,发现颜料层再次空鼓、起甲。综合分析,说明实验中所使用的该种PVAc稳定性和抗老化能力较弱,在修复彩绘类文物中应慎重选择PVAc的种类,综合考虑PVAc的使用浓度、环境因素对其性能的影响,以达到最佳使用效果。     

慈利白公城遗址出土木材种属的鉴定研究

慈利白公城遗址历史悠久,具有重要的考古价值。该遗址出土了大量木质井壁及少量其他木质文物,为了解这些木材的特点,以及为木材保护提供相关的参考,通过徒手切片,并利用光学显微镜对该遗址出土的10件木质样品进行鉴定。结果表明其中1件为无患子(Sapindus. mukorossi Gaertn.),1件为冷杉(Abies fabri(Mast.)Craib),2件为湖南杨桐(Adinandra. acutifolia Hand.-Mazz.),2件为香椿(Toona sinensis A. Juss.),4件为润楠(Machilus pingii Cheng ex Yang)。通过实验结果,初步推测井壁的制作在当时是比较重要的工作,此时已经在选择性地使用木质井壁原料。从树种适宜生长的环境上看,同时期该遗址附近可能是以阔叶材为主的针阔叶混交林,气候温暖湿润。     

拉曼光谱在纸质文物研究中的应用

纸张的老化程度一直是纸质文物保护中的重要研究方面,以往多采用目测法和经验来推断纸张的老化程度。纸张物理强度、聚合度等能表征老化状态的理化性能测试由于需要大量的样品而无法用于文物检测。近年来随着显微共聚焦拉曼光谱、近红外傅里叶变换拉曼光谱、表面增强拉曼光谱等技术的发展,作为一种原位、无损、微区的分析方法,拉曼光谱被越来越多地应用到了纸质文物的相关分析研究中,为纸质文物的保护修复提供科学依据。结合国内外文献,对拉曼光谱在纸张老化、碳黑颜料以及其他颜料上的应用和研究现状进行了梳理归纳。随着拉曼光谱应用的不断深入,以及与其他分析技术、化学计量学等的结合,未来将在纸质文物研究中发挥更多的作用。     

饱水木质文物的风冷干燥脱水研究

许多出土饱水木质文物因其降解严重、含水率较高,容易在脱水过程中出现不可逆的收缩变形以及开裂现象,从而遭到严重破坏。因此,饱水木质文物脱水方法的研究是文物保护工作中的重要课题。为探究风冷冷冻法对饱水木质文物脱水的效果,以一批无法复原的出土饱水木质文物为研究对象,在对其材种、含水率、基本密度及化学成分进行了测定和分析后,使用一台风冷电冰箱在-18℃条件下对样品进行了风冷干燥脱水处理,记录脱水时间和脱水效果,并分析了该方法的传质传热特点,证明了风冷干燥法用于饱水木质文物的脱水干燥能够取得良好效果,并且具有对文物干预小、适用性广、操作简便、成本低廉等优点,为饱水木质文物的脱水处理提供了一种新的思路。     

从“良渚全考古”到“良博全展示”——以良渚博物院2018年改陈策展为例

良渚考古工作历经八十余年,考古内涵不断丰富,考古价值不断提升,已进入到"良渚全考古"时代,是边发现、边研究、边保护、边利用、边传承的模式。2018年良渚博物院改陈,进入"良博全展示"阶段。现有的展览全面展示良渚考古成果,全面呈现良渚文化内涵,全面阐释良渚文明价值,全面解读良渚遗存信息。良渚的展示除了依靠文物本身或图文所呈现和传递的信息,还采用过程性展示、功能性展示、复原性展示、对比性展示、演变性展示、场景性展示等多种手段,多角度、全方位地解读和展示遗物,力图将良渚文物的故事讲清楚、讲明白。     

Climate change,conflict, and cooperation: Global analysis of the effectiveness of international river treaties in addressing water variability

Climate-driven water variability is a natural phenomenon that is observed across river basins, but one that is predicted to increase due to climate change. Environmental change of this kind may aggravate political tensions, especially in regions which are not equipped with an appropriate institutional apparatus. Increased variability is also likely to challenge regions with existing institutional capacity. We argue that our best attempts to assess the ability of states to deal with variability in the future rest with considering how agreements have fared in the past. In this paper, we explore treaty effectiveness, or treaty resilience, by investigating whether particular water allocation and institutional mechanisms help mitigate inter-country tensions over shared water. We use water-related events from the Basins at Risk events database as a dependent variable to test particular hypotheses regarding the impact of treaty design on conflict and cooperation over time. A broad set of climatic, geographic, political, and economic variables are used as controls. The analysis is conducted for the years 1948–2001 using the country dyad as the level of observation. Findings pertaining to our primary explanatory variables suggest that country dyads governed by treaties with water allocation mechanisms exhibiting both flexibility and specificity evince more cooperative behavior. Country dyads governed by treaties with a larger sum of institutional mechanisms likewise evince a higher level of cooperation, although certain institutional mechanisms appear to be more important than others.     

纸质藏品修复用水考量

本工作借鉴已有的研究成果,并辅以相关调研,试图探究修复用水选择的重要性以及如何选择修复用水的问题。为此,通过对国内外文献的分析以及相关问题的调研,综述了生活饮用水中对纸张长期保存有害的污染物及其对纸张纤维的危害。通过对修复用水实例的讨论,指出:纸质藏品的修复须采用净化水,即通过逆渗透、去离子处理等方法净化后并达到一定电阻率的纯水,在条件许可的情况下,采用电阻率更高的超纯水更好;须现制现用以保证使用过程中净化水不被再次污染;在设备方面,选择小型纯水系统更能保证用水质量。     

河南安阳县固岸墓地2号墓发掘简报

为配合南水北调工程建设,河南省文物考古研究所对安阳固岸墓地进行了考古发掘,清理出大批战国至隋代的墓葬,其中M2是一座保存较为完整的北齐时期的墓葬,出土器物60余件,尤其是出土的陶俑和镇墓兽十分精美,为研究北齐时期葬俗、葬制提供了珍贵的实物资料。     

远古时期三峡地区长江洪、枯水位的考古研究(距今约15万年～1万年)

通过对三峡地区长江沿岸的考古发掘,发现了远古时期人类居住遗址的所处位置、海拔高度,尤其是遗址地层堆积中往往还叠压有洪水过后的淤积,根据这些洪水淤沙层的位置以及其上、下堆积层中包含物的年代,我们可推测出远古时期三峡地区长江发生洪水的大致年代,洪水水位的海拔高度,看看那时的河床究竟是比现在高、还是低,从而为当今人们治理长江、开发长江提供科学的证据。