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。     

Burial offerings in intramural tombs at Middle Bronze Age Megiddo

Tel Megiddo is a major type-site for the Middle Bronze in the Levant. During this period a new burial custom appeared in which the dead were interred beneath occupied houses. This tradition is well attested in Area K at the site. Area H, near the palatial complex, revealed a monumental masonry-constructed chamber tomb. This article presents the results of residue analysis conducted on ceramic vessels placed in these tombs as burial offerings. Hundreds of intramural Middle Bronze tombs with ceramic offerings were excavated in the Levant, but this is the first time the content of the vessels is revealed.     

A missing link? Network analysis as an empirical approach for critical physical geography

Critical physical geography (CPG) calls for integrative research on material landscapes and the socio-political dynamics of scientific knowledge production. Network analysis, a rich tradition of tools and approaches for analyzing relational information, has seen little use in the CPG literature to date. This represents a fruitful opportunity, as many of CPG's core interests—knowledge politics, histories of scientific concepts, and ecosocial relations—can be effectively analyzed using network techniques. In this article, I argue for adapting network approaches to CPG. First, I provide an overview of various network concepts, approaches, and their origins. I then discuss bibliometric network techniques for “science mapping” including co-word, co-authorship, and citation analyses. Next, I describe discourse network analysis, a recent mixed-method approach from political science. Finally, I discuss overlaps with emerging approaches from qualitative and visual network analysis. In each section, I provide existing and hypothetical examples, as well as software and visualization techniques, that demonstrate how network approaches could add new insights to CPG and related scholarship. Linking CPG with the diverse traditions of network analysis has the potential to produce new empirical understandings and bring the field into conversation with a growing body of research that spans the social sciences, natural sciences, and humanities.     

MORE THAN MEETS THE FACT: THE UNIVERSALITY OF HISTORY AND THE COLONIAL MEDIATION

This article examines how mediation is not just limited to the format that's selected to convey the findings of previously conducted research that supposedly followed the conventional protocols of the historical discipline. Rather, it considers mediation as a fundamental part of building historical knowledge, for it assumes that every part of the historiographical operation can be defined as “mediation.” Specifically, it deals with colonial historical mediation, a concept that refers to the combination of an overt or concealed agenda, intentional or unnoticed bias, commonsense assumptions, inherited academic and political traditions, conceptual constellations, and more or less informed theoretical beliefs that configure the subtext upon which historical explanation is built, particularly in Latin America.     

Rediscovering regional science: Positioning the field's evolving location in science and society

This study aims to provide a comprehensive examination of the evolution of regional science, a scholarly domain in the social sciences that applies analytical and quantitative approaches and methods to understand and address urban, rural, or regional problems. We conducted a bibliometric analysis of 8509 articles published in six regional science flagship journals (including the Journal of Regional Science, Annals of Regional Science, Regional Science and Urban Economics, Papers in Regional Science, Regional Science Policy and Practice, and International Regional Science Review) from 1958 to 2021. The analysis presents an objective data-driven and unprecedented visualization of the field's intellectual, social, and conceptual structure and trends from the beginning to the present. It also provides a rich portrayal of the epistemology of regional science and illuminates matters related to regional science education and training. We find that regional science has moved well beyond its origins, shifting away from a heavy focus on theory and abstraction to modeling/simulation, empirical analysis, and policy research. We also find that there has been increasing attention to “people” in regions and the spatial characteristics of social problems, and some important shifts in the regional science community itself, particularly in terms of patterns of collaboration and the geography of scholarship. The findings of this paper provide implications for future directions of research and education for regional science.     

Current archaeological research in the Middle Atlantic region of the eastern united states

A major theme of current archaeological research in the Middle Atlantic region of Eastern North America is the recognition of cultural variability across space and through time. The most significant culture change experienced during the entire time frame of regional prehistory occurred ca. 5000 B.P., when there were major changes in regional environments. Before 5000 B.P., adaptations were characterized by small groups of mobile hunters and gatherers. After 5000 B.P., there were continued growth in regional populations and increases in sedentism, intensive use of a limited range of food resources, social group size, and social complexity.     

The coming of age of the history of archaeology

Publications and organizational developments relating to the history of archaeology from 1989 until June 1993 are critically examined. Attention is paid to the changing motivations for producing such publications, their shifting intellectual orientation, controversies, especially as they relate to internal vs external approaches and the epistemological status of explanations, problems of verification, and the status of these studies as a subfield within archaeology.     

The prehistory of Cyprus: Problems and prospects

The archaeological record of prehistoric Cyprus is rich, diverse, well-published, and frequently enigmatic. Regarded by many as a bridge between western Asia and the Aegean, Cyprus and its past are frequently seen from scholarly perspectives prevalent in one of those two cultural areas. Its material culture, however, differs radically from that of either area. Apart from the early colonization episodes on the island (perhaps three during the pre-Neolithic and Neolithic), evidence of foreign contact remains limited until the Bronze Age (post-2500 B. C.). This study seeks to present the prehistory of Cyprus from an indigenous perspective, and to examine a series of archaeological problems that foreground Cyprus within its eastern Mediterranean context. The study begins with an overview of time, place, and the nature of fieldwork on the island, continues with a presentation and discussion of several significant issues in Cypriot prehistory (e.g., insularity, colonization, subsistence, regionalism, interaction, social complexity, economic diversity), and concludes with a brief discussion of prospects for the archaeology of Cyprus up to and beyond 2000.