用示踪气体法检测文物展柜换气率技术研究

摘要文物展柜为文物的展示和保存提供了一个相对独立的空间,展柜密封度的高低影响着展柜内微环境调控的效果。为评价文物展柜的密封度,用示踪气体法检测展柜换气率,从检测便捷、安全和实验数据可靠角度分析比较了二氧化碳和乙烯的实验结果。结果显示,两种示踪气体均可用于检测展柜的密封度。其中,二氧化碳气体检测法比较方便,但其密度较大,易于沉降,检测结果偏低。环境湿度对二氧化碳示踪气体法检测的结果有一定影响。应用二氧化碳示踪气体法测试了多种展柜的换气率表明,各展柜的密封度有较大差别,每天换气率从0.1次到37次不等。检测结果提示,二氧化碳示踪气体法为评价展柜的密封度提供了一个简便易行的方法。     

Age and exploitation of obsidian from the Medicine Lake Highland,California

The relationship between major and minor elements, trace element composition, and age of obsidian sources within a volcanic field, is of considerable interest for obsidian source and artifact research in the New and Old World. The present study investigates this relationship in the Medicine Lake Highland of western North America. Geological evidence had indicated a very young age for all obsidian sources in the Highland, yet archaeological evidence suggested that obsidian was utilized for several thousand years. X-ray fluorescence analysis distinguished the latest flow (Glass Mountain) from the Cougar Butte, Grasshopper Flat, and Lost Iron Wells sources. Data obtained from two nearby archaeological sites showed that obsidian from the latter two sources was used by c. 7500 bc, while Glass Mountain material was not used (or available) until after 1360± 240 bp. These findings indicate that inferences of an extremely recent age for all obsidian sources in the volcanic field were unwarranted. Further analysis of major and minor elements indicated different hydration rates for these sources. The results argue that significant geochemical variability, as well as age differences, can exist between obsidian sources within the same volcanic field.     

文物展柜密封性能检测方法研究

The ventilation rate of a museum showcase is an important indicator for evaluating its sealing performance. In order to evaluate the ventilation rate of a showcase accurately, objectively and scientifically, some details of the detection and evaluation methods were comprehensively studied on the basis of GB/T 36110—2018. The results show that in order to achieve a better fitting effect, the carbon dioxide concentration outside a showcase should be fixed—a fixed concentration between 300 X 10 and 600 X 10 (volume fraction) had little influence on the fitting results. The average ventilation rate of the showcase at each moment was obtained by the numerical calculation method. When the detection time was short, values were unstable and fluctuated greatly; after stabilization, they were close to the fitted ventilation rates. The initial carbon dioxide concentration had a great influence on the fitting results of ventilation rate. The initial concentration of carbon dioxide gas in a showcase should be basically fixed between 20 000 X 10" and 25 000 X 10 ~ (volume fraction) during detection, so that the testing results were comparable. The carbon dioxide mixture in the airtight showcase is relatively uniform, and no obvious dip occurred. The location of detection equipment has little influence on the fitting results of ventilation rate. If the fitted R reaches 0. 9, the results are considered valid, due to various errors in the detection process. © 2023, Sciences of Conservation and Archaeology. All Rights Reserved.     

九十年代我国人口地理学研究的瞻望

本文在分析我国人口形势的基础上,提出了九十年代结合我国人口实际情况开展人口地理研究的主要课题.同时对人口地理研究中理论与方法的提高也进行了讨论.     

受控冷冻灭虫法的风险控制

受控冷冻灭虫的关键在受控,受控指标包括冷冻温度、降温速度与冷冻时间,受控的目的是要达到彻底灭虫。冷冻温度与降温速度直接影响到被冷冻物品的形体安全,保障物品安全为前提的受控冷冻灭虫需要管控风险。基于文献分析、相关问题的调研与理论研究发现,温度不够低、降温速度不够快以及灭虫时间过短都会造成灭虫不彻底的风险。极端低温与快速降温带来物品的损伤与被冷冻物品的材料性质相关,将在极端低温与热冲击力下必然会损坏的材料排除在冷冻灭虫的许可范围之外,科学地选择冷冻温度与加强冷冻灭虫过程管控,可使受控冷冻灭虫化险为夷,即以保证藏品安全为前提的彻底灭虫。     

Reconstructing age distribution,season of capture and growth rate of fish from archaeological sites based on otoliths and vertebrae

The growth increments of otoliths and vertebrae of plaice (Pleuronectes platessa) derived from a 15th century single depositional event at Raversijde (Belgium) are analysed with the aim of reconstructing (a) the age distribution of the population, (b) the season of capture, and (c) the growth rate. Otoliths and vertebrae give slightly different age distributions but it is possible to arrive at similar seasonality estimations in both structures when information from the literature and our own data from monthly captures of plaice from the North Sea are taken into account. These modern data show that the timing of annulus formation in otoliths and vertebrae is more or less similar. Back‐calculations on vertebrae and otoliths yield similar growth curves. The age distribution, the edge condition of both vertebrae and otoliths, and the growth rate obtained on the material from Raversijde all show that the plaice from the studied assemblage were captured during spring in the southern part of the North Sea. Vertebrae are commonly preserved in archaeological sites whereas otoliths rarely survive. Although they are more difficult to read than otoliths, vertebrae of plaice can be used for growth increment analyses, and the growth rates obtained from vertebrae from archaeological sites can, therefore, be compared in the future to growth data from modern otoliths studied in sea fisheries research. Archaeozoological material predating industrialized fishing since the 19th century can hence serve as a reference in the study of the compensatory response of commercially important species to heavy exploitation. Copyright © 1999 John Wiley & Sons, Ltd.