Evaluation of Quantitative XRF Analysis Applied to Determine Cobalt Sources in Chinese Blue‐and‐White Porcelain

A method using the ratios between MnO, Fe₂O₃ and CoO to differentiate the cobalt sources for Chinese blue‐and‐white porcelain was developed in Oxford in the 1950s using X‐ray fluorescence (XRF) analysis directly on the glaze. In this paper, six blue‐and‐white porcelain sherds from the Luomaqiao kiln were analysed by XRF on the glaze and by scanning electron microscopy with energy‐dispersive spectrometry (SEM‐EDS) in cross‐section. The ratios between MnO, Fe₂O₃ and CoO calculated by quantitative XRF and EDS analyses are different. The analysis depths for MnO, Fe₂O₃ and CoO are < 60 μm by XRF analysis. However, the average glaze thickness of samples is > 400 μm, and the MnO, Fe₂O₃ and CoO mainly remain in the lower layer of the glaze, which is beyond the analysis depths of XRF analysis. The limitations of major and minor quantitative analyses for differentiating cobalt sources are discussed.     

Further Insight into Mesoamerican Paint Technology: Unveiling the Colour Palette of the Pre‐Columbian Codex Fejérváry‐Mayer by Means of Non‐invasive Analysis

Here, we report on the analytical findings and their cultural implications of a multidisciplinary study of the pre‐Columbian Codex Fejérváry‐Mayer. Today conserved at the World Museum in Liverpool, it is one of the finest Mesoamerican codices among the few extant. Thanks to the exploitation of non‐invasive analytical methodologies accessible through the MOLAB European mobile facility, the study allowed us to disclose the chemical composition of the painting materials used in the codex, which have never been analysed before. The results are discussed and compared with the outcomes of previous studies on other Mesoamerican codices.     

汉阳陵东阙门出土黑色颜料的科学分析

为了科学分析汉阳陵东阙门西壁黑色颜料的组成和进一步探讨汉代皇陵颜料的使用状况,采用超景深显微观察、扫描电镜能谱(SEM-EDS)以及面扫描技术、X射线衍射(XRD)等测试方法,结合文献资料进行了科学分析鉴定与深入探讨。结果表明该黑色成分是氧化铜,应是原先含铜的蓝绿色颜料经过火烧氧化后所造成,属后呈现色彩。这一结果为后续彩绘类文物颜料鉴定提供科学思维,即不仅使用现代分析测试手段分析鉴定当前状态下的颜料种类,还应结合文物所处的环境变化,科学系统地指明其色彩呈现形式。另外,实验中使用的扫描电镜能谱面扫描技术可清楚确认颜料颗粒的分布情况,在微观分析颜料颗粒方面具有不可比拟的优越性。     

铁基与铜基颜料对纸质文物的化学腐蚀降解

古籍、档案、书画、碑帖等纸质文物记录了人类社会的历史发展,是不可再生的文化遗产。然而,大量纸质文物在长期保存过程中发生了老化劣化现象,甚至造成纸质文物的永久失传。值得注意的是,部分颜料与墨水中含有的铁铜金属物种会引起纸张较为严重的腐蚀降解,使得色块或墨迹周围的纸张明显泛黄,甚至在着墨位置形成空洞。铁铜颜料引起纸质文物损害的原因复杂且多样,在其作用下纤维素高分子的反应路径与降解机理值得深入研究。本研究介绍了纸质文物中常见的铁基与铜基颜料,包括铁盐墨水、普鲁士蓝、赭石、蓝铜矿、孔雀石、醋酸铜等。总结了纸张纤维素的酸性水解、碱性降解和氧化降解反应路线,探索了金属物种作用下纸张纤维素的酸碱反应与氧化还原反应机理。其中含铁颜料的纸张纤维素主要经历芬顿(Fenton)氧化降解和酸性水解,含铜颜料腐蚀纸张纤维素的主要途径为菲林(Fehling)氧化降解和碱性降解。 本研究聚焦于铁基与铜基颜料对纸质文物腐蚀降解的化学反应机理,总结出铁铜离子参与的氧化反应是纸张纤维素加速降解的主要因素。在此基础上,提出了添加抗氧化剂以减缓氧化反应发生的纸质文物保护策略,包括预防性抗氧化剂与断链性抗氧化剂。重点介绍了络合剂配位铁铜金属离子的预防性抗氧化保护法,如使用植酸/植酸盐、溴化铵、明胶蛋白等络合剂与铁铜离子络合,以减缓氧化降解反应的发生。同时也分析了络合剂方法存在的一些问题,如植酸只能在酸性条件下使用、苯并三唑会造成颜料变色、部分抗氧化剂具有毒性等。最后,本研究针对铁基与铜基颜料腐蚀降解纸张的机理研究与保护策略提出展望。在机理研究方面,过渡金属游离态与络合态的分布情况、过渡金属引发氧化反应的条件控制、氧化降解反应与纤维素超分子结构的相互关系等仍有待研究。在保护策略方面,所选择的保护方法应当不仅可以有效减缓过渡金属对纸张的降解,而且不会对纸张纤维与颜料墨迹造成损坏。本研究从化学角度对过渡金属颜料所导致的纤维素降解演化机理提出更深刻的认识,为含有过渡金属颜料纸质文物的多方位保护提供引导和借鉴。     

The Green Economy Research Centre – positioning geographical research in Aberdeen to address the challenges of green economy transitions

ABSTRACT

The necessity to address climate change has resulted in a widespread debate about the need for a transition to a ‘greener’ economy. How such an economy emerges, by what drivers and at what scale is a significant source of speculation amongst the geographical research community. In the context of longstanding contributions to environmental geography from scholars working at Aberdeen University, this paper outlines a novel research agenda for the Green Economy Research Centre (GERC). The contours of the green economy are examined in the context of economic sectors of food production, tourism, energy and the blue economy. Cross-cutting themes of green transitions, governance, people and place and ecosystem services inform our academic contribution to this evolving and controversial societal issue.     

基于融合光谱分析的墓葬壁画颜料色彩虚拟修复方法研究北大核心

墓葬壁画是一种重要的彩绘文物,对其进行揭取搬迁并加固修复是目前主要的保护方式。而在揭取搬迁时,对壁画绘画内容和颜料进行数字化记录及特性分析,是后续壁画表层合理修复的重要依据。光谱成像技术作为一种属性与视觉同步感知的信息探测手段,可以用于壁画表面颜料层的高维信息记录与材质属性分析;同时,利用高光谱伪彩色显示技术可以实现颜料色彩的虚拟复原。基于此,提出一种基于融合光谱分析与带通能量积分的壁画颜料色彩虚拟修复方法,并利用采集的颜料光谱数据、壁画高光谱成像数据与模拟真实场景下的混合颜料光谱数据进行壁画颜料识别与色彩虚拟复原实验。实验结果表明,对于选取的唐墓壁画上的红、黄、蓝、绿四种颜料,其融合光谱识别结果是:武惠妃墓的红色颜料为朱砂/银珠、韩休墓的黄色颜料为石黄/雌黄、武惠妃墓的蓝色颜料为石青/青金石、韩休墓的绿色颜料为石绿的匹配度最大;同时,基于上述识别结果,得到了纯色复原和壁画基底绘制复原的壁画颜料色彩虚拟复原结果,可以为壁画实体修复提供颜料层视觉修复的参考依据。上述研究成果在壁画保护及活化利用领域具有重要的创新示范意义。     

清代梅花玉版笺的科学分析与加工工艺复原研究

梅花玉版笺是一种久负盛名的清代宫廷御用粉蜡笺。本研究通过多种检测方法对故宫博物院藏的一件白色梅花玉版笺的制作材料进行了科学分析:在透光摄影中观察到纸张表面施粉时的涂刷痕迹,涂刷工具宽度约为5 cm；三维视频显微镜显示纸张表面描金的泥金碎片宽度为0.8~12 μm；通过纤维分析发现此件梅花玉版笺为皮竹混料纸；使用傅里叶变换红外光谱仪分析纸张表面施粉为铅白颜料；通过大面积X射线荧光成像光谱仪对冰梅纹及钤印进行了面扫,结果显示钤印处主要元素为Hg、Fe、Ca；微区X射线荧光光谱仪检测结果显示冰梅纹所用为两种纯度不同的泥金。根据检测分析结果对梅花玉版笺的加工工艺进行了复原尝试,制作的复制样品与文物材质相同、外观相似。基于以上工艺流程结合各色粉蜡笺染料成分分析结果,可进一步尝试复原各色粉蜡笺与梅花玉版笺。     

A preliminary study on the photo - degradation of printing pigments on banknotes issued during the period of the Republic of China北大核心

为了初步评价光照对民国纸币的影响,为博物馆纸币文物的展陈照明和保存提供建议,本研究选取了八枚纸币分别进行LED灯和自然光老化实验,并通过拉曼光谱仪和X射线荧光光谱仪确定了纸币样品颜料的主要成分——合成有机颜料红49:1、普鲁士蓝、铬酸铅和炭黑。通过老化前后的色差分析可知,纸币红色颜料变化最大,其他颜色变化相对较小。因此,对于民国纸币类文物,尤其是含有红色合成有机颜料的纸币文物,需要控制其光照条件以防止老化变色。     

Iron-57 Mössbauer spectral studies of medieval stained glass

⁵⁷Fe Mössbauer spectral data for six excavated and two simulated medieval stained glass samples are reported. Iron-containing precipitates are observed in the two simulated medieval glasses and are responsible for the amber colour of these samples. The ferrous/ferric ratio of the other samples is dependent on the glass composition and glass making conditions. The green glasses are associated with the presence of both ferrous and ferric iron, the ratio being very similar in three of the glasses studied, while in the purple and emerald green glasses the iron which is constitutionally incorporated in the glass is solely in the ferric oxidation state. The UVvisible spectra of some of the glasses are used to assist in interpretation of the colourant action of iron, and the role of Mössbauer spectroscopy in linking separate glass fragments with a common source is also indicated.