Study of ancient Islamic gilded pieces combining PIXE-RBS on external microprobe with sem images

Numerous metallic objects with very aesthetic and technological qualities have been recovered by archaeological excavations. Adequate processes of restoration and conservation treatments require the accurate determination of the elemental composition and distribution within the objects, as well as the identification of the nature and distribution of the corrosion products. Ideally the identification method should cause no alteration in the sample. In this work, different archaeological pieces with a gilded look have been characterized using simultaneously PIXE and RBS at the CMAM external microprobe in order to study the gilding metalworking done in the Iberian Peninsula during the Middle Ages. The gold layer thickness and its elemental concentrations of Ag, Au and Hg were determined by both techniques and compared with the scanning electron microscopy images obtained for some fragments of pieces. PACS  29.30.Kv; 87.64.-t     

Colorando Auro: contribution to the understanding of a medieval recipe to colour gilded silver plates

The colour of gildings can be modified by many artistic techniques. This article refers to the possibility of a specific chemical treatment to change the colour of gildings. The model samples—gilded silver plate, the mixture and the application of a medieval recipe based on ancient writings from Theophilius and Cellini have been described. We propose a strategy to identify the chemical processes involved in the change of colour of the metallic surface through the advanced study of these model samples. Synchrotron X-ray photoelectron spectroscopy and X-ray absorption spectroscopy were carried out both on the gilding with and without the application of the treatment with the aim to understand the chemical reactions occurring during the treatment.     

PIXE分析技术在大气环境研究中的应用

概述了ＰＩＸＥ分析技术在大气颗粒物特性、来源等研究中的几个应用实例． Some examples of applying PIXE on the atmospheric particulate are briefly introduced in this paper.     

应用PIXE技术对书写字迹的分析

在国内首次应用质子激发X射线荧光法对常见的书写字迹进行刑事检验分析,确认PIXE技术可以作为文件检验当中字迹同一认定的有效方法。同时,质子激发X射线荧光法也是一种有效的无损检验的方法。提出了不同于现在的解决途径的质子激发X射线荧光技术解决法庭科学当中的两大疑难问题——书写时间的鉴定、毒品源头的认定。     

用激光清洗金膜表面硅油污染物

采用CO2激光对镀金K9玻璃表面的二甲基硅油污染物进行清洗,在激光器单点作用模式下,分别研究了激光功率和作用时间对清洗效果的影响;并研究了连续扫描工作模式下的激光清洗效果。采用光学显微镜和傅里叶变换红外光谱仪表征激光清洗效果,研究结果表明:通过良好的控制激光参数,采用CO2激光清洗二甲基硅油具有明显的效果;此种非接触式清洗方式可确保K9玻璃表面的金膜完好无损。采用有限元分析软件模拟计算了激光功率和作用时间对清洗过程中温度的影响,计算结果与实验结果规律一致。     

Study of the elemental composition of wine stoppers using PIXE

Analysis of stoppers has been restricted mostly to the determination of organic compounds and microorganisms, but none of these studies aimed at the mineral contents of stoppers. Therefore, the aim of this work is to determine the elemental concentration of cork and synthetic stoppers. Wine, cork, and synthetic stoppers were analyzed through the particle‐induced X‐ray emission and micro‐particle‐induced X‐ray emission techniques. The analysis of the internal and external layers of cork and synthetic stoppers showed striking differences in their elemental composition and concentrations and depend on the nature of the stopper. For instance, Si, S, K, and Ca have higher concentrations in the external layer than in the inner portion of the stoppers. Moreover, our results show that elements are not distributed homogeneously throughout the surface of cork stoppers. This study provides, for the first time, data on the elemental composition of different stoppers, which could serve as a database for future research in this field. Finally, it is important to mention that wine and stoppers were analyzed with the same technique, which allows a straightforward comparison between them. Copyright © 2013 John Wiley & Sons, Ltd.     

Pigments and enamelling/gilding technology of Mamluk mosque lamps and bottle

On‐site Raman spectroscopy is used to investigate four mosque lamps and a bottle dating back to the 13–14th centuries (Syria and/or Egypt, Mamluk period) from the Department of Islamic Art, Musée du Louvre, Paris. The pigments and the enamelled glass matrix have been identified in order to discuss their technology. A comparison is made with one masterpiece from the 19th century made by Brocard. The results obtained for blue (lapis lazuli or Co‐coloured glass), yellow (Naples yellows or zinc/chrome yellow), green (mixture of the aforementioned blue and yellow pigments or lead chromate for restorated foot) red (hematite), white (cassiterite or arsenate) and pink (hematite and cassiterite) pigments are presented. The consistency of the pigments period of use/technology with the datation proposed for each artefact is evaluated. For one lamp, the detection of quartz in some places of the hematite‐rich glassy layer supporting the gold is related to the search of a physical bonding with the artefact body. Carbon residues in such enamel are consistent with the use of an organic medium to place the enamel powder before the firing. Copyright © 2012 John Wiley & Sons, Ltd.     

用激光清洗金膜表面硅油污染物

采用CO2激光对镀金K9玻璃表面的二甲基硅油污染物进行清洗,在激光器单点作用模式下,分别研究了激光功率和作用时间对清洗效果的影响;并研究了连续扫描工作模式下的激光清洗效果。采用光学显微镜和傅里叶变换红外光谱仪表征激光清洗效果,研究结果表明：通过良好的控制激光参数,采用CO2激光清洗二甲基硅油具有明显的效果;此种非接触式清洗方式可确保K9玻璃表面的金膜完好无损。采用有限元分析软件模拟计算了激光功率和作用时间对清洗过程中温度的影响,计算结果与实验结果规律一致。     

Thickness determination of gold layer on pre‐Columbian objects and a gilding frame,combining pXRF and PLS regression

In conservation, restoration and characterization studies of art and archaeological objects, the improvement of analytical techniques is a tendency. X‐ray fluorescence (XRF) is a versatile technique, and it has been widely used in the last decades for characterization of a great variety of materials (metals, glass, paints, inks, ceramics, etc.) applied to cultural heritage studies. Besides the chemical composition, it is possible to infer the layer thickness through XRF, enabling a general knowledge of the manufacturing techniques implemented by the culture of origin, as well as the association with the technological level reached for the production of each kind of artefact. The aim of this study is to introduce an alternative way for gold thickness determination of coatings in cultural heritage objects, combining portable XRF data and partial least square regression. As a case of study, we present the use of this methodology in portable XRF measurements performed in situ on a gilding frame in Brazil and in two pre‐Columbian artefacts from Chavin culture in Peru. Gold layers with thicknesses determined by Rutherford backscattering spectrometry (RBS) were used as standards to perform a calibration model and to check the methodology before its application to unknown artefacts. Copyright © 2016 John Wiley & Sons, Ltd.     

相位物可视化的研究

从理论、实验和数值模拟3方面对几种常见相位物可视化方法进行了分析比较,得出了各种方法的优劣点和适用范围.提出了新的图像处理方法,其核心思想是利用低频正弦光栅替代复合光栅滤波,用三重干涉来达到类似微分运算的效果,以此实现相位物可视化.     

Review and perspectives on energy dispersive high resolution PIXE and RYIED

Until 2008, high-resolution particle-induced x-ray emission (HR-PIXE) work used mostly wavelength dispersive spectrometers and aimed at fundamental problems and application demonstrations. The method was hardly used for applications in general, mostly due to the small energy window and solid angle of most equipment. In the last 14 years, a few facts pushed HR-PIXE out and beyond this framework. Here, we focus on the developments following the observation of x-ray relative yield ion energy dependence (RYIED) effects on transitions to the same sub-shell, in PIXE experiments, in 2004, and the installation, in 2008, of the first energy dispersive HR-PIXE (EDS HR-PIXE) system. Both facts are among those that were concurrent to the emergence of new problems and perspectives in PIXE and in fundamental atomic physics in the recent past. This review covers these 14 years of results on these issues and the answers they recently led to. Evidence for new problems and perspectives, including the potential access to chemical bonding and/or solid state information, based on EDS HR-PIXE work, are discussed. Furthermore, the grounds for the possibility of developments leading to a new field of atomic solid state physics are presented.     

Mössbauer Spectroscopy, NAA and PIXE Study on Some Archeological Problems of Ancient Chinese Ru Celadon

By Mössbauer spectroscopy, NAA and optical spectroscopy, the coloring and the firing technology of ancient Ru celadon were studied. Also, the relationship between Ru Kuan celadon from Qingliang Temple and Ru celadon from Zhanggongxiang was studied by PIXE. The glaze color of Ru celadon depends on the ratio of the structural iron ions, i.e. the Fe²⁺/Fe³⁺ ratio. Further, it depends on the firing conditions. As the Fe²⁺/Fe³⁺ ratio gradually increases, the glaze color of Ru celadon will gradually change from pea green to sky green. All the Ru celadons were fired in a reducing atmosphere. The sky green Ru celadon was fired in the most reducing atmosphere and at the highest temperature, the powder green in a more reducing atmosphere and at a lower temperature and the pea green in a lightly reducing atmosphere and at the lowest temperature. The PIXE experimental results showed that Ru Kuan celadon from Qingliang Temple and Ru celadon from Zhanggongxiang were incompletely identical in the recipe of glaze and they could be differentiated by the cluster analysis of the major element concentration of glaze.     

放置不同物体三线摆转动周期变化规律研究

针对三线摆上放置的常用物体,如:圆盘、圆环、两圆柱体等,探讨放置物体前后、质量分布及位置改变时转动周期的变化规律.结果表明:理论分析与实验结果有较好的一致性.     

PIXE microanalysis of human serum and amniotic fluid

Summary Twenty serum and amniotic-fluid samples, drawn from different pregnant womens at the end of their gestation period, have been analysed by proton-induced X-ray emission (PIXE) analysis. Sample preparation, as thin film, is treated in detail and method characteristics are discussed. Qualitative and quantitative results show a similarity between two biological liquids. All samples include Cl, K, Ca, Cr, Fe, Cu, Zn and Br in different concentrations from 7.6 mg/ml to 0.1 μg/ml.

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Riassunto Venti campioni di siero e di liquido amniotico, prelevati a differenti donne incinte alla fine del loro periodo di gestazione, sono stati analizzati tramite l'analisi PIXE (proton-induced X-ray emission). La preparazione dei campioni, come film sottili, è trattata in dettaglio e le caratteristiche del metodo sono discusse. I risultati qualitativi e quantitativi delle analisi mostrano una similitudine tra i due liquidi biologici. Tutti i campioni contengono Cl, K, Ca, Cr, Fe, Cu, Zn e Br in differenti concentrazioni comprese tra 7.6 mg/ml e 0.1 μg/ml.

     

Influence of different mass absorption coefficient datasets on PIXE yields

Tabulated mass absorption coefficient data from the XCOM, Chantler and ion beam analysis (IBA) Handbook are compared, and differences are shown against X‐ray energy and target atomic number. Over the X‐ray energy range 1–40 keV systematic differences of several tens of percent are noted between these datasets, particularly for the earlier IBA Handbook dataset. The influence of these different mass absorption coefficients on the X‐ray yields for thick target proton‐induced X‐ray emission (PIXE) are investigated and compared as a function of X‐ray energy and target atomic number. For contemporary experimental PIXE users trying to work quantitatively over a broad range of elements and X‐ray energies, differences between PIXE results obtained using these three separate mass attenuation coefficient datasets can be larger than the typical accuracy limits of ±3% to ±5%. There are systematic differences in the mass attenuation coefficients of 5–10% between the XCOM and Chantler, while the differences for the IBA Handbook dataset can be larger (up to 40% and greater) at high X‐ray energies. At this time, we recommend the dataset of Chantler as it is more recent, and the synchrotron experimental results seem to favour it over the older XCOM and IBA Handbook data. Copyright © 2013 John Wiley & Sons, Ltd.     

Materials and technological aspects of gilded buckles from a North Eastern Medieval Italian context

This study concerns the archaeometric characterization of two artefacts from the medieval site of San Rocco (Castelfranco Veneto, Italy). Both of them belong to a larger set of metallic objects, some being part of tomb ornaments belonging to two very well distinct periods of frequentation of the site. Both items are buckles and they have been selected as representative of two very well-known and established typologies. The older one, at the end of the sixth—beginning of the seventh century AD, is made of silver, although relicts of gold have been found. A number of relevant counterparts of this item have been found in different sites of the Longobard Italy. The main body of the second artefact (second half of the fourteenth century AD) consists of a bent strip of a copper rich alloy, coated on one side with a nearly continuous, decorated, gold layer. This is a so-called lyre-buckle, with a widespread diffusion not only in Italian, but also North European contexts. From the results of the analyses carried out using low-vacuum scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffractometry, information on manufacturing, gilding technology and materials have been obtained that will be an useful benchmark for the archaeometric characterization of similar items from selected collections. In this way, the already established typological affinity of these two classes of items will be extended to technological and materials aspects, also.     

Broad‐beam PIXE and µ‐PIXE analysis of normal and in vitro demineralized dental enamel

Dental enamel has been widely studied by particle‐induced x‐ray emission (PIXE), but less attention was paid to its demineralization, which leads to caries formation. Using broad‐beam PIXE and µ‐PIXE, we investigated normal enamel and the in vitro formation of pre‐carious lesion in lactic acid solution, aiming also to evaluate intercusp differences within the same tooth. Broad‐beam PIXE was performed using 3.0 MeV protons, and µ‐PIXE maps of Ca, Fe and Zn were collected with 3.1 MeV protons at ～4 µm resolution. In normal enamel a differentiated Ca‐rich surface layer was observed, where Fe and Zn reached their highest levels. In deeper layers, Fe and Zn evidenced quasiperiodic patterns of maxima, possibly due to coupled diffusion‐reaction catalytic processes involved in the enamel growth. Both Fe and Zn appeared to be located in a few distinct types of pools. Near the surface, demineralization induced an increase of Fe, Cu, Zn, Sr and Pb with respect to Ca, attributed to partial hydroxyapatite dissolution and/or to chelate extraction and concentration of trace metals. Ca maps revealed limited changes in the surface layer and a massive loss in the inner enamel; here, Fe was almost depleted and Zn partially removed. The maps of Ca, Fe and Zn demonstrated major intercusp variations in both normal and altered enamel. Thus, broad‐beam PIXE and µ‐PIXE, which do not require (semi)thin sectioning of the tooth as the conventional methods, provide compositional and structural insight of normal dental enamel, of its intercusp variability and of the alterations produced by in vitro demineralization, largely not accessible to the current techniques, and highly relevant for understanding the incipient caries formation. Copyright © 2008 John Wiley & Sons, Ltd.     

Ion beam and infrared analysis of medieval stained glass

Ion beam analysis and Fourier Transform Infrared (FTIR) spectroscopy were used to characterize 15^th century stained glass fragments from Batalha Monastery. This information is being used to help establish their origins as well as the art schools and artistic trends involved in the manufacture of these panels.As the preservation of art objects and artefacts is a major issue, the combination of Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE) with FTIR spectroscopy aims at determining non-destructively the elemental compositions of the bulk glass and painted layers as well as identifying corrosion products. Elemental spatial distributions were obtained with a nuclear microprobe, and compared with the results of micro-FTIR.Although the bulk composition determined is consistent with the glass manufacturing practices of the Middle Ages, the grisailles were found to have a significant Zn concentration, at variance with those same reported practices.The analysis also revealed a surface layer impoverished in Si and K and enriched in Ca. That may be due to the migration of Ca ions to the surface, a known glass corrosion process consistent with the presence of CaCO₃, as indicated by micro-FTIR. PACS 81.05.Kf; 33.20.Ea; 82.80     

Traffic flow of mobile objects through obstacles: Turning and translational objects

We study the unidirectional flow of mobile objects through obstacles on a square lattice. Two models are presented: one is the lattice gas model consisting of translational particles and the other is that of turning particles. Fundamental diagrams for the two models are presented. The traffic flow of translational particles is compared with that of turning particles. In the traffic flow of translational particles, the fundamental diagram shows a trapezoid shape in the random configuration of obstacles, while it shows a parabolic shape in the periodic configuration of obstacles. The traffic flow of turning particles with a back step shows a similar behavior to that of translational particles. In the traffic flow of turning particles without backward moves, the current becomes zero when the density is higher than a critical density. In the traffic flow of turning particles without a back step, the dynamical transition between free traffic and a perfectly jammed state occurs at the critical density, while dynamical transition does not occur in traffic flow of translational particles.     

成都金沙遗址古代陶片的PIXE和RBS分析(英文)

成都金沙遗址的年代覆盖了商代晚期至西周时期（公元前1200年—公元前650年）, 一般被认为是三星堆文化的延续。初步建立了质子激发X射线发射（PIXE）和卢瑟福背散射（RBS）实验装置, 并采用PIXE和RBS方法研究了从金沙遗址出土的部分陶片的元素组成。通过因子分析, 观察到来自不同地层的陶片的元素组成存在一定的差异, 这可能意味着制作陶器的陶土在不同时期取自不同的地点。也观察到来自不同发掘坑的陶片的元素组成没有明显的聚类现象, 这可能意味着制作不同使用用途的陶器所用的陶土是没有区别的。Jinsha Ruins Site, Chengdu, China, spanned the age from late Shang Dynasty to Western Zhou Dynasty (B.C.1200—B.C.650), was generally considered as the inheritance of Sanxingdui Culture. This paper focuses on the studies of the pottery unearthed from Jinsha. PIXE and RBS experimental setup was preliminarily established and these techniques were employed to find the elemental composition of those collected shards. From the results of factor analysis, the differences can be seen among pottery shards from different stratums, which may suggest that the clay gathered from different sites was used in different periods. The authors also found that there was no obvious assemblage phenomenon in the factor analysis among the pottery shards from different pits, this may be the evidence for “no special clay for special use”.