臭氧浓度变化对馆藏银器文物腐蚀变色的影响

博物馆环境中的臭氧作为氧化剂,对文物起到氧化腐蚀的作用,会使馆藏银器文物腐蚀变色。本研究主要采用石英晶体微天平(QCM)反应性监测技术,监测电沉积金属银石英晶振片在不同臭氧浓度、不同相对湿度中的质量变化,从而推测银在臭氧中的腐蚀机理。研究结果表明,臭氧浓度对银的腐蚀具有较大的影响。随着臭氧浓度的升高,银表面质量不断增大,腐蚀程度加剧。银对相对湿度具有较小的敏感性,在不同的相对湿度下,银表面质量变化相差不大。据此推断银在臭氧中的腐蚀首先表现为银与臭氧分解产生的原子氧反应生成氧化银(Ag2O),随着Ag2O膜的不断变厚,氧化膜顶层生成过氧化银(AgO),AgO是由Ag2O与原子氧反应生成。     

ROMANO‐EGYPTIAN RED LEAD PIGMENT: A SUBSIDIARY COMMODITY OF SPANISH SILVER MINING AND REFINEMENT*

Samples of red pigment from a group of seven Roman‐period Egyptian mummies, known as red‐shroud mummies, are investigated. Elemental analysis by inductively coupled plasma time‐of‐flight mass spectrometry (ICP–TOFMS) shows that the samples contain mostly Pb (83–92% by weight), along with 0.2–2.0% Sn. All of the samples are found to have similar trace element distributions when normalized to the continental crust, suggesting that they share a common geological origin. Lead isotope ratios are found to match the mixed lead sources typically associated with Rio Tinto, Spain – a site extensively mined for silver during the first century ad . Raman microspectroscopy identifies the major phase of each sample to be red lead (Pb₃O₄) with a minor phase of lead tin oxide (Pb₂SnO₄). Lead tin oxide does not occur naturally, and its incidental occurrence within the sample indicates that the material was heated under oxidative conditions at temperatures in excess of 650°C. In archaeological contexts, the high‐temperature oxidative treatment of lead is typically associated with metallurgical refinement processes such as cupellation. Based on this evidence, it is argued that the pigment was produced out of litharge associated with silver cupellation at the Rio Tinto site.     

五代耀州窑天青瓷的研究

为揭示五代天青瓷釉的呈色机理以及胎体的透光机理,本研究以五代耀州窑天青瓷为主要对象,分别采用EDXRF、XRD、XPS和SEM/EDS等测试方法,分析了化学组成、物相、着色元素的化学状态及微观结构对瓷釉的呈色及瓷胎透光性的影响。结果表明,天青瓷釉为复合呈色方式,釉中Fe_2O_3产生的化学着色作用和釉层中物理结构(残余晶体和分相液滴)对入射光的散射作用产生的结构色,或加深或淡化了呈色,且对釉面的色饱和度和乳浊度也有一定的影响。天青瓷胎的透光性主要与着色氧化物对入射光的吸收以及晶界、气泡对入射光的散射有关。低含量的Fe_2O_3和铁钛固溶体,大大减少了其对入射光的吸收。同时,较少的晶界也减弱了对入射光的散射。因此,天青瓷的透光性良好。     

山东临淄山王村俑坑出土陶质彩绘颜料初步分析

2008年5月山东临淄山王村俑坑出土了数量较多的彩绘陶质文物,为了了解彩绘颜料结构和成分,采用粉末偏光显微法、剖面观察结合拉曼光谱分析对彩绘文物表面颜料样品进行分析。结果表明,这批陶质文物表面彩绘是以白灰做地仗层,由碳酸钙、白土、铁黑（Fe₃O₄）、铁红（Fe₂O₃）、朱砂等颜料调和而成,且厚度不均。在个别样品中发现了少量的中国蓝颗粒(BaCuSi₄O₁₀),这是这次分析中较为重要的发现,此分析结果也可为考古研究提供科学信息。     

A Discussion on the Emergence and Development of Ancient Chinese Artificial Barium Copper Silicate Pigments from Simulation Experiments

The ancient Chinese barium copper silicate minerals mainly comprise Chinese purple (BaCuSi₂O₆) and Chinese blue (BaCuSi₄O₁₀), which were widely used from the late Warring States Period to the late Eastern Han Dynasty. In order to clarify the raw material of the pigment, a series of simulation experiments was conducted to produce Chinese purple pigment under varying mineral conditions. The minerals that we applied in the experiment were quartz as the source of silicon, malachite and copper oxide as the sources of copper, barite and witherite as the sources of barium and lead oxide as the source of lead. Simulation experiments showed that the barium copper silicate minerals and the purple pigment can be produced easily when witherite is used as the barium‐containing raw material. From the perspective of mineral resources, the birth of the ancient Chinese pigment associated with a unique barium mineral resource. The Chinese copper‐based pigments are assumed to have been developed independently and are presumably an outcome of historical developments in glazing techniques.     

Multi-Isotope Investigations for Scientific Characterisation and Provenance Implication of Banded Travertines from Tripolis Antique City (Denizli–Turkey)

The coloured stones used in buildings and monuments were an indicator of power and wealth during the ancient times. In this study, Tripolis city samples have been compared with Tripolis quarry samples in order to recognise the provenance of the banded travertine blocks in the ancient city. The banded travertine samples have similar mineral compositions and mainly consist of calcite with minor amounts of dolomite, aragonite, clay and iron oxide minerals. These results are also supported by CRS studies. Calcite is in the form of needle-shaped crystals ranging between 0.163–1.418?mm (in city) and 0.303–1.270?mm (in quarry). Tripolis banded travertine samples show the similar compositional spread in terms of major oxide, trace elements. δ¹³C_V-PDB values of banded travertines range from 1.93 to 5.25‰ (in city) and 2.99 to 3.99‰ (in quarry), δ¹⁸O_V-PDB values change between (?16.93)–(?10.08) ‰ and (?15.93)–(?13.01)‰, respectively. The U–Th radiometric ages are determined between ～267 and 9?ka in Tripolis city samples and ～350 and 2?ka in Tripolis quarry samples. The minero-petrographic, geochemical, C–O and U–Th isotope results fairly matched with each other. It seems highly probable that the banded travertines in Tripolis city were extracted from the Tripolis quarry, which is located at the northeast of the antique city with a distance of 3?km.     

Rocket-borne measurements of atmospheric infrared fluxes

In the Energy Budget Campaign two rockets, one from Andøya Rocket Range, Norway, and one from Esrange, Sweden, each carrying a liquid helium cooled infrared spectrometer, were simultaneously launched as part of salvo B. The launches occurred during the recovery phase of the last of four auroral magnetic events after a Joule heating criteria was exceeded. At Andøya, zenith radiance altitude profiles were obtained of nitric oxide (NO) near 5.4μm from 70 to 185 km (rocket apogee), of ozone (O₃) near 9.6 μm from 70 to 105 km (instrument sensitivity) and of carbon dioxide (CO₂) near 15 μm from 70 to 150 km (instrument sensitivity). Measured CO₂ spectra at 72 km are shown to compare favorably to those calculated for local thermodynamic equilibrium conditions and instrument resolution. By comparing Andøya and Esrange CO₂ radiance profiles it is shown that there is evidence for spatial variation in the emission. Further, it is shown that the very disturbed conditions of salvo B prior to and during these launches appears to have significantly changed the O₃ 9.6μm radiance profiles compared to previous rocket measurements in polar disturbed and quiet atmospheres. Using the nitric oxide radiance profiles and spectrum, previous rocket results and computed models it is shown that no radiance increase could be detected from prompt auroral energy deposition. The results support the thesis that the NO density in auroral regions is significantly enhanced over mid-latitude values and that for weak auroras, the reaction NO(v = 0) + O → NO(r = 1) + O is the dominant radiation mechanism.     

馆藏金属器物上浅蓝色铜锈蚀物的辨别与成因分析

不同于新出土青铜器上的锈蚀物,博物馆藏金属器物上经常可见浅蓝色铜的锈蚀物。为辨别和探析其成因,通过采用扫描电子显微镜-能谱仪(SEM-EDX)、X射线衍射仪(XRD)和激光拉曼光谱仪(Raman)进行元素成分和物相综合分析,发现其为铜的有机盐。这些有机盐包括简单(或碱式)的甲酸铜和乙酸铜,也包括复杂的含有钠离子和碳酸根的乙酸铜NaCu(CO₃)(CH₃CO₂)、含有钠离子和氧离子的水合甲酸铜Cu₄Na₄O(HCOO)₈(OH)₂·4H₂O。这种浅蓝色铜的有机盐形成根源主要有两种:储存或展览环境的不当;用于除锈的化学试剂的残留。要杜绝这类锈蚀物的形成需要确保储存和展览器物的环境低湿度且无有机酸释放材料的存在。对经过化学处理的器物应确保将化学试剂清理干净且无任何残留以绝后患。对复合材料器物的处理更应谨慎,因为对不同材质的处理和保存环境要求不一样,要个例对待。     

虢国墓地M2009出土麻织品上红色染料的鉴定

三门峡虢国墓地是研究西周晚期诸侯文化的重要考古遗址。在M2009虢仲墓中发现了一件麻织短裤和一件麻织短褂,这套麻织品文物是为数不多的保留至今的西周服饰,最为重要的是这套麻织品分为两层,内层着鲜艳红色,明显进行过人工染色。本研究采用能谱分析仪和激光共焦显微拉曼光谱仪对麻织短裤上的红色颗粒进行检测分析,结果表明该红色颗粒主要成分为Fe_2O_3,而天然赭石的主要成分也为Fe_2O_3,因此确定麻织物上的红色是由赭石染色的结果。这一发现为西周时期织物染色应用石染提供了实证。     

Characterization of some ancient glass beads unearthed from the Kizil reservoir and Wanquan cemeteries in Xinjiang,China

A total of 33 ancient glass beads unearthed from the Kizil reservoir cemetery and Wanquan cemetery in Xinjiang are studied using Raman spectroscopy, scanning electron microscopy with energy‐dispersive spectrometry (SEM–EDS) and other methods. The detailed study of the glassy matrices, the crystalline inclusions and the microstructural heterogeneities for these glass beads has revealed some valuable information to help in the understanding of their possible manufacturing technology and provenance. At least two different types of glass were present in the two cemeteries. For the first time, antimony‐based colourant/opacifier—for example, Pb₂Sb₂O₇ or CaSb₂O₆—was systematically identified in some beads of plant‐ash type soda–lime glass dated to about 1000–500 bc . The limited number of potash glass beads from the Kizil reservoir cemetery, which were dated to about 500–300 bc , used tin oxide as an opacifier. The diverse resources of the soda–lime and potash glasses indicate the existence of a complex trade network between China and the West much earlier than the Western Han Dynasty.     

LUSTRE COLOUR AND SHINE FROM THE OLLERIES XIQUES WORKSHOP IN PATERNA (SPAIN), 13TH CENTURY AD: NANOSTRUCTURE,CHEMICAL COMPOSITION AND ANNEALING CONDITIONS*

Lustre is a medieval ceramic decoration, corresponding to a nanostructured thin layer formed by metallic copper and silver nanocrystals embedded in a glass matrix, which required deep knowledge on the part of the artisans with regard to the raw materials used and the kiln conditions. Their empirical knowledge led to the achievement of colourful lustre decorations ranging from reddish to yellowish or even greenish, some of them with a metallic shine with an associated purplish iridescence. Lustre ceramics dating from the 13th century from the Olleries Xiques workshop in Paterna (Spain) have been studied, linking their chemical composition and nanostructure with their colours and shine. Two kinds of nanostructures are found, yellowish lustre decoration constituted by a silver metal–glass nanocomposite, and reddish lustre decoration constituted by metallic copper nanocrystals and copper oxide nanocrystals; in some cases, metallic copper nanocrystals covered with an oxidized shell of CuO and partly Cu₂O have been found. However, even with significant amounts of copper oxide, the lustre still exhibits a copper metal‐like shine. The bluish iridescence observed at a specular angle in the lustre could not be explained completely by means of the chemical composition, and metallic silver nanoparticle light scattering is proposed as a possible explanation.     

MOSAIC GLASS FROM ST PETER'S,ROME: MANUFACTURING TECHNIQUES AND RAW MATERIALS EMPLOYED IN LATE 16TH‐CENTURY ITALIAN OPAQUE GLASS

A recent restoration of late 16th‐century mosaics in one of the vaults beneath the dome of St Peter's Basilica in Rome allowed sampling and analysis of a group of glass tesserae. The aim of this work is the characterization of opaque coloured glasses possibly produced in Rome. The characteristics of the glass from St Peter's were compared with those of Venetian and Tuscan production, in order to assess possible common origins. Chemical analysis of 30 samples was carried out by electron microprobe, while the nature and morphology of opacifiers were determined by X‐ray diffraction and scanning electron microscopy. Almost all the opaque samples were characterized by the presence of SnO₂ crystals. In addition, depending on the colour of the glass, other crystalline phases were identified: lead‐tin oxide (PbSnO₃) in yellow glass, cuprite (Cu₂O) in orange glass and two calcium‐tin silicates with different stoichiometry (CaSnSiO₅ and Ca₃SnSi₂O₉) in the green‐yellow variety. A frame of reference for identifying raw materials and glass‐making techniques is provided by textual sources, here examined in comparison with the compositional characteristics of the tesserae from St Peter's.     

陕西咸阳出土东汉陶器表面彩绘成分研究

为掌握陕西省咸阳市渭城区周陵镇费家村南两座东汉墓葬M17和M19出土15件陶器表面彩绘成分及保存现状,通过XRF,XRD,FTIR和SEM-EDS等分析仪器进行检测。经分析检测发现:M17出土6件陶器表面使用铅丹作为颜料,部分铅丹已转化为白色碳酸铅(PbCO_3)。M19出土陶器表面分别使用朱砂和铁红颜料,同时确定在部分器物表面使用了髹漆工艺。在M19出土的3件器物口沿处发现二氧化锡层,通过扫描电镜能谱分析和文献研究,确定其应为单质锡氧化而来,且使用锡汞齐方法镀锡,为进一步认识和理解这批器物提供了基础。     

Malkata and Lisht Glassmaking Technologies: Towards a Specific Link between Second Millennium BC

Elemental analyses have been conducted on 61 coloured opaque glasses from the Malkata and Lisht New Kingdom glass factories. The presence of tin in several of the blue glasses suggests that a bronze casting byproduct or corrosion product was the source of the copper colorant for these glasses. A positive correlation between the lead and antimony concentrations of the yellow and green opaque glasses, plus a consistent excess of lead oxide in these glasses, suggests the use of antimony‐rich cupellation litharge as the source for the Pb₂Sb₂O₇ , colorant in these glasses. The metallurgical byproducts used to colour the Malkata and Lisht glasses provide an explicit mechanism for Peltenburg's theory of interaction between second millennium BC glassmakers and contemporary metalworkers.     

MICROSTRUCTURAL CHARACTERIZATION OF EARLY WESTERN GREEK INCUSE COINS*

In this research, we studied the compositional, crystallographic and microstructural properties of a series of incuse silver didrachmae stemming from the Achaean colonies of Metapontum and Caulonia. In this paper, we address the following points: (i) the metal sources, (ii) the fabrication process and (iii) degradation phenomena, such as incrustation and embrittlement. In this investigation, we employed energy‐dispersive X‐ray fluorescence spectroscopy, X‐ray diffractometry, and scanning electron and optical microscopies. The patina is mainly composed of chlorargirite. The coins consist of a silver‐rich alloy containing ～ 1% of Au and Cu. Metallographic and local compositional analyses revealed a complex scenario of inclusions. In one instance, unalloyed copper grains, two‐phase copper/bismuth globuli and high‐bismuth filaments were observed. In other cases, globular Cu ₂ S (chalcocite) inclusions were noticed. The presence of SiO ₂ and iron oxide inclusions is ubiquitous in these samples. Distorted twin lines and strain lines can be detected, denoting work‐hardening of recrystallized flans. Grain polygonalization can occasionally be noticed, hinting at secondary recrystallization processes. The irregularly shaped iron oxide particles often act as crack initiation sites. Fracture facets are generally intergranular. On some areas, intergranular decohesion is also observed. Open cracks sometimes contain AgCl. The strain lines that can be noticed on the fracture surfaces indicate work‐hardening and residual microstructural deformation. Information regarding inclusions and the presence of significant amounts of gold can be tentatively used to address provenancing and fabrication issues.     

Iron precipitation in a natural CO2 reservoir: Jurassic Navajo Sandstone in the northern San Rafael Swell,UT, USA

Diagenetic iron (oxyhydr)oxide minerals are common precipitates expected in CO₂ reservoirs, and these minerals record fluid flow for application to carbon capture and sequestration (CSS). Multiple mineralogy and spectroscopy analyses on a pore to meter scale characterize a well‐exposed, lithologically controlled, iron (oxyhydr)oxides reaction front in the Jurassic Navajo Sandstone. Dolomite is the most prevalent cement (up to 23 area%), followed by only several percent or less of iron (oxyhydr)oxides, kaolinite, illite, and gypsum cements. Bulk geochemistry based on diagenetic mineralogies in the reaction front is compared with the water chemistry from nearby modern spring effluent emanating from the Navajo Sandstone to conclude that similar fluids (i.e., CO₂‐charged, saline waters containing hydrocarbons) are responsible for the precipitation. A second comparison of bulk geochemistry and diagenetic mineralogies of the reaction front with data from other abundant Navajo Sandstone concretions in the Spencer Flat region (in south central Utah) shows that reservoir fluids likely vary spatially and temporally in the porous and permeable Navajo Sandstone. CO₂ injection into porous and permeable, quartz arenite, saline aquifers will likely result in minor clay and abundant dolomite precipitation that will significantly decrease porosity.     

MINERALOGICAL AND PETROLOGICAL INVESTIGATIONS OF EARLY BRONZE AGE COPPER‐SMELTING REMAINS FROM THE KIECHLBERG (TYROL,AUSTRIA)

The prehistoric settlement on the Kiechlberg hilltop is located a few kilometres to the north‐east of Innsbruck, in the Tyrolean Inn Valley. Despite its rather isolated location, a multiphase settlement between the fifth and the second millennium bc was confirmed by archaeological investigations in 2007 and 2008. Metallurgical artefacts, such as copper ore fragments, copper slag and raw copper, as well as finished copper and bronze artefacts, are concentrated mainly in Late Copper Age to Middle Bronze Age layers. The chemical compositions of the slag and raw metals confirm Fe—Zn tetrahedrite–tennantite (fahlore) smelting. The ore was most probably imported from the 30–50 km distant copper ore deposits (mainly fahlore) of Schwaz–Brixlegg, in the Lower Inn Valley. The small amount of slag and the presence of slagged and thermally altered ceramic fragments suggest copper production in small‐scale workshops. Most probably, sulphide‐rich ores were smelted in crucibles in a hearth fire. The process was relatively reducing below the 2Sb + 1.5O₂ → Sb₂O₃ reaction (?8.5 log fO₂ at 1100°C), producing Sb‐rich (>10 wt% Sb in metal) raw copper. Inhomogeneous slag remains containing high amounts of sulphide and metal inclusions suggest a poor separation of the metal, matte (copper sulphide) and silicate/oxide melt during the smelting process.     

Recent Investigations on Holocene Occupations in Northeastern Algeria: The Contribution of Kef en-Naga

The discovery of Kef en-Naga site, an open-air human occupation in northeastern Algeria, was favored by a sandstone quarrying where work truncated much of the archaeological sequence on its cross-section. A multidisciplinary rescue excavation conducted on this site provided, for the first time in the region, the evidence of superimposition of two stratigraphic levels (lower and upper) of sandy clay deposits formed in humid paleoenvironmental conditions. Besides, XRD analysis show that a large amount of hematite (Fe₂O₃) is localized at the lower level of the stratigraphic section, where iron is found in oxide form due to the moisture. As for rock magnetic property characterization analysis, the various magnetic parameters have strong values in the upper level, and the grains are small-sized. However, various magnetic parameters are lower at the lower level and the magnetic grain concentration is reduced. Although the site is lacking faunal and carpological remains, thereby depriving us of reliable dates, the two stratigraphic levels are correlated to the Holocene according to archaeological and paleoenvironmental considerations. The lower level likely corresponding to an early Epipaleolithic culture marked by the production of microliths using a microburin blow technique, while the upper level is related to a subsequent Epipaleolithic phase, characterized by the disappearance of microburin blow technique, the dominance of an industry on flakes and the existence of pressure debitage.     

An observational study of the D-region winter anomaly in lower latitudes during sudden stratopsheric warmings

An observational study of the D-region winter anomaly of HF radio wave absorption in lower latitudes has been made during the period of a sudden stratospheric warming of the 1967/1968 winter. By means of large-scale isopleth analysis of the absorption index, ƒ_min, and of meridional winds near 70 km height along 60°N, it is found that there exists a winter anomaly in lower latitudes which is comparable in order to that in middle latitudes, resulting from a nitric oxide (NO) increase due to southward transport from higher latitudes by well-developed planetary wave winds. From the daily changes of absorption in the equatorial region, it is found that the enhanced absorption reveals an oscillation with a period of about 2 weeks and has its maximum in the region south of 20°N. The period is similar to that of planetary wave amplitudes in the winter stratosphere and mesosphere, suggesting that an effect of planetary waves could contribute to the equatorial anomaly of the absorption in the D-region.     

Stratospheric negative ion composition measurements,ion abundances and related trace gas detection

Negative ion spectra obtained during four flights with a balloon-borne quadrupole mass spectrometer are reported and critically investigated. Ion abundances for NO₃⁻ and HSO₄⁻ core ions are reported and concentrations of HNO₃ and H₂SO₄ at altitudes between 32 and 35 km are deduced. The detection of minor mass peaks in negative ion spectra obtained at an altitude of 32 km is discussed. Major mass peaks observed at lower altitudes (from 20 to 28 km) are mainly NO₃⁻ due to core ions.