污染大气中浑仪,简仪的带锈防护

浑仪、简仪（以下简称两仪）在高PH、大气污染和日晒雨淋环境中的腐蚀是一种动态加速腐蚀过程。采用合成的双唑胺铜缓蚀剂和有机硅改性的甲基丙烯酸树脂,并分别复配成协同缓蚀剂群和含有增效稳定剂的封护剂。采用这两种材料和脱水后再防护的工艺,使带锈防护后的浑仪、简仪的腐蚀低于无污染大气中的速率。用电化学方法评价了防护技术的可行性,根据腐蚀与人工老化试验结果讨论了防护材料性能与腐蚀环境和带锈防护的关系,采用XPS分析方法探索了双唑胺比BTA更适用于两仪防护的原因。     

William Scott Owen, 1853–1920: an English-born land agent in mid Wales

William Scott Owen figured prominently in Montgomeryshire history by being deeply involved with the lives of working people and active in local politics. He was an incomer from the south of England and a stalwart of the Anglican faith and the Tory party. He spent the whole of his working life in Montgomeryshire and came to be deeply respected in a part of Britain noted for its Nonconformity and Liberalism. Scott Owen was agent on the Gregynog Estate, which lies in the south east of the county, much of it now belonging to the University of Wales. This study of his life provides a vivid picture of the county in the late Victorian and Edwardian period and discusses why he became so well regarded.     

A technological study of ancient faience from Egypt

The chemical compositions and microstructures of some 35 faience objects from Egypt spanning the period from the Middle Kingdom through to the 22nd dynasty are determined using analytical scanning electron microscopy. Replicate faience beads glazed in the laboratory using the efflorescence and cementation methods are similarly investigated. In efflorescence glazing, there appears to be preferential efflorescence of soda over potash, and in cementation glazing, preferential take up of potash over soda into the glaze. These data are then used to try to infer the raw materials and methods of glazing employed in the production of the ancient faience. The glaze/glass phases present in the faience differ significantly in composition from that of New Kingdom glass. This could be due either to the use of different plant ashes or to changes in the composition of the plant ashes during the production of faience and/or glass. Although it is only rarely possible to determine with certainty whether ancient faience was glazed by efflorescence, cementation or application, the observed microstructures provide an indication of the approach adopted to achieve desired performance characteristics such as strength.     

Sustainability of Highway Bridge Networks Under Seismic Hazard

In order to evaluate the seismic risk of transportation networks, it is necessary to develop a methodology that integrates the probabilities of occurrence of seismic events in a region, the vulnerability of the civil infrastructure, and the consequences of the seismic hazard to the society, environment, and economy. In this article, a framework for the time-variant seismic sustainability and risk assessment of highway bridge networks is presented. The sustainability of the network is quantified in terms of its social, environmental, and economic metrics. These include the expected downtime, expected energy waste and carbon dioxide emissions, and the expected loss. The methodology considers the probability of occurrence of a set of seismic scenarios that reflect the seismic activity of the region. The performance of network links is quantified based on individual bridge performance evaluated through fragility analyses. The sustainability and risk depend on the damage states of both the links and the bridges within the network following an earthquake scenario. The time-variation of the sustainability metrics and risk due to structural deterioration is identified. The approach is illustrated on a transportation network located in Alameda County, California.     

汉代彩绘的回贴修复研究

针对出土的汉代生漆彩绘和胶料彩绘的破损状况,用自行研制的增塑剂(SC1,主要成分为水性环氧及有机锡),加固剂(水性氟),胶粘剂(环氧树脂与聚酰胺及508的混合物),对生漆彩绘耳杯进行回贴修复;用显现加固剂(508及有机氟材料)对西汉兵马俑胶料彩绘进行显现加固,然后采用水性氟试剂作为胶粘剂进行回贴。两类彩绘的回贴效果理想,说明这种新型的回贴技术可以应用于文物彩绘修复。     

Roman blue-green bottle glass: chemical–optical analysis and high temperature viscosity modelling

Chemical analysis, optical absorption spectroscopy and mathematical modelling of high temperature viscosity have been carried out on five 1st–2nd century AD Roman blue-green bottle glass fragments from Coppergate, York. Modelled viscosities indicate remarkable consistency within the sample set studied and support the suggestion that temperatures of ∼1000–1150 °C were required to remelt these glasses and to provide suitable viscosities for forming articles. Iron redox ratios (Fe²⁺/ΣFe), analysed SO₃ contents and the absence of characteristic Fe³⁺–S²⁻ amber absorption bands suggest that melting conditions for all studied glasses were mildly, rather than strongly, reducing (estimated pO₂ ≈ 10⁻¹–10⁻⁶ bar). These furnace conditions are consistent with the effects of combustion gases and carbonaceous matter contained in the raw materials.     

Degradation processes in colourless Roman glass: cases from the Bocholtz burial

A group of Roman glass objects from the Bocholtz burial in the SW of Limburg (The Netherlands) was found to have been subject to varying degrees of degradation. Many of the 25 colourless glass objects were fragmented to pieces <0.1 cm (“sugared”), whereas the three transparent blue-green glass objects were in near-pristine state. Analyses using SEM, XRF and EDS revealed that the fragmentation was the direct result of the intense leaching of Na₂O from the glass structure and its replacement with water. The resulting gel layers with low-Na₂O contents and large amounts of water are sensitive to cracking when they dry out. Thin-walled glass appears to be less sensitive to cracking from the resulting stress than thick-walled glass. Local differences in the moisture regime during burial also influence the severity of the glass degradation. Glass with low concentrations of CaO seems to be the most sensitive to this form of degradation. The typical blue-green Roman glass is less sensitive as it generally has considerably higher concentrations of CaO.     

Pliny the Elder and Sr–Nd isotopes: tracing the provenance of raw materials for Roman glass production

In Roman and Byzantine times, natron glass was traded throughout the known world in the form of chunks. Production centers of such raw glass, active from the 4th to 8th century AD, were identified in Egypt and Syro-Palestine. However, early Roman primary glass units remain unknown from excavation or scientific analysis. The ancient author Pliny described in 70 AD that besides Egyptian and Levantine resources, also raw materials from Italy and the Gallic and Spanish provinces were used in glass making. In this study, the primary provenance of 1st–3rd century AD natron vessel glass is investigated. The use of combined Sr and Nd isotopic analysis allows the distinguishing and characterizing of different sand raw materials used for primary glass production. The isotope data obtained from the glass samples are compared to the signatures of primary glass from known production centers in the eastern Mediterranean and a number of sand samples from the regions described by Pliny the Elder as possible sources of primary glass. Eastern Mediterranean primary glass has a Nile dominated Mediterranean Nd signature (higher than −6.0 ? Nd), while glass with a primary production location in the western Mediterranean or north-western Europe should have a different Nd signature (lower than −7.0 ? Nd). Most Roman glass has a homogeneous ⁸⁷Sr/⁸⁶Sr signature close to the modern sea water composition, likely caused by the (intentional) use of shell as glass raw material. In this way, strontium and neodymium isotopes now prove that Pliny's writings were correct: primary glass production was not exclusive to the Levant or Egypt in early Roman days, and factories of raw glass in the Western Roman Empire will have been at play.     

Computer programmes for the correction of matrix effects in the XRF analysis of glass,ceramics and related silicate systems

The quantitative analysis of glass, ceramics and related silicate systems by means of energy dispersive X-ray fluorescence spectrometry is considered and problems arising from the selective absorption of X-rays in multi-element specimens are discussed. A computer programme written in FORTRAN and based upon a “semi-fundamental parameters” approach to the correction of matrix effects in glass and chemically similar materials is fully described. Model data are provided to enable the programme to be run and tested. An “empirical coefficients” computer programme for the quantitative analysis of silicate systems is outlined and the limitations of this type of programme are pointed out. The importance of adequate sample preparation prior to X-ray spectrometric analysis is stressed.     

迎头色谱法在评价调湿剂性能上的应用

利用迎头色谱脱附曲线,测定了水蒸汽在调湿剂中的扩散系数。结果表明,当清除了载气流速、调湿剂粒径以及色谱柱轴向扩散等众多干扰因素的影响后,由迎头色谱法测得的水蒸汽在调湿剂中的扩散系数值可用于评价调湿剂的响应速度。