Digital photoelasticity of glass: A comprehensive review

The recent advances in digital photoelasticity have made it possible to use it conveniently for the stress analysis of articles and components made of glass. Depending on the application, the retardation levels to be measured range from a few nanometres to several thousand nanometres, which necessitates different techniques and associated equipments. This paper reviews the recent advances in the photoelasticity of glass with a focus on the techniques/methods developed in the last decade. A brief introduction to the residual stress in glass is provided initially to bring out its tensorial nature. The subsequent sections are organised thematically rather than chronologically, for better readability and easy access of information.     

CdS/TiO2/漂珠复合光催化剂制备及其降解高效氯氰菊酯研究

采用溶胶-凝胶-浸渍法制备了Cds/TiO2/漂珠复合光催化剂,通过SEM,XRD对其结构进行了表征.以高效氯氰菊酯(BEC)杀虫剂的光催化降解为模型反应,研究了CdS/TiO2/漂珠的光催化性能,探讨了影响催化剂活性的因素及采用太阳光作光源处理BEC的可行性.结果表明,CdS/TiO2/漂珠投加量为3 000mg·L-1,初始浓度为45 mg·L-1、初始pH为6.5,通气量为200 mL·min-1时间为60 min,BEC降解率分别为92.1%(125W高压汞灯)和79.3%(5 W紫外灯),采用太阳光照射300 min,BEC降解率可达93.4%.BEC的降解反应遵从L-H动力学模型,测得反应速率常数9.80 mg·(L·min)-1,吸附常数4.36×10-3 L·mg-1.     

In situ study of stones adorning a silver Torah shield using portable Raman spectrometers

A silver Torah shield fitted with a set of precious stones and glass imitations crafted in Poland in the first half of the 19th century was investigated using two of the currently distributed portable and relatively low‐cost Raman spectrometers in situ at the Jewish Museum in Prague. Observed Raman peaks corresponded well (+/− 3 cm⁻¹) to the reference values. The hand‐held instruments operated at 785‐ and 532‐nm laser excitations showed good performance in the fast and unambiguous identification of nearly 60 stones which were fitted on the shield: one blue aquamarine, three purple amethysts, thirteen red garnets (all classified as high‐percentage almandines), three white pearls, fifteen pieces of red coral and five chalcedonies (one white and four red). All of the other stones were identified as colored glass. The rather chaotic mixture of stones of various colors, cuts and sizes and the total volume of imitation glass support the theory that the mounted stones were gathered from Jewish households and donated for the adornment of the shield. The common portable Raman instruments represent an ideal tool for the quick and accurate identification of gemstones mounted in historical artifacts in situ in the framework of museum or collection sites in a non‐destructive way. Copyright © 2014 John Wiley & Sons, Ltd.     

Raman spectroscopy of synthetic,geological and biological vaterite: a Raman spectroscopic study

Raman spectroscopy was used to study vaterite samples of biological, geological and synthetic origin. The Raman band positions and the full width at half‐maximum (FWHM) of the lattice modes and the internal modes of the carbonate ion of all specimens show no significant differences between vaterites of different origin. With increasing Mg concentrations, synthetic vaterite samples show increasing FWHM in the region of the lattice modes and the three ν₁ bands, whereas no change in luminescence was detected. In contrast, in situ measurements of vaterite areas in freshwater cultured pearls (FWCPs) by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) together with the Raman spectra obtained at the same points show that the luminescence intensity in biological samples is affected by the magnesium content. The Raman spectroscopic features of vaterite and parisite‐(Ce) are compared, and their similarities suggest that the structure of vaterite contains at least three crystallographically independent carbonate groups and similar carbonate group layers. A band at 263 cm⁻¹ is observed for the first time in this study, whereas it could be demonstrated that bands previously reported at 130 and 190 cm⁻¹ do not belong to vaterite. Copyright © 2009 John Wiley & Sons, Ltd.     

金属目标表面气体放电单元放电过程的PIC-MCC模拟

 对目标表面的浮地导体边界的存在及其对单元气体放电过程所产生的影响进行了研究，针对导体边界条件，应用高斯定理和电荷守恒定律推导出这种边界条件的数值处理方法，得到了有界等离子体空间电势的数值分布。电场的数值计算表明，浮地导体的电势随着内部场的变化而变化，其大小介于两个电极的电势之间，对放电区域的电场分布产生较大的影响。 对金属目标表面放电单元的放电过程的PIC-MCC模拟结果表明， 浮地导体的存在能够改变放电空间的电场结构，形成不均匀场，有利于气体的电离和等离子体区域的形成，同时将使虚阳极所形成的电势平台在边界附近下陷，导致等离子体壳层的厚度变小。     

光度法测定浮法玻璃下表面渗锡

研究了用二溴苯基羟基荧光酮比色法测定浮法玻璃下表面渗锡的反应条件。在0.2mol/L盐酸介质中,OP乳化剂（聚乙二醇对异辛基苯基醚）存在时,锡与该试剂形成橘黄色螯合物,最大吸收波长513nm,表观摩尔吸光系数为1.20×10^5L.mol^-1.cm^-1,锡的质量浓度在0—8μg/25mL范围内符合比耳定律。反应选择性好,不经分离直接测定浮法玻璃下表面渗锡。回收率试验在93.01%—106.85%之间。     

基于色度学与拉曼光谱的安徽淡水养殖白色珍珠研究

珍珠的颜色是影响其品质最关键因素之一.目前珍珠颜色的研究大多集中在不同颜色珍珠的组成元素、致色机理及结构差异,但对于如何直观分辨同种颜色珍珠的研究却很少.选用三批产自安徽不同时期的淡水养殖白色珍珠,对其进行色度学、激光拉曼光谱测试及宝石显微镜观察,建立白色系淡水养殖珍珠的白度值与拉曼光谱的关系并结合宝石显微镜的观察对其...     

Tactical level planning in float glass manufacturing with co-production,random yields and substitutable products

We investigate tactical level planning problems in float glass manufacturing. Float glass manufacturing is a process that has some unique properties such as uninterruptible production, random yields, partially controllable co-production compositions, complex relationships in sequencing of products, and substitutable products. Furthermore, changeover times and costs are very high, and production speed depends significantly on the product mix. These characteristics render measurement and management of the production capacity difficult. The motivation for this study is a real life problem faced at Trakya Cam in Turkey. Trakya Cam has multiple geographically separated production facilities. Since transportation of glass is expensive, logistics costs are high. In this paper, we consider multi-site aggregate planning, and color campaign duration and product mix planning. We develop a decision support system based on several mixed integer linear programming models in which production and transportation decisions are made simultaneously. The system has been fully implemented, and has been in use at Trakya Cam since 2005.     

淡水和海水养殖珍珠的微量元素特征

珍珠中的微量元素有其特征规律及作用。前人很早就关注到淡水珍珠和海水珍珠微量元素特征的差异,但限于测试技术及分析方法,测出的微量元素种类相当有限,并且对测试结果也缺乏深入分析。电感耦合等离子体质谱议(ICP-MS)具有检测能力高, 速度快,可同时测试多种痕量及超痕量元素。采用ICP-MS对淡水和海水养殖珍珠的微量元素进行测定,并通过数据处理方法分析, 对比。结果表明：(1) 珍珠中含量较高的微量元素种类(Sr, Zn, Ni, Ba, Mn, Cr, Cu, Pb, Ti, Co, Ce, Zr, La, Rb)大致相同,但淡水养殖珍珠的微量元素总量明显少于海水养殖珍珠;(2) 淡水养殖珍珠的微量元素含量较为规律,具有较为固定的含量序列,即Sr>Mn>Ba>Ni>Cr>Pb;而海水养殖珍珠的微量元素含量差异较大,除了各样品都最富集Sr元素外,没有明显的含量顺序;(3) 珍珠中某些微量元素之间存在显著相关性。结论对养殖珍珠的环境指示, 养殖技术, 鉴定,以及综合开发利用具有一定的指导意义。     

Micro‐Raman spectroscopy of pigments contained in different calcium carbonate polymorphs from freshwater cultured pearls

The metastable calcium carbonate polymorph vaterite has recently been found to occur commonly in freshwater cultured pearls from Japan and China. Organic pigment molecules in these vaterite regions of freshwater cultured pearls were analysed by resonance and near‐resonance micro‐Raman spectroscopy, in single spectra and in mapping modes and are compared with their aragonitic counterparts. Four different excitation wavelengths (487.9, 514.5, 532.2 and 632.8 nm) were used, resulting in differential increase of resolution for the pigments. Although vaterite areas were always lightly coloured (light yellow, light brown or white), ten different pigments were identified and a single colour is formed by a combination of three and up to nine polyenes of different lengths. The molecules were identified as unmethylated polyenes with effective chain lengths between 8 and 12 conjugated double bonds and FWHMs of 10 ± 2 cm⁻¹. Additionally, and for the first time in pearls, methylated polyenes were detected together with unmethylated pigments in aragonite. Polyenes with chain lengths shorter than 8 or longer than 12 were not found in vaterite, whereas both shorter and longer pigment chains were observed in aragonite from the same pearls. Pigments have lower concentrations in vaterite and are distributed more homogeneously, while they have higher concentrations in aragonite and are arranged along the annual growth lines of the pearls. Copyright © 2008 John Wiley & Sons, Ltd.