Effect of SnO2 intermediate layer on performance of Ti/SnO2/MnO2 electrode during electrolytic-manganese process

SnO₂ intermediate layers were coated on the titanium (Ti) substrate by thermal decomposition. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that uniform SnO₂ intermediate layers with rutile crystal structure were successfully achieved. According to the results of linear sweep voltammetry (LSV), oxygen evolution potential (OEP) of the Ti/SnO₂/MnO₂ electrodes decreases with increasing SnO₂ content, indicating that the electro-catalytic oxidation activity of the electrode increases. Accelerated service life tests results demonstrate that SnO₂ intermediate layer can improve the service life of the Ti/SnO₂/MnO₂ electrode. As the content of SnO₂ intermediate layer increases, the cell voltage and the energy consumption decrease apparently.     

Spectrally selective and adaptive surfaces for protection against radiative heating: ITO and VO2

Two surface materials for reducing absorptivity of heat radiation from fires have been investigated. The first is VO₂, which is a thermochromic material. When the temperature of a VO₂ surface increases over a certain temperature, it switches, ideally, from infrared (IR)‐absorbing to IR‐reflecting. VO₂ window coatings are still on a research level, yet to be commercialized. In this study, VO₂ powder available on the market was investigated. The thermochromic effect could be identified but was not large enough to significantly improve the fire properties of treated surfaces. Some thoughts concerning how to improve the performance of VO₂ are discussed. The second investigated material is indium tin oxide (ITO), which is a so called low‐e coating, which means that it has low emissivity and absorptivity in the IR part of the spectrum. ITO is spectrally selective in the sense that it transmits visible light while reflecting a large fraction of the IR radiation, which is a rare property for surfaces in general but a typical property of thin electrically conducting non‐metallic films. It is shown that the application of ITO to poly(methyl methacrylate) (PMMA) significantly improves its fire properties. ITO coating is a mature technology already in widespread use today in the electronics industry. Copyright © 2012 John Wiley & Sons, Ltd.     

Charge Transfer Variability in Misfit Layer Compounds: Comparison of SnS-SnS2 and LaS-TaS2

The present paper compares and discusses two selected misfit (layer) compounds exemplarily, namely SnS-SnS₂ and LaS-TaS₂. We have employed a density-functional theory-based approach to calculate structural, energetic, and electronic properties of these structures. We have put emphasis on the difference between single layers, combined double-layer systems and periodically stacked bulk structures. Especially the varying magnitudes of charge transfer between the sublayers were studied. We demonstrate how the chemical constitution of the sublayers affects the interlayer interactions: these may be a weak non-bonding van-der-Waals dominated interlayer interaction as in SnS-SnS₂ and many other layered structures or a strong interaction related to a remarkable charge transfer between the layers as in LaS-TaS₂.     

Synthesis of Co2SnO4@C core-shell nanostructures with reversible lithium storage

This paper reports the synthesis of Co₂SnO₄@C core-shell nanostructures through a simple glucose hydrothermal and subsequent carbonization approach. The as-synthesized Co₂SnO₄@C core-shell nanostructures have been applied as anode materials for lithium-ion batteries, which exhibit improved cyclic performance compared to pure Co₂SnO₄ nanocrystals. The carbon matrix has good volume buffering effect and high electronic conductivity, which may be responsible for the improved cyclic performance.     

观察裂纹路径及组织演变的SEM样品制备方法研究

本试验利用SEM和电阻炉研究一种SEM样品的制备方法,用于观察裂纹路径,并分析断裂后的显微组织变化。结果表明:通过浸镀焊锡,能够在不同断裂方式形成的裂纹轨迹上形成一条明显的"纯锡带",呈现出裂纹路径。同时该方法能够观察分析拉伸、冲击、断裂韧性及疲劳断裂等过程中产生的二次裂纹路径及断裂表层下的组织演变。     

Enhanced boron removal from metallurgical grade silicon by the slag refining method with the addition of tin

An effective boron removal method was developed through a process of combining Si–Sn alloy with slag treatment. Boron content in refined silicon and boron removal fraction by slag containing 5 wt% CaO, 25 wt% SiO₂ and 70 wt% Na₂SiO₃ and was investigated under varied Si–Sn alloy composition, slag/Si–Sn alloy mass ratio and refining time. Boron was effectively removed by adding tin to metallurgical grade silicon. In particular, the boron content in metallurgical grade silicon decreased from 12.92 ppmw to 0.79 ppmw by adding 50 at% tin under a mass ratio of 2:1 (slag:alloy) at 1723 K. The amount of boron removed increased with increasing amount of tin added, mass ratio and refining time.     

电镀层状锡工艺的研究

采用电沉积方法在酸性体系下制得具有层状结构的镀锡层。研究了主盐、明胶、HIT-905添加剂及电流密度对镀锡层外观的影响,确定了较优的镀液组成及工艺条件。在优化工艺下得到了具有明显层状结构的镀锡层。     

热扩散对镀锡银钎料界面组织及熔化特性的影响

对带锡镀覆层的银钎料进行热扩散处理,采用差示扫描量热仪(DSC)、扫描电镜(SEM)、X射线衍射仪(XRD)研究热扩散工艺对其熔化温度和扩散界面组织、物相的影响. 结果表明,在扩散时间一定条件下,随着扩散温度升高,扩散界面层厚度增加;随着扩散温度升高或扩散时间延长,钎料的固、液相线温度均降低,熔化温度区间缩小;扩散界面层物相主要由棒状Ag₃Sn相和块状Cu₃Sn相组成;最佳热扩散工艺为220 ℃,24 h. 经最佳工艺处理后,扩散界面层厚度为9.1 μm,钎料中Sn含量为7.2%,此时钎料熔化温度区间为642.34 ℃~676.37 ℃. 与传统熔炼合金化方法相比,钎料中Sn含量提高近31%.     

广西大厂锡矿田100号矿体成矿模型的建立

为了在广西大厂周围找到类似100号矿体的矿床,作者对100号矿体的控矿构造,与花岗岩和生物礁的关系,矿石的铅、硫、氢、氧、氦同位素,稀土元素和成矿温度进行了分析。结果表明,100号矿体是含矿有机流体溶蚀交代礁核骨架灰岩微相而形成的矿床,同时建立了成矿模型。