高频红外碳硫仪用瓷坩埚的重复使用及助熔剂加入量研究

高频红外碳硫分析仪应用于分析生铁中硫、硅锰合金及锰铁合金中硫时,具有操作简便、快速、分析结果准确等特点[1]。但坩埚和钨粒、锡粒、纯铁助熔剂消耗大,分析成本较高。根据红外碳硫分析仪分析试样后的氧化渣有助熔的特效,我公司化验室进行了瓷坩埚重复使用及减少助熔剂加入量的试验工作,通过试验分析,证明用于分析生铁或钢样中硫的瓷坩埚在一定条件下可以重复使用3次,节省钨及锡助熔剂约40%,提高了分析质量,同时也大大减少了固体废弃物的污染。     

三月桂酸单丁基锡作PVC热稳定剂的研究

用刚果红试纸测试加入三月桂酸单丁基锡的PVC的静态热稳定性,用流变仪测试其动态热稳定性。与PVC二月桂酸二丁基锡比较,加入三月桂酸单丁基锡的PVC的脱HCl温度大致一样,初期热稳定更好,而长期热稳定性较差;三月桂酸单丁基锡与硬脂酸钙复配比例为4：1、与硬脂酸钡复配比例为7：3、与环氧大豆油复配比例为2：5,协同效应最好。     

Tin-nitrogen/carbon for superior oxygen reduction reaction at fuel cell cathode

This work reports on the synthesis of tin-nitrogen/carbon (Sn–N/C) catalysts suitable for the electroreduction of molecular oxygen at the cathode of proton exchange membrane fuel cells. The catalysts were synthesized through a simple pyrolysis process of folic acid as the carbon and nitrogen source, tin chloride as a tin source and Vulcan carbon as the substrate. The synthesized catalyst exhibited excellent oxygen reduction activity with a half wave potential of 0.82 V and a mass activity of 15.5 mA mg⁻¹. Successful application at the cathode of a self-breathing fuel cell further confirmed the superior performance of this catalyst leading to a power density of 29.4 mW cm⁻². This is very comparable to the reference platinum/Vulcan carbon catalyst (28.4 mW cm⁻²). In addition, this Sn–N/C catalyst showed good stability under accelerated stress tests with only a 12% decrease in fuel cell performance after 10,000 cycles. The superior performance was assumed to be due to the presence of both metal-nitrogen and nitrogen-carbon active sites, which facilitate the four-electron path of the oxygen reduction reaction.     

云南省东南部新寨锡矿床矿化趋势面分析

本文系统收集整理了云南省东南部新寨锡矿资源勘查过程中形成的85个探矿工程编录资料，建立了三维空间数据库，对具有空间属性的锡品位数据进行了基本统计分析和矿化趋势分析，并绘制了矿化等值线图和矿化趋势图，认为新寨矿区矿化富集带走向与矿化趋势等值线走向均与地层走向方向一致，显示出赋矿地层对锡的富集具有明显的控制作用；矿区南东浅部矿化富集带较北西深部矿化富集带锡矿化强度高，总体矿化趋势北西低南东高，结合地质背景推测矿区发育的向斜挠曲构造影响了锡的富集，远离向斜轴部锡品位有增强趋势。     

Electrospun Sn-doped TiO2: Synthesis,structural, optical and catalytic performance as a function of Sn loading and calcination temperatures

A series of tin (Sn)-doped titania (TiO₂) composites were prepared by electrospinning and then calcined at temperatures of 500 °C, 600 °C, and 700 °C. The morpho-structural and optical properties of the resulting composites were assesed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. In this way, the effect of the dopant amounts and calcination temperatures on the composition, morphology, band gap energy (E_g) of the prepared composites was established, as well as their photocatalytic activity towards ciprofloxacin (CIP) photodegradation. The kinetics of ciprofloxacin photodecomposition reactions was analyzed. Herein, it is reported that the nanostructured material based on ([1.5%]Sn:TiO₂) sintered at 500 °C shows a remarkable photocatalytic activity with a removal efficiency of about 100% and a rate constant of 9.685 × 10^?2 min^?1. The photocatalytic stability of this material was evaluated by reusability tests with five cycles under identical conditions for CIP photodegradation. In-depth structural investigations were undertaken to explain this remarkable photocatalytic activity towards water decontamination.     

Sn基无铅焊料的研究进展

随着世界各国“限铅令”的颁布，Sn基无铅焊料被广泛研究以代替传统Sn-Pb焊料。然而，近年来大规模集成电路及先进电子封装架构的发展对无铅焊料的性能提出了更高要求。本文介绍了Sn-Sb、Sn-Cu、Sn-Ag、Sn-Zn、Sn-Bi和Sn-In系等主要无铅焊料体系的最新研究进展，综述了添加合金元素、稀土元素以及纳米颗粒对焊料显微组织、润湿性能、力学性能、耐蚀性能和接头服役性能的影响。文章最后讨论了高性能无铅焊料的研发方向，提出了创新的研究理念及研究方法，为下一代钎焊材料的研发提供了参考。     

PC在电解镀锡生产工艺上的应用

本文概述我厂电解镀锡生产工艺流程,根据其工艺流程,由传统的继电——接触器改为可编程序控制器(下文简称PC)来实现对电解镀锡生产工艺自动控制,使镀层均匀、致密光亮、可焊性好,提高电镀质量.     

云锡公司某锡尾矿预抛及铁回收试验研究

云锡公司二次资源锡尾矿中有价元素品位较低,主要目的矿物钨、锡均达到“双零”级别,考虑到综合回收目的元素价值有限。需要先进行预抛和回收铁矿物,以降低粗粒级和铁矿物对后续作业的干扰,同时节约后续选别成本,对锡尾矿进行筛分预抛、弱磁选、强磁选试验研究。试验结果表明,当采用筛分粒径为0.150mm、磁滚筒磁场强度为0.12T；高梯度磁选机磁场强度0.4T、矿浆流量为12L/min、脉动冲次为200次/min、磁介质为3.0mm。最终可获得粗粒级抛除率12.64%,弱磁选Fe精矿品位54.83%、回收率4.83%,强磁选Fe精矿品位42.52%、回收率8.26%。     

Coaxial structured Bi2S3–SnS2-MWCNT hybrid nanocomposite with its improved thermoelectric properties

Bismuth(III) sulfide (Bi₂S₃), tin(IV) sulfide (SnS₂), and a multi-walled carbon nanotube (MWCNT) are prepared as a hybrid composites (Bi₂S₃–SnS₂-MWCNT) using a simple hydrothermal method. The as-prepared hybrid composite exhibit n-type thermoelectric (TE) characteristics and an enhanced power factor (PF) value. Bi₂S₃–SnS₂ composites are anchored to the surface of MWCNT and form a coaxial structure. The nanostructure formation through bonding between these different materials is confirmed via scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). The TE properties of the Bi₂S₃–SnS₂-MWCNT composite is improved by changing the Bi₂S₃, SnS₂ and MWCNT content. The maximum PF (∼150.8 μ·W/m·K²) was obtained for Bi₂S₃–SnS₂-MWCNT composite with Bi:Sn ratio of 7:3 and 2 wt% of CNT. The highest PF values were ∼34 and ∼58 times higher than the PF of Bi₂S₃ and SnS₂ at room temperature. The synthesized Bi₂S₃–SnS₂-MWCNT hybrid nanocomposite can provide important components for fabrication CNT-based TE composites with high conversion efficiency, further advancing TE device.     

Computer modeling of Young's modulus and thermal conductivity changes during sintering without shrinkage

Sintering without shrinkage can occur when non-densifying sinter mechanisms are dominating. In this case, properties change without changes in porosity, but the key question is, what are the microstructural parameters determining the properties. In order to answer this question, digital random microstructures with a porosity of 0.50 ± 0.16 are generated from monosized spherical particles that are allowed to overlap. It is shown that with increasing grain overlap one obtains an increase of the size of solid domains, the sinter neck and pore throat diameters, and relative properties (Young’s modulus and thermal conductivity, which are correlated by a power-law cross-property relation with exponent 1.493). Empirical fits are given for the relative properties as functions of different non-dimensional size ratios and the relative surface area. Since the latter is accessible from specific surface measurements via gas adsorption, it can be recommended when planar sections for quantitative image analysis are not available.