酸性光亮电镀锡铈合金工艺的研究

采用赫尔槽试验研究了镀液中各种成分的作用及工艺条件,用扫描电镜(SEM)观察了镀层形貌。研究发现,在酸性光亮镀锡镀液中添加铈盐和自制的光亮剂,可获得一种铈含量达0.5%的锡铈合金镀层,该镀层外观光亮、平整。通过镀层性能测试,并与纯锡镀层性能进行比较,发现:当镀层厚度大于5μm时,锡铈合金镀层表面致密均匀,结晶细致光亮;其抗氧化性、耐蚀性、防变色性能及可焊性明显优于纯锡镀层,解决了纯锡镀层在焊锡时易发生变色,提高了焊接温度。     

SiO_2气凝胶/Sn复合负极材料的制备及电化学行为

以工业水玻璃为硅源,采用溶胶-凝胶法制备了Si O2气凝胶;以Sn Cl2为Sn源,采用水热合成法制备了Si O2气凝胶/Sn复合负极材料。采用X射线衍射(XRD)、扫描电子显微镜(SEM)对材料的结构和形貌进行了表征,采用恒电流充放电测试了材料的电化学性能。结果表明Si O2气凝胶/Sn复合材料为三维多孔网络结构,金属Sn颗粒均匀地钉扎在Si O2气凝胶表面,该结构不仅可以改善颗粒的团聚性能,还可以大大缓解在充放电过程中的体积膨胀。电化学性能测试结果表明,在100 m A/g的电流密度下,复合材料首次可逆比容量可达472.93 m Ah/g,首次充放电效率86.19%。30次循环后可逆比容量仍可维持在417.70 m Ah/g,容量保持率76.13%,充放电效率接近100%,具有较好的电化学性能。     

工艺参数对高速镀锡电流效率及镀锡层表面形貌的影响

采用自制旋转阴极装置模拟带钢的高速运动,并研究了电流密度、阴极转速及Sn~(2+)的质量浓度对甲基磺酸盐高速镀锡电流效率和镀锡层表面形貌的影响。结果表明:提高阴极转速和Sn~(2+)的质量浓度及降低外电流密度,可以提高电流效率;提高阴极转速和降低外电流密度,有利于镀锡层形成多晶态的形貌。电流效率与镀锡层结晶状态有良好的对应关系,电流效率越高,结晶越细致。另外,增大阴极转速能减小扩散层厚度,提高电流密度上限和电流效率,降低Sn2+的质量浓度下限,从而提高生产效率并降低生产成本。     

云南个旧锡多金属矿成矿演化与成矿模式

个旧锡多金属矿区处于多个深大断裂和丁字型裂谷交汇部位，燕山期花岗岩穿切三个大的含锡铜多金属高背景地层。成矿期矿化体上部帽状泥质地层为遮挡层。矿床具有明显的矿物、元素分带。根据已知成矿模式，可成功预测数百米乃至千米埋深的矿体空间分布和储藏远景     

Improving the ethanol sensing of ZnO nano-particle thin films—The correlation between the grain size and the sensing mechanism

ZnO and Sn doped ZnO (ZnO:Sn) thin films at various doping concentrations from 1 to 10 at.% were prepared by the sol-gel method for an ethanol sensing application. The Sn doping significantly influenced the film growth, grain size and response of the films. The XRD patterns showed that the hexagonal wurtzite structure of the ZnO film was retained even after the Sn doping. The crystallite grain sizes of the ZnO:Sn thin films at 0, 2 and 4 at.% were estimated by using the typical Scherrer's equation. The crystalline quality of the films at 6, 8 and 10 at.% of Sn was degenerated. Typical FESEM images demonstrated the different morphologies for the ZnO:Sn thin films at various Sn concentrations; many pores of various dimensions were observed depending on the doping level. A TEM analysis of the ZnO:Sn thin films at 0, 2 and 4 at.% was performed to verify the grain size. The optimum Sn doping level of ZnO:Sn thin film for ethanol sensing was estimated to be 4 at.%. The 4 at.% sample obtained the highest response to ethanol vapor in the 10-400 ppm level range at a low operating temperature of 250 °C. The sensing mechanism was explained by a variation in the sensitivity model from a neck-grain-boundary controlled sensitivity to a neck-controlled sensitivity. Our work demonstrates the ability to reduce the working temperature as well as to increase the response of ZnO thin film based gas sensors to detect ethanol, which would be of great merit for commercialized applications.     

Highly Efficient Sn/Pb Binary Perovskite Solar Cell via Precursor Engineering: A Two‐Step Fabrication Process

Regulation of the crystallization of perovskite films and avoiding the oxidation of Sn²⁺ during the deposition process are very important for achieving Sn/Pb binary perovskite solar cells (PVSCs) with high power conversion efficiency (PCE) and producibility. In this work, a high‐quality HC(NH₂)₂Pb_0.7Sn_0.3I₃ (FAPb_0.7Sn_0.3I₃) film deposited from the two‐step solution process by introducing methylammonium thiocyanate (MASCN) as a bifunctional additive into the precursor solution containing PbI₂ and SnI₂ is reported. MASCN can not only tune the morphology of the perovskite film but also stabilize the precursor solution via retarding the oxidation of Sn²⁺ through a strong coordination between SCN^? and Sn²⁺. The Sn/Pb binary inverted PVSCs based on FAPb_0.7Sn_0.3I₃ present a high fill factor of 0.79 and the best PCE of 16.26% in the case of 0.25 MASCN addition. The device fabrication producibility is also greatly improved due to the stabilized precursor solution with the aid of MASCN. The PCE of the device is almost independent of the storage time of the precursor solution within 124 d in the N₂‐filled glove box. These results indicate that the precursor engineering with multifunctionality additive is an effective approach toward highly efficient and producible PVSCs for future commercialization.     

Experimental investigations and thermodynamic modelling of the Cr–Nb–Sn–Zr system

This work reports the Calphad modelling of the Cr–Nb–Sn–Zr quaternary system. In a previous paper, the thermodynamic modelling of the Cr–Nb–Sn system was presented. Since no experimental data were available for the Cr–Sn–Zr ternary system, new experimental data are provided, within this study, on the isothermal section at 900 °C. A ternary C14 phase has been identified on the Sn-poor side of the phase diagram. In addition to these experimental data, Density Functional Theory (DFT) calculations are carried out in order to determine formation enthalpies of the stable and metastable compounds. At last, the Special Quasirandom Structures (SQS) method is jointly used with DFT calculations in order to estimate the mixing enthalpies of the A2 and A3 binary solid solutions. Finally, these experimental and calculated data in addition to those from the literature, are used as input data for the Calphad modelling of the Cr–Zr, Nb–Zr and Sn–Zr binary systems and the Cr–Nb–Zr, Cr–Sn–Zr and Nb–Sn–Zr ternary systems. A complete database for the Cr–Nb–Sn–Zr quaternary system is provided.     

Design and experiment of optical transparent microstrip antenna on glass and polycarbonate substrates

Microstrip antennas have the advantages of light weight, low profile, and conformal to the attached surface with antenna feed line. This work presents the design of transparent microstrip antennas by In₂O₃:Sn thin film on glass and polycarbonate substrates. The transparent conducting thin films of 21–300 nm thickness deposited by magnetron sputtering are measured by X‐ray diffraction for microstructure, 4‐point probe for electrical resistance, and spectrometer for optical transmittance. Analyses show that the 2.4 GHz antenna can achieve 5.1 and 4.7 dB antenna gain on glass (1.2 mm) and polycarbonate (0.7 mm) substrate, respectively. Experimental verification on glass substrate shows that the antenna achieves 3.1 dB gain and 86% optical transmittance on 550 nm wave length.     

多群粒子输运问题在多核集群系统上的混合并行计算

本文分析了非结构网格多群粒子输运Sn方程求解的并行性,拟合多核机群系统的特点,设计了MPI/OpenMP混合程序,针对空间网格点采用区域分解划分,计算结点间基于消息传递MPI编程,每个MPI计算进程在计算过程中碰到关于能群的计算,就生成多个OpenMP线程,计算结点内针对能群进行多线程并行计算。数值测试结果表明,非结构网格上的粒子输运问题的混合并行计算能较好地匹配多核机群系统的硬件结构,具有良好的可扩展性,可以扩展到1024个CPU核。