杂质对金属锂电解过程的影响

以50%KCl-50%LiCl体系为熔盐电解质体系,研究杂质包括NaCl、CaCl_2、MgCl_2、FeCl_3、Li_2SO_4在420℃下对电解过程的影响。结果表明:NaCl、CaCl_2、MgCl_2优先于金属锂在阴极析出钠、镁、钙,进入金属锂产品中,同时引起金属锂聚集性变差,降低电流效率和锂收率;FeCl_3在阴极上析出海绵铁形成钝化膜,影响电解过程;Li_2SO_4在阴极上与金属锂发生氧化还原反应,消耗金属锂生成Li_2O和Li_2S,降低电流效率和锂收率。     

基于异构宏模型的MEMS系统级建模方法

针对含复杂结构的MEMS器件,提出基于异构宏模型的系统级建模方法,即将基于解析法和基于数值计算的宏建模方法结合起来提取复杂器件的参数化宏模型,在此基础上实现MEMS系统级仿真。以z轴加速度计为例,在Saber中进行其系统级的时域、频域仿真,将仿真结果与有限元分析进行了比较,其仿真时间小于3min,相对误差小于3%,表明该方法能够快速有效地实现复杂结构MEMS器件的系统级仿真。     

一次成形现浇大面积混凝土耐磨楼面施工技术

文章主要就现浇大面积混凝土耐磨楼面一次成形工艺在实际工程中的应用作了简要阐述,并对其技术优点和经济效益进行了总结。     

建筑与书法

建筑与书法有许多相似和相通之处。本文从汉字的产生、造型、结构入手,从艺术的抽象性等诸多方面对书法与建筑进行了比较,从传统文化的角度阐述了它们的联系,并由此进一步说明了建筑的特征与本质。     

Microfluidic direct methanol fuel cell by electrophoretic deposition of platinum/carbon nanotubes on electrode surface

Carbon nanotubes (CNTs) supported platinum (Pt) nanoparticles prepared via electrophoretic deposition are used as catalyst layer of a microfluidic direct methanol fuel cell (DMFC), to study the influence of catalyst layer materials and deposition methods on the cell performance. A Y‐shaped channel is designed and microfabricated. It is verified by cyclic voltammetric measurements that shows ca. 317.7% increase in the electrochemical active surface area for the electrode with CNTs over that without CNT. Scanning electron microscopy observations indicate the network formation within the electrode because of a 3‐D structure of CNTs, which could be beneficial to the increasing electrode kinetics and to the improvement in fuel utilization. Comparison between the DMFCs with and without CNTs as support shows that the proof‐of‐concept microfluidic DMFC with Pt/CNTs electrode is able to reach a maximum power density of 5.70 mW cm^?2 at 25 °C, while the DMFC with plain Pt electrode only has a maximum power density of 2.75 mW cm^?2. Copyright © 2015 John Wiley & Sons, Ltd.     

The dependence of shear modulus on dynamic relaxation and evolution of local structural heterogeneity in a metallic glass

Starting from the nanoscale structural heterogeneities intrinsic to metallic glasses (MGs), here we show that there are two concurrent contributions to their microscale quasi-static shear modulus G_I: one (μ) is related to the atomic bonding strength of solid-like regions and the other (G_II) to the change in the possible configurations of liquid-like regions (dynamic relaxation). Through carefully designed high-rate nanoscale indentation tests, a simple constitutive relation (μ = G_I + G_II) is experimentally verified. On a fundamental level, our current work provides a structure–property correlation that may be applicable to a wide range of glassy materials.     

邢钢套筒窑生产不锈钢AOD炉用灰实践

邢钢不锈钢AOD炉用灰对冶金灰的灼减、CaO等指标均提出了新的、更高的要求。邢钢在无任何经验可以借鉴的情况下,为了更好地满足不锈钢用户需求,进行了一系列"不锈钢AOD炉用灰生产试验",积累了大量宝贵的原始数据和实践经验,为今后向不锈钢生产提供更优质的产品和服务奠定了扎实的基础,同时提出了试验中的注意事项。     

Cladding and characteristics of LiNbO3 single crystal fibre

Abstract

A magnesium ion indiffusion process is applied to LiNbO₃ single crystal fibres deposited with MgO thin film on their surface. A core–cladding waveguide structure with different refractive index profile is formed in LiNbO₃ single crystal fibres by selecting suitable diffusion parameters such as diffusion temperature, diffusion time and MgO film thickness. An electron probe microanalysis was used to measure the Mg-ion concentration distribution of the Mg diffused layer. The propagation loss of the clad crystal fibre (Mg-diffused crystal fibre) is measured to be 14 times lower than that of the unclad crystal fibre and the transmission modes were observed. The microstructural characteristics of the Mg diffused crystal fibres were also characterized by using Laue X-ray diffraction and scanning electron microscopy. It was shown that a good starting single crystal of the Mg diffused crystal fibres can be preserved by controlling suitable diffusion parameters and matching suitable crystal fibre diameter.