Formation of a protective layer against corrosion on Mg alloy via alkali pretreatment followed by vanillic acid treatment

Although Mg alloy possesses high specific strength, low density, and good biocompatibility, poor corrosion resistance hinders its further applications. In the present study, an innovative protective layer against corrosion was prepared on the AZ31 Mg alloy via alkali pretreatment followed by vanillic acid treatment. The alkali pretreatment supplied –OH for the AZ31 Mg alloy surface to react with vanillic acid. The vanillic acid treatment played a crucial role in enhancing the corrosion resistance due to the excellent ability to act as a barrier and retard aqueous solution penetration, which effectively isolated the underlying Mg alloy from the corrosive environment. The corrosion current density of alkali and vanillic acid-treated Mg alloy (AZ31V) almost showed two orders of magnitude lower values in comparison with that of the AZ31 Mg alloy, and the corrosion potential of AZ31V Mg alloy increased from −1.41 to −1.25 V. The immersion tests proved that there was no occurrence of severe corrosion. Hence, the alkali pretreatment and vanillic acid treatment may represent a promising method to improve the corrosion resistance of Mg alloy.     

Tensor Q-rank: new data dependent definition of tensor rank

Machine Learning - Recently, the $${ Tensor}~{ Nuclear}~{ Norm}~{ (TNN)}$$ regularization based on t-SVD has been widely used in various low tubal-rank tensor recovery tasks. However, these models...     

Transformation of the reabsorption characteristics of lignite treated by low and high temperature drying process

Abstract

The reabsorption characteristics of the lignite treated by low and high temperature drying process were addressed in the paper. The information about the moisture form, functional groups, effective water-filled porosities and equilibrium moisture content of the lignite before and after the drying process was investigated using Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and a self-made reabsorption device, respectively. The results show that the low drying temperature (140, 190, 230?°C, 10?min, N₂) has little impact on the effective water-filled porosities of the resulted samples, whereas it has a great influence on the main oxygen-containing functional groups, which amount firstly decreases and then increases with the drying temperature increasing. In the case of the lignite samples dried under high-temperature (600, 700, 800?°C, 30?s, N₂), the amount of the effective water-filled porosity of the sample decreases and the amount of oxygen-containing functional groups increases as the temperature increasing. The reabsorption capability of the high temperature dried sample is much lower than that of the sample treated under low drying temperature. The reabsorption characteristics of the low-temperature dried samples are affected by the amount of the oxygen-containing functional groups, while the effective water-filled porosity is main factor for the lignite samples derived from high temperature drying process. Moreover, the work gives a good evidence that the high-temperature drying process is an effective choose for lignite upgrading.     

基于ASP.NET技术的新闻发布系统的设计与实现

完整描述了一种在部队师旅级单位通用的新闻发布系统。首先根据用户的特点,对系统进行了需求分析与功能模块划分,然后在此基础上从系统架构、系统流程和数据库设计等3个方面阐述了系统设计中的关键点,并以设计用户登录界面为例写出了部分功能的实现程序,最后对其在中小型企业建站中的应用进行了展望。     

基于加速度计的坐标系匹配方法研究

为了提高加速度计应用中坐标系的匹配精度,提出了基于加速度计的坐标系匹配方法,介绍了其基本原理,并对加速度计的测角方法进行了深入研究.试验结果表明:该方法测量最大误差≤0.3°,满足实际应用要求,有效地解决了加速度计应用中的坐标系匹配问题.     

BaTiO3基Au纳米颗粒复合薄膜的制备及其光学性质研究

采用溶胶-凝胶（sol-gel）方法，成功的将高体积面分比的Au纳米颗粒复合到BaTiO3的非晶薄膜中，并对其光学性质进行了研究。用XRD、TEM、椭偏仪、吸收光谱、光克尔效应OKE（Optical Kerr Effcet）方法对薄膜进行了表征和测试。从吸收光谱观察到表面等离子体共振SPR（Surface Plasma Resonance)峰随热处理温度升高而红移的现象。光学非线性测试表明薄膜具有高的三阶非线性极化率Χ^(3)和超快的响应时间。     

低阻VDMOSFET的优化设计与制造

文章对9926型双N沟增强型VDMOSFET进行了结构和版图的优化设计。给出了该器件的纵横向结构参数,材料的物理参数和版图总体结构。单胞结构的优化设计使单胞密度达到204万个/cm2,比国际市场现有产品的单胞密度(156万个/cm2)提高了30%。这种设计采用浅n+注入工艺可使器件生产成本下降31%。最后对研制结果进行了分析讨论。     

催化裂化装置沉降器内结焦物的基本特性分析及其形成过程的探讨

采用扫描电镜（SEM）和X射线能谱分析仪对催化裂化装置（FCCU）沉降器内结焦物的微观组织结构和成分进行了分析，将结焦物划分为软焦和硬焦。焦的硬度与油气液滴和催化剂颗粒的沉积过程有关，尤其是结焦部位的油气流动方式和催化剂颗粒的运动状态，决定着未汽化的重质油组分液滴和催化剂颗粒的沉积形式和沉积物的构成，从而影响着焦的软硬程度。软焦是催化剂颗粒或油气在油气静止空间以自由沉降和扩散方式堆积在器壁表面而产生的结焦，形成的焦块松散，易粉碎，含催化剂比较多，颗粒粒径比较大，是一种堆积型结焦；而硬焦是油气液滴和细小催化剂颗粒在油气流动状态下，在器壁表面的附面层内以沉积方式粘附在器壁表面形成的结焦，焦块质地坚硬，含催化剂比较少。颗粒粒径细小，足沉积型结焦。还有相当一部分结焦物介于软焦和硬焦之间。