Corrosion behavior of under‐, peak‐, and over‐aged 6063 alloy: A comparative study

The mechanical property of age‐hardenable Al‐alloys is governed by the state of ageing, which determines the microstructure and consequently, their corrosion behavior which is a vital aspect for a number of applications. This article presents a comparative assessment of corrosion behavior of under‐, peak‐ and over‐aged Al‐Mg‐Si alloy. Corrosion characteristics have been determined via immersion tests in 0.1 M ortho‐phosphoric acid solution and intergranular corrosion (IGC) tests. Corroded surfaces are examined by field emission scanning electron micrographs‐energy dispersive spectroscopy and 3D optical profilometer. The obtained results reveal that the corrosion rate at a specific immersion time as well as the depth of IGC increases in the order for under‐, peak‐, and over‐aged states. Irrespective of the state of ageing, corrosion loss increases linearly but the rate of corrosion decreases rapidly with increasing immersion time. The dominant mode of corrosion in under‐aged alloy is identified as localized pitting, while peak‐aged is highly susceptible to IGC in contrast extensive pitting corrosion is observed for over‐aged alloy. The observed differences in corrosion behavior are explained considering characteristics of precipitates. Formation of β (Mg₂Si) in case of over‐aged alloy and presence of inclusions like AlFeMnSi particles are found to accelerate pitting corrosion.     

国有科研单位人才流失原因分析及对策

近年来,国有科研单位,尤其是地处经济不发达地区的国有科研单位,出现了较为严重的人才流失现象,一定程度上影响和制约了国有科研单位的发展。通过对国有科研单位人才流失原因的分析,提出了相应的对策。     

Housing Tenure: Pacific Families in New Zealand

Home ownership has been associated with health, social and economic benefits. However, a decline in ownership has been observed over the past decade in New Zealand. Minority groups, including Pacific people, have been disadvantaged in the housing sector. This study investigated housing tenure and the relationship between tenure and health among mothers of a birth cohort of Pacific children in New Zealand. Findings showed that most families lived in state or private rental accommodation with few (15.4 per cent) owning their own homes. Homeowners were more likely to be older, partnered and have higher incomes. Better mental health was observed for homeowners compared to renters. Findings can inform housing and public health policy for Pacific families.     

知识管理研究

通过对知识管理内容、过程、人和技术等方面的研究，提出今后知识管理研究在这些方面的重点。     

论老年教育的地位、作用和发展方向

老年教育在社会中具有重要的地位和作用。它是终身教育的重要组成部分,是社会发展的客观需要,是解决老龄问题的重要途径和方法。探讨了随着社会经济的发展和老龄化社会进程的加快,在21世纪老年教育的发展方向。     

老年人紧急呼救产品设计要素分析

中国已进入老龄化社会,老龄人口基数庞大,老年人问题已然成为社会的焦点。而我国目前社会基础设施、医疗配套设施、社会福利养老保障设施等都不完善,老年产品比较缺乏。尤其是随着经济的发展和人口的流动,空巢老人已成为社会不可忽视的一类群体,紧急呼救产品将会成为一种必需品。本课题通过对老年人紧急呼救产品设计要素进行详细的分析,从而对产品的开发起到一定的帮助和指导作用,为老年人的养老贡献一点力量。     

纳米材料在涂料中的应用

简述了纳米微粒的基本性质，介绍了几种典型的功能纳米材料在涂料中的应用．并探究其对涂料的改性原理．对应用中存在的问题进行了剖析。     

基于改进Hough变换的电梯轿厢内人数统计算法

考虑电梯轿厢内人数的电梯群控调度算法,可以在有限的时间内,找到更优解,对电梯的调度具有重要意义。针对目前基于视觉的人数统计算法正确率不够稳定,速度较慢的问题,提出了一种基于改进Hough变换检测人头轮廓的电梯轿厢内人数统计算法。该算法将标准Hough变换检测圆时的三维空间转换为一维空间,利用圆的几何特性遍历图像数据,通过一维Hough变换进行半径累积,并和阈值进行比较来确定人头轮廓的半径和圆心。结果表明,和用Hough变换检测人头轮廓的传统方法相比,该算法具有速度快,正确率高,抗噪性能好等优点。     

论蒙古族传统马具设计的系统性

文章以作者亲身参与的编著项目及田野考察为契机,将蒙古族传统马具设计作为研究对象,以蒙古族传统马具设计的系统性为论点,探讨其系统构成、单元功能及三个子系统的分工与关联。