激光退火对化学镀Ni-W-P镀层硬度的影响

本文主要研究激光退火对镀层硬度的影响.采用Jade软件对镀层中的晶化程度、晶粒尺寸及微应变进行定量分析,利用维氏显微硬度计测量镀层的硬度.结果表明随激光扫描速度的减小,镀层晶化程度增加、Ni和Ni3P相的晶粒尺寸增大、Ni相含量变化不大,非晶相减少,Ni3P相增多、而微应变逐渐减小.实验结果显示镀态镀层的硬度最低,硬度随激光速度的减小而增加,主要是各相晶化程度、晶粒尺寸及微应变三者相互作用的结果.     

激光熔覆铁基合金涂层在液压油缸内壁中的研究

利用内孔激光熔覆技术在液压油缸内表面制备铁基合金涂层,利用单因素试验法研究各工艺参数对于熔覆层形貌特征的影响规律。利用扫描电镜分析内孔熔覆层的微观组织结构,并对其硬度性能进行测试,结果发现熔覆层无缺陷,性能优异,在一定程度上提升油缸的综合性能,从而延长其使用寿命。     

汽车尾气净化器中活性氧化铝涂层性能改进综述

介绍了汽车尾气净化器中活性氧化铝涂层的基本概况,简述了制备活性氧化铝涂层的不同方法的改进效果,表明溶胶-凝胶法制备出的活性氧化铝比表面积较大且杂质很少,但其在工业化进程中需要进一步优化加水量、溶剂种类、pH值、陈化时间等影响因素的工艺条件;在分析添加剂对活性氧化铝涂层性能改善机理的基础上,综述并比较了稀土元素、碱土金属、SiO_2及其他添加剂对涂层性能的影响效果,可知在活性氧化铝涂层中引入添加剂可以增加涂层的比表面积、抑制活性氧化铝的晶型转变、提高涂层的高温稳定性能,指出同时添加La,Ba可以使活性氧化铝得到更好的热稳定性。因此,溶胶-凝胶法和同时掺杂La,Ba是活性氧化铝涂层性能改善研究的发展方向。     

探究焊接热循环对X120管线钢组织和性能的影响

在热模拟试验技术的协助下,解析焊接热循环对X120管线钢的组织与性能产生的影响。研究结果表明,在X120管线钢的焊接热影响区中存在粗晶区和两相临界区两个脆化区,前者伴随焊接热量的传入量的增加,脆性程度有弱化趋势。     

硫酸法制备高白度蓝相钛白粉

文章采用锌盐、钾盐和磷盐三种盐处理剂同时对水解偏钛酸进行盐处理,考察了不同盐处理剂对钛白粉的影响,再经过氧化铝表面包覆处理,提升钛白粉分散性和颜料性能,制备硫酸法金红石型钛白粉成品。对钛白粉产品晶型结构、表面形态及粒径进行分析表征,并与市售国内外硫酸法金红石型钛白粉对比分析,结果表明制备的钛白粉高白度、蓝底相,颜料性能优异,可以应用于生产。     

氧乙炔喷涂层性能的检测技术

氧乙炔焰喷涂层性能检测内容包括涂层与基体表面的结合强度、涂层本身的粘结强度、涂层的孔隙度、涂层的硬度、涂层金相组织、涂层的环境试验等。参考国内外有关资料和文献,我单位在推广应用氧乙炔焰喷涂技术的过程中,对涂层主要性能的检测进行了一些探索和实践,写出来供同行参考。 一、涂层与基体表面的结合强度试验     

钼酸铋薄膜的化学溶液制备技术及其性能表征

使用化学溶液制备技术在硅衬底上制备出符合化学计量比的钼酸铋薄膜.采用X射线衍射分析的研究结果表明,所制备的薄膜具有单一的单斜晶相结构;利用原子力显微镜(AFM)对其表面形貌进行表征,验证了实验过程中溶剂的改变对薄膜结构和表面形貌产生的影响;使用荧光发射仪研究了薄膜在室温下的发光特性.结果表明,通过化学溶液制备技术可以制备出具有单一晶相的钼酸铋薄膜,该薄膜具有良好的光致发光特性.     

以Mo/Al/B2O3/金刚石粉体热爆反应体系在金刚石颗粒表面形成镀覆涂层

以Mo/Al/B₂O₃/金刚石粉体为热爆反应体系,在金刚石颗粒表面形成镀覆涂层,采用X射线衍射(XRD)研究热爆反应产物和金刚石颗粒的物相组成,采用扫描电镜(SEM)观察金刚石颗粒表面的显微形貌。研究发现：热爆反应产物易于粉碎,易于将金刚石颗粒与结合剂分离;随着金刚石含量的增加,试样膨胀逐渐加剧,在高纯Ar气保护下,基体会形成以MoAlB为主相的材料;热爆反应会在金刚石表面形成由Al、Mo₂C、Al₂O₃和AlMo₃组成的多元涂层,涂层由大量平均粒径为2 μm的晶粒组成。总体而言,当金刚石含量较低(10%和20%)时,产物中金刚石颗粒表面镀覆良好。     

实验优化激光淬火工艺参数研究

激光淬火工艺是一种新型的热处理加工工艺。为了提高激光淬火质量,本研究对轴承钢GCr15试件进行激光淬火实验。在实验中分别改变激光淬火主要工艺参数——光斑大小以及激光束扫描速度等,测量淬火后淬火区域表面硬度,以分析激光淬火工艺参数对试件表面硬度的影响。在此基础上采用正交试验的方法对激光淬火工艺参数进行优化。结果表明,采用优化后的工艺参数可以得到较高的淬火硬度。本研究为实验确定较佳激光淬火工艺参数提供了指导。     

现代加工技术在设备维修中的应用（二）

3.表面合金化技术表面合金化技术是利用外来材料与基体相混合,形成成分既不同于基材,也不同于添加材料的表面合金化层,如热扩渗（化学热处理）、离子注入、电火花强化和激光表面合金化等。     

旋光法测定三氮唑核苷注射液的含量

采用旋光法测定三氮唑核苷注射液的含量 ,与河北药品标准 1 991年版采用的定氮法比较 ,方法简单 ,快捷 ,准确。两法测定结果偏差为± 0 .1 %。对制剂车间半成品的质量快速控制提供了一个可行的方法。     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

快速成形技术的应用及热点分析

基于快速成形技术的原理,展示了快速成形技术在快速模具制造、金属零件直接成形、反求工程等领域的广泛应用,总结了快速成形制造技术研究的热点,即研发新材料和新设备、提高成形精度、建立RPM的反求工程系统、建立成形技术的统一标准和扩大成形技术的应用领域。     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

增强Linux系统安全性的措施

L inux系统的安全取决于系统管理员如何来管理它。本文探讨了一系列可以增强安全性的技巧与策略 ,包括 :系统安装原则、BIOS安全、口令安全策略、设计帐户自动注销功能、文件系统和日志安全策略、使用 SSH及 TCP-WRAPPERS,隐藏系统信息、删除所有特殊帐户、关闭控制台程序、限制系统中的 SUID/ SGID程序等。本文最后向 L inux系统管理员提出了一些安全管理方面的建议     

HSE走进中国石油

企业管理水平的好坏直接影响着企业的经济效益,运用HSE管理能提高企业管理水平,HSE管理模式将健康,安全,环境三者视为一个有机的整体。HSE管理认为人的安全是第一位的,人是创造财富的原动力,是企业的最大财产,HSE管理体系强调的是“蝴蝶效应”。     

CIS与现代企业管理美学

概括性介绍了 ＣＩＳ（Ｃｏｒｐｏｒａｔｅ Ｉｄｅｎｔｉｔｙ Ｓｙｓｔｅｍ）的三大基本组成，并阐述了它与现代企业管理密不可分的相互联系及所处的举足轻重的地位，指出导入ＣＩＳ是现代企业谋求发展的重要手段。     

Material power and normative conflict in global and local agrifood governance: The lessons of ‘Golden Rice’ in India

This special section aims to investigate the interaction of global and local forces in shaping agrifood governance. It starts from the recognition that a multitude of actors and norms shape today’s agrifood system. The resulting opaqueness of the systems makes it extremely difficult to understand and explain processes and outcomes of agrifood governance. Given the sustainability challenges facing the agrifood system, improvements in our understanding of what the interaction of global and local actors and norms means on the ground are urgently needed, however. The section, therefore, analyses agrifood governance in India across a selected group of cases. It does so by employing a systematic framework emphasizing the material and ideational dimensions of power and their interaction. The section has chosen India as the setting in which to analyze this interaction due to the crucial role the food demand and supply of this rising power plays in today’s agrifood system. This article provides the special sections’ analytical framework, which uses the interplay of material and ideational dimensions of power as a focal lens. In addition, the article applies this framework to an empirical study of the political conflict around GMO foods in India, specifically the case of ‘Golden Rice’.     

蒸汽热量计量应用的探析

研究了石油化工企业的燕汽计量情况,着重对蒸汽热量计量的合理性进行了分析,阐述了蒸汽热量计量的依据及计算方法,以及蒸气热量计量对节能降耗的重要意义.     

论传统旗袍文化与现代时装

中国的旗袍文化蕴含着非常丰富的文化内涵和设计思想,如今旗袍的普及受到一定的限制,只有经过改良,才可变局限性为可行性,才可使旗袍焕发青春,走向新时代。