化工料浆循环泵轴承故障诊断

利用频谱分析的方法,成功地诊断出01140#料浆循环泵的后轴承损坏故障,在对其发展趋势做出准确判断的前提下,选择最佳时机进行了更换处理.     

电机故障的诊断与研究

本文分析了各类电机常见如转子不平衡、转轴弯曲、轴承损坏与松动、轴系不对中、动静件摩擦等故障的类型,产生的原因,以及故障排除的主要方法,进而及时、准确地排除故障。     

高线精轧机电机故障频谱分析诊断

使用设备综合故障诊断系统,对高线精轧机电机存在的异常振动故障进行现场检测、诊断,通过特征频率的分析、计算,判断轴承外圈出现点蚀等缺陷,分析故障趋势,及时安排检修。     

海上中心平台机泵远程云诊断系统的应用与实践

传统的机泵设备运行状态检测,通过安装在机泵现场一次仪表获得轴承振动、温度数据,管理人员根据所获数据与运行范围分析判断设备运行状态,存在故障判断不准确、故障点模糊的难点。为准确获得设备先期故障,提高设备管理质量,实现自动识别和诊断,引入机泵远程云诊断系统,构建"智能传感+远程监控+专家分析"三位一体的机泵远程云诊断系统。该系统能够及时准确地采集机泵的振动和温度数据,并且根据数据的异常状况及时报警、提出针对性的检维修方案、达到智能化检修效果,大大减低了机泵故障率、减少故障停机时间,实现机泵效益最大化。     

基于振动频谱的滚动轴承故障诊断方法研究

轴承是一种通用的标准零件,快速、准确地识别轴承故障对设备的维护非常重要。传统的手工检测方法以经验为主,对维护人员的要求很高。同时,一些故障的表现十分类似,维护人员很难快速、准确地判断出具体原因,因此迫切需要一种能快速、准确判断轴承运行状况的方法。     

双级动调轴流引风机动叶调节失控故障分析及处理

通过对双级动调轴流引风机液压缸反馈轴承失效的机理进行分析,能够快速和准确判断故障原因,并采取恰当的措施,及时消除设备异常,确保机组安全稳定运行。为准确判断及时处理风机动叶调节失控故障提供帮助,同时为下一步杜绝此类故障提出改进思路。     

预防维修比预知维修更有效（续）

离心泵 用预知的振动监测技术诊断离心泵的轴承故障、转子的不平衡、轴的不同轴度和其它故障是很有效的。但是,如果仅仅依赖预知维修技术,就无异于宣告他们不防止故障发展,而是在等待故障。 尽管实践已证明,定期更换润滑油可以显著地减少轴承损坏,但并没有多少化工厂按照图1推荐的换油周期及时更换润滑油。     

多技术融合的电机轴承故障诊断方法

利用振动频谱分析及电信号分析技术相融合的方法,准确判断了电机轴承故障等级及故障原因,并通过检修实践验证了诊断的准确性,证明了多技术融合的故障诊断方法对电机故障诊断的有效性。     

纸机导辊轴承振动诊断分析

介绍三个纸机导辊轴承振动诊断案例,总结利用噪声、振动值与包络值大小、振动频谱等分析方法,综合考虑各种因素,准确判断轴承故障的几点要领。     

共振解调技术在风力发电机滚动轴承故障诊断中的应用

将共振解调技术应用于风力发电机滚动轴承的故障检测与诊断中,通过对轴承振动信号进行时域监测和频谱分析,实现对轴承早期故障的诊断,确保风力发电机的稳定运行。     

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.     

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     

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.     

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。     

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”。     

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’.     

Diffusion and usage of public e-services in Europe: An assessment of country level indicators and drivers

We analyze the state of the art of indicators on e-government, e-health, e-procurement and e-participation. We survey the main methodological properties of these indicators, and highlight their heuristic potential. Further, we address empirically the issue of the explanation of the availability scores, i.e. how the supply of the various e-services in each country is affected by political, institutional and socio-economic differences, and is followed by actual usage. The econometric analysis uncovers the importance of broadband penetration and higher education as drivers for most of the types of e-services and users (citizens and businesses). Moreover, a corruption-free and agile public sector proves to be an important pre-condition for more effective supply and usage. Despite data limitations and the complexity of the underlying diffusion phenomena, our study is the first truly longitudinal contribution aimed at disentangling the common drivers of such an important phenomenon – the e-services availability and usage across European countries. As such, this work appears useful to inform the policy debate and practice, in a phase characterized by a prospective reorientation of the public e-services provision and policy agenda.     

一种高精度的频率标准比对系统

频率标准源可以提供精确的标准频率,在测定频率标准源的各项性能指标时,要求测试系统必须具有很高的比对精度。所设计的频率标准比对系统采取多级倍频 混频方式使频率偏差逐级扩大后再测量,从而避免了直接进行高次倍频的困难,提高了测量精度,可以对高精度的频率标准的准确度、长短期频率稳定度进行快速测量,是一种高精度时畴参数测量系统。     

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.