起重机钢丝绳特点及维护

钢丝绳是起重机械的重要零件之一,广泛用于机重机的起升机构、变幅机构、牵引机构,也可用于旋转机构。钢丝绳有多种构造形式,一般应优先选用线接触型钢丝绳,常用的绳芯为麻芯,制绳前绳芯浸涂润滑油,可减少钢丝间互相摩擦所引起的损伤。高温作业宜用石棉芯或软钢丝拧成的金属芯。在有腐蚀性的环境中工作时应采用镀锌钢丝绳。钢丝绳破断的主要原因是超载,同时还与在滑轮、卷筒的穿绕次数有关,每穿绕一次钢丝绳就产生由直变曲再由曲变直的过程,穿绕次数越多就易损坏、破断;其次钢丝绳的破断与绕过滑轮、卷筒的直径、工作环境、工作类型、保养情况有关。     

煤矿立井多绳摩擦式提升机平衡尾绳选型、损坏原因简析

多绳摩擦式提升机以其提升高度大,钢丝绳安全系数大等显著优点,被越来越多地用于煤矿立井提升。结合提升机实际运行过程中,平衡尾绳使用寿命甚至不及提升首绳的现象,对平衡尾绳选型、损坏原因做一分析总结。     

A New Technology of Stecl Rope Change Used on the RTG

为了缩短轮胎式集装箱起重机（简称场桥）的钢丝绳替换时间,为此,设计了新型的钢丝绳固定装置,采用了新的换绳工艺。分析了影响钢丝绳换绳时间的原因。介绍了钢丝绳固定装置改造的具体办法和装绳工艺的改进。运行实践证明,改造达到了预期效果。     

对立井多绳提升机钢丝绳尾绳的选型和常见问题探讨

立井提升系统是煤矿安全生产的咽喉,提升机钢丝绳是其中的重要组成部分,多年来人们始终将关注的重点放在提升钢丝绳上,也就是常说的"首绳",尾绳仅是被当做平衡首绳重量的"配重"。近年来,煤矿因尾绳断裂出现的事故频发,所以尾绳安全合理的选型和使用也成为了提升系统安全管理工作中的一个重要环节。     

关于门座式起重机自动开闭斗改造应用

门座式起重机抓斗作业,在采用抓头作业时,经常因钢丝绳过松或过紧而导致电机过载或钢丝绳缠绕损坏,经过长时间观察发现,钢丝绳的过紧和过松主要原因是司机在开闭斗作业时,主要以个人的熟练程度和目测估计来进行操作,不能准确控制自动开闭斗时机.为解决此现象,通过改造门机控制程序,用起升电机编码器做钢丝绳位置检测,利用开闭绳差,实现抓斗的自动控制,解决起升电机的过载和钢丝绳缠绕损坏.神华黄骅港1633门座式起重机采用先进的电控系统.该机起升、变幅、回转、运行机构均采用变频调速,起升机构采用闭环控制,应用PLC集中控制和检测.调速性能优良,起、制动运行平稳、快速.     

煤矿提升用钢丝绳破断事故的防范

钢丝绳破断事故产生的原因主要有钢丝绳使用中强度下降、立井提升容器受阻后松绳、多绳摩擦提升断绳等,提出了保证钢丝绳的质量,坚持日检、加强维护、执行更换标准等钢丝绳破断事故的防范措施。     

浅谈桥式起重机的事故防范

一、桥式起重机事故分析 (一)承栽系统零部件损坏 1.钢线绳损坏 (1)动、定滑轮组碰撞引起钢丝绳挤轧或折断当吊钩吊起物品上升,如果起升机构的上升限位开关失灵,吊车司机又未察觉,继续上升操作时,会引起动滑轮组碰撞定滑轮组或小车架,钢丝绳被构件边缘或滑轮轮缘挤压切割;或者由于电动机的扭矩和传动系统的功能全部由钢丝绳吸收,超过了钢丝绳承载能力,以至折断.     

YHC换绳车在立井多绳摩擦式提升系统钢丝绳更换工作中的应用

近年来,由于煤炭市场的繁荣,矿井开采规模和井筒深度的较大增加,摩擦式提升系统在煤矿生产中得到了广泛应用。更换摩擦式提升系统钢丝绳一直是一项人力投入大、有较大安全风险的工程,利用换绳车更换摩擦式提升系统钢丝绳是对原有换绳工艺的革新,有较好的发展前景。文章介绍了利用YHC换绳车更换立井多绳摩擦式提升系统钢丝绳的工艺及建议。     

大连D发电公司脱硫氧化风机电机轴瓦损坏、跳闸原因分析及改进措施

脱硫系统氧化风机运行中因电机轴瓦损坏继而温度升高而跳闸,通过对风机运行工况与轴瓦损坏表象以及风机设计结构的进一步分析研究,确定轴瓦损坏原因是风机因实行经济运行方式,传动轴受热膨胀所造成。及时采取并改进氧化风机传动轴护套密封等技术改造措施,最终解决了上述问题。     

矿井提升钢丝绳的选择计算

为合理科学地选择矿井提升钢丝绳,从钢丝绳的安全系数、结构、捻向、使用环境等方面介绍了选绳时的参考因素。按钢丝绳在天轮(或导向轮)切点处所承受的最大静载荷,并考虑一定的安全系数,分别给出了立井单绳缠绕式、立井多绳摩擦式提升钢丝绳,以及斜井提升钢丝绳的选择计算公式及其推导过程。列举一实例,根据介绍了的选绳时的参考因素,用实际的矿井提升系统所对应的计算公式,对矿井提升钢丝绳进行了详细的计算、选型。     

Development in Information and Communications Technology (ICT) Statistics at the Australian Bureau of Statistics

This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field.     

Value at Risk in the Suburbs: Eminent Domain and the Geographical Politics of the US Foreclosure Crisis

Several US counties and local governments have recently considered a novel solution to the foreclosure crisis. They plan to use eminent domain to compel the owners of mortgage debt—and specifically of private‐label mortgage‐backed securities—to sell the debt to the government at a price reflecting the loan's market value. The government would then restructure the debt and resell it to new investors. The plans are striking because—in contrast to both development‐driven eminent domain and the federal subprime bank bailout—they would force investors to assume asset devaluation and increased long‐term risk. Notably, the plans have emerged as an instance of financialization‐focused politics in suburbs and suburban cities of color, specifically majority‐black and ‐Latino/a suburbs. Local support for the plans, we argue, is rooted in the long‐term disinvestment of these ‘suburbs of exception', which became targets of subprime lending and eventually sites where the ‘financial exception' has been localized. But these demographic shifts, fragmentation and fiscal pressures have at the same time created a suburban political terrain in which the plans have gained their strongest political support.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Accountability of NGOs in Bangladesh A critical overview

NGOs in Bangladesh have been recognized as effective change agents in the socio-economic arena throughout the world. Their contributions in micro credit, non-formal education and primary health care are widely known. NGOs play a significant role in society. NGO accountability, as a result, has become a critical issue. NGO accountability in Bangladesh has been examined here in relation to patrons, clients and themselves. Of the three relationships only accountability to patrons is in a near satisfactory state. Accountability to clients is handicapped by lack of opportunities of beneficiaries to participate meaningfully in NGO policy making. Accountability to themselves is adversely affected due to the adherence to a strictly hierarchical system and the influence of founding and charismatic NGO leaders.     

Towards an Asian model of human resource management? A comparative analysis of China,Japan and South Korea

There has been much discussion regarding the possible decline and weakening of national systems of human resource management (HRM). Yet, culture and institutions are often cited as the major stumbling blocks to this outcome. Such constraints may dissipate in the analysis, particularly if ‘regional clusters’ are considered where geographic and cultural closeness and ‘openness’ to similar economic pressures exist. In such cases, it might be postulated that convergence in HRM will occur. We argue that China, Japan and South Korea represent such a cluster. This article examines these countries, to see if a degree of convergence is taking place and if it is towards an identifiable ‘Asian’ model of HRM. A model of change is presented that distinguishes between levels of occurrence and acceptance. Details of the development and practice of HRM in each country are then set out. The article ends with a discussion and implications section and a brief conclusion.     

Ansätze und Ergebnisse anglo-amerikanischer M&A-Forschung

Based on a review of established U.S. management journals (1995–2003), six schools of thought are identified within the Anglo-American M&;A research: “Capital Market”, “Principal/Agent”, “Industrial Organization”, “Organizational Behavior”, “Human Resources” and “Strategic Management”. The literature review shows that the definition of M&;A success, the methods applied, and insights from empirical research differ according to the respective school of thought. Empirical studies focus on the resource combinations of merger partners, the specific circumstances of merger negotiations, and on integration management as antecedents of merger performance. Unfortunately, empirical findings have not yet provided reliable explanations for M&;A success. Based on the current state of Anglo-American M&;A research, the authors discuss implications for business practice, identify research gaps, and propose areas for future research.     

Introduction of New Technology with a Sound Transition of the Input-Output Structure

We examine the general equilibrium repercussions associated with the introduction of new technologies, using the generalized Leontief system that allows technological substitutions. We show that an untested introduction of cost-increasing technologies in any industry may result in creating a non-productive technological structure that does not satisfy the Hawkins-Simon condition, following the autonomous dynamic adjustment process with structural transitions in the economic system. Therefore, we propose a practicable control scheme of introducing cost-increasing technologies that strictly avoids the creation of non-productive structures in all periods of structural transition, using the available information on the ex ante technological structure.     

The Creation of the Office for National Statistics

A new Office for National Statistics was created in the United Kingdom in 1996 following a series of developments designed to strengthen the relevance and integrity of statistics. This paper describes these fundamental changes and sets out a blueprint for future progress. It also sets current developments in the United Kingdom in an historical and international context.     

What helps? Women engineers' accounts of staying on

We have considerable understanding of the obstacles that women engineers encounter and the reasons that they leave the field, but we know less about what enables them to remain. Adopting an interpretivist approach, this article examines how a group of British women engineers in two FTSE 100 companies account for “staying on” in their male‐dominated work settings. We delineate four specific forms of help that facilitate women's retention in the field. We argue that exposure to help leads to women developing a habitus that enables them to continue working in engineering. To conclude, we draw on our findings to outline HR practices that will facilitate supportive relationships in the workplace and pave the way towards developing more positive organisational climates.     

论现代物流企业的发展观

物流业经过诸多年的发展目前已经成为最热门的行业之一,物流企业的注册数量也与日俱增,达到前所未有的规模。毋庸置疑,任何企业都希望自己迅速做强做大,并成为真正现代物流企业的典型代表,要实现这一目标一个首要问题就是要解决现代物流企业的发展观问题。