汽轮机叶轮键槽裂纹的焊接修复

汽轮机叶轮的材料大都是34CrNi3Mo,叶轮与轴的联接是键联接,叶轮键槽底部转角处常有裂纹产生,因裂纹造成叶轮飞裂者时有发生。我们选择了挖修裂纹焊补法,并对叶轮键槽的焊接性能和焊补工艺作了分析和研究。 一、叶轮键槽焊接性能分析 根据国际焊接学会规定的碳当量公式来估算可焊性,34CrNi3Mo的碳当量为1.05％,当钢的碳当量超过     

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。     

门式刚架厂房钢结构焊接工艺优化

参考GJBT 590—2002标准02SG518-1图集,预制安装1座门式刚架轻型房屋钢结构,长×宽×高=18 m×18 m×7.2 m。单榀门式刚架跨度18 m,引用02SG518-1标准中的GJ18-1a、1b图集,立柱及横梁为非标准H形钢,由Q235B钢板组焊预制而成,18 m长横梁由3根非标H形钢使用高强螺栓组装。在施工过程中,克服钢板薄,焊接变形大的特点,做好相应焊接工艺控制措施,最终取得良好预制和安装效果。     

地震断裂带穿越用X80 HD2抗大变形钢管对接环焊缝焊接工艺质量分析及控制

介绍了西气东输三线西段工程X80 HD2抗大变形钢管力学性能、焊接接头技术要求、主要焊接方法及焊接热影响区存在的软化问题。针对X80 HD2抗大变形钢管焊接难点,通过对焊条电弧焊、半自动焊和自动焊,以及上述焊接方法的组合焊接方法、质量特性进行分析,同时结合西气东输三线工程实际,优化选择焊接工艺,确定补强覆盖焊接法为X80 HD2抗大变形钢管对接环焊缝焊接工艺。在焊接质量管理方面,通过焊工资格的审定、上岗资格的认定、上岗资格证管理,开展“双证”管理;在焊接过程质量管理方面,通过对焊接工艺补强覆盖、流水作业模式等影响焊接质量的各个关键环节实施有效控制,并针对补强覆盖存在的问题分析原因、制定措施,使焊接质量达到了预期效果。     

数控机床交流主轴驱动单元通用技术条件(摘要)(续)

4 .3　部件及辅件的基本要求4.3 .1　元件、器件、辅助件及部件元件、器件、辅助件及部件等应符合相应标准的规定和安装规程。4.3 .2　印刷电路板印刷电路板应符合GB/T 45 88.2 -1996中第 5章和GB/T45 88.4-1996中第 5章的规定。4.3 .3　指示灯和按钮的颜色指示灯和按钮的颜色应符合GB/T 5 2 2 6.1-1996中第 10章的规定。4.3 .4　导线及母线的颜色导线及母线的颜色应符合GB/T 5 2 2 6.1-1996中第 15章的规定。4.3 .5　压接、焊接和绕接接线压接、焊接和绕接接线应保证有长久良好的导电性 ,连接线的线径和配线要符合GB/T 5 2 2 6.1-199…     

反相高效液相色谱法测定潮安胶囊中齐墩果酸的含量

目的建立测定潮安胶囊中齐墩果酸的含量测定方法。方法采用Kromasil-C18柱（4．0mm×150mm,5μm）,乙腈-水-磷酸（80：20：0．5）为流动相,流速0、8mLmin^-1,检测波长为208nm,柱温2℃．结果齐墩果酸在1．124～5．620μg的范围内线性良好,回归方程为：Y=381943×X＋1651（r=0.9999）,平均回收率100．39％,RSD为1．10％．结论该法简便、准确、重现性好,可用于本制剂的质量控制。     

探究焊接热输入对X90管线钢CGHAZ组织和冲击性能的影响

文章以推动石油运输行业发展为前提,围绕焊接热输入对X90管线钢CGHAZ组织以及冲击性能的影响展开分析。首先介绍了研究发展现状,其次探讨了试验所需要的材料以及方法、过程,阐述了试验结果,最后总结了三点结论,旨在清楚了解焊接热输入的影响,以免对石油运输带来严重的影响。     

NW-350AH-Ⅱ等离子焊机焊接不良的解决方法

日铁熔接工业株式会社的NW -3 5 0AH -Ⅱ等离子焊接机,其焊接条件及参数对焊接都极为敏感。如等离子气体流量、保护气体流量、气体纯度、焊接电流、起弧电流、初期起弧时间、收弧气体流量及收弧处理位置、焊枪位置及高度,冷却水状况、伺服参数、焊枪内部零部件损伤及清洁度等,任何一个条件稍有变化,都会对焊接效果产生明显的影响。一、工作原理1.等离子弧的形成NW -3 5 0AH -Ⅱ等离子焊接机由高纯度氩气( 99.99% )作为等离子气,氩氢(Ar60 % +H2 10 %的混合气)作为保护气。直径4.8mm的钨电极接电源负极,母材接电源正极,等离子弧产生于钨…     

探究高压天然气管道焊接工艺选择及质量控制

针对高压天然气管道焊接工作中存在的核心问题,进行全方位的分析,并简单介绍了常见的高压天然气管道焊接工艺,例如焊根、热焊、填充盖面等工艺,提出提升高压天然气管道焊接质量的重要措施,可以避免高压天然气管道出现漏焊现象,提高焊接效果,希望能够给有关工作人员提供良好的帮助与参考。     

铝硅镀层22 MnB5高强钢高温拉伸性能及本构模型

为了分析和表征热成形用的铝硅镀层22MnB5高强钢的热变形行为,采用Gleeble-3800热模拟试验机,在成形温度750～900℃、应变速率0.1～10 s~(-1)试验条件下实施了铝硅镀层22MnB5高强钢的板材等温拉伸试验,采用双曲正弦型Arrhenius本构模型描述铝硅镀层22MnB5高强钢的高温流变行为,并考虑应变影响构建了模型。结果表明:1)铝硅镀层22MnB5高强钢的真应力随成形温度的升高而降低,随应变速率的增大而升高,在高温低应变速率条件下(900℃,0.1 s~(-1)),峰值应力为134.24 MPa;在低温高应变速率条件下(750℃,10 s~(-1)),峰值应力为381.25 MPa; 2)本构模型预测值与等温拉伸试验值线性拟合的相关系数R~2为0.978,表明构建的本构模型在整个应变范围具有良好的预测精度。研究成果能够准确表征铝硅镀层22MnB5高强钢的热变形行为,为其数值模拟提供材料模型数据支持,并为其热加工工艺研究提供了参考。     

Comparing FTTH access networks based on P2P and PMP fibre topologies

There is an ongoing discussion in the market which Next Generation Access (NGA) architecture best suits future needs and which investment and cost differences exist. The discussion can be subsumed as P2P vs. GPON, which is somewhat misleading as this article reveals. The discussion is driven by the fact that the high capital cost and the long asset life time of fibre mean that the technology choices made today will dominate the opportunities for telecommunication business of all market players, incumbents, competitors, content providers and business and residential users for many years in the future.The paper analyzes the cost and other differences between Fibre-to-the-Home (FTTH) access network architectures and their related different wholesale approaches by using the well-known and understood steady state approach applied in other NGA analyses in the past. In addition to the steady state analysis a dynamic cost evaluation is included taking into account the different investment behaviour of the FTTH architectures over time. The results describe investment and cost differences between architectures, incumbents and wholesale based competitive operators. The analysis has been performed for different geotypes (clusters) of decreasing population density in a representative European settlement structure.     

面向对象的程序设计

用Ｃ＋ ＋ 语言阐述面向对象程序设计中封装和继承的概念以及在实际中怎样运用这些概念提高程序设计水平。     

Indigenous peoples’ nutrition transition in a right to food perspective

In indigenous communities the nutrition transition characterized by a rapid westernization of diet and lifestyle is associated with rising prevalence of chronic disease. Field work and literature reviews from two different policy environments, Argentina (Jujuy) and Canada (Nunavut), identified factors that add to indigenous peoples’ disease risk. The analytical framework was the emerging human right to adequate food approach to policies and programmes. Indigenous peoples’ chronic disease risk tends to increase as a result of government policies that infringe on indigenous peoples’ livelihoods and territories, undermining their economic system, values and solidarity networks. Policies intended to increase food security, including food aid, may also fuel the nutrition transition. There is a need to explore further the connection between well-intended policies towards indigenous peoples and the development of chronic diseases, and to broaden the understanding of the role that different forms of discrimination play in the westernization of their lifestyles, values and food habits. Food policies that take due account of indigenous peoples’ human rights, including their right to enjoy their culture, may counteract the growth of chronic disease in these communities.     

应用CGI技术创建CAI网页计数器

:CGI( Common Gateway Interface)是应用程序与 Web服务器交互的一个标准接口 ,利用该技术可以实现 HTML不具备的交互式主页功能。本文将通过“教育窗”主页的访问 (点击 )计算器的开发应用实例 ,提出了两种使用 CGI技术实现点击计数的方案     

钻井现场H2S气体的探测及防护

在钻井生产过程中，实施HSE管理体系，预防和控制H2S，保护每一位员工不受H2S气体危害，是钻井生产过程中HSE工作的重要一环。阐述了有害气体H2S的物理特性、毒性标准，介绍了几种常用的H2S气体探测器，以及具体操作方法。     

A strategic skill based model of supplier integration and its effect on supply management performance

Supplier integration is a tool to help organizations gain competitive advantage. Strategic supply management skills and the supply management function's perceived status are hypothesized as antecedents to supplier integration leading to supply management performance. The sample for this study includes 152 executive level supply management professionals. The empirical results suggest that strategic skills and perceived status are essential antecedents to supplier integration and subsequent performance. Further, the relationship between strategic skills and performance is mediated by supplier integration. Results of a dominance analysis also suggest which strategic skills are most likely to explain status integration, and performance. These findings have significant implications for supply management theory and practice.     

Migration to 3G wireless broadband internet and real options: The case of an operator in India

The paper focuses on third generation wireless technologies and on alternative technologies for wireless local area networks. The authors present the evolutionary migration path from second to third generation systems. Technological, economic and behavioral factors related to decision-making towards the migration are proposed. As an example, the paper studies the case of the national incumbent operator of India. It analyzes qualitatively the migration problem from the perspective of the operator, the equipment manufacturer and the users. For the quantitative analysis, real options are used to value the investment decisions. The analysis suggests that the initial (sunk) investment cost, the average revenue per user, the growth of the subscriber base and the volatility of the markets are the key factors in the investment process.     

Collectivism,individualism, and outgroup cooperation in a segmented China

A consistent theme in cross-cultural management research is that collectivists are more cooperative than individualists. We use Hofstede's measure for individualism–collectivism and combine it with an experimental measure of cooperation to test this relationship in China. In contrast to the established paradigm, we find that groups with higher individualistic scores are more cooperative than those groups with higher collectivistic scores. We attribute these results to groups being composed of outgroup members. In addition, we find that subjects from the more developed coastal area are more individualistic and cooperative than are subjects from inland China.

Cost allocation of WCDMA and wholesale pricing for mVoIP and data services

This study estimates cost-based prices for wholesale voice and data services provided to 3G (WCDMA) MVNOs according to their distinct types. For estimation, 3G MVNOs are classified into different types, and the overall cost of WCDMA facilities are separated into voice and data components based on their subscriber rates, actual traffic rates, as well as efficiency consideration of traffic rates. The study then calculates cost-based wholesale prices of voice and data services for each of the 3G MVNO types. The result of this study shows that a cost-plus pricing scheme can help achieve the policy goals of the regulator, namely, lowering telecommunications tariffs and facilitating the introduction of new convergent-type services, far more effectively than the current retail-minus pricing scheme. The findings of this study may assist firms in developing business models based on 3G networks and telecom regulators in designing policies related to interconnection, mVoIP, prepaid calls, wholesale services, and network neutrality.     

压入式局部通风技术及管理

局部通风技术及管理在大中小型煤矿广泛应用,如何管理和应用局部通风是掘进安全生产不可忽视的环节,无论从风量的设计、各种安全设施的使用等都是非常重要的。有一套系列化的设计和管理模式是掘进安全生产的重要保证,本文从掘进设计到掘进结束做了详细的使用和管理。