应用自控系统 减少气体放散

济南鲍德气体有限公司的气体主供出管道 ,主要供炼钢氧气、炼铁氧气、中压氮气、低压氮气。目前气体公司的氧气生产量共约 370 0 0m3/h ,其中炼钢由于生产的间断性 ,用量波动较大 ,在 2 5 0 0 0～ 32 0 0 0m3/h之间 ,炼铁的使用量在 4 0 0 0～ 130 0 0m3/h之间 ;炼钢氧气的用量必须保证。高压氮气的生产量约 30 0 0 0m3/h ,使用量为 2 0 0 0 0～30 0 0 0m3/h ;低压氮气生产量约 12 0 0 0m3/h ,使用量为 80 0 0～ 15 0 0 0m3/h ,其中低压氮气压力要求尽可能稳定 ,高压氮气要避免出现压力突然升高 (用户用量急剧下降 ) ,防止对压缩机造成影响…     

数码相机大降价

据北京、广州、上海、杭州等城市数码相机市场行情观察 ,进入 5月份富士数码相机率先大幅降价 ,带动数码相机市场价格全线回落。笔者注意到近几个月不同品牌数码相机的价格动态 ,列表对比如下。几款品牌数码相机价格对比品牌 (公司 )型号原价 ( 4月份　元 )现价 (元 )富士S70 0 0 70 0 0 43 0 0S5 0 0 0 3 5 0 0 2 65 0S3 0 0 0 2 65 0 2 10 0A3 10 2 15 0 15 2 0F42 0 2 80 0 2 180S3 0 42 5 5 0 180 0F70 0 3 80 0 2 45 0索尼F82 882 0 0 73 5 0V14 3 0 0 3 95 0T14 3 0 0 3 980P10 3 60 0 3 10 0P -92 3 0 3 0 2 780P -72 2 3 0 0 …     

聚萘醌电流变液体的性能研究

以聚萘醌为分散相 ,对溴二苯甲烷和二甲基硅油为分散介质 ,聚硅氧烷侧链高分子液晶为添加剂 ,配制成电流变液体 (ER液体 ) ,应用德国RV2 0电流变仪测试性能 ,研究其ER效应 ,以求获得高性能的ER液体。结果表明 ,该ER液体有很强的ER效应。 77℃ ,电场强度 (E)由 0增至DC2 0 0 0V/nm ,剪切速率为 30 0s- 1时 ,剪切应力由 30Pa增至 90 0 0Pa ,表观粘度由 4 0mPa·s增至 30 0 0 0mPa·s ;剪切速率为 5 0 0s- 1时 ,剪切应力由 30Pa增至 15 0 0 0Pa ,表观粘度由 4 0mPa·s增至2 35 0 0mPa·s。 4 4℃ ,同样条件下 ,剪切速率为 6 0s- 1时 ,剪切应力由 2Pa增至 2 4 0 0 0Pa ,表观粘度由 4 5mPa·s增至 2 2 0 0 0mPa·s     

中国标准化及合格评定工作简介

20 0 0年 10月中国标准化协会同日本规格协会进行了为期 1周的技术交流。本刊选编了参加交流的部分文章 ,包括 :李春田“中国标准化及合格评定工作简介” ,郎志正、郎元“2 0 0 0年版ISO 90 0 0族标准实施的研讨” ,龙辉“质量管理体系文件如何向 2 0 0 0版标准转换” ,赵祖明“2 0 0 0版ISO 90 0 0族标准强调‘员工参与’的新特点” ,以供大家参考。     

QS 9000质量体系与产品设计质量控制

ＱＳ 90 0 0质量体系标准是美国福特、通用和克莱斯勒三大汽车公司 (以下简称三大公司 )在ＩＳＯ 90 0 0标准的基础上联合推出的质量标准 ,受到国际汽车界的广泛重视 ,因此 ,初步了解ＱＳ 90 0 0有关产品设计方面的标准 ,对提高产品设计素质 ,规范产品设计开发活动大有益处 ,并有益于ＧＢ 190 0 0的宣贯和认证工作的开展。1 ＱＳ 90 0 0质量体系与ＩＳＯ 90 0 0ＩＳＯ 90 0 0的推出 ,受到国际社会各行业的普遍认可 ,美国三大公司为了全球战略的需要 ,在ＩＳＯ 90 0 0的基础上协调一致 ,携手推出了ＱＳ 90 0 0质量体系。其目的是针对三大公…     

如何理解ISO9001:2000版标准的理念变化

2 0 0 0版与 94版的根本区别在于理念的变化。 2 0 0 0版强调“一个中心 ,二个基本点” ,弱化了文件化的质量体系要求 ,强调的是质量体系运行的有效性。文章对 2 0 0 0版标准转化工作提出一些建议。     

首台国产30000m~3/h空分设备的诞生历程与评述

简述了国产 30 0 0 0m3/h空分设备的研制过程 ,分析了 30 0 0 0m3/h空分设备的工艺流程 ,主要技术参数及各系统流程 ;介绍了 30 0 0 0m3/h空分设备的考核结果 ,试车中出现的主要问题及其处理方法 ;最后阐述了 30 0 0 0m3/h空分设备国产化成功的意义     

10年来数码相机像素的变化

进入 2 0 0 4年以来 ,有多家公司相继推出了他们的 80 0万像素的数码相机。数码相机的像素已进入了一个新纪元。不夸张地说 ,数码相机的发展历史就是像素不断提高的历史。笔者回顾并列举出近10年数码相机像素的变化 (见附表 ) ,可领略出数码相机飞速发展一二。附表　 10年来数码相机像素的变化年份最高像素1995 5 0万1996 80万1997 110万199815 0万19992 5 0万2 0 0 0 380万2 0 0 14 5 0万2 0 0 2 5 2 0万2 0 0 36 2 0万2 0 0 4 80 0万　　　注 :此表不包括单反数码相机和后背数码相机的像素。10年来数码相机像素的变化@中原…     

加拿大实施ISO9000族标准和ISO14000标准的情况

由中国标准化协会组织的 2 0 0 0版ＩＳＯ 90 0 0族质量管理标准和ＩＳＯ 140 0 0环境管理标准培训团 ,于 2 0 0 0年 8月 18日至 9月 8日对加拿大进行了为期 2 1天的业务培训和考察 ,详细了解了加拿大标准化管理的基本体系、认证的基本程序以及咨询工作要点 ,了解到加拿大对ＩＳＯ 90 0 0标准、ＩＳＯ 140 0 0标准的实施情况、对新版ＩＳＯ 90 0 0标准的跟踪研究情况以及推行国际标准的先进经验。其主要情况如下 :1 加拿大认证情况( 1)加拿大标准理事会 (ＳＣＣ)是加拿大的惟一认可机构 ,负责ＩＳＯ 90 0 0质量管理体系和ＩＳＯ 140 0 0环境…     

建筑企业如何体现质量管理八项原则

现阶段向 2 0 0 0版ISO90 0 0族标准实施过渡 ,已成社会各界广泛关注的焦点 ,质量管理的八项原则作为 2 0 0 0版ISO90 0 0族标准的基础 ,为企业建立质量管理体系提供了理论依据 ,建筑企业实施质量管理八项原则应体现在企业的各项质量管理活动之中。     

A study on capacity allocation scheme with seasonal demand

This paper studies a game-theoretical capacity allocation problem in a two-echelon supply chain comprised of one supplier and N retailers. With demand fluctuating seasonally and significantly, supply is sufficient in low-demand periods but is insufficient in high-demand periods, especially when the supplier’s capacity decreases in high-demand periods. Retailers compete for the supplier’s capacity in high-demand periods, but do not want to absorb the supplier’s redundant capacity in low-demand periods. A turn-and-earn allocation scheme is proposed to encourage retailers to increase their order quantity in low-demand periods. Under the turn-and-earn allocation scheme, in high-demand periods, the supplier is willing to offer a guaranteed portion of supply capacity for the primary retailer. The remaining capacity in high-demand periods is allocated based on orders retailers placed in low-demand periods. In response, the retailers will decide how much they should order in low-demand periods. Then, a competitive game based on Nash equilibrium among the supplier and her retailers is analysed. In order to solve the problem of unreasonable distribution of interest caused by competition, a contract is designed to make it possible for subsidy to be transferred from the supplier to the retailers. Usually, the supplier and her primary retailer can both be better off under turn-and-earn allocation compared with fixed allocation, and the system efficiency in Nash solution is close to it in optimal solution. A numerical study is also conducted to discuss the parties’ sensitivity to different demand level and guaranteed allocation portion of capacity.     

Controlled Drug Release and Chemotherapy Response in a Novel Acoustofluidic 3D Tumor Platform

Overcoming transport barriers to delivery of therapeutic agents in tumors remains a major challenge. Focused ultrasound (FUS), in combination with modern nanomedicine drug formulations, offers the ability to maximize drug transport to tumor tissue while minimizing toxicity to normal tissue. This potential remains unfulfilled due to the limitations of current approaches in accurately assessing and quantifying how FUS modulates drug transport in solid tumors. A novel acoustofluidic platform is developed by integrating a physiologically relevant 3D microfluidic device and a FUS system with a closed‐loop controller to study drug transport and assess the response of cancer cells to chemotherapy in real time using live cell microscopy. FUS‐induced heating triggers local release of the chemotherapeutic agent doxorubicin from a liposomal carrier and results in higher cellular drug uptake in the FUS focal region. This differential drug uptake induces locally confined DNA damage and glioblastoma cell death in the 3D environment. The capabilities of acoustofluidics for accurate control of drug release and monitoring of localized cell response are demonstrated in a 3D in vitro tumor mode. This has important implications for developing novel strategies to deliver therapeutic agents directly to the tumor tissue while sparing healthy tissue.     

The Grid Method for In‐plane Displacement and Strain Measurement: A Review and Analysis

The grid method is a technique suitable for the measurement of in‐plane displacement and strain components on specimens undergoing a small deformation. It relies on a regular marking of the surfaces under investigation. Various techniques are proposed in the literature to retrieve these sought quantities from images of regular markings, but recent advances show that techniques developed initially to process fringe patterns lead to the best results. The grid method features a good compromise between measurement resolution and spatial resolution, thus making it an efficient tool to characterise strain gradients. Another advantage of this technique is the ability to establish closed‐form expressions between its main metrological characteristics, thus enabling to predict them within certain limits. In this context, the objective of this paper is to give the state of the art in the grid method, the information being currently spread out in the literature. We propose first to recall various techniques that were used in the past to process grid images, to focus progressively on the one that is the most used in recent examples: the windowed Fourier transform. From a practical point of view, surfaces under investigation must be marked with grids, so the techniques available to mark specimens with grids are presented. Then we gather the information available in the recent literature to synthesise the connection between three important characteristics of full‐field measurement techniques: the spatial resolution, the measurement resolution and the measurement bias. Some practical information is then offered to help the readers who discover this technique to start using it. In particular, programmes used here to process the grid images are offered to the readers on a dedicated website. We finally present some recent examples available in the literature to highlight the effectiveness of the grid method for in‐plane displacement and strain measurement in real situations.     

Quality Management in Pakistan's Bedwear Industry

Pakistan's bedwear industry contributes significantly to Pakistan's industry in general and to its textile industrial output and exports in particular. The exports of bedwear have increased steadily. However, its key basis of competitive advantage has been low cost. After greater liberalization from 2005 onwards and due to tariffication of quotas, the bedwear industry will not only have to scale higher tariff walls but will be more exposed to the threat of anti-dumping duties as it relies primarily on low prices to penetrate the export markets. To enhance its competitiveness, it will have to combine better quality with low costs and quick response. Research in quality management in Pakistan's bedwear industry was, therefore, undertaken. A postal self-completion questionnaire was mailed to 38 members of Pakistan Bedwear Manufacturers' and Exporters' Association (PBMEA). The response rate was almost 79%. It was found that this industrial segment was in various stages of development. This study demonstrates both the effectiveness and the limits of quality assurance in improving the levels of quality which remain a moving target in a dynamic liberalizing international trade environment that is more competitive since 2005. The bedwear industry, therefore, needs to graduate to advanced practices in quality management in order to remain competitive in rapidly changing times.     

Product-service system innovation capabilities: linkages between the fuzzy front end and subsequent development phases

In an attempt to remain competitive, manufacturers increasingly offer integrated product-service systems (PSSs). This transition from physical products to PSSs calls for new ways of working, for example in the product development process. However, so far only limited attention has been put on capabilities needed to succeed with PSS innovation in the very early development phases – often referred to as the fuzzy front end (FFE). This article, therefore, has a dual aim: first, to further our understanding of capabilities for PSS innovation in the FFE, and second, to determine how these capabilities are linked to PSS innovation capabilities needed in subsequent development phases. Empirical data were collected from an ongoing industrial project developing an innovative PSS offering in a large manufacturing company. Individuals connected to the project reported major challenges, both experienced in the FFE and anticipated in later phases, which provided valuable information regarding capabilities needed to succeed with the endeavour. Findings reveal four links of PSS innovation capabilities: (1) adapting vocabulary and mental models to PSS, (2) handling the ‘intangible aspect’, (3) bridging organisational structures, and (4) managing new business models. PSS innovation capabilities in the FFE are also found to be of higher order (dynamic) compared to capabilities in later development phases.     

Factors influencing transit fatigue of seamless pipes

Full‐scale fatigue tests simulating real pipe stock conditions in ships were carried out in order to reproduce failures of seamless pipes due to fatigue crack growth during shipping. Simple mechanical analyses were then used to assess the factors that influence transit fatigue. As seen in several actual failures, fatigue cracks were found to propagate from both sides of the pipe wall. It is possible to have transit fatigue (TF) when piling up a few pipes for transportation, if there is previous plastic indentation. Susceptibility to TF was found to be independent of the nature of discontinuities in the surfaces of the pipes. Precautions to reduce the probability of TF in sea shipment include preventing plastic indentation of the pipes and storing stiffer pipes in the bottom part of the hold.     

Viscoelastic Creep Crack Growth: A Review of Fracture Mechanical Analyses

The study of time dependent crack growth in polymers using a fracture mechanics approach has been reviewed. The time dependence of crack growth in polymers is seen to be the result of the viscoelastic deformation in the process zone, which causes the supply of energy to drive the crack to occur over time rather than instantaneously, as it does in metals. Additional time dependence in the crack growth process can be due to process zone behavior, where both the flow stress and the critical crack tip opening displacement may be dependent on the crack growth rate. Instability leading to slip-stick crack growth has been seen to be the consequence of a decrease in the critical energy release rate with increasing crack growth rate due to adiabatic heating causing are duction in the process zone flow stress, a decrease in the crack tip opening displacement due to a ductile to brittle transition at higher crack growth rates, or an increase in the rate of fracture work due to more rapid viscoelastic deformation. Finally, various techniques to experimentally characterize the crack growth rate as a function of stress intensity have been critiqued. This revised version was published online in July 2006 with corrections to the Cover Date.     

Localization of Strain Rate at Mesoscale and Its Effect on the Measured Strain Rate Sensitivity During Superplastic Deformation

Microstructural observations on specimens deformed in regions I, II and III of superplasticity suggest that the dislocation activity is restricted to limited grains in region I but spreads to almost all grains in the region III. Analysis has been carried out to show that the transition from the localized plastic flow in region I to relatively homogeneous plastic flow in region III significantly contributes to the high strain rate sensitivity observed in region II.     

Technology transfer,outsourcing, capability and performance: A comparison of foreign and local firms in Ghana

Owing to intense competition in today's business environment, organisations that aspire to excel in their respective sectors need to develop the appropriate capabilities in order to gain and sustain a competitive edge. Outsourcing and technology transfer provide firms with the platform for developing capability to achieve superior performance in the marketplace. However, in the setting of a developing economy, the relative effects of outsourcing and technology transfer on corporate performance among foreign and local companies when investigated together in an amalgamated model is yet to be examined empirically. To obtain a deeper understanding, two pathways through which outsourcing and technology transfer enhance corporate performance of companies in Ghana are presented. Results of this research indicate differences in the extent to which outsourcing and technology transfer influence capability and subsequently affect corporate performance. Limitations of this study as well as implications of the findings for managers and researchers are ultimately highlighted.     

A multi-agent protocol for multilateral negotiations in supply chain management

Within a supply chain network, it is common for companies to engage in negotiations to resolve conflicts in task allocation and order fulfilment problems. This kind of supply chain negotiation is usually regarded as buyer–seller negotiation. In recent years, multi-agent systems have been established to automate buyer–seller negotiations. However, most have limitations in handling complex negotiation scenarios such as multilateral negotiations and multi-issue negotiations. This paper presents ECNPro (the Extended Contract-Net-like multilateral Protocol), which is a new multi-agent protocol for handling buyer–seller negotiations in supply chain management. ECNPro is designed to handle agent bargaining and interactions in complex multilateral and multi-issue negotiations in which the buyer has to negotiate with many suppliers. The multi-attribute utility theory (MAUT) approach is adopted to establish the utility functions for a set of negotiation issues in the bargaining process. It adopts a multi-threaded approach to allow the buyer to bargain concurrently with multiple suppliers. ECNPro is able to split an order to more than one supplier to achieve a better negotiation payoff. In addition, mobile agents are employed in ECNPro, the buyer sends mobile agents to sites of the sellers to conduct bargaining locally. This approach improves the negotiation efficiency significantly.