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91.
五强溪水电站主体工程混凝土浇筑垂直运输在大坝两岸分高、低层布置4台平移式20t缆索起重机。其中2台高缆从德国引进,属世界上首次采用全遥控的缆机,同时也是国内塔架最高的缆机;2台低缆属我国目前自行设计制造安装的规格最大、速度最高的缆机。 相似文献
92.
本文简要介绍了国外在开发超酸性气体过程中遇到的材料选择、腐蚀监测、水化物堵塞、超酸性气的处理和加工等问题所采取的措施和办法。 相似文献
93.
Diedrichsen J?rn; Ivry Richard B.; Hazeltine Eliot; Kennerley Steven; Cohen Asher 《Canadian Metallurgical Quarterly》2003,29(1):64
Four experiments were conducted to identify the locus of interference observed during the preparation of bimanual reaching movements. Target locations were specified by color, and the right-hand and left-hand targets could be either the same or a different color. Movements of different amplitudes (Experiment 1) or different directions (Experiment 2) to targets of the same color were initiated more quickly than symmetric movements to targets of different colors. These results indicate that costs observed during bimanual movements arise during target selection rather than during motor programming. Experiments 3 and 4 further examined the interference associated with target selection. Reaction time costs were found with unimanual movements when the target was presented among distractors associated with responses for the other hand. Interference observed during bimanual reaching appears to reflect difficulty in segregating the response rules assigned to each hand. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
Although methods of product design and materials selection have been developed, the recent rise of multimaterials (composites, hybrids, etc.) has shown a lack of tools for engineering in this domain. The present contribution aims at the development of a multimaterials design method based on the adaptation of existing methods and on the conclusions of a case study. In comparison with materials selection, the originality of multimaterials design relates to searching materials coupling mechanisms to satisfy a set of requirements. More, it appears that manufacturing process and validation tests are very important points that must be integrated early in the design process. 相似文献
95.
文章较全面的介绍了如何根据设备、装置、构件所处的工作环境及使用条件进行防腐蚀设计,及其防腐蚀设计的内容和注意事项,选择合适的防腐蚀材料,确保产品的使用寿命 相似文献
96.
Abstract. While a large body of research exists on the development and implementation of software, organizations are increasingly acquiring enterprise software packages [e.g. enterprise resource planning (ERP) systems] instead of custom developing their own software applications. To be competitive in the marketplace, software package development firms must manage the three-pronged trade-off between cost, quality and functionality. Surprisingly, prior research has made little attempt to investigate the characteristics of packaged software that influence management information system (MIS) managers' likelihood of recommending purchase. As a result, both the criteria by which MIS managers evaluate prospective packaged systems and the attributes that lead to commercially competitive ERP software products are poorly understood. This paper examines this understudied issue through a conjoint study. We focus on ERP systems, which are among the largest and most complex packaged systems that are purchased by organizations. In a conjoint study, 1008 evaluation decisions based on hypothetical ERP software package profiles were completed by managers in 126 organizations. The study represents the first empirical investigation of the relative importance that managers ascribe to various factors that are believed to be important in evaluating packaged software. The results provide important insights for both organizations that acquire such systems and those that develop them. The results show that functionality, reliability, cost, ease of use and ease of customization are judged to be important criteria, while ease of implementation and vendor reputation were not found to be significant. Functionality and reliability were found to be the most heavily weighted factors. We conclude the paper with a detailed discussion of the results and their implications for software acquisition and development practice. 相似文献
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范忠礼 《电信工程技术与标准化》2002,(4):43-46
本提出了一种标准化的光控制平面。阐明了开了用于光传输网的控制平面所遇到的选择与挑战。光控制平面被分解成邻居发现、服务发现、连接控制和拓扑、资源发现等几个基本的过程。不同的网络组织和分割导致了几个不同的自动配置模型:软性持久链路模型、用户接口模型和对等模型。这是构成以IP为中心的光传输网的控制和管理基础。同时也介绍了基于SDH光交换的新一代CIENA公司智能光网络,它具有大容量光交换能力和网络拓扑结构自动发现、端对端电路配置、带宽动态分配等功能及特点,将大大提高数据、电路业务的服务质量,新一代智能光网络是干线和城域网络交换传输最佳的选择。 相似文献
100.
在重点说明影响传输光纤设计的主要问题的同时,简要介绍了各种升级方式所面临的主要技术挑战,并详细说明这些挑战对传输光纤提出的技术要求。 相似文献