精馏过程的节能和优化设计的探讨

精馏过程的节能,对于减少能源消耗,降低生产成本和保护环境具有十分重要的意义.在精馏过程中可以采用最适宜回流比操作和最佳进料状态,使用中间冷凝器和中间再沸器,高效精馏、热泵精馏.合理安排多组分物料分离流程,直接利用过程热量及开发应用高效换热器等措施.本文从最佳回流比R的选择、进料温度及进料状态的确定等方面,详细的分析了在精馏塔的设计过程中,如何实现设计的优化问题,以实现节能降耗.     

技术性贸易壁垒与合格评定程序

随着WTO和贸易自由化的发展，各国的关税水平大幅度降低，以及配额、许可证等非关税措施的逐步取消，大大促进了国际贸易的发展，技术贸易措施在国际贸易中的地位日益重要。合格评定程序是指任何直接或间接用以确定产品是否满足技术法规或标准要求的程序。合格评定程序是企业扩大对外出口、突破技术贸易壁垒的有效措施。     

谈安徽中小企业产业群的建立

本文针对生物工程产业的特点和国家发展政策 ,根据美国风险投资协会等机构的调查 ,阐述风险投资在生物工程领域的发展状况 ,指出风险投资既是生物工程产业发展的重要动力 ,也是我国生物工程产业发展的战略选择。     

Supplier relations and management: A survey of Japanese,Japanese-transplant,and U.S. auto plants

This article presents the results of a questionnaire survey sent to a sample of automobile manufacturers in the United States and Japan (including Japanese-managed plants in the United States) during the spring of 1990. The data support observations that Japanese and U.S. practices tend to differ in key areas and Japanese suppliers perform better in dimensions such as quality (defects) and prices (meeting targets, reducing prices over time); and that Japanese-managed auto plants established in the United States have, in general, adopted Japanese practices and receive extremely high levels of quality from Japanese as well as U.S. suppliers. These findings provide evidence that Japanese practices and performance levels are transferable outside Japan and suggest that considerable improvements are possible for U.S. suppliers supplying U.S. auto plants. In addition, the survey indicates that U.S. firms have adopted at least some practices traditionally associated with Japanese firms, apparently reflecting some convergence toward Japanese practices and higher performance levels in supplier management.     

风险投资问题研究

作为高新技术的推进器 ,风险投资在我国的发展相当迅速。然而 ,在发展过程中暴露出了一系列的问题。如何认识和解决这些问题 ,不仅关系到风险投资在我国的进一步发展 ,也直接关系到我国高新技术和产业的发展 ,进而影响中国经济的快速发展。     

区域主导产业发展中的地方政府行为研究

地方政府的活动范围应根据市场发挥作用的程度、社会自治的能力加以界定,更好地发挥市场的作用,优化市场经济运行的环境应是政府行为的着眼点。从地方政府官员的意识、赶超愿望、获得新闻界的关注程度等角度探讨地方政府的行为诱导机制,阐明地方政府财政能力、协调能力等方面是导致区域主导产业畸型增长的内因,提出改变地方政府行政模式,是实现地方政府目标与区域主导产业可持续发展的关键所在。     

Learning in Design and Technology: The Impact of Social and Cultural Influences on Modelling

The paper introduces the highly problematic nature of modelling in design and technology education and examines the relationship between cognitive and concrete modelling. Its aim is to gain insight into what learners do, rather than what others say they ought to do in their learning activities. The variety of purposes that educators have for learners’ modelling are discussed through examining the contested curriculum justification for design and technology education itself. The paper proposes that learners’ modelling cannot be extracted from the social milieu in which they act and it provides some insights of these social influences through the analysis of two case studies. Their settings are a girls’ secondary school and a college of higher education. Each case study is presented independently but organised with a common format to consider a) the impact of assessment on learning intentions and outcomes; b) cultural influences on learning and modelling; c) social influences on learning and modelling. A discussion of the emergent themes considers implications for teachers. This revised version was published online in July 2006 with corrections to the Cover Date.     

Another view on optimal design for estimating the point of extremum in quadratic regression

In this paper we illustrate how certain design problems can be simplified by reparametrization of the response function. This alternative viewpoint provides further insights than the more traditional approaches, like minimax, Bayesian or sequential techniques. It will also improve a practitioner’s understanding of more general situations and their “classical” treatment.     

技术站运输分析管理信息系统设计

在对我国铁路技术站运输分析手段和管理信息资源进行分析的基础上,提出技术站运输分析管理信息系统的设计,充分利用和整合技术站铁路运输管理信息系统(TMIS)和办公自动化网络等信息资源,实现统计工作自动化、分析工作网络化和车站作业组织的动态模拟,准确、即时地分析车站运输生产情况,挖掘潜能,为决策提供适时、可靠的依据,适应运输市场的快速变化。     

Airbus versus Boeing revisited: international competition in the aircraft market

This paper examines international competition in the commercial aircraft industry. We estimate a discrete choice, differentiated products demand system for wide-body aircraft and examine the Airbus-Boeing rivalry under various assumptions on firm conduct. We then use this structure to evaluate two trade disputes between the United States and European Union. Our results suggest that aircraft prices increased by about 3.7% after the 1992 US-EU agreement on trade in civil aircraft that limits subsidies. This price hike is consistent with a 5% increase in firms' marginal costs after the subsidy cuts. We also simulate the impact of the future entry of the Airbus A-380 super-jumbo aircraft on the demand for other wide-bodied aircraft, notably the Boeing 747. We find that the A-380 could reduce the market share of the 747 by up to 14.8 percentage points in the long-range wide-body market segment (depending upon the discounts offered on the A-380), but would reduce the market for Airbus's existing wide-bodies by an even greater margin.