共查询到20条相似文献,搜索用时 125 毫秒
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介绍了国内外裂解碳五馏分分离技术的研究进展。对几种生产工艺的技术特点进行了分析,着重叙述了加热二聚法分离环戊二烯、萃取精馏法分离异戊二烯等工艺。提出优化现有工艺、开发新型萃取剂是今后碳五馏分分离技术发展的新方向。 相似文献
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争取石蜡出口更上一层楼王晓霞石蜡是用于制造合成脂肪酸和高级醇,也是用于制造火柴、蜡烛、蜡纸、蜡笔、防水剂、电子绝缘材料等产品原材料。该产品是由天然石油、人造石油或页岩油的含蜡馏分经冷榨或溶剂脱蜡等方法提炼而成。主要分为半炼石蜡和全精炼石蜡。该产品由于... 相似文献
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我国社会经济的不断发展,工业化、城镇化进程的不断推进对石油的需求也越来越多。为了保证国内的石油安全,经济健康、可持续运行,必须不断提高我国石油开采业的工作效率,大力开发国内石油资源。但是我国现在的开采环境对钻井工程提出了更大的挑战,钻井技术也越来越难。本文首先探讨了我国发展石油钻井技术的必要性,然后分析了我国钻井技术的发展现状,并对未来石油钻井技术的发展进行了展望。 相似文献
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使用物理方法处理印染废水具有绿色、清洁、节能等许多优点,近年来得到国内外学者的广泛重视和开发应用。通过对几种物理方法处理印染废水的介绍,简述了近年来研究人员的研究成果并分析了其发展现状和方向。 相似文献
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ANNA V. A. RESURRECCION 《International Journal of Consumer Studies》1986,10(4):317-332
Consumer use patterns for 43 fresh and processed vegetables were studied in an effort to explain recent shifts in vegetable consumption practices. Data on the appropriateness of each of the vegetables for 10 different uses were collected and analysed to determine food and food use patterns. Nine vegetable factors and two use factors were extracted. Results indicate that in the majority of cases respondents perceive different forms of the same vegetable to be inappropriate substitutes for each other. Patterns were found which reflect the changes in usage patterns for certain forms of vegetables that have occurred in recent years. 相似文献
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MARIAN BURKE GEORGE E. BELCH RICHARD J. LUTZ JAMES R. BETTMAN 《The Journal of consumer affairs》1979,13(2):297-310
This paper investigates significant gaps in the information available to prospective home buyers as perceived by recent purchasers. The gaps in available information perceived by recent purchasers included the fair value of the house, its structural condition, and the ambience of the neighborhood. It was found that independent or personal sources were used for subjective information while objective data tended to be obtained from marketer-dominated sources. 相似文献
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We present a dynamic monetary model that consistently explains various phenomena such as unemployment, deflation, zero nominal interest rates and excess reserves held by commercial banks. These phenomena were observed during the Great Depression in the USA, the recent long‐run stagnation in Japan and the recent depression triggered by the subprime loan problem in the USA. We show that an excessive liquidity preference leads to a liquidity trap and thereby generates the phenomena. 相似文献
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Julian Birkinshaw 《Thunderbird国际商业评论》1995,37(3):279-301
The role of the country manager in the multinational corporation has changed substantially in recent years in both North America and Europe. Where the country manager previously held full responsibility for the national operations, frequently the role is now reduced to that of spokesperson and figurehead. This article describes four generic country management functions that were identified in a recent study of 15 multinationals, and describes the structural and environmental contingencies associated with each. The future role of the country manager is also assessed. © 1995 John Wiley & Sons, Inc. 相似文献
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