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.     

DS-optimal designs in one way ANOVA

Characterization and construction of optimal designs using the familiar optimality criteria, for example A-, D- and E-optimality are well studied in the literature. However the study of the Distance Optimality (DS-) criterion introduced by Sinha (1970) has very recently drawn attention of researchers. In the present article, we consider the singularly estimable full rank problem of estimating the full set of elementary treatment contrasts using the DS optimality criterion in the set up of a one way ANOVA model. Using a limit argument it turns out that a CRD in which difference between any two allocation numbers is at the most unity is uniquely DS-optimal. Acknowledgement. We are thankful to Prof. B. K. Sinha for suggesting the problem to us and many helpful discussions with him. We are also thankful to the referees for drawing our attention to the reference of Bischoff (1995) and many helpful comments.     

Budget deficits and real interest rates: Updated empirical evidence on causality

Using error-correction model (ECM) estimation, the paper empirically examines the causality relationship between the federal government budget deficit and the ex ante real interest rate yield on high grade long term tax free municipal bonds in the U.S. To clarify this deficit or interest rate relationship, the budget deficit is measured by the primary budget deficit, which excludes net interest payments by the Treasury. In a model that includes federal personal income tax rates and net international capital flows, as well as money supply growth, the ECM estimates strongly suggest a bi-directional relationship between the primary budget deficit and the ex ante real interest rate yield. Budget deficits apparently do matter! William Simon's concerns were justified.The author is indebted to P. A. V. B. Swamy for ideas and helpful suggestions and Will Perry for data assembly and processing.     

会计准则国际趋同的报告

全球六家主要的国际会计师事务所在2003年2月12日发布了一份最新的国际财务报告准则(IFRS)调查报告:《会计准则的国际趋同报告——2002年全球调查》。该项调查的目的是评价世界各国采纳《国际财务报告准则》的情况和完备程度。调查背景介绍随着国际投资者越来越多地在全球范围内考虑其投资决策,对一个全球一致的财务会计框架的要求也越来越强烈。2001年4月,国际资本市场提出,改组后的国际会计准则委员会应该担负起制定全球统一的、高质量会计准则的使命。世界上主要的会计师事务所对国际会计准则委员会在制定全球统一的会计准则方面所作出…