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.     

Aggregate Dividend Behavior and Permanent Earnings Hypothesis

The study examines the aggregate dividend behavior of U.S. corporations based on the permanent earnings hypothesis. Using annual data of aggregate earnings and dividends from 1871–1993, I find that although managers change dividends proportional to permanent earnings changes, they make revisions with a larger percentage change in dividends than in permanent earnings. The results from the post‐war data show that firms follow a partial adjustment policy with a long‐term dividend payout target in mind and make revisions with a delay. The quarterly data analysis yields results similar to those of the post‐war annual data.     

FACTORS THAT AFFECT THE LONG‐TERM SURVIVAL OF MICRO,SMALL AND MEDIUM ENTERPRISES IN ETHIOPIA

There is an increasing recognition of the potential importance of micro, small and medium enterprises (MSMEs) for employment, income and poverty reduction in Ethiopia. Although the MSME sector contributes significantly to the national economy, the high failure rate among well established small businesses and enterprises is a matter of major concern. A random sample of 500 small businesses and enterprises selected from five major cities in Ethiopia were followed up for 6 years in order to assess the impact of influential factors that affect the long‐term survival and viability of small enterprises. Hazard ratios estimated from the Cox Proportional Hazards Model were used to quantify the impact of key predictors of survival. Businesses that ceased operation were characterised by inadequate finance (61%), low level of education (55%), poor managerial skills (54%), shortage of technical skills (49%), and inability to convert part of their profit to investment (46%). The study shows that participation in social capital and networking (iqqub schemes) was critically helpful for long‐term survival. Businesses that did not participate in iqqub schemes regularly were found to be 3.25 times more likely to fail in comparison with businesses that did. Results of the study have implications that could be used for developing policy initiatives that are aimed at fostering long‐term growth in small businesses and enterprises.     

上市公司利润操纵的经济动机

政府的每一次政策出台都为企业带来了新的生机与动力,但同时也诱导着一些企业进行着利润操 纵,我们应该看到,中国股票市场走过的10年道路中,规范与反规范的争斗从来没有停止过,正是由于 这样,促使我国证券市场不断发展。     

养老保险金替代率研究

养老保险金替代率是指一定地区当年离退休(含退职，下同)人员的养老金平均水平与该地区当年职工平均工资水平的比率，其是否合理，将影响到养老保险制度安排和政策取向。养老保险金替代率目标的确定，将受到一个国家或者地区的社会保障水平和经济发展水平等因素的影响。按照中国对基本养老保险制度改革的总体思路，未来基本养老保险金替代率目标确定为60％左右。目前，中国基本养老保险金替代率目标已经接近制度改革的目标，北京市的基本养老保险金替代率明显低于全国水平。企业退休金的替代率又明显低于事业和机关单位的退休金替代率，并呈现持续下降的趋势，应当设法进行遏止。     

刍议我国增值税转型

实行消费型增值税有利于加快企业发展,提升产品竞争力。目前我国已具备增值税转型条件,宜采用“一步到位”方式,但不宜提高税率。     

企业长期激励机制创新

长期激励机制匮乏问题一直是我国理论界和实业界最为关注的核心问题。指出目前在我国实行的长期激励措施的不足,提出了以“股息期权”,代替“股票期权”的激励方案,从而有效解决了我国目前的资本市场和法律法规对于“长期激励形式”的约束,可以为现阶段企业管理者进行薪酬激励机制设计时提供重要的参考和借鉴。     

价值型投资在中国证券市场上的有力证据

本文给出了1994年至2005年间价值型投资在中国A股市场中的有力证据。Fama—MacBeth回归表明在中国A股市场中存在着显著的市盈率和市净率溢价，1994年至2005年中牛市和熊市的滚动策略显示了我国A股市场中的价值效应，并且风险和收益之间基本上呈现出收益大、风险大的特征。本文的实证研究结果将有助于中小投资者以及机构投资者的长期投资决策。     

浅议增值税税负的税收筹划

该文从增值税税负分析着手,对增值税的税收筹划进行,不同层次的阐述,为降低增值税税负提供了多渠道、多方位的筹划空间.     

中国上市公司负债比率偏低的影响因素分析

本文在国外资本结构理论的基础上，将西方公司与中国公司的资本结构特点进行比较，从内因和外因两个方面解释了中国上市公司负债比率偏低的现象。