基于三线流模型的垂直裂缝井采油指数研究

针对低渗透地层垂直裂缝井的渗流过程,考虑了启动压力梯度和介质变形系数的影响,建立了三线流模型。根据此模型可得到不同地层及裂缝参数条件下油井采油指数变化规律。计算结果表明：在相同的生产压差条件下,采油指数随着变形系数的增大而减小,随着启动压力梯度的增大而减小,随着裂缝半长增大而增大。     

中国城市居住分异研究

对城市居住空间的研究是城市社会学的一个重要内容.自建国以来,我国城市居住空间经历了逐渐分异的历史变迁过程.如果不对居住分异加以适当的调控就会出现居住空间极化与隔离问题.城市居住空间极化是社会不公正在居住空间上的表现.城市政治经济转变与城市规划、土地制度改革与房地产开发、住房制度改革与住房商品化是转型过程中城市居住分异形成的三个主要原因.扩大中等收入群体规模、增加社会自组织力量、制定公正的社会政策是优化城市居住空间结构的有效途径.     

316L不锈钢脱硫塔的焊接制造

文章介绍了3l6L不锈钢脱硫塔在焊接制造中控制几何形状与垂直度的焊接工艺条件和质量控制方法。     

同步生物除磷脱氮新工艺探讨

近十年来,同步生物除磷脱氮一直是城市污水处理的新热点,磷氮排放标准严,除磷脱氮研究步步深入,除磷脱氮新工艺不断涌现。文章列出了当前城市污水同步生物除磷脱氮的几种新工艺流程及其一些特点,初步讨论了“工况交替”、“固液分离”和“曝气形式”有关问题。     

上市公司终极控制人两权分离度的决定因素分析——基于2004年上市公司经验数据研究

本文以2003-2004年我国上市公司的股权结构、资产状况、现金收入与发展前景等方面的数据,采用理论分析、描述性统计与多元回归假设检验等方法,分析了我国上市公司两权分离度的影响因素。结果发现:上市公司终极控制人两权分离度的大小主要取决于上市公司的企业规模、企业资产可控性、现金流状况、企业发展前景、第一大股东持股比例、终极控制人控制层级与股权性质。     

上海人口郊区化与产业郊区化协同发展研究

上海市人口郊区化和产业郊区化发展的过程中,由于人口规划和城市基础设施建设、产业发展和城市之间缺少有效地协调机制,公共服务资源配置相对滞后,造成郊区新城人户分离、产城分离问题日益严重。通过对社会、经济、政策等相关因素的分析,鉴于郊区经济发展对人口的导入功能将进一步增强,郊区人口还将持续增加,从人口郊区化与产业郊区化协同发展的角度对产业发展、人才引进、公共资源配置等方面提出了建议。     

Vertical differentiation,product innovation,and dynamic competition

This paper presents an infinite horizon dynamic model in which two firms compete in a market vertically differentiated by the qualities of their products and consumers have heterogeneous preferences for quality. Given the product qualities offered, the firms engage in price competition that segments the market. In each period each firm can spend on product innovation that if successful increases the quality of its product. Three types of Markov perfect equilibria are identified. A running–coasting equilibrium exhibits increasing quality dominance with one firm undertaking innovation and the other coasting to free ride on the innovation by the first firm. The firm that coasts can have the larger dynamic payoff, so quality dominance does not imply payoff dominance. A second is a leap‐frog equilibrium in which the trailing firm undertakes innovation to leap into the lead. The trailing firm never innovates solely to narrow the gap with the leader, so catch up strategies are never used. In the third both firms undertake innovation, but if both have innovation successes, product differentiation remains the same and profits are reduced by the cost of innovation. The rivalry between Intel and AMD in microprocessors for personal computers provides a motivating example.     

Vertical separation of transmission control and market efficiency in the wholesale electricity market

This study examines how vertical separation of transmission control affects the wholesale market efficiency in the electric power industry. We analyze a unique regional electricity wholesale market in the U.S. where initially restructuring only occurred in the transmission sector. Following a commonly-used best dispatch model (Wolfram, 1999; Borenstein et al., 2002), we simulate competitive benchmark prices and compare with the best estimates available for actual prices to measure price-cost markups of the wholesale market. Empirical results demonstrate that the vertical separation of transmission control led to a significant increase in market markups in peak-load hours, documenting evidence of enhanced market power. Although we also find a reduction in the price-cost margin in low-demand hours, we reserve caution for this finding.     

High-quality bias in vertically differentiated oligopolies—a note on skills, trade, and welfare

In a vertically differentiated Cournot oligopoly where the high-quality variant of the good requires the use of high-quality labor, firms may either all supply the same quality or differentiate their product. In differentiated configurations the number of firms choosing to supply the high-quality variant is generally above the optimum. The opening of trade between symmetric countries entails a pro-competitive effect that raises welfare through a reduction in average quality. This result contrasts with previous findings concerning the opening of trade in vertically differentiated oligopolistic industries (Gabszewicz, Shaked, Sutton, and Thisse,International Economic Review 22 [1981]; Shaked and Sutton, in Kierzkowski, ed.,Monopolistic Competition and International Trade, Oxford 1984).     

论信托财产权的三重二元结构

我国信托法有关信托财产权配置不明、当事人权利义务不清等问题不解决,即使银监会转变对信托公司的监管思路也无法从根本上化解信托兑付危机。构建信托财产权的“三重二元”结构,即信托财产权包含信托财产物权和债权,信托财产物权由受托人和受益人分别享有,信托财产债权由受托人注意义务和对信托财产享有的债权构成,或可廓清信托公司不能兑付信托计划时的责任承担,赋予受益人竞合性请求权,既可化解刚性兑付危机,亦保障了受益人权益。