中国股市市盈率分布特征及国际比较研究

本文对市盈率的内涵、计算方法、区间确定等理论问题进行了剖解 ,针对中国股市流通股、非流通股并存等特征 ,对市盈率在中国股市的计算方法进行了分析 ;在此基础上对中国股市市盈率分布特征进行实证分析和国际比较研究 ,认为目前沪深股市泡沫成份已较少 ,市盈率在合理区间之内 ,中国股市具有投资价值     

TCP/IP拥塞控制研究

综述了Internet上TCP/IP拥塞控制研究方面一些最新的工作,分析了拥塞控制的原理、TCP/IP拥塞控制所使用的典型技术,并着重论述了TCP/IP拥塞控制所面临的问题,包括自相似性问题、效率问题、区分服务等问题,并提出进一步研究的方向。     

The Sanaga discharge at the Edea Catchment outlet (Cameroon): An example of hydrologic responses of a tropical rain‐fed river system to changes in precipitation and groundwater inputs and to flow regulation

The Sanaga River is one of Sub‐Saharan Africa's largest and greatly regulated rivers. Available flow data for this hydrosystem largely cover the pre‐ and post‐regulation periods. From comparisons between unregulated (hypothetical) and observed scenarios, it has been possible to separate and to quantify hydro‐climatic (groundwater + rainfall) change effects from anthropogenic impacts (especially dam‐related alterations). To appreciate shifts in the river regime, discontinuity detection tests and the IHA model were applied to discharge data series reflecting average and extreme flow conditions, respectively. Results obtained principally from the Hubert segmentation method reveal that a major discontinuity occurred in 1970–1971 separating a surplus phase between 1945–1946 and 1969–1970, and a deficient and much contrasted one, from 1971/1972. This implies that the Sanaga catchment is dominantly affected by hydro‐climatic changes. However, wide land cover/land use changes experienced here since 1988 have resulted in an increase in surface runoff. Additional quickflows linked to these changes may have partly compensated for the substantial decline in the dry season rainfall and groundwater inputs observed from this date. Although at the monthly scale, dam‐related impacts on average flows increase with stage of regulation, the seasonal variability of the river regime remains generally unaffected. A comparison of the IHA statistics, calculated from unregulated and observed streamflow data, show that hydrologic shifts occurring in maximum and minimum discharges are mostly significant from 1971/1972 and are mainly due to the action of dams. Minimum flows appear, however, widely impacted, thus reflecting the prime objective assigned to the existing reservoirs, constructed to supplement flows for hydroelectricity production during the dry season. Copyright © 2010 John Wiley & Sons, Ltd.     

三峡水情遥测系统中心站的设计与应用

三峡水情遥测系统中心站在通信组网设计上采用甚高频（VHF）、公共交换电话网络（PSTN）、全球移动通信系统（GSM）、北斗卫星和海事卫星5种通信方式,在系统软件设计上采用了客户／服务器（C／S）的结构模式。实践证明,三峡水情遥测系统中心站既保证了三峡水情遥测系统非常高的畅通率和准确率,又降低了通信成本;既保证了三峡梯级水库调度、防洪、发电和航运的要求,同时还为系统运行维护工作提供了方便。     

漳河水库入库径流序列变化趋势分析

依据漳河水库1963-2008年入库径流资料,采用R/S分析方法和M ann-Kendall参数秩次相关检验法对其未来入库径流变化趋势进行了分析。结果表明:①水库流域未来径流量将呈缓慢下降的趋势,且未来1月和7月的径流量变化趋势的随机性成份可能很大,应采取必要对策和措施,以应对未来可能出现的干旱或暴雨洪涝等自然灾害。②1995年为突变点,前后两个系列的统计特征值均具有明显的差异,已经不符合"一致性"的要求。③对于20世纪70~80年代的持续枯水期,应理解为这只是其径流丰枯周期变化中的一个枯水期。④流域人类活动日趋频繁,使得流域下垫面条件发生了较大的变化,对入库径流量有较大的影响。     

Fenton接触氧化法强化石英砂—锰砂滤料处理铁锰矿井废水

为了解决目前常用的接触氧化法除铁除锰工艺中铁离子存在时锰离子难去除的问题,本文重点研究了Fenton接触氧化法强化石英砂-锰砂滤料的除铁除锰效率和机理。结果表明:Fenton试剂+锰砂+石英砂工艺除铁锰的效果很好,影响因素的最佳值如下:加入H2O2形成Fenton试剂后可以强化石英砂-锰砂工艺除铁除锰的效果,当H2O2投加量为0.15 mg/L、滤速为8 m/h、pH为7时,铁离子的去除率可达到92%,当H2O2投加量为0.17mg/L、滤速为8 m/h、pH为7时,锰离子的去除率可以达到97%。     

Managerial judgment and forecast combination: An experimental study

This paper examines the role of managerial judgment in forming a final forecast, or judging the achievability of a critical level of sales, when multiple forecasts or opinions are available to the decision maker. Several factors that can help improve the quality of human intervention are identified and incorporated in a decision aid. Experimental results show that aided combination can help the decision maker exploit her relevant private information and mitigate the generally observed negative effects of human intervention. Further, the results suggest that emphasizing expected sales, even when the organization is primarily interested in go/no-go decisions, helps improve performance. Several suggestions for future research are presented.

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