Reservoir Operation Incorporating Hedging Rules and Operational Inflow Forecasts

Reservoir operation incorporating a naïve hedging strategy and operational inflow forecasting is studied in this paper. Gridded precipitation forecasts from climate model, ECHAM4.5, are used as potential predictors for reservoir inflow forecasting. In building a statistical predicting model, principal component analysis (PCA) is used to reduce the dimension of the regression model. Performance evaluation indices, including water supply satisfaction ratio, environmental flow satisfaction ratio, end-of-month storage satisfaction ratio and flood prevention capacity index, are defined. Three scenarios where a naïve hedging operation rule under different set of reservoir inflow are investigated. These are evaluated for a water supply reservoir, Falls Lake Reservoir, at Neuse River in the southeast United State. Reservoir simulation with monthly average inflow serves as a benchmark. The utility of operational inflow forecasts is quantified by the improvements of performance indices. Results show that reservoir operation under perfect inflow forecasting has the highest values for most indices. Compared to climatology, operational inflow forecasts result in higher index values. Among all the performance indices, end-of-month storage satisfaction ratio is the most sensitive index to inflow information. Limitation of this study and further work is also discussed.     

水利对粮食生产贡献率的认识与思考

针对目前很多人对农业科技进步贡献率和水利对粮食生产贡献率的不同认识,从发展历程、概念内涵、测算思路方法等方面,剖析了二者差异,认为二者在测算范围上存在大口径与小口径的差异,在测算对象上存在增量与总量的差异,在测算指标上存在产值与产量的差异,在测算方法上存在余值法与有无对比法的差异,为正确认识这两个指标提供了参考。     

Odour emission ability (OEA) and its application in assessing odour removal efficiency

Odourous emissions from sewer networks and wastewater treatment plants (WWTPs) can significantly impact a local population. Sampling techniques such as wind tunnels and flux hood chambers are traditionally used to collect area source samples for subsequent quantification of odour emission rates using dilution olfactometry, however these methods are unsuitable for assessing liquid samples from point sources due to the large liquid volumes required. To overcome this limitation, a gas phase sample preparation method was developed for assessing the total Odour Emission Ability (OEA) from a liquid sample. The method was validated using two volatile organic sulphur compounds (VOSCs), dimethyl-trisulphide (DMTS) and bismethylthiomethane (BMTM) that are frequently detected from sewers and WWTPs and are relatively stable compared with common VOSCs like mercaptan or methyl mercaptan. The recovery rates of DMTS and BMTM were quantified by injecting a known volume of a standard liquid sample into Tedlar bags using a static injection and a dynamic injection methodology. It was confirmed that both dynamic and static injection methods at ambient condition achieved high recovery rates with no need to consider increasing evaporation by elevating the temperature. This method can also be used to assess odour removal effectiveness of liquids by comparing the OEA before and after the treatment tests. Two application examples were presented.     

移动台车栏板辅助浇筑系统的设计与应用

蒲石河工程下水库大坝顶部混凝土护栏位于坝顶临空边沿,钢筋绑扎和模板支立作业难度大,施工时存在安全隐患。为此,蒲石河工程设计了移动台车栏板辅助浇筑系统并成功应用。实践表明,作业台车设计可靠、安全稳定、操作简便、定位准确、移动方便,保障了施工人员人身安全,节约了成本,加快了工期,提高了模板支立质量,值得类似工程借鉴并推广使用。     

Biochemical responses of the copepod Centropages tenuiremis to CO(2)-driven acidified seawater

An ecophysiological experiment was conducted to examine the biochemical effects of acidified seawater containing elevated concentration of CO(2) (C(CO2) 0.08, 0.20, 0.50 and 1.00%) on the copepod Centropages tenuiremis. AchE, ATPase, SOD, GPx, GST, GSH level and GSH/GSSG ratio of the copepod were analyzed. The results showed that elevated C(CO2) and the duration of culture time significantly influenced several biochemical indices in C. tenuiremis (ATPase, GPx, GST, GSH and SOD). Furthermore, the principal component analysis results indicated that 72.32% of the overall variance was explained by the first three principal components (GPx, SOD and GSH). Changes in GPx and GSH levels may play a significant role in the antioxidant defense of copepods against seawater acidification. The long-term response of copepods to seawater acidification and the synergistic effects of acidification with other environmental factors, such as temperature, salinity and trace metal need further investigation.     

Enhanced P, N and C removal from domestic wastewater using constructed wetland employing construction solid waste (CSW) as main substrate

Construction solid waste (CSW), an inescapable by-product of the construction and demolition process, was used as main substrate in a four-stage vertical subsurface flow constructed wetland system to improve phosphorus P removal from domestic wastewater. A 'tidal flow' operation was also employed in the treatment system. Under a hydraulic loading rate (HLR) of 0.76 m3/m2 d for 1st and 3rd stage and HLR of 0.04 m3/m2 d for 2nd and 4th stage of the constructed wetland system respectively and tidal flow operation strategy, average removal efficiencies of 99.4% for P, 95.4% for ammoniacal-nitrogen, 56.5% for total nitrogen and 84.5% for total chemical oxygen demand were achieved during the operation period. The CSW-based constructed wetland system presents excellent P removal performance. The adoption of tidal flow strategy creates the aerobic/anoxic condition intermittently in the treatment system. This can achieve better oxygen transfer and hence lead to more complete nitrification and organic matter removal and enhanced denitrification. Overall, the CSW-based tidal flow constructed wetland system holds great promise for enabling high rate removal of P, ammoniacal-nitrogen and organic matter from domestic wastewater, and transforms CSW from a waste into a useful material.     

承德水资源与经济社会发展关系及对策建议

结合承德市历史与现实经济发展,从水资源对人口、环境、农业、工业、地区生产总值等五方面的影响,分析其经济发展与水资源的关系,反映出水资源对当地经济社会快速发展的重要支撑作用,同时深入分析承德水资源开发利用中存在水资源紧缺、河流水体污染严重、水资源利用效率低等突出问题,从五方面提出对策建议,以期利用好水资源,为承德经济发展提供有力支撑.     

切实采取措施推动证券市场健康持久的发展

王光远,第九、第十届全国政协委员,民建中央常委,厦门大学会计系教授、博士生导师,福建省审计厅副厅长。王教授是会计界知名学者,其博士论文《外向型管理审计的规范化问题》和博士后研究报告《管理审计理论》在国内相关审计研究领域被引用的频率相当高。作为连续两届的全国政协委员,王教授一直十分关注注册会计师行业的改革和发展。在本次政协会议上,他多次发言呼吁,要切实采取措施,推动证券市场健康持久的发展。所谈内容十分精采,既有现实高度,又有理论深度,且与注册会计师职业生存环境息息相关。大家可从中开阔视野,更加全面和深刻地认识注册会计师在社会经济生活中应有的位置和责任。本刊特将王教授的发言摘要刊出,以飨读者。     

石油企业发展电子商务的意义及应注意的问题

针对石油企业如何利用电子商务，加快自身发展建设为主题，从电子商务的概念，优点和意义入手，对石油企业如何实施电子商务，实施的条件和应注意的几个问题等进行了详细的阐述。认为在网络经济发展的今天，石油石化企业只有抓住机遇，大力利用电子商务，提高传统产业的竞争力，才能在市场竞争中立于不败之地。