潜水蒸发对农业生产的影响与对策

近年来国家对农业种植生产活动给予了诸多优惠政策,激发了农民参与农田种植生产的积极性。水资源供应是农田作物生长的核心条件,维持水分持续供应是保障农作物成活率的关键要素。受到自然环境的营销,农田土壤中水分常出现异常蒸发现象,大大降低了土壤里水分的含有量,对农作物生长造成了不利因素。文章分析了潜水蒸发对农业种植活动带来的不利影响,提出控制潜水蒸发现象的具体对策。     

气象因子在海河流域蒸发悖论中的作用机理

蒸发是水文循环的重要环节。利用Mann-Kendall趋势检验方法检测了海河流域1961-2006年蒸发皿蒸发量的演变趋势。结果表明:海河流域蒸发皿蒸发量呈现出显著的下降趋势。利用相关分析、偏相关分析和主成分分析方法,研究了蒸发皿蒸发量与平均气温、相对湿度、平均风速和日照时数4种气象因子之间的关系。基于这4种气象因子,建立了模拟蒸发皿蒸发量的经验公式(E-THWS公式),并利用这一公式的微分形式揭示了这4种气象因子在海河流域"蒸发悖论"中的作用。结果表明:平均气温和相对湿度对海河流域蒸发皿蒸发量的增加作用要小于平均风速和日照时数的减少作用;平均风速的下降是蒸发皿蒸发量下降的主要原因。     

中水电如东海上风电场（潮间带）100 MW示范项目静载荷试验异常情况分析与处理

本文介绍了中水电如东海上风电场（潮间带）100MW示范项目升压站综合楼静载荷试验异常情况分析与处理情况,提出了施工中应进行实时监测等需注意的问题。     

经济体制的概念诠释及其精神实质

经济体制指的是国家在一定的经济制度基础上建立起来的具体经济关系和经济运作模式。经济体制总的来说可以划分为计划集权型经济体制、市场分权型经济体制以及混合型经济体制,它们有着各自的理论诉求及精神实质。社会主义初级阶段的经济体制就其精神实质来说是具有社会主义性质,能够解放和发展生产力的一种新型混合型经济体制。     

On Conformity Testing and the Use of two Stage Procedures

Conformity testing is a systematic examination of the extent to which an entity conforms to specified requirements. Such testing is performed in industry as well as in regulatory agencies in a variety of fields. In this paper we discuss conformity testing under measurement or sampling uncertainty. Although the situation has many analogies to statistical testing of a hypothesis concerning the unknown value of the measurand there are no generally accepted rules for handling measurement uncertainty when testing for conformity. Usually the objective of a test for conformity is to provide assurance of conformity. We therefore suggest that an appropriate statistical test for conformity should be devised such that there is only a small probability of declaring conformity when in fact the entity does not conform. An operational way of formulating this principle is to require that whenever an entity has been declared to be conforming, it should not be possible to alter that declaration, even if the entity was investigated with better (more precise) measuring instruments, or measurement procedures. Some industries and agencies designate specification limits under consideration of the measurement uncertainty. This practice is not invariant under changes of measurement procedure. We therefore suggest that conformity testing should be based upon a comparison of a confidence interval for the value of the measurand with some limiting values that have been designated without regard to the measurement uncertainty. Such a procedure is in line with the recently established practice of reporting measurement uncertainty as “an interval of values that could reasonably be attributed to the measurand”. The price to be paid for a reliable assurance of conformity is a relatively large risk that the procedure will fail to establish conformity for entities that only marginally conform. We suggest a two‐stage procedure that may improve this situation and provide a better discriminatory ability. In an example we illustrate the determination of the power function of such a two‐stage procedure.     

Hypsometric Integral Estimation Methods and its Relevance on Erosion Status of North-Western Lesser Himalayan Watersheds

Assessment of erosion status of a watershed is an essential prerequisite of integrated watershed management. This not only assists in chalking out suitable soil and water conservation measures to arrest erosion and conserve water but also helps in devising best management practices to enhance biomass production in watersheds. The geologic stages of development and erosion proneness of the watersheds are quantified by hypsometric integral. The estimation of hypsometric integral is carried out from the graphical plot of the measured contour elevation and encompassed area and by using empirical formulae. In this study, efforts were made to estimate the hypsometric integral values of the Sainj and Tirthan watersheds and their sub watersheds in the Lesser Himalayas using four different techniques, and to compare the procedural techniques of its estimation and relevance on erosion status. It was revealed that the hypsometric integral calculated by elevation–relief ratio method was accurate, less cumbersome and easy to calculate within GIS environment. Also comparison of these hypsometric integral values revealed that the Sainj watershed (0.51) was more prone to erosion than the Tirthan watershed (0.41). Further, the validation of these results with the recorded sediment yield data of 24 years (1981–2004) corroborated that the average annual sediment yield during this period for Sainj watershed (0.53 Mt) was more than that of the Tirthan watershed (0.3 Mt). Thus, the hypsometric integral value can be used as an estimator of erosion status of watersheds leading to watershed prioritization for taking up soil and water conservation measures in watershed systems.     

谈设计阶段建设单位对工程造价的控制

设计阶段的建设项目工程造价的控制是建设项目在做出投资决策后的控制重点,设计阶段是建设单位工程造价控制的关键和重点。阐述了建设单位加强设计阶段工程造价控制的意义以及采取的主要措施。     

浅谈施工阶段监理对质量的控制

监理是施工质量控制的一种必要措施,对工程的良好运行有着重要的意义。本文根据实际的工作情况及对《建设工程质量管理条例》的研究,浅谈了工程项目中监理工作应从事的具体内容与施工阶段的质量控制措施。     

浅谈设计阶段对工程造价的有效控制措施

工程造价的有效控制关键在于设计阶段。从工作实际出发，重点探讨了设计阶段对工程造价有效控制的原则和措施。     

浅谈各阶段工程造价控制及实例分析

建筑市场的竞争日益激烈,其中最主要的就是价格的竞争,该文讨论了如何在建筑工程项目设计全过程如何对造价进行更好地控制,最后并通过实例来检验。