流动环境中平面负浮力排放的数值模拟

建立流动环境中平面负浮力倾斜射流的二维k-ε湍流模型，采用D M Shahrahani和J D Ditmars(1976)的试验资料进行检验，并且对平面负浮力倾斜射流流动特性进行了数值预报。给出了射流的分区及分区的界限，同时亦给出了涡心断面的物理量的分布及典型断面上湍动能平衡图。     

含中心孔的椭圆区域内位势流动分析

本文利用相似流动替换方法，解决了中心有圆孔的椭圆形区域内的位势流动问题；采用分区域解法，给出了中心有椭圆孔的椭圆形区域内位势流动问题的解析通解。该问题在油气田开发工程等许多领域中有重要意义。     

恒定有压扩散流中的局部非稳态流动试验研究

试验研究了恒定二元水平有压扩散流中的局部非稳态流动现象。利用壁面丝线流动显示技术观测了局部非稳态流动现象，给出了发生局部非稳态流动的临界扩散角；利用三维点流速仪对局部非稳态流动的流速进行了数据采集，通过功率频谱分析和互相关分析，得出了非稳态流动的基本特征；探讨了局部非稳态流动的成因和条件。     

温盐双扩散系统中均势场的二维模拟

本文主要对二维情况下温盐浮力比λ为Ｉ的温盐均势场的流动情况进行了探讨，地在温盐均势场中不同的流动参数对流场流动的结构所产生的影响作了大量的数值模拟工作，发现在温盐均势即使是给出第一类边界条件，流动仍然存在多种不同的平衡态，出现多胞流的稳定平衡和周期震荡，而且在不同参数下稳定流状态和周期震荡的运动周期有较大的差别。     

流动电流法混凝投药控制应用技术的研究

本文从实践应用技术的角度出发，（1）系统地分析和研究了流动电流法混凝投药控制系统的取样部分，包括取样系统中的取样点的选择、预处理器的构造和设计、取样流量的分析等，给出了取样系统的设计原则，总结了控制系统中存在的应用问题和解决方法；（2）提出了流动电流法混凝投药串级控制系统；（3）给出了串级控制系统的理论，为该系统的实验室试验和生产应用奠定理论基础；（）进行了流动电流串级控制系统实验室的模型试验研究。模型试验包括实验室模型的构造设计、模拟工艺的选择，控制系统的启动和运行等。模型试验初步考察了该串级控…     

从二相流方程出发研究平衡输沙—扩散理论和泥沙扩散系数的讨论

根据力平衡原理研究泥沙汲工的垂向分布，参照湍流混合气体运动中组元间作用力的本构式的构成，给出了湍流二相流相间阻力的本构式，并由此推导了充分发展的明渠流动中泥沙浓度的垂向分布。以本文给出的泥沙力平衡方程为基础，引入某些近似可推导出沿用至今的（泥沙运动的）扩散理论所给出的方程。     

二平行流之间幂率流体层流剪切流动的数学模型

非牛顿流体的平行剪切流动是一种在自然界和工程实践中常见的流动。本文应用流体力学和非牛顿流体力学理论，利用Ｐｒａｎｄｔｌ边界层方程，在未作任何其它假设的情况下，得出了幂率流体平行剪切层流流动时的相似变量，给出了两充体指数ｎ相同时的常微分方程和定解条件。     

混流式转轮三维湍流流动计算方法

本文研究了基于κ-ε模型的全三维湍流计算技术在水轮机转轮流动计算中的应用方法。文中给出了以求和下标表示的在贴体坐标下的湍流基本方程组，介绍了计算中计算体、初边值的给定方法。最后，介绍了应用该程序对某电站水轮机所作优化后的主要流动计算结果显示。     

平行平板缝隙流中粘性阻力的研究

随着流体传动和控制在机械领域中的广泛的应用．正确分析和计算流体在流动中的粘性阻力，已成为很重要的课题．文中对不同边界条件下、平行放置的平板之间的层流缝隙流动给出了粘性阻力和沿程损失系数的计算公式，为正确、方便地计算平行平板间流动提供了理论依据。     

水轮机转轮内部的三维固液两相紊流计算

利用K-ε-AP两相紊流模型和SIMPLEC法计算水轮机转轮内部的三维固液两相紊流.计算结果给出了水轮机转轮内部的三维固液两相流动的主要流动参数，例如，连续相(液相)和离散相(固相)速度，两相速度滑差，固液两相流动下的压力分布等。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

浅谈优化Vray渲染在制作三维场景的应用研究

用Vray三维渲染引擎来渲染三维场景,其质量和速度是由一些影响因素和参数设置决定的,不同的参数和因素,可以得出不同的三维渲染效果.因此,分析、优化三维渲染质量和速度的影响因素,正确、合理的选择参数对提高Vray最后渲染阶段的质量和速度非常重要.     

固结、渗流和沉积控制方程研究

本文从两相流体动力学的守恒方程出发，考虑固相、液相的相对运动，推导了可以考虑场的不均匀性和流体压缩性的统一形式的控制方程，并对方程所基于的物理概念和相互联系进行了必要的分析。通过对方程适当形式的表达，可导出用于大、小变形固结、渗流和沉积的简化方程，显示了在不同领域的三个理论存在一定的统一性。方程推导过程并未对本构关系加以限制，适用范围较广。依据实际问题的要求，作了不同形式的简化。     

四川省及重庆市中型水电站效益分析

该文分析了四川省及重庆市几座中型水电站的调查材料表明：四川省及重庆市中型水电站不仅在川渝主网和地方电网中起着很大的作用，并具有巨大的社会效益，同时还有综合利用效益，说明修建中型水电站的优越性．     

Site modelling methods for detecting hydrologic alteration of flood frequency and flood duration in the floodplain below the carlyle dam,lower Kaskaskia River,Illinois, USA

Reports concerning the influence of dams on river hydrology vary among researchers, interest groups and government agencies. These often contradicting statements may occur because changes in hydrology caused by dams are distinct for each dam and river watershed. The objective of this research was to use site specific techniques to determine if the 1967 installation of the Carlyle Dam, lower Kaskaskia River, Illinois, altered flood frequency and duration within the forested floodplain located below the dam. Results indicated a decrease in flood duration and frequency, and a decrease in annual flood frequency variation at a site 6.4 km below the dam. Pre‐dam versus post‐dam differences in flood frequency and duration at the site 32.2 km below the dam were related to climate rather than dam effects. Although dam impacts are a concern, this research shows that distance downstream from the dam and downstream tributary and watershed characteristics should be considered before assuming that the dam has changed hydrologic parameters for portions of rivers. This research also indicates that areas of the lower Kaskaskia River may still maintain hydrologic ecological integrity, and could be targeted for restoration and adaptive management purposes. Hydrologic modelling combined with river gage and on‐site well measurement techniques presented in this study could provide detailed flood frequency and duration information for land use, sociological and geomorphological questions in focus areas within river floodplains. Copyright © 2008 John Wiley & Sons, Ltd.     

Statistical tools for thermal regime characterization at segment river scale: Case study of the Ste‐Marguerite River

Suitable thermal fish habitats are constrained by both maximum and minimum temperature tolerances. A multivariate and geostatistical approach was developed to estimate stream thermal characteristics at the river segment scale. Data from 22 temperature‐monitoring stations during summer 2007 were used to estimate monthly maximum temperature as well as thermal characteristics such as the number of events, the cumulative degree–days and the associated duration over specific temperature thresholds of 19 and 21°C. The probability of exceeding these temperature thresholds has also been interpolated. The methodology relies on the construction of a multivariate space using physiographic and hydrological characteristics of gauging stations as inputs in a canonical correlation analysis (CCA). A geostatistical interpolation technique, ordinary kriging, was subsequently used to perform interpolation in the physiographical space constructed using CCA. Results from this study were obtained for thermal characteristics estimated into two different interpolation spaces: (1) a 7 metrics space, and (2) an 8 metrics space. Cross‐validation technique has been performed and satisfactory results were obtained. Kriging thermal characteristics (magnitude and duration) into the 7 metric space for a 19°C threshold exceedance leads to best results with Relative Root Mean Square Error (RRMSE) ranging between 9.66 and 15.08%. The study shows that kriging in a multivariate space is a promising tool for water resources managers, especially in cases where risk mapping for lethal or sub‐lethal temperature thresholds may be required for a specific fish species. Copyright © 2010 John Wiley & Sons, Ltd.     

掺MgO混凝土的宏细观试验研究

利用MgO膨胀剂的延迟微膨胀效应能显著提高大体积混凝土的力学性能,产生的预压应力还能有效提高大体积混凝土抵抗温度开裂的能力,但目前对其微观机理研究不多。采用宏观与微观相结合的方式,研究了不同活性指数、不同掺量的MgO混凝土的力学性能,利用SEM/EDS微观分析手段揭示了MgO对混凝土性能影响的作用机理。试验结果表明：MgO取代部分水泥掺入混凝土中,混凝土的力学性能降低;掺量为4%~5%时,活性指数为100s的MgO混凝土的膨胀率大于活性指数为50 s的MgO混凝土;MgO混凝土的膨胀特性与Ca,Si,Mg,Al等元素的分布情况有关,掺入的MgO将改变界面区Ca,Si,Mg元素的富集特性,Ca元素和Mg元素更易于在界面区富集,导致混凝土宏观力学性能的降低。     

基于MIDAS软件探讨施工工序对深基坑稳定性的影响

基于武汉地铁名都站深基坑工程与水文地质勘察资料,建立了三维工程地质仿真计算模型。依据名都站深基坑开挖支护方案,利用有限元软件MIDAS的摩尔-库仑本构模型,对武汉地铁名都站深基坑施工过程中,不同施工工序下每步开挖之后,基坑的变形情况做仿真模拟计算,并对比分析其对基坑稳定性的影响。结果表明：基坑围护结构的变形情况与施工工序有很大的关系,施工工序越合理,上部土体变形越小,反之越大。因此,在基坑工程的施工过程中,要注重施工步骤的划分与合理安排,从而保证基坑工程的安全。研究成果为以后武汉地区基坑工程的施工设计提供了值得借鉴的经验。