外掺MgO砼快速筑拱坝施工导流与度汛初探

该文是2001年度广东省水利重点科研项目“外掺MgO砼不分横缝快速筑拱坝新技术应用研究”中有关专题的主要内容之一．通过剖析广东5座拱坝工程实例,研究外掺MgO砼快速筑拱坝与常规砼拱坝在施工导流、度汛和下闸蓄水的特性与规律．表明采用常规砼拱坝同样的施工导流基本条件即可完成外掺MgO砼快速筑拱坝施工。并且坝体砼浇筑高程能满足挡水度汛条件的要求达到提前下闸蓄水发电。     

乳源坝美水电站拱坝工程外掺MgO砼不分横缝筑坝主要施工技术

该文重点介绍了坝美水电站工程外掺MgO砼不分横缝筑拱坝施工配合比优化、施工布置、浇筑方案、MgO施工均匀性质量控制、砼表面保温和养护等主要施工技术。     

坝美拱坝MgO掺量拟定的一些体会

MgO掺量拟定是外掺MgO砼不分横缝快速筑拱坝的关键技术问题之一，目前尚未有规范和相关指引可循，工程实践经验仍不多。坝美拱坝是广东省第二宗应用外掺MgO砼不分横缝快速筑拱坝技术的工程实践，在此对坝美拱坝MgO掺量拟定作简要介绍，并浅谈一些体会。     

坝美拱坝MgO掺量的拟定

MgO掺量的拟定是外掺MgO砼不分横缝拱坝的关键技术问题之一。在总结广东省长沙拱坝采用外掺MgO砼不分横缝快速筑拱坝技术成功实践经验的基础上，通过外掺MgO砼试验和仿真分析，拟定了坝美拱坝的MgO掺量并付诸工程实施。本文对坝美拱坝MgO掺量的拟定作了简要的介绍。     

广东长沙拱坝裂缝分析

广东阳春长沙拱坝是国内首座应用外掺MgO砼不分横缝快速筑拱坝新技术的工程，建成后第一年越冬下游坝面出现了一些局部裂缝，备受同行关注。该文从仿真计算的坝体应力状态、坝体施工质量与养护、原体砼抽芯检验等影响因素分析裂缝原因；对产生同类裂缝的常规砼拱坝实例进行对比，分析裂缝与MgO砼不分横缝快速筑拱坝新技术无必然联系性；根据原体观测分析目前大坝处在安全正常运用状态。     

外掺MgO砼快速筑拱坝浇筑模式的探讨

结合广东省几个实例工程砼拱坝的特性，阐述了外掺MgO砼不分横缝快速筑拱坝实施可行性的内在因素，分析了浇筑方案及影响施工进度的主要因素，并提出了值得进一步探讨的问题。     

关于外掺MgO砼快速筑拱坝应用技术研究的问题

通过广东长沙拱应用外掺MgO砼不分横缝快速筑拱坝新技术的工程实践,提出了完善“新技术”应用研究的主要问题，研究成果将对推广应用“新技术”具有重大意义和价值。     

外掺MgO砼不分横缝快速筑拱坝的工程实践

以广东省长沙拱坝工程实践为例,从设计,施工方面较全面阐述了外掺MgO砼不分横缝快速筑拱坝新技术,并提出原型观测初步成果和今后要进一步研究的主要问题。     

外掺MgO砼在变温条件下的膨胀特性试验研究

外掺MgO砼筑坝技术是项新技术,我国应用该技术已成功建成了多座大坝,广东在应用该技术方面已经从重力坝发展到双曲拱坝,长沙拱坝是世界上第一座外掺MgO砼不分横缝快速筑坝的成功范例。实践证明,应用MgO砼筑坝技术可以节省温控措施、简化施工工艺．缩短工期,技术和经济效益显著。“外掺MgO砼在变温场条件下的膨胀特性试验研究”是广东省水利厅重点科研项目“外掺MgO砼不分横缝快速筑拱坝技术应用研究”课题的关键内容之一,它是MgO砼筑坝技术中设计仿真计算和原形观测资料分析时不可缺少的关键资料。该文介绍了该课题研究的意义、目的、方法及研究成果。     

外掺MgO混凝土不分横缝快速筑拱坝施工研究

广东省阳春市长沙双曲拱坝、贵州省贵阳市沙老河双曲拱坝、三江双曲拱坝和广东乳源坝美双曲拱坝．均采用“外掺MgO混凝土不分横缝快速施工”技术建成。本文在总结这四座拱坝的施工实践经验的的基础上，提出了适合外掺MgO混凝土快速筑拱坝技术特点的优选施工方案，可为同类工程借鉴。     

Tastes associated with products in contact with drinking water.

Over the past 9 years the Australian Water Quality Centre (AWQC) has conducted testing in accordance with Australian and New Zealand Standard AS/NZS 4020--"Products for use in contact with drinking water" (1999). A test included as part of this standard is taste of water extracts. This test assesses the ability of products to impart discernible taste to drinking water using panellists trained in accordance with Standard Methods for the Examination of Water and Wastewater--Flavour Profile Analysis 2170 B (1999). Over 1000 products from companies worldwide, have been assessed at the AWQC in accordance with AS/NZS 4020 including pipes, valves, tap fittings and numerous other products used in contact with water. The products must not impart any discernible taste to obtain compliance and be deemed suitable for use in contact with drinking water. This study compiles the products assessed and the types of tastes obtained from both chlorinated and non-chlorinated extracts. In particular the study focuses on taste associated with polyethylene pipes, coatings and valves, which in some instances have been problematic. Analysis revealed that most taste problems occur when chlorinated water has been used in extraction experiments and this is in line with consumer complaints regarding taste imparted by plumbing products. The collation of this data provides a valuable assessment for manufacturers, the water industry and consumers.     

大尺度水文模型及其与气候模型的联结耦合研究

本文综述陆地表面水文过程，大尺度水文模型及其与气候模型联结耦合研究的最新进展和存在问题。介绍ＧＥＷＥＸ－ＧＡＭＥ研究项目的目标和内容，科学价值和现实意义及其在我国开展研究的计划。     

不同改性膨润土处理染料废水的实践

钙基膨润土经不同的改性,可用来处理染料废水.分析比较了不同改性后的膨润土处理染料废水的效果.处理效果由强到弱,依次是柱撑酸化膨润土、柱撑膨润土、酸化膨润土、酸化柱撑膨润土、钠化膨润土、钙基膨润土.     

Hydrological daily rainfall-runoff simulation with BTOPMC model and comparison with Xin'anjiang model

A grid-based distributed hydrological model, the Block-wise use of TOPMODEL (BTOPMC), which was developed from the original TOPMODEL, was used for hydrological daily rainfall-runoff simulation. In the BTOPMC model, the runoff is explicitly calculated on a cell-by-cell basis, and the Muskingum-Cunge flow concentration method is used. In order to test the model's applicability, the BTOPMC model and the Xin'anjiang model were applied to the simulation of a humid watershed and a semi-humid to semi-arid watershed in China. The model parameters were optimized with the Shuffle Complex Evolution (SCE-UA) method. Results show that both models can effectively simulate the daily hydrograph in humid watersheds, but that the BTOPMC model performs poorly in semi-humid to semi-arid watersheds. The excess-infiltration mechanism should be incorporated into the BTOPMC model to broaden the model's applicability.     

Coping with Hydrological Extremes

Abstract

Coping with hydrological extremes, floods, and droughts has been a major concern since the dawn of human civilization. Freshwater, a necessary condition of life and a raw material used in very high volumes in virtually every human activity, is becoming increasingly scarce. Water use has risen considerably in the last hundred years at a pace exceeding the population growth. Therefore, societies are increasingly vulnerable to droughts and water deficits. Although the 21st century is heralded as the age of water scarcity, flood losses continue to grow. Increasing global vulnerability results to a large extent from soaring anthropopressure: settlements in hazardous locations and adverse land use changes. Deforestation and urbanization lead to reduction of the storage volume and higher values of runoff coefficient. In more wealthy countries, it is the material flood losses that continue to grow, while the number of fatalities goes down. Advanced flood preparedness systems can save lives and reduce human suffering. In some regions of the world, long-term forecasts (e.g., ENSO) help improve the preparedness for hydrological extremes, both floods and droughts, and hopefully will even more so in the future. Scenarios for future climate indicate the possibility of sharpening the extremes and changes of their seasonality. For instance, in Western Scotland and Norway, an increase of winter floods has already been observed. According to recent assessments, there is a growing risk of summer droughts in the Mediterranean region: less precipitation in summer and higher temperature will coincide, causing higher evapo-transpiration and less runoff. Fighting with floods and droughts has not been quite successful. Humans have to get used to the fact that extreme hydrological events are natural phenomena that will continue to occur. While doing one's best to improve the preparedness systems, it is necessary to learn to live with hydrological extremes.     

Spillway with nappe aeration

Conclusion Investigations showed that aeration of the flow by jump-off aerators is a simple, reliable, and economic means of protecting the overflow surface against cavitation erosion or suppressing it on an operating structure. Flow aeration can be regulated by the size of the jump-off aerators and change of the capacity of the air-supply system. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 16–20, May, 1973.     

只以今生续画缘

此生能够画画并以此为业,可算是与画有缘。对画画感兴趣可能是大多孩子的爱好。余少时亦能在乡贤教诲下描摹动物、鞍马、人物,那也只不过是一种儿时的游戏。延伸下来慢慢地竟成了养家糊口安身立命的职业,可以说这真的是一种幸运,可谓与画有缘。