水电站尾水管混凝土施工期温控仿真分析和防裂

水工混凝土结构中裂缝的存在和发展,既影响建筑物的外观,引发渗漏,同时也影响混凝土结构强度和稳定性。采用数值计算方法对某拟建的水电站尾水管混凝土进行施工过程仿真计算,根据气候、材料、约束等实际情况研究防裂工作的有利及不利条件,分析多种表面保温条件下的温度场和应力场情况,据此对混凝土施工中的温控防裂措施提出合理的建议。     

组态技术与动态分析在大坝安全远程在线监测DSROMS系统中的应用

在突发事件或特定的环境状态下,快速、准确地获取大坝重要部位或对大坝结构有控制作用的部位的安全运行状态资料是至关重要的,在大坝安全在线监测中,运用组态技术与动态在线智能分析能在特定的环境中发挥巨大作用,可更加直观地给出大坝的安全运行状态和近期的变化趋势。     

正确处理水利发展过程中的关系问题

本文从治水理念与治水措施、防洪与兴利、不同类型河流、开源与节流、工程措施与非工程措施、工程建设与生态环境等六个方面,阐释了在水利发展过程中需要认真思考与对待的几种关系,旨在为可持续的水利发展提供新的思路与发展方向。     

碾压混凝土坝分层浇筑施工风险及其控制措施研究

坝区高温低湿、大风等极端天气会使分层浇筑混凝土层间结合性能发生劣化。通过测定极端天气环境（如：高温低湿、大风）下混凝土的层面状态（含水量、贯入阻力）和层间劈裂抗拉强度,对3种施工措施（如表面不处理、覆盖保温被和界面凹槽）进行了研究。结果表明：碾压混凝土坝在极端环境下浇筑存在施工风险。在高温低湿条件下覆盖保温被并不能有效避免层间结合质量的下降,界面凹槽可以小幅度地提高坯层间结合强度;在大风条件下坯层表面覆盖保温被及采用界面凹槽处理是比较可行的措施,可以保证坯层间结合质量满足要求。在大风条件下覆盖保温被,一方面防止了水分的散失,另一方面延缓了混凝土的凝结速率,使得层间劈拉强度得到保证。     

Fluorescence spectroscopy characteristics of humic acid by inoculating white-rot fungus during different phases of agricultural waste composting

The white-rot fungus, Phanerochaete chrysosporium (P. chrysosporium), was inoculated during different phases of agricultural waste composting, and its effect on the fluorescence spectroscopy characteristics of humic acid (HA) was studied. The results show that the emission spectra have a sharp peak at 400 nm and a broad shoulder with the maximum centered at 460 nm. The excitation spectra have two peaks and exhibit red shift (shift to longer wavelengths) at 470 nm. The synchronous scan spectra present a number of peaks and shoulders, and the peaks at shorter wavelengths disappear gradually and form a shoulder. At the final stage of composting, the fluorescence spectra have similar shapes, but the fluorescence intensities decrease. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase. Compared with the fluorescence spectroscopy characteristics of HA from soil, the structure of HA from compost is simpler and the activity is higher. Foundation item: Project(2005CB724203) supported by the Major State Basic Research and Development Program of China; Project(IRT0719) supported by the Program for Changjiang Scholars and Innovative Research Team in University of China; Projects(50608029, 50808073) supported by the National Natural Science Foundation of China; Project(2007185) supported by the Environmental Protection Technology Research Program of Hunan Province, China