斜拉桥动力特性的参数分析

建立了斜拉桥动力分析的三维有限单元模型 ,研究了单元类型和参数变化对斜拉桥动力特性的影响。详细地讨论了斜拉桥非线性来源 ,并运用 6节点薄壁单元和 4节点索单元分别考虑了斜拉桥弯曲构件和索的非线性特性。通过对一斜拉桥的数值分析 ,得到了关于斜拉桥动力参数敏感性的一般结论。     

防渗涂料在蔺河口碾压混凝土拱坝中的应用

蔺河口碾压混凝土拱坝以二级配富胶凝材料碾压混凝土及变态混凝土自身作为防渗体为主,大坝死水位以下涂刷LJP型合成高分子防渗涂料,作为辅助防渗措施。通过涂料材质性能试验,证明该涂料可以满足施工需要,并可以简化防渗结构,方便施工,大坝自2003年10月27日蓄水运行以来,防渗效果良好。     

沙牌RCC拱坝坝肩稳定三维地质模型试验研究

通过三维地质力学模型试验，研究了沙牌RCC拱坝坝体和坝肩的变形规律、破坏机理，综合评价了坝肩的超载安全度，为工程设计提供依据。     

Transport of chromium(VI) through a Cyanex 921‐supported liquid membrane from HCl solutions

The transport of chromium(VI) through a flat‐sheet supported liquid membrane containing Cyanex 921 as a carrier has been investigated. The permeation of the metal is investigated as a function of various experimental variables: hydrodynamic conditions, concentration of chromium(VI) and HCl in the feed phase, carrier concentration and diluent in the membrane and strippant concentration in the stripping phase. The mass transfer coefficient and the thickness of the aqueous boundary layer were calculated from the experimental data. Furthermore, the selectivity of Cyanex 921‐based flat‐sheet supported liquid membrane towards different metal ions and the behaviour of the system against other carriers are presented. Copyright © 2003 Society of Chemical Industry     

乙基叔丁基醚/β分子筛膜反应精馏

研究了混合碳四和乙醇合成乙基叔丁基醚(ETBE)的反应精馏过程。实验以支撑β分子筛膜为催化精馏元件，异丁烯转化率高达95％，回流比和醇烯摩尔比是影响异丁烯转化率的主要因素。与甲基叔丁基醚(MTBE)的反应精馏过程相比，以乙醇取代甲醇，只需对MTBE生产的操作条件作一些简单的调整，就可在其生产装置上合成ETBE。     

钢包烘烤装置的发展

概述了钢包烘烤的意义，钢包烘烤装置的进展。     

南哨水电站拱坝体型设计

南哨水电站位于雷公山暴雨中心区， 洪水峰高量大， 水库基本无滞洪削峰， 由于坝址处河床深切而狭窄， 溢洪道作拱坝坝身表孔溢流短鼻坎挑流的布置。为使溢洪道既有较好的挑流消能效果， 又能达到控制大坝工程投资的双重目的， 将混凝土拱坝体型作了一反常规的设计布置， 即河床部分悬臂梁的上部向水库倒悬呈负坡， 岸边悬臂梁渐变为竖直呈正坡； 水平拱圈曲率由高到低逐渐变小， 而曲率半径则逐渐加大。拱坝的体型适应了溢洪道作高落差挑流鼻坎的布置， 使其溢洪舌远离坝脚， 经运行１３ 年来多次洪水的检验， 在下游不做消能防冲工程措施的情况下， 保证了大坝和下游两岸岩体的稳定安全， 而大坝和溢洪道运行状态良好。     

Cryogenic temperature measurement for large applications

We have developed a resistance thermometry system for the acquisition, control and monitoring of temperature in large-scale cryogenic applications. The resistance of the sensor is converted to a voltage using a self-balancing AC bridge circuit featuring square-wave excitation currents down to 1 nA. The system is easily scalable and includes intelligent features to treat special situations such as magnet quenches different from normal operation.     

Analysis of XANES for identification of highly dispersed transition metal oxides on supports

XANES of vanadium and niobium oxide on silica or alumina have been analyzed quantitatively by a deconvolution technique. Based on the results for reference compounds, local structures of supported vanadium and niobium species were identified. The composition was estimated from difference spectra for the samples which consisted of two kinds of species.