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1.
水电站对外公路设计既要满足水电站施工期间对外交通运输要求,又要便于水电站完工后移交地方交通部门统一管理。结合金沙江上游乌东德等梯级水电站对外公路设计实践,通过对水电站对外公路的任务、功能及特点的分析,从公路设计等级、设计速度、建筑限界、荷载标准、平曲线设计等方面,对主要技术标准和指标的运用进行了论述;总结了设计经验和体会。对类似工程设计具有参考作用。 相似文献
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The difficulty of selecting appropriate rheological model and parameters for the alternating distribution of soft and hard rock layers was often encountered due to the unhomogeneity, discontinuity and anisotropy of rock mass. The Burgers and generalized Kelvin models were applied to the soft and hard rock respectively and the rheological parameters were obtained based on the method of optimum separation. By using the simulated code FLAC^3D, the stability of surrounding rocks of a certain underground plant was analyzed. The effect of surface load and weakening the parameters intensity of argillaceous and bioclastic interlayers between soft and hard rock on rheological behavior of layer composite rock mass was investigated. The results indicate that the rheological characteristics of soft and hard rock layer in composite rock mass can be described well with above two rheological models. 相似文献
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支持向量机(Support Vector Machine,SVM)是在统计学习理论基础上发展起来的一种新的机器学习方法,已成为目前研究的热点,并在模式识别领域有了广泛的应用.首先分析了支持向量机原理,随后引入一种改进的径向基核函数,在此基础上,提出了一种改进核函数的SVM模式分类方法.与基于IRIS数据,进行了计算机仿真实验,与基干模糊k-近邻的模式分类仿真结果比较,结果表明改进的SVM方法分类性能比模糊k-近邻算法(Fuzzy k-Nearest Neighbor,FKNN)的分类性能更好,运算时间更短,更易于实时实现. 相似文献
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《Engineering Analysis with Boundary Elements》2005,29(9):903-911
In this paper, a new boundary condition accounting for energy radiation at the far end of covered reservoirs is proposed. Using boundary element modelling (BEM), the boundary condition is investigated through analysis of the hydrodynamic pressure within a two-dimensional ice-covered reservoir impounded by a gravity dam. The proposed boundary condition accounts for reservoir bottom absorption effects and the presence of an ice cover at infinity. Seismic excitation is introduced by subjecting the dam and the reservoir to a horizontal harmonic ground motion. The effectiveness of the proposed method and the accuracy of the boundary condition are examined through a parametric study. The boundary condition is shown to be accurate even when placed near the dam upstream face, and the results obtained are in excellent agreement when compared to those from a mathematical model developed by the authors in a previous work. Some fundamental aspects of hydrodynamic pressure within ice-covered reservoirs are also discussed. 相似文献
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《Hydrometallurgy》1986,16(3):325-334
The dissolution rate of synthetic scheelite in an alkaline EDTA leach solution under atmospheric pressure has been determined by use of a rotating disc method. The effects of disc rotation speed, temperature, reagent concentration and pH of leach solution have been investigated. The dissolution rate was proportional to the square root of the disc rotation speed. The apparent activation energy of dissolution of synthetic scheelite was 22 kJ mol−1 within the experimental temperature region of 24 to 99°C. A first order dependence of dissolution rate on EDTA concentration was observed. It has been shown from the experimental results that the dissolution reaction was controlled by the mass transfer in the aqueous solution. 相似文献
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