Comparative study of adsorption behavior of copper, lead, and zinc onto goethite in aqueous systems   总被引：2，自引：1，他引：2  

Z. S. Kooner 《Environmental Geology》1993,21(4):242-250

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A systematic and efficient method of computing normal modes for multilayered half-space   总被引：15，自引：0，他引：15  

Xiaofei Chen 《Geophysical Journal International》1993,115(2):391-409

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四阶矩准正态分布和三阶矩剪切近似的验证   总被引：1，自引：0，他引：1  

张强  胡隐樵 《大气科学》1994,18(4):396-404

本文利用近地面层大气湍流量的观测资料对四阶矩的准正态分布假定和三阶矩的剪切近似进行了实验验证。结果表明，四阶矩能够较好地符合准正态分布假定；三阶矩不仅完全满足剪切近似，甚至还可以对剪切程度进一步加强，并且得到了一系列剪切近似的加强修正系数。  相似文献   

随机效应线性模型中随机回归系数的泛岭估计类     

归庆明 《测绘学院学报》1994,(1)

本文提出了随机效应线性模型中随机回归系数的一个线性有偏估计类（称为泛岭估计类）；通过偏参数的不同选择，构造了许多很有意义的线性有偏估计；并讨论了泛岭估计的优良性和可容许性，获得了若干深入的结果。  相似文献   

解混合边值问题直接计算位系数的变分原理     

郭俊义 《武汉大学学报(信息科学版)》1993,(3)

本文提出了利用变分法解混合边值问题直接计算位系数的原理。根据这一原理可解第一、第二和第三边值问题的混合边值问题直接求得位系数。利用这一原理可较简单地联合利用经典重力测量(即重力点的平面位置由天文或三角测量确定,高程由水准或三角高程确定)、卫星重力测量(即利用卫星定位技术确定重力点的平面位置和大地高)以及卫星测高数据研究地球的重力场。  相似文献   

Improving Numerical Weather Prediction in Low Latitudes by Optimizing Diffusion Coefficients     

Liu Jinda 《大气科学进展》1993,10(3):345-352

The horizontal diffusion coefficients of the operational model (T42L9) in numerical weather prediction are optimized by the steepest descent search of multi-dimensional optimization. In order to improve prediction accuracy in low latitudes, the optimum horizontal diffusion coefficients are chosen, with changing variation of the basic diffusion coefficient with the passage of time, and later forecasts are also made better. In view of the averages of forecast verifications of 9 cases, the forecasts with optimum diffusion coefficients are an improvement on operational forecasts. It means that the forecasts are got much better with optimum values of some important parameters by optimization in numerical weather prediction.  相似文献   

精度和可靠性标准作为第一,二准则的优化设计     

周世健 《华东地质学院学报》1994,17(2):178-183

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双淹没矩形体的透反射特性分析   总被引：1，自引：0，他引：1       下载免费PDF全文

刘鹏飞  游亚戈  胡城 《海洋学报》2007,29(1):133-138

采用解析方法研究了斜向入射波作用下双淹没矩形体的透反射系数特性.首先利用特征函数展开法导出了绕射势函数的分析解并进一步得到透反射系数的计算公式,然后利用边界元方法验证了解析解.与单个的淹没矩形体相比,双淹没矩形体在一定范围内有较高的反射系数.最后利用解析解分析了若干工况下的双淹没矩形体的透反射特性,给出了影响透反射系数的几何因素.  相似文献   

Significant wave height forecasting using wavelet fuzzy logic approach   总被引：2，自引：0，他引：2  

Mehmet Özger 《Ocean Engineering》2010,37(16):1443-1451

Wave heights and periods are the significant inputs for coastal and ocean engineering applications. These applications may require to obtain information about the sea conditions in advance. This study aims to propose a forecasting scheme that enables to make forecasts up to 48 h lead time. The combination of wavelet and fuzzy logic approaches was employed as a forecasting methodology. Wavelet technique was used to separate time series into its spectral bands. Subsequently, these spectral bands were estimated individually by fuzzy logic approach. This combination of techniques is called wavelet fuzzy logic (WFL) approach. In addition to WFL method, fuzzy logic (FL), artificial neural networks (ANN), and autoregressive moving average (ARMA) methods were employed to the same data set for comparison purposes. It is seen that WFL outperforms those methods in all cases. The superiority of the WFL in model performances becomes very clear especially in higher lead times such as 48 h. Significant wave height and average wave period series obtained from buoys located off west coast of US were used to train and test the proposed models.  相似文献   

A new method for separation of 2D incident and reflected waves by the Morlet wavelet transform   总被引：1，自引：0，他引：1  

Yuxiang Ma  Guohai Dong  Xiaozhou MaGang Wang 《Coastal Engineering》2010

A new method based on the Morlet wavelet transform for separating a 2D wave field into incident and reflected waves is proposed in this paper. The principle of this method, first, is derived for constant depths. Then, using the linear shoaling theory, the method is extended to an arbitrary sloping bathymetry. Owing to the time-frequency characteristic of wavelet transform, the present method can separate waves in the real time domain and is not confined by the stationary assumption of waves. The efficiency and accuracy of this method are demonstrated using numerical simulated data.  相似文献