萍乡地区风能资源分布初探

分析了萍乡地区风能资源的形成。采用风速的韦布尔双参数方法测算出平均风能密度、平均有效风能密度,以及年风能可利用时间。根据风能区划标准,对萍乡地区的风能资源可利用程度和分布特征进行了初步分析。分析结果表明,萍乡地区风能随海拔高度呈梯度分布,且北部高于南部;萍乡市和莲花县属“风能贫乏区”,武功山属“风能可利用区”。     

A comparison of numerical schemes to solve the magnetic induction eigenvalue problem in a spherical geometry

We compare various methods of solving the magnetic induction eigenvalue problem in a sphere, each using toroidal–poloidal decomposition and spherical harmonics, but with a different radial discretisation. In the case of quiescent flow where only diffusion acts upon the magnetic field, we benchmark numerical convergence against the analytic decay rates, and find that a Galerkin scheme based on Chebyshev polynomials with an associated projection chosen such that the diffusion operator is self-adjoint, exhibits the fastest convergence of the schemes described. The importance of the speed of convergence becomes heightened with the introduction of a non-quiescent flow because of the reduction in the magnetic field length scales. We find that sufficiently converged solutions are generally difficult to locate unless we use the optimal Galerkin scheme.     

基于重力梯度结构张量特征值斜导数边界识别方法及其在南海的应用

边界识别对地质构造解释具有十分重要的意义,其可以指出地下断层、接触带和其他构造单元的边界位置.现有的边界识别滤波器大多数基于重力梯度数据及其水平和垂直导数.然而,这些传统方法具有一定的局限性,对噪音的敏感,且不能有效的均衡深浅异常的振幅,尤其是当测量异常中同时出现正异常和负异常将产生假的边界结果,对后期构造解释带来误导.针对传统方法的缺点,本文提出Tilt-Eigen边界识别方法,利用重力梯度结构张量矩阵特征值通过倾斜角计算结果的最大值实现边界识别.通过理论模型试验,该方法不仅能均衡深部浅部振幅异常的边界,避免引入额外的虚假边界异常,且识别的边界结果更加准确、收敛.将Tilt-Eigen方法用于南海实际重力数据处理,获得了20条比较清晰的边界结果.根据这些边界结果,本文推断红河断裂往ES方向延伸到南海南部区域后,开始朝正南方向延伸,与越东万安断裂相连接;推断出南沙海槽东北部为古南海缝合带,而其西南部并不是缝合带,缝合带位于其南侧的文莱沙巴附近;将南海分为8个地质构造单元.

     

Modeling spatial dependence in high spatial resolution hyperspectral data sets

 As either the spatial resolution or the spatial scale for a geographic landscape increases, both latent spatial dependence and spatial heterogeneity also will tend to increase. In addition, the amount of georeferenced data that results becomes massively large. These features of high spatial resolution hyperspectral data present several impediments to conducting a spatial statistical analysis of such data. Foremost is the requirement of popular spatial autoregressive models to compute eigenvalues for a row-standardized geographic weights matrix that depicts the geographic configuration of an image's pixels. A second drawback arises from a need to account for increased spatial heterogeneity. And a third concern stems from the usefulness of marrying geostatistical and spatial autoregressive models in order to employ their combined power in a spatial analysis. Research reported in this paper addresses all three of these topics, proposing successful ways to prevent them from hindering a spatial statistical analysis. For illustrative purposes, the proposed techniques are employed in a spatial analysis of a high spatial resolution hyperspectral image collected during research on riparian habitats in the Yellowstone ecosystem. Received: 25 February 2001 / Accepted: 2 August 2001     

门头沟区斋堂镇东河沟泥石流发育特征及防治工程

泥石流是北京地区危害性严重的地质灾害之一,其形成原因复杂、暴发突然、危害性大。针对门头沟区斋堂镇向阳口村东河沟泥石流发育特征,通过钻探、槽探、试验、物探等勘查手段,查明泥石流发育的自然环境、形成条件、基本特征及危害,对重要泥石流特征值包括泥石流流体重度、流速、流量、一次冲出量、一次固体冲出物质总量、泥石流整体冲压力、爬高和最大冲起高度等,进行定量计算。并根据勘查成果和泥石流沟发育特征,设计以稳拦、排导、清淤为综合工程治理思路,采用钢筋混凝土拦挡坝、浆砌石谷坊、排导槽、挡墙、沟道清理工程等多种措施,进行综合防治。