The reference spectral noise ratio method to evaluate the seismic response of a site

The seismic response of several sites in the Durban area of South Africa has been investigated using a refined version of the spectral ratio (H/V) generated by cultural seismic noise. Two samples of noise separated by an interval of several minutes for the vertical and the two orthogonal horizontal components were taken at each site. Though the two samples differed noticeably in the time as well as in the frequency domain, when the components are considered separately, the ratios of the horizontal to the vertical spectra were very similar for most of the pairs. This similitude was obvious not only in the frequencies of the peaks, but also in the range of amplifications involved. These observations have been used to introduce a refinement to the Nakamura Method. This refinement consists in using as a reference the H/V spectral ratio of a well-known, hard rock site. All the other soft sites of interest are then compared with this standard reference site. This comparison provides valuable information on the frequencies and amplification factors introduced by the critical soft sediments. This refined method will be referred here as the ‘Reference spectral noise ratio’.This method, is compared to a similar one devised to investigate the response of horizontal layers to longitudinal seismic waves, using the ratio of the spectra generated by long- period waves.     

几种农作物矿物增效复合专用肥的应用研究

由沸石、膨润土和麦饭石等几种物化性能优越的非金属矿物按一定比例配合并粉碎成一定的粒度,再根据不同农作物生长所需的养分特点,与氮、磷或氮、磷、钾肥和微素（ 肥） 混合制成矿物增效复合专用肥。这种肥料既具有普通复合专用肥的特点,还具有保水、保肥和改良土壤之功能     

基于新参考系的极移改正

本文利用IAU2000决议中关于CIP的定义阐述了极移坐标系和极移坐标的定义,在总结微分旋转矩阵的性质的基础上给出了极移旋转矩阵的详细推导,结合极移产生的主要原因,详细介绍了目前国际上关于极移模型化工作的最新进展,最后给出了获取极移坐标和TIO位置的方法和途径。     

斜轴墨卡托投影方法在郑西客专中的应用研究

介绍了斜轴墨卡托投影,分析了其具体实现过程,实现了在郑西客运专线精密控制测量的应用,有效地解决了东西走向线路投影差对工程影响较大的问题。     

LRS在城市地下管网数据管理中的应用

随着城市现代化建设的飞速发展,城市地下管网的更新越来越频繁,实现管网数据的高效、规范管理尤为重要。文中分析线性参照系统和动态分段技术在表达线性特征网络中的优点,结合城市地下管网布置更新的特点,提出基于线性参照系统和动态分段技术的城市地下管网的实体表达。     

3维地理空间信息布景关键技术研究

3维地理空间表达和描述的地理要素,往往具有多样性和复杂性的特点。3维布景作为地理空间信息表达的一种方式,可以针对特定需求,实现空间地理现象的灵活配置和合理化布设,满足人们对地理要素与环境认知的多方面需求,促进地理空间信息应用服务。此处描述了地理空间中3维布景的基本概念;论述了空间信息布景所涉及的5项关键技术,包括插件式软件架构、渲染引擎、数据结构与索引、海量数据调度和3维符号化配置;通过软件平台的开发进行了实验。     

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分数阶微积分在医学图像处理中的应用

简要介绍了分数阶微积分和医学图像的概念,然后从分数阶微分基本定义出发,得到了可以作用于二维医学图像的分数阶微分掩模,掩模可以根据对图像的需求进行增强,最后通过实验证明,这个方法可以有效完成对医学图像的处理,并且弥补了传统方法不能连续改变处理效果的缺点,是一种简单可行并且效果较好的图像增强方法。     

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