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31.
在分析遥感信息服务的领域特征及其概念的事件名词特点的基础上,结合框架语义学理论,提出了基于事件框架提取遥感信息服务概念的语义特征并在此基础上利用形式概念分析构建遥感信息服务分类本体的方法。实验结果表明了此方法的有效性。 相似文献
32.
藻蓝蛋白与叶绿素a作为特征色素常用于表征蓝藻的生物量.藻蓝蛋白与叶绿素a通常用荧光光谱或原位荧光强度检测,但是在实际水体中藻蓝蛋白与叶绿素a的荧光效应相互干扰会影响测量精度,极大限制了该方法的应用.本文根据朗伯比尔定律,利用二阶矩阵模型设计了一套在荧光检测过程中"激发光-发射光"优化抗干扰的波长选择方法,并利用多元线性回归分析建立了两种色素浓度与荧光强度之间的多元校正线性模型,实验验证了所筛选蓝藻荧光分析法中特定激发光和发射光波长的有效性.本研究实现了两种色素检测过程中的成功解耦,可在藻蓝蛋白的原位检测中排除水体中藻蓝蛋白与叶绿素a之间的相互干扰,提高藻蓝蛋白和叶绿素a的原位检测精度,为开发便携式蓝藻检测传感器时的波长选择提供理论基础. 相似文献
33.
Satellite-tracked Lagrangian drifters are used to investigate the transport pathways of near-surface water around the Luzon Strait. Particular attention is paid to the intrusion of Pacific water into the South China Sea(SCS).Results from drifter observations suggest that except for the Kuroshio water, other Pacific water that carried by zonal jets, Ekman currents or eddies, can also intrude into the SCS. Motivated by this origin problem of the intrusion water, numerous simulated trajectories are constructed by altimeter-based velocities. Quantitative estimates from simulated trajectories suggest that the contribution of other Pacific water to the total intrusion flux in the Luzon Strait is approximately 13% on average, much smaller than that of Kuroshio water. Even so, over multiple years and many individual intrusion events, the contribution from other Pacific water is quite considerable. The interannual signal in the intrusion flux of these Pacific water might be closely related to variations in a wintertime westward current and eddy activities east of the Luzon Strait. We also found that Ekman drift could significantly contribute to the intrusion of Pacific water and could affect the spreading of intrusion water in the SCS. A case study of an eddy-related intrusion is presented to show the detailed processes of the intrusion of Pacific water and the eddy-Kuroshio interaction. 相似文献
34.
南洞流域东部重点区石漠化现状及治理对策 总被引：8，自引：6，他引：2
为了探讨南洞流域东部重点区石漠化现状及其治理对策,通过遥感数据分析结果并结合地面实地调查验证,对云南南洞流域东部重点区石漠化分布特征、成因、危害及其区域林地生态环境质量状况进行了分析。结果表明,南洞流域东部重点区石漠化面积占岩溶区面积的17.2%,集中分布于大庄盆地西北部,以轻度石漠化为主,轻度、中度、重度石漠化的面积比例约为7∶3∶1,石漠化与水土流失问题突出,岩溶区林地生态环境质量等级以三级、四级为主,占区域总面积的53.77%,整体水平较低,且明显低于区内的非岩溶地区林地。粗放型畜牧和农耕方式是导致区内石漠化形成和加剧的最重要因素。提出休垦弃焚、恢复次生植被、合理开发利用土地资源、优化农林畜牧产业结构,实施林草建设工程、草食畜牧业工程、水利水保设施工程,建立保障制度和监督机制,开展全面的石漠化综合治理对策,以确保区域生态恢复、农林畜牧经济健康发展及南洞地下河流域生态安全和水资源开发利用。 相似文献
35.
Soundings on nautical charts provide information about the shape of the ocean bottom between chart depth curves. A single chart may have thousands of soundings posted on it. This article describes a system for automatic cartographic sounding selection. In this system, a new algorithm for automated selecting soundings is developed. The algorithm is employed in such a way that it can guarantee (a) fast and accurate selecting sounding, (b) processing the circular depth curves, (c) solving the overplotting problems between depth curves and soundings, and (d) keeping selected soundings “prettier.” The system was intensively tested using real data sets, and its superiority has been revealed by the testing results. 相似文献
36.
为揭示多级压气机中上下游叶轮对中间叶片叠加气动影响特性,阐述不同叠加干涉情况下下游叶轮进气角度变化,采用数值方法模拟了一级轴流和一级离心组成的组合压气机非定常流场。详细讨论了上游动叶尾迹和下游动叶势流对中间导流叶栅段气流非定常流动的异频和同频叠加干涉特性,依据计算结果,直观地展示了静叶通道中两种干涉间相互激励和抑制作用的位置和时间,与数学公式的推导结果相互印证。研究结果表明:当上下游动叶对中间静叶段异频干涉时,干涉的激励、抑制区域的轴向位置随时间发生变化;当上下游动叶对中间静叶干涉频率相同时,干涉的相互激励、抑制区域的轴向位置不随时间发生变化,但干涉的激励、抑制区域的轴向位置受时序位置影响。另外,上游动叶尾迹与下游离心叶轮势流的不同叠加情况,决定着下游离心叶轮进口相对气流角的大小及波动幅值。 相似文献
37.
Yao Daquan Shuo Zhi Shen Xiaoqi Chen Anguo Zheng Yingping Zheng Haigang Li Lingli 《中国地震研究》2010,24(3):363-370
During an excavation survey to the Daijiayuan vestige of the Western Zhou Dynasty-Late Spring and Autumn Period at Huoshan in Western Anhui,a ground crack related to tectonic movement and filled with silty fine sand was found. This phenomenon was initially confirmed to be due to seismic liquefaction. Many microscopic seismic relics,such as load structure,flow structure,cutoff plane and flotation of organic matter were found in the directional microscopic analysis of deformation. These discoveries and cognitions prove that there were two earthquake events taking place in the Western Zhou Dynasty-Late Spring and Autumn Period in this area. Above-mentioned works enrich and develop the research methods to identify prehistoric earthquake event in eastern China area to a certain extent. 相似文献
38.
39.
Up to now, detailed strategies and algorithms of automatic change detection for road networks based on GIS have not been discussed. This paper discusses two different strategies of automatic change detection for images with low resolution and high resolution using old GIS data, and presents a buffer detection and tracing algorithm for detecting road from low-resolution images and a new profile tracing algorithm for detecting road from high-resolution images. For feature-level change detection (FL-CD), a so-called buffer detection algorithm is proposed to detect changes of features. Some ideas and algorithms of using GIS prior information and some context information such as substructures of road in high-resolution images to assist road detection and extraction are described in detail. 相似文献
40.
济阳坳陷南部横向变换带构造演化及其油气聚集规律 总被引：1，自引：0，他引：1
利用高精度三维地震资料解释成果,分析了济阳坳陷南部中、新生代不同构造运动期与多位态主断裂(系)相伴生的横向变换带特征。研究表明,印支运动期横向变换带为NNE向展布,由侧向挤压褶皱和侧断坡组成;燕山运动期横向变换带走向为NEE向,由传递断层和横向凸起构成;而喜马拉雅运动期横向变换带则表现为NW向,由走向斜坡和传递断层组成。横向变换带构造演化使其不同构造部位具有叠加与迁移演化的差异性变化,从而形成不同的构造背景,造成了油气的差异聚集,其中变换带叠加可形成复式油气聚集带,变换带迁移则造成"满洼含油"的油气分布格局。 相似文献