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421.
利用双阳台水管观测资料检测地球自由振荡 总被引:2,自引:2,他引:0
基于双阳台水管倾斜仪的数字化观测资料,利用功率谱密度估计方法,在没有对资料进行去固体潮处理的情况下,准确获得了2004年12月26日苏门答腊大地震激发的0S3~0S31基频球型自由振荡。并与PREM模型的理论自由振荡周期进行了对比,发现实测振荡周期与PREM预测的振荡周期相吻合,除0S3、0S4振型的观测周期和PREM模型理论周期的相对误差大于0.3%外,其他振型的观测周期和PREM模型理论周期的相对误差大都集中在0.1%左右。同时还检测到了5个谐频球型振荡和8个环型振荡。 相似文献
422.
介绍野外型断层活动连续监测系统的组成、布设及主要技术指标。 相似文献
423.
424.
1 INTRODUCTION Pit connection is an important feature in Rhodophyta and significant in algal phylogeny. Various documents have illustrated the existence of pit-connection in red alga previously (Migita, 1967; Ramus 1969a, b; Bourne et al., 1970; Lee and F… 相似文献
425.
The Wenchuan Earthquake that occurred in May of 2008 caused damages to large areas of Sichuan, Gansu, and Shaanxi provinces
in China. Reports from local governments and related management agencies show that the giant panda nature reserves in the
earthquake-hit areas were heavily damaged. Our estimates in this paper of the impacts of the earthquake on the giant panda
in the earthquake-hit areas were made based on the interpretation of remote sensing images and information collected by field
survey. A rapid assessment method was designed to estimate the damages of the earthquake on giant panda habitats. By using
visual interpretation methods, we decoded the remote sensing images of the disaster area in the 49 giant panda nature reserves.
Research results showed that the Wenchuan Earthquake and the succeeding secondary geological disasters caused great damages
to the giant panda nature reserves and disturbed the normal life of the giant pandas there (e.g., landscape fragmentation
increased significantly). Undoubtedly, the life of the giant pandas there was affected. However, although the earthquake caused
certain impacts on the giant pandas, it did not really threat their survival. Even so, we still strongly advocate for protection
of the giant pandas, and have prioritized a couple of measures to be taken to restore the giant panda nature reserves in the
earthquake-hit areas. 相似文献
426.
Remote sensing image segmentation is the basis of image understanding and analysis. However, the precision and the speed of segmentation can not meet the need of image analysis, due to strong uncertainty and rich texture details of remote sensing images. We proposed a new segmentation method based on Adaptive Genetic Algorithm (AGA) and Alternative Fuzzy C-Means (AFCM). Segmentation thresholds were identified by AGA. Then the image was segmented by AFCM. The results indicate that the precision and the speed of segmentation have been greatly increased, and the accuracy of threshold selection is much higher compared with traditional Otsu and Fuzzy C-Means (FCM) segmentation methods. The segmentation results also show that multi-thresholds segmentation has been achieved by combining AGA with AFCM. 相似文献
427.
Wenjie Wang Hua Zheng Chao Xu Weiguo Jiang Yunhui Du Wei Wang Zhe Zhang Xiaofu Liu 《中国地理科学(英文版)》2014,24(1):71-82
Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China.In order to clarify the interrelation among key ecological zone plans,this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas(key ecological function areas,key regions of ecological service function,national nature reserves) and the research on ecological conditions,based on multi-scale ecological spatial theme information,which incorporates elements like ecologi-cal quality and type,and by the aid of spatial information analysis and GIS modeling.The results showed a contrastively fine spatial consistency with 68.8% of priority areas of biodiversity conservation overlapping with three key ecological areas.Although the envi-ronment in priority areas of biodiversity conservation were in good conditions,protection pressure is also increasing,powerful supervi-sion and protection should not be ignored.The environmental conditions in the overlapping areas,as a whole,were superior to those in the non-overlapping areas.Since two areas have different characteristics,targeted protection measures should be formulated based on this difference,which will be very important for biodiversity conservation in priority areas of biodiversity conservation. 相似文献
428.
使用搭载200&400 MHz复合天线的LTD系列探地雷达,对埋设的未爆弹进行探测试验,并运用克希霍夫积分偏移法及三维插值算法对探地雷达数据进行三维成像。试验结果能准确地反映出浅埋未爆弹的位置信息,可指导排爆人员进行精确的开挖及排除。 相似文献
429.
����ɽ-�����ִ��ؿ��α�������Ӧ�䳡�ֲ� 总被引:1,自引:1,他引:1
????1998??2011?????????????90??GPS?????????????????????-????????????????????????????????????????????????????GPS????????????1???о??????????????????????????????????????????????????????2)?????????????????????????????????????????????????????????3)????????????????????????й????????????????з?????????????????????????????? 相似文献
430.