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91.
通过地震活动性周期估计、地震活动性层次模型和对大震前地震活动异常分布的分析,研究了帕米尔东北侧地区未来地震危险性以及可能发生强震的地点。研究结果表明:该区未来几年存在着发生7级以上或8级左右地震的危险性,其发震地点可能在帕米尔东北侧的西半部。 相似文献
92.
本文通过分析当今水化台站面临的观测水点及观测手段越来越少、经费普遍紧张、分析预报水平难以提高等问题及其解决办法 ,进而提出了台站今后工作的努力方向。 相似文献
93.
Gürcan Büyüksalih Güven Koçak Hüseyin Topan Murat Oruç Aycan Marangoz 《The Photogrammetric Record》2005,20(110):130-146
SPOT 5 HRG Level 1A and 1B stereo scenes covering Zonguldak testfield in north-west Turkey have been analysed. They comprise the left and right image components with base to height ratio of 0·54. The pixel size on the ground is 5 m. The bundle orientation was executed by the PCI Geomatica V9.1.4 software package and resulted in 3D geopositioning to sub-pixel accuracies in each axis provided that at least six control points were used in the computation. Root mean square error (rmse) values and vectors of residual errors for Levels 1A and 1B are similar, even for different control and check point configurations. Based on the scene orientation, Level 1A and 1B digital elevation models (DEMs) of the testfield have been determined by automatic matching and validated by the reference DEM digitised from the 1:25 000 scale topographic maps, interferometric DEMs from Shuttle Radar Topography Mission (SRTM) X- and C-band SAR data and the GPS profiles measured along the main roads in the testfield. Although the accuracies of reference data-sets are too similar to the generated SPOT DEMs, these are the only high quality reference materials available in this area. Sub-pixel height accuracy was indicated by the comparison with profile points. However, they are in favourable locations where matching is always successful, so such a result may give a biased measure of the accuracy of the corresponding DEMs. 相似文献
94.
陆良气田和保山气田为云南第三系较为典型的小型气田,埋藏浅、胶结疏松、水体发育。气砂体识别、合理完善开发井网、控水和控砂采气、多层合采、排水采气等项关键技术成功应用,是气田能够实现成功开发的重要保证。 相似文献
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97.
数字水准仪视距公式的探讨 总被引:3,自引:0,他引:3
本文探讨了数字水准仪视距公式的来源,常数与仪器光学参数的关系,提出了用最小二乘拟合求常数的方法并给出了算例。 相似文献
98.
南极晚更新世40,000年B.P.和在20,000年B.P.间曾有两次海侵,当时的海面比现在高6-35m。在18,000年B.P.全球低海面时,中国南极长城给所在的南设得兰群岛为一相连大岛,当时的海面比现在低100-130m。冰后期南极海面上升,在6,000年B.P.为高海面,当时海面比现在高2m。随后的6,000年以来,南极处于地壳均衡上升阶段,形成海拔20m以下连续发育的海岸阶地。 相似文献
99.
从地震综合预报实际出发,提出了地震前兆信息的系统结构思想。运用系统结构值P定量和综合地反映前兆系统的信息变化,并应用于滇西地震短临预报的实践中。通过23次震例内检,结果表明对提高地震综合预报能力具有积极作用。 相似文献
100.
The Bonarelli Level (BL) from the upper Cenomanian portion of the reference Bottaccione section (central Italy) is characterized by the presence of black shales containing high TOC concentrations (up to 17%) and amounts of CaCO3 near to zero. In the absence of carbonate and, consequently, of relative carbon- and oxygen-isotopic data, the elemental geochemistry revealed to be a very useful tool to obtain information about the palaeoclimatic and palaeoceanographic evolution of the Tethys Ocean during the OAE2. Based on several geochemical proxies (Rb, V, Ni, Cr, Si, Ba), the BL is interpreted as a high-productivity event driven by increasingly warm and humid climatic conditions promoting an accelerated hydrological cycle. The enrichment factors of peculiar trace metals (Zn, Cd, Pb, Sb, Mo, U) provide further insight about the H2S activity at the seafloor during the organic-rich sediment deposition and permitted us to evaluate the use of Ba as palaeoproductivity tracer in conditions of high rate of sulphate reduction.By comparing geochemical records from the reference Bottaccione section (central Italy) with those previously obtained for the coeval Calabianca section (northwestern Sicily), different degrees of oceanic anoxia were delineated and ascribed to different abundance and type (degradable or refractory) of organic matter, which are limiting factors in the bacterial sulphate reduction reactions and in subsequent euxinic conditions at seafloor in the Tethys realm. Based on a ciclostratigraphic approach, consistent fluctuations at 100 ky scale in the chemostratigraphic signals from the two sections are inferred to be expression of a strong orbital-climatic forcing driving changes in the oceanic environment during the BL deposition. 相似文献