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61.
The seismic hazard in the Sannio-Matese area has been worked out by a modification of the McGuire (1976) computing programme, taking into account the influence of nine potential seismic source zones.The method uses truncated-quadratic intensity-frequency distribution and azimuth-dependent intensity attenuation derived from isoseismal maps for each of the seismogenetic sources. A new modification has been introduced to take into account different decay of the intensity in the near (to VIII degree) and far (from VIII degree) field.Different assumptions about maximum possible intensities and truncation of intensity-frequency laws are used to evaluate the effects of the uncertainties on the computed hazard at high intensities. Intensities associated with different level of annual probability are computed for five test sites in the considered area. Maps displaying the expected intensity for a mean return period of 500 years (pa 0.002) are presented and compared with observed intensities.Presented at the XXIst General Assembly of the European Seismological Commission, Symposium on Methods of Seismic Hazard Assessment in Europe, Sofia, 23–27 August 1988. 相似文献
62.
我们建立了用于地球物理信号对比的一种人机联作的处理方法.对多种信号匹配的算法做了研究、改进和实现,把算法研究和人工测井对比的知识和经验进行归纳,形成基于规则的信号处理,并设计了层次化分解处理结构,实现多种算法的混合运用和数据驱动的算法参数选择.由于结合了相关资料信息和解释人员判断,信号对比问题才能更为适定.人机联作的处理模式以用户的参与来克服一些智能化处理实现的困难.实测结果证明该方法有效. 相似文献
63.
不同补给源的水,其水质、水温存在差异。根据质量和热量守恒原理,通过对不同补给水源进行长期观察,可确定矿坑水的补给源及其比例。作者推导出了存在二种和三种补给水源情况下各补给水源所占比例的计算公式,并应用到湖南洞口县的石下江煤矿,取得了良好效果。 相似文献
64.
TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE
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Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinearmodification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Re-suits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in theneighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic modeplay a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely onthe Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the pairedsources. 相似文献
65.
66.
TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE*
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Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinear modification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Resuits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in the neighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic mode play a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely on the Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the paired sources. 相似文献
67.
本文针对山区电测深的结症,通过实例介绍了一种新方法──多源电测深法的应用效果。在三面环山、岩石裸露等物探自然条件极为不利的情况下,应用多源电测深法成功地圈定了8411西段铀-硅质体的展布,预测了银竹凹铀成矿远景区段,为8411矿床的扩大指明了方向。实践表明:多源电测深法具有探测深度大、工作效率高、资料解释直观可靠等优点,是一种行之有效的物探方法。 相似文献
68.
69.
More than a thousand acoustic-emission (AE) hypocenters were determined in a cylindrical andesite specimen under two-stage uniaxial creep at stresses of 204 and 214 MPa. Strains were monitored for 6 peripheral points at the middle part of the cylindrical specimen's wall. The strain data indicate gradual increase of nonuniform deformation during steady creep and strong intensification of the nonuniformity during acceleration creep and, therefore, biased stress distribution within the specimen. The correlation between dilatant strain and AE hypocenters was investigated for whether or not tensile cracks emit AE. The region with high AE activity shows only a small dilatant strain. This negative correlation between AE and the dilatant region may eliminate tensile cracks as possible AE sources. A composite focal-mechanism solution of local AE events, covering a wide solid angle of the focal hemisphere, indicates that shear fractures emit AE waves. The direction of the compressional axis in this solution shows a significant deviation from that inferred from the applied external force, suggesting that the local stress field is governed by preexisting weak zones that are, presumably, produced by tensile cracks within the specimen. AE hypocenters tended to form clusters during steady creep under the constant compressional stress. During acceleration creep caused by a small step increase of the external stress, the preceding clusters disappeared while a new cluster appeared in an incipient fault plane. This suggests that changes in seismicity pattern such as migrations or quiescences of swarm—important clues for earthquake predictions—may be caused by an instantaneous change in the tectonic-stress levels. 相似文献
70.
The concentrations of lipids were determined in atmospheric particle, gas and rain samples collected from the tropical North Pacific to assess lipid sources, transport mechanisms and fluxes to the ocean surface. Four lipid compound classes (aliphatic hydrocarbons, fatty alcohols, fatty acid esters, and salts) all unequivocally show a terrestrial vascular plant source. These aerosol lipids originate from wind erosion of Asian and American soils and direct emission from vegetation. The major fluxes result from rain rather than dry deposition. These fluxes are large enough to have a major potential impact on the inventory of terrestrially derived lipid material found in deep-sea sediments. This has been showm for n-alkanes, fatty alcohols, fatty acids, total lipids and for organic carbon. By comparing atmospheric and sediment trap fluxes with sediment accumulation rates, it is suggested that some biogenic terrestrial material is more protected from degradation than marine-derived material. 相似文献