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101.
本文利用青海地区近几十年的大地测量资料,探讨了该区现今地壳垂直形变与现代构造运动及强震活动之间的关系,认为青藏高原北部目前仍处于强烈的构造运动活跃期,判定了两处有可能是未来发生强震的场所,并对青藏高原北部强震成因提出了作者的看法。 相似文献
102.
LIU Bin LIU Jianzhong ZHANG Guangliang LING Zongcheng ZHANG Jiang HE Zhiping YANG Benyong ZOU Yongliao 《中国地球化学学报》2014,33(1):86-94
In 2013, Chang'E-3 program will develop lunar mineral resources in-situ detection. A Visible and Near-infrared Imaging Spectrometer (VNIS) has been selected as one payload of CE-3 lunar rover to achieve this goal. It is critical and urgent to evaluate VNIS' spectrum data quality and validate quantification methods for mineral composition before its launch. Ground validation experiment of VNIS was carried out to complete the two goals, by simulating CE-3 lunar rover's detection environment on lunar surface in the laboratory. Based on the hyperspectral reflectance data derived, Correlation Analysis and Partial Least Square (CA-PLS) algorithm is applied to predict abundance of four lunar typical minerals (pyroxene, plagioclase, ilmenite and olivine) in their mixture. We firstly selected a set of VNIS' spectral parameters which highly correlated with minerals' abundance by correlation analysis (CA), and then stepwise regression method was used to find out spectral parameters which make the largest contri- butions to the mineral contents. At last, functions were derived to link minerals' abundance and spectral parameters by partial least square (PLS) algorithm. Not considering the effect of maturity, agglutinate and Fe~, we found that there are wonderful correlations between these four minerals and VNIS' spectral parameters, e.g. the abundance of pyroxene correlates positively with the mixture's absorption depth, the value of absorption depth added as the in- creasing of pyroxene's abundance. But the abundance of plagioclase correlates negatively with the spectral parame- ters of band ratio, the value of band ratio would decrease when the abundance of plagioclase increased. Similar to plagioclase, the abundance of ilmenite and olivine has a negative correlation with the mixture's reflectance data, if the abundance of ilmenite or olivine increase, the reflectance values of the mixture will decrease. Through model validation, better estimates of pyroxene, plagioclase and ilmenite's abundances are given. It is concluded that VNIS has the capability to be applied on lunar minerals' identification, and CA-PLS algorithm has the potential to be used on lunar surface's in-situ detection for minerals' abundance prediction. 相似文献
103.
104.
Yinpo Xu Cheng Yin Xuefeng Zou Yudong Ni Yingjie Pan Liangjun Xu 《Geophysical Prospecting》2020,68(4):1228-1252
As the application of high-density high-efficiency acquisition technology becomes more and more wide, the areas with complex surface conditions gradually become target exploration areas, and the first-break picking work of massive low signal-to-noise ratio data is a big challenge. The traditional method spends a lot of manpower and time to interactively pick first breaks, a large amount of interactive work affects the accuracy and efficiency of picking. In order to overcome the shortcoming that traditional methods have weak anti-noise to low signal-to-noise ratio primary wave, this paper proposes a high accurate automated first-break picking method for low signal-to-noise ratio primary wave from high-density acquisition in areas with a complex surface. Firstly, this method determines first-break time window using multi-azimuth spatial interpolation technology; then it uses the improved clustering algorithm to initially pick first breaks and then perform multi-angle comprehensive quality evaluation to first breaks according to the following sequence: ‘single trace → spread → single shot → multiple shots’ to identify the abnormal first breaks; finally it determines the optimal path through the constructed evaluation function and using the ant colony algorithm to correct abnormal first breaks. Multi-azimuth time window spatial interpolation technology provides the base for accurately picking first-break time; the clustering algorithm can effectively improve the picking accuracy rate of low signal-to-noise ratio primary waves; the multi-angle comprehensive quality evaluation can accurately and effectively eliminate abnormal first breaks; the ant colony algorithm can effectively improve the correction quality of low signal-to-noise ratio abnormal first breaks. By example analysis and comparing with the commonly used Akaike Information Criterion method, the automated first-break picking theory and technology studied in this paper has high picking accuracy and the ability to stably process low signal-to-noise ratio seismic data, has a significant effect on seismic records from high-density acquisition in areas with a complex surface and can meet the requirements of accuracy and efficiency for massive data near-surface modelling and statics calculation. 相似文献
105.
北京地区脑卒中发病率的气象条件研究 总被引:12,自引:1,他引:12
根据北京抽样人群的脑卒中发病资料和前期气象资料的对比分析,揭示出不同年龄段人群发病率的年变化特点和多年变化趋势,讨论了前期气象因子与发病率的关系,并在此基础上设计对发病率有预测意义的分辨率为5级的统计模型,经F检验表明,预测效果较好。 相似文献
106.
The statistical structure of Lorenz strange attractors 总被引:2,自引:0,他引:2
The statistical characteristic quantities and marginal probability distribution of the Lorenz strange attractors were computed numerically. The results indicate that after a sufficiently long time the statistical characteristic quantities and marginal probability distribution tend to stable states, and the motion on the strange attractor is ergodic. 相似文献
107.
The relationship of N2O distributions with the Arctic vortex breakup is first analyzed with a probability distribution function (PDF) analysis. The N2O concentration shows different distributions between the early and late vortex breakup years. In the early breakup years, the N2O concentration shows low values and large dispersions after the vortex breakup, which is related to the inhomogeneity in the vertical advection in the middle and high latitude lower stratosphere. The horizontal diffusion coefficient (Kyy) shows a larger value accordingly. In the late breakup years, the N2O concentration shows high values and more uniform distributions than in the early years after the vortex breakup, with a smaller vertical advection and Kyy after the vortex breakup. It is found that the N2O distributions are largely affected by the Arctic vortex breakup time but the dynamically defined vortex breakup time is not the only factor. 相似文献
108.
用铁屑微电池原理深度处理了医院废水 ,分析了废水pH、铁屑用量、反应时间对处理效果的影响。结果表明 ,最佳的反应条件为 :废水进水pH为 3.5 ,铁屑用量为 12 .5 % ,常温反应 80min。 相似文献
109.
我国的暴雨洪水大、人口众、土坝多。为了保障人民生命财产和工农业的安全,许多大型、重要的中小型水库多采用可能最大暴雨洪水作为设计、校核的标准。在水文与气象人员的协作下,我国近十年来的可能最大暴雨与洪水计算方法得到一定的发展,提出了具有中国特色的方法、论文和一些专著,并开始了国际交流。本文综述这方面的进展并提出了几点看法。 相似文献
110.
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