Seismic prediction method of multiscale fractured reservoir

Common prestack fracture prediction methods cannot clearly distinguish multiplescale fractures. In this study, we propose a prediction method for macro- and mesoscale fractures based on fracture density distribution in reservoirs. First, we detect the macroscale fractures (larger than 1/4 wavelength) using the multidirectional coherence technique that is based on the curvelet transform and the mesoscale fractures (1/4–1/100 wavelength) using the seismic azimuthal anisotropy technique and prestack attenuation attributes, e.g., frequency attenuation gradient. Then, we combine the obtained fracture density distributions into a map and evaluate the variably scaled fractures. Application of the method to a seismic physical model of a fractured reservoir shows that the method overcomes the problem of discontinuous fracture density distribution generated by the prestack seismic azimuthal anisotropy method, distinguishes the fracture scales, and identifies the fractured zones accurately.     

兰州新区建设用地生态适宜性评价

在地理信息技术的支持下,修正单纯的权重叠加法,采用潜力-限制性分析法分析了兰州新区建设用地的生态潜力和生态阻力,对其生态适宜性做出科学评价,得到兰州新区可用作建设用地的理想区域。结果表明：（1）兰州新区建设用地开发的生态潜力总体以一级为主,二级次之,三级和四级区所占比重较小;（2）一级生态阻力主要分布在新区南部山地,主要表现为地形复杂、工程地质条件差、地质灾害发生频繁等;（3）兰州新区建设用地生态适宜性达一级的面积所占比重最大,为39 425.91 hm²,占新区总面积的48.91%。三级适宜区面积最小,仅为6 513.2 hm²,占新区总面积的8.08%。对应于生态适宜性评价结果,兰州新区土地应用可划分为集中建设区、重点开发区、限制建设区和禁止建设区。其中,集中建设区和重点建设区应为兰州新区建设用地开发的理想区域。     

福建德化下坂斑岩金矿地质特征及成因探讨

下坂金矿位于中国东南沿海中生代陆相火山岩带之中,是近年来勘查的金矿床。通过对矿床的地质学、矿床学、地球化学等特征的研究,该矿床成因上与流纹斑岩关系密切,具有广义斑岩型矿床特点。     

深圳产业演进规律及空间分布格局

根据1979—2012年深圳企业数据,以ADF方法进行单位根检验,发现企业时序变量为1阶单整序列,继而进行协整检验和Granger检验,结合VAR和VEC模型计量结果,探讨了深圳第二产业和第三产业企业在演进过程中的长期均衡关系、短期因果关系和动态冲击影响,并基于企业区位熵法对产业演进结果的空间表现形态进行了分析,发现深圳产业发展过程中存在协整关系,第三产业企业增长是第二产业企业出现的Granger原因,脉冲响应函数反映两者相互的动态影响,产业协同演进结果空间分布上存在着分异现象。在研究结果的基础上提出相应的政策建议,以期促进城市产业合理演进。     

The first near real-time inverted echo sounder observation in the South China Sea

正We report the first near real-time inverted echo sounder (IES) observation in the South China Sea (Fig.1).Although the first IES observation in the South China Sea was in 2005,and the near real-time IES observation module was first developed in 2012(http://www.po.gso.uri.edu/dynamics/IES/hist.html),the real-time IES has never been deployed in the South China Sea until the reporting of observations in this study.IES is a bottom-mounted mooring that records the round-trip acoustic travel time from the bottom to the surface and back (τ),     

Status of Macrobenthic Community and Its Relationships to Trace Metals and Natural Sediment Characteristics

Laizhou Bay, located in the northwest of Shandong Peninsula, has complex transitional environments between terrestrial and marine ecosystems. In the present study, a total of 122, 131, and 139 species were collected in spring, summer, and autumn 2011, respectively. Species constitutions of macrobenthos were grouped into four phyla, of which annelida were the most abundant phylum, the average biomass proportion of echinodermata was the lowest, and the proportion of important species for mollusca was the highest. The structure of the macrobenthic community showed significant differences between sites, and greater divergence was observed between the third site (S03) and other stations. The ABC plots showed that the biomass curve lay below the abundance curve, and the W‐statistic value was negative. The result of the BOPA index showed that two stations had moderate ecological status in spring and that there were two heavily polluted sites and one moderately polluted site in summer. The BIO‐ENV analyses indicated that the grain‐size fractions together with trace metals (Hg, Pb, Zn, Cu, and Cr) could be considered as the major environmental variables influencing the macrobenthic patterns. The results together demonstrated that the macrobenthic communities in Laizhou Bay were negatively affected, perhaps by the tremendous impact of heavy metals in the sediments.     

青藏高原冬小麦田辐射能量收支的初步研究

通过对青藏高原冬小麦田净全辐射各分量的观测资料分析，论述了净全辐射及其各分量的日变化特征；计算得出冬小麦抽穗—乳熟期麦田平均反射率为13.3%，净全辐射占总辐射百分率:白天75%，包括夜间67.4%；指出了净全辐射和总辐射间存在良好的线性关系，给出了由总辐射计算净全辐射的经验公式。     

数字磁变仪的设计与实现

本文介绍了石英光电磁变仪及其数字化采集，记录的设计和实现，并讨论了数字磁变仪系统在地磁台站的应用结果。     

基于改进EWT和LogitBoost集成分类器的地震事件分类识别算法

快速、准确地识别天然地震和人工爆破事件是地震台网监测的重要工作之一,也是提高地震观测记录质量、开展地震研究工作的重要基础。针对反向传播神经网络、支持向量机等主流分类识别方法在地震事件分类识别应用上的不足,提出一种基于改进EWT和LogitBoost集成分类器的地震事件分类识别算法。首先,基于S谱能量曲线对传统经验小波变换进行改进,将信号自适应分解为按频率和能量分布的本征模函数;其次,提取P波与S波最大振幅比,前4个本征模函数的香农熵、对数能量熵,以及去噪后重构信号主频等特征;最后,采用基于集成学习LogitBoost的决策树集成分类器进行分类。实验结果表明,所提算法具有较高的鲁棒性,能有效解决样本不足的问题,识别准确率达93.1%以上,比集成学习AdaBoost、反向传播神经网络和支持向量机等方法提高了1%以上,且分类识别效果好。     

Source parameters determination for earthquakes in Kushiro,Japan considering source time function

This paper applies a new formulation to do moment tensor inversion for earthquakes in the Kushiro area of Japan. Comparing with conventional moment tensor inversion method, the new one takes the effect of source time function into consideration. For the inversion, best solution is obtained by minimizing the difference between the observed seismograms and the synthetic ones. And the best-fitting focal depth is determined from the variance reduction. The results indicate that half duration of source time function is proportional to the magnitude of earthquakes. Large earthquakes have long half duration, whereas that of moderate-small earthquakes is comparatively shorter. The focal mechanisms of all three earthquakes are of thrust fault type, which is mainly ascribed to the collision of the North American plate with the Eurasia plate in the late Cretaceous or Paleogene.