干涉合成孔径雷达及其在火山研究中的应用(第二部分:阿拉斯加火山的InSAR成像)(英文)

干涉合成孔径雷达是一项能够对地表变形进行测量的遥感技术,在一个巨大区域内,它的变形测量精度可达亚厘米级,而其空间分辨率则在数十米以内。本文对我们应用InSAR技术对阿拉斯加火山进行研究的最新成果进行了总结,同时包括火山的喷发和非喷发活动。这些研究成果表明InSAR不仅能够增进我们对阿拉斯加火山活动的理解,而且还能够增强我们对未来火山喷发情况及其灾害的预测能力。     

Time and tide wait for no animal: Seasonal and regional opportunities for tidal stream transport or retention

Many species appear to selectively use tidal currents for transport into or out of estuaries, or to maintain residence within an estuary. Further, some species are preferentially active during nocturnal hours, possibly to reduce their vulnerability to predators. The interaction between predicted tidal current flow and the day-night cycle was investigated for 11 locations within the United States. Tidal current constants for each of these were obtained from the United States National Ocean Survey. Additionally, times of sunrise and sunset were computed for each location and day between the years 1978 and 2000. These sets of information were combined by integrating the predicted current velocity between successive times of sunrise or sunset or times of slack current for each day and location. The result is the average daily net transport possible at that time and location. Plots of these transport values reveal seasonal patterns when either transport in a preferred direction or retention is more readily accomplished. Such calculations do not incorporate other influences on tidal currents, such as variations in winds or freshwater discharge, but they do reveal the consistent seasonal and regional opportunities for transport or retention that a species would encounter over long time spans.     

湖南省核电厂侯选厂址的工程地质评价

１９９２年以来，湖南省电力勘测设计院在省内开展了核电普查选址工作，经过３年多的勘查，现已筛选出４个侯选厂址。作者著文探讨了这４个厂址的地震地质特征和工程地质条件，可供进一步选址参考     

华东地区评估和推算场地最大水平加速度的一种实用方法

本文提出华东地区以地震地质确定性方法为场地工程勘察估算最大水平加速度的具体步骤,并指出如何考虑远、近场地震对场地地震动的影响,使提出的场地地震动参数更加合理,从而达到提高重大工程的安全度。     

Application of integrated geophysical interpretation on accumulation body

Integrated geophysical interpretation is a method of combinating different geophysics prospecting methods based on different physical properties of accumulation. As different geophysical methods own different interpretations and varying detection accuracies, the key issue becomes how to integrate the results of several geophysical methods to corrently carry out a comprehensive explanation. Based on different geophysical results, the authors proposed an integrated geophysical explanation method and successfully applied it in practical engineering problems.     

Lognormality in the observed size distribution of oil and gas pools as a consequence of sampling bias

Economic filtration has been offered as an explanation of the observed lognormality in the size distribution of discovered oil and gas deposits. The result leads to the conclusion that one cannot impute the shape of the underlying parent distribution from the observed discoveries size distribution. The fact that the largest pools tend to be discovered early in the exploration history of an area of interest suggests the existence of an inherent sampling bias in the discovery process. The bias is influenced by the levels of geologic knowledge and technological sophistication. Furthermore, the existence of the bias leads to lognormality in the observed discoveries size distribution of oil and gas pools. A discovery process model explicitly incorporating the notion of sampling bias was applied to a series of Weibull parent frequency size distributions. The selected parent distributions are of a class suggested in the literature as more reflective of nature's size distribution and have empirical support. The distribution of discoveries resulting from the application of the model to the chosen parent size distributions were tested for lognormality using a chi-squared test. Lognormality was found to be an acceptable model of the discoveries size distribution over a wide range of resource exhaustion measures. When combined with the notion of economic filtration, sampling bias leads to the conclusion that one should not expect the lognormal distribution to accurately represent the underlying parent size distribution of oil and gas deposits.     

Biologically induced mineralization of dypingite by cyanobacteria from an alkaline wetland near Atlin,British Columbia,Canada

Background  

This study provides experimental evidence for biologically induced precipitation of magnesium carbonates, specifically dypingite (Mg₅(CO₃)₄(OH)₂·5H₂O), by cyanobacteria from an alkaline wetland near Atlin, British Columbia. This wetland is part of a larger hydromagnesite (Mg₅(CO₃)₄(OH)₂·4H₂O) playa. Abiotic and biotic processes for magnesium carbonate precipitation in this environment are compared.     

2007年7月16日日本新溻地震对柏崎刈羽核电站的影响

2007年7月16日日本新溻县柏崎市附近海域发生Mw6．6地震（日本气象局震级MJMA6．8）。该地震引发世界最大核电厂——柏崎刈羽核电站多起核安全事件，是世界范围内有记载的对核电站影响最为严重的一次地震。本文根据收集到的资料，详细介绍了该地震对柏崎刈羽核电站造成的影响，文章最后概述了日本、国际原子能机构对该地震的反思以及我们应该从中吸取的经验教训。     

A high‐resolution local RBF collocation method for steady‐state poroelasticity and hydromechanical damage analysis

In this work, we describe a meshless numerical method based on local collocation with RBFs for the solution of the poroelasticity equation. The RBF finite collocation approach forms a series of overlapping nodal stencils, over which an RBF collocation is performed. These local collocation systems enforce the governing PDE operator throughout their interior, with the intersystem communication occurring via the collocation of field variables at the stencil periphery. The method does not rely on a generalised finite differencing approach, whereby the governing partial differential operator is reconstructed at the global level to drive the solution of the PDE. Instead, the PDE governing and boundary operators are enforced directly within the local RBF collocation systems, and the sparse global assembly is formed by reconstructing the value of the field variables at the centrepoint of the local stencils. In this way, the solution of the PDE is driven entirely by the local RBF collocation, and the method more closely resembles the approach of the full‐domain RBF collocation method. By formulating the problem in this fashion, high rates of convergence may be attained without the computational cost and numerical ill‐conditioning issues that are associated with the full‐domain RBF collocation approach. An analytical solution is formulated for a 2D poroelastic fluid injection scenario and is used to verify the proposed implementation of the method. Highly accurate solutions are produced, and convergence rates in excess of sixth order are observed for each field variable (i.e. pressure and displacement) and field‐variable derivative (i.e. pressure gradients and stresses). The stress and displacement fields resulting from the solution of the poroelasticity equation are then used to describe the formation and propagation of microfractures and microfissures, which may form in the presence of large shear strain, in terms of a continuous damage variable which modifies the mechanical and hydraulic properties of the porous medium. The formation of such hydromechanical damage, and the resulting increase in hydraulic conductivity, is investigated for a pressurised injection into sandstone. Copyright © 2014 John Wiley & Sons, Ltd.