地震信号的相位恢复及误差分析

常见的几种地震子波有:零相位子波、最小相位子波、最大相位子波和混合相位子波。以不同类型的信号为激发子波,对不同地层模型合成地震道。仅用原始合成地震道记录的振幅谱来恢复原始记录,讨论不同方法下,由于激发子波的不同,对比分析原始记录与恢复记录的差异,及其恢复效果。     

利用钻孔超声成像的图像特征进行岩石风化程度分类

钻孔超声成像方法能精确地反映井壁的光滑情况, 进而判断岩石的风化发育程度, 确定风化层的厚度。阐述了钻孔超声成像的走时和振幅图像特征, 给出了1个在香港地区的应用实例。     

叶尔羌河冰川阻塞性洪水发生的气象因素

2002年8月12日，叶尔羌河再次发生因高原冰川阻塞形成的洪水。本文对叶尔羌河历次高原冰川阻塞性洪水的成因以及与气象的关系做了较详尽的分析，并提出了从气象角度预报该类型洪水的方法和利用卫星遥感技术对冰川阻塞湖进行监测的建议，期望对叶尔羌河今后的防洪工作有一些指导意义。     

Probabilistic analysis of peak response of MDOF systems with uncertain PSD function

The use of uniform hazard spectra which have the same probability of exceedance at different frequencies has been proposed for the future version of the National Building Code of Canada. Commonly used combination rules to estimate the peak responses of multi‐degree‐of‐freedom (MDOF) systems are the square root of sum of squares rule and the complete quadratic combination rule. However, the probability that the peak response of a MDOF system exceeds the one estimated by using these rules with the peak modal responses from the uniform hazard spectra cannot be inferred directly. The assessment of the probability of exceedance of the peak response of MDOF systems is presented by considering that the uncertainty in seismic excitation due to all potential earthquakes can be lumped in the power spectral density function of the ground acceleration with uncertain model parameters. This probability is evaluated based on the random vibration of linear systems and the first‐order reliability method. It is found that the under‐ or over‐estimations are less than about 5 or 10% if the modal contributions are not within 10–90% of, or not within 20–80% of, the absolute sum of the effective modal peak responses, respectively. Otherwise, severe under‐ or over‐estimation could result. Copyright © 2002 John Wiley & Sons, Ltd.     

X射线衍射峰五基本要素的物理学意义与应用

本文根据Bragg衍射方程、Scherrer方程、衍射强度计算原理，研究讨论了X射线衍射5构成要素中的衍射峰位置、衍射峰宽度、衍射峰高度的物理学意义。根据实验研究证明了衍射峰不对称性的几何条件特征，并用地质事实验证了衍射形态变化与晶格应变和粒度大小的内在联系。从而阐明了单个衍射峰5基本构成要素的完整物理学意义，并以实例论证了5要素的实际应用价值。     

Seismic Hazard for Selected Sites in Greece: A Bayesian Estimate of Seismic Peak Ground Acceleration

A procedure for estimating maximum values of seismic peak ground accelerationat the examined site and quantiles of its probabilistic distribution in a future timeinterval of a given length is considered. The input information for the method areseismic catalog and regression relation between peak seismic acceleration at a givenpoint and magnitude and distance from the site to epicenter (seismic attenuation law).The method is based on Bayesian approach, which simply accounts for influenceof uncertainties of seismic acceleration values. The main assumptions for the method are Poissonian character of seismic events flow and distribution law of Gutenberg-Richter's type. The method is applied to seismic hazard estimation in six selected sitesin Greece.     

饱和岩石的各向异性及非线性黏弹性响应

在MTS伺服压机上对不同饱和状态的砂岩、大理岩标本进行了垂直层理和平行层理两个方向的正弦波加载试验,研究了饱和岩石的各向异性及非线性黏弹性行为. 在最大载荷低于岩石的屈服点时,获得的衰减、杨氏模量、泊松比、波速都表现出显著的各向异性,同时它们还具有较明显的应变振幅效应和频率效应. 随着应变振幅的增大,衰减近似呈线性增长,杨氏模量和泊松比近似呈线性下降. 在0.005-4Hz频段内除衰减不明显依赖频率以外,杨氏模量、泊松比、波速对频率的依赖性都较强; 当频段扩大到15Hz时,这4个参数都表现出较强的频率效应. 饱和岩石的衰减、杨氏模量、泊松比、波速均随饱和液体的黏滞系数增大而增大.     

TEM法在寻找煤矿突水巷道中的应用

在地质勘探中,TEM法体积效应影响小,探测深度大,对低阻反映灵敏,因此,其作为一种物探手段,已被广泛应用于地球物理勘探的各个领域。TEM法在煤矿突水巷道勘探中,曲线形态为高电位单峰异常,这个特征用于煤矿充水巷道探测准确度高,效果明显。     

江苏高邮地震台地磁变化与地震关系的初探

分析了江苏高邮地磁台1980年至2002年地磁垂直分量日变幅逐日比值的高值异常与江苏及邻区ML5．0以上地震之间的关系，发现它们之间有良好的对应关系，通过分析地磁垂直分量谐波幅度的逐日比，提出了适用于高邮地磁台的地震分析预报参数，并对其内检预报效能进行了评价。