“十五”期间我省地震分析预报数据库建设展望

本文阐述了地震分析预报数据库在地震中短期预报系统中的重要性 ,同时具体提出建立该数据库系统所用的方法和技术途径 ,并给出预期的成果。另外 ,本文还介绍了建立该数据库系统的有利条件极其存在的困难 ,并对解决困难提出了建议。     

利用煤层裂隙地震各向异性寻找煤层气气藏

煤层气是以吸附状态储集在煤层的微裂隙、裂缝中，煤层既是煤气的源岩层，也是煤层气的储集层。由于煤层裂隙的存在，将导致煤层的各向异性；根据横波分裂理论：横波通过方位各向异性介质时，横波将发生分裂现象，分裂为两个偏振方向近乎正交的横波，即传播方向平行于裂隙方向的快横波和传播方向垂直于裂隙方向的慢横波。本文介绍了煤层裂隙引起的横波分裂现象的实验室研究及实际野外试验成果。实际结果表明，利用转换横波探测煤层裂隙是可行的。本文最后给出了试验煤层裂隙发育范围和裂隙发育方向。     

重质碳酸钙表面改性及充填丁苯橡胶试验研究

重质碳酸钙是一种重要的无机矿物填料，经过表面改性，可以将其由普通填料变成性能优越的功能填料。本次研究选用鄂西优质重质碳酸钙为试验样品，采用干法表面化学改性方法对重质碳酸钙实施了改性，通过测定改性重质碳酸钙的活化率、湿润接触角、固液悬浮体的粘度、白度及表面化学成分对其性能进行考察，并对改性效果进行评价。在丁苯橡胶中的应用试验显示，改性重质碳酸钙充填丁苯橡胶的性能良好，其应用前景广阔。     

聚类分析在暴雨预报和环流形势分型中的应用

数值预报投入业务运行以来，高空形势预报具有较高的准确率，要素预报的准确率也在不断提高，对数值预报产品的释用是近年来人们极为关注的问题，作者早用数值预报５００ｈＰａ高度场及降水实况资料，采用聚类分析法，研究暴雨落区预报和我国暴雨环流形势特征，所得结果在暴雨预报业务中有一定参考价值，同时也给出我国暴雨环流型。     

On the physical model of earthquake precursor fields and the mechanism of precursors′ time-space distribution (II) — How do the stress and strain fields evolve while a strong earthquake is in preparation and how does the evolution affect the seismicity and earthquake precursors?

In this paper, the stress concentration process and the time-space distribution of stress when earthquakes are in preparation in one or more earthquake-generating bodies in a tectonic block have been analyzed and their relation with seismicity and earthquake precursors have been studied. The results show that: 1 When the regional stress field has intensified to a certain level, fracture begins in some block or blocks. The regional stress field will vary with time and the occurrence of strong earthquakes in groups is the result of the evolution of this dynamic stress field. In this process, the existence and development of more than one high stress concentration zone may give rise to a variety of pre-seismic anomaly-to-earthquake relations. 2 The process of stress variation in an earthquake-generating block generally appears as a nonlinear one. After the long-term elastic deformation, there may be more than one time of inelastic deformation and fault-softening from the beginning of the stage of inelastic deformation to just before the main fracture. Corresponding to such a nonlinearity, the stress and strain fields in the earthquake-generating block will display a complex pattern of time-space evolution; and thus the earthquake precursor fields controlled by stress and strain must display complexities in many aspects.     

Seismic anisotropy beneath Southern Tibet

ＳｅｉｓｍｉｃａｎｉｓｏｔｒｏｐｙｂｅｎｅａｔｈＳｏｕｔｈｅｒｎＴｉｂｅｔＱＩＮＧ－ＴＩＡＮＬＵＩ（吕庆田），ＫＡＩ－ＹＩＭＡ（马开义），ＭＥＩＪＩＡＮＧ＇（姜枚），Ａ．ＨｉｒｎａｎｄＡ．Ｎｅｒｃｅｓｓｉａｎ（ＩｎｓｔｉｔｕｔｅｏｆＭｉｎｅｒａｌＤｅ...     

天水地震区深部地温场的有限元计算

用有限元方法计算了天水地震区上地壳地温场。结果表明，影响该区浅部（层）地温场的主要因素是基底构造和断裂构造。祁连褶皱系为高热异常区，秦岭褶皱系为低热异常区，西秦岭北缘断裂带为地温梯度带。认为该带历史地震的发生与热应力差有关     

淹没不整合型碳酸盐三级旋回层序——兼论碳酸盐台地的“凝缩作用”

与层序地层学定义的类型Ⅰ层序（ＬＳＴ＋ＴＳＴ＋ＣＳ＋ＨＳＴ）及类型Ⅱ层序（ＳＭＴ＋ＴＳＴ＋ＣＳ＋ＨＳＴ）不同，淹没不整合型碳酸盐三级旋回层序以凝缩段直接覆盖在层序界面之上形成的，“ＣＳ＋ＨＳＴ”序列为特征，而且其底界面为一淹没不整合面或加深饥饿间断面。该类型三级旋回层序是碳酸盐台地淹没事件产生的凝缩作用过程的产物，它以总体向上变浅的非对称相序为特征。华北北部晚寒武世地层中发育的四个淹没不整合型三级旋回层序的相序特征表明，台地淹没事件及其相关的凝缩作用，只要沉积背景适合，并非三级旋回层序所独有，高频率海平面变化也常产生“瞬时淹没”，因而凝缩段并非都发育在最大海侵期，并且凝缩段也存在级别归属问题。     

The influence of stiffness of the true triaxial testing machine on the rupturing and acoustic emission of rocks and its correlation with seismic activities

This paper introduces how the ratioR of the characteristic stiffness of rock samplevs. the stiffness of testing machines would influence the rupturing process and the acoustic emission (AE) on the part of the tested rock samples. Result of the experiment shows: WhenR>0.20, the rock sample would rupture abruptly; whereas whenR<0.20, the rock samples would rupture slowly. When the samples rupture abruptly, the time-dependent variation of the AE rate takes such a pattern:peak value—stable low values—rises to the maximum value (concentration)—drops back to the minimum value (quiescence)—(rises again)—ruptures. Moreover, smallerR-value tends to be associated with longer quiescence and vice versa. WhenR>1.50, no pre-failure quiescence is detected. When the rock samples rupture slowly, the variation pattern of the AE rate (after the stress has increased to more than 50% of the rupturing stress) is as the following:stable low (or high) values—rises (or drops) to its maximum (or minimum) values and then continues for some time—ruptures. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 223–233, 1991. This study is supported by the Chinese Joint Seismological Science Foundation.     

A data collection and analysis system for research on rock fracturing

We have made a data collection and analysis system for recording microcracks in rock to study the three dimensional pattern of fracture and the dynamic properties of rock during pressurization. This system, with 8 channel data detection, records in real-time, from the initial microcracks to the final vibration waveform excited by the master fracture. The detected data are recorded digitally at the hard disk of an IBM computer (or 286, 386 personal computer) as well as transmitted to disk. The sampling rate for each channel is 10 MHz. Collecting every acoustic emission events in the loaded rock sample with 8 channels by this system, mathematically modelling the AE event travel time, and taking the coordinates of the AE event hypocenter and the three components of P wave velocity as unknown parameters, we set up a set of residual equations for joint inversion, so that the three dimensional localization of AE event hypocenters can be completed under variable velocities, which will lay foundations for the research on rock fracture clearly. The Chinese version of this paper appeared in the Chinese edition ofActa Seismological Sinica,13, 489–495, 1991. The design and development of the system, and the experiments are sponsored by the Chinese Joint Seismological Science Foundation.