西风带研究动态

本文较为详细地介绍了影响我国气候的重要因子——西风带的一些国内外最新研究动态,这些研究动态和研究成果将对山西省的气候研究起到积极作用。     

Observed Evolution of Linear and Nonlinear Effects at the Dahan Downhole Array,Taiwan: Analysis of the September 21, 1999 M 7.3 Chi-Chi Earthquake Sequence

— In this paper, the site characteristics of the Dahan downhole array are studied by analyzing the September 21, 1999 M 7.3 Chi-Chi earthquake sequence including the main shock and some aftershocks. The four-level array (0 m, 50 m, 100 m and 200 m) is located to the north of Hualien City in eastern Taiwan. Polarization analysis is used to check the orientation errors of the seismometers at different levels of depth. If the surface instrument is chosen as reference, the angle between the major polarization axes of the surface and any downhole records is the orientation error that must be corrected for the downhole accelerographs. The orientation errors at depths of 50 m, 100 m and 200 m are 32°, 120° and –84°. After the corrections, the coherency between the surface and downhole records is substantially improved. Spectral ratio analysis shows that the predominant frequency of the Chi-Chi main shock shifts to a lower frequency. We also simulate ground motions at different depths by using the Haskell method with a linear velocity structure model. The record at surface is chosen as the input motion. Compared with the observed data, ground acceleration can be well reproduced for the aftershocks (weak-motion events) of the September 21, 1999 M 7.3 Chi-Chi earthquake. However, for the Chi-Chi main shock, the synthetic waveform cannot match well with the observation neither in amplitude nor in phase. This indicates that large ground shaking probably induced the nonlinear site effect at that time, and the model used cannot support it.Acknowledgement. The authors would like to express their thanks to Dr. L.F. Bonilla and one anonymous reviewer for their valuable suggestions. This research was supported by the National Science Council under grant number NSC 89-2921-M-194-007. The Institute of Earth Sciences, Academia Sinica supplied the strong-motion data. The support of these organizations is gratefully acknowledged.     

Active Fault and Volcanic Activity in the Longhai-Zhangpu Coastal Area, Fujian Province

INTRODUCTION TheLonghai ZhangpucoastalareaofFujianProvinceliesonthesouthernsideoftheoutletofthe JiulongjiangRiver.Tectonically,itislocatedonthesouthernsegmentoftheChangle Zhao’anfault zone.Previously,alotofseismogeologicresearchworkhasbeencarriedoutinthi…     

形变数字化观测曲线畸变与处理——兼论资料预处理中遇到的一些问题

数字化形变台站日常下载、处理直至管理数据,都应用《数字化通讯控制软件》、《形变前兆台站(网)数据处理系统》及《形变前兆数据库服务软件(台站版)》等三个软件交互进行,在实际使用过程中会遇到一些棘手的问题。本文结合我台的观测工作的实践,总结经验,以供台站同行共享。     

UPS在福建省地震局网络中心机房中的运用

本文分析了我局现有UPS的特点,并着重介绍了UPS在我局网络中心机房中的运用,阐述了我们对UPS进行选择比较的主要指标,对今后UPS的使用和维护提出了相关建议。     

Multi-dimensional Seismic Response Analysis of Base-Isolated Frame Structure with 3D Isolator

INTRODUCTIONAs a new and effective method for withstandingthe horizontal component of earthquake motion on abuilding structure, the base isolation technique hascome to the engineering application phase ( Hu,1988). However, for some important buildings andfoundation facilities in an earthquake region, it is im portant to consider the effects of 3D aseismatic analy sis, including the vertical component, due to themulti dimensional characteristics of earthquakes (Suand …     

北黄海盆地构造几何学研究新进展

北黄海盆地是发育于隆起背景之上的中、新生代沉积盆地。新一轮资源调查研究表明，北黄海中、新生代沉积盆地的基底由古生界沉积岩层和前寒武纪变质岩系等组成，盆地不同程度地发育下构造层（J3-K1）、中构造层（E2-E3）和上构造层（N）；从油气资源和中、新生代地层发育情况出发，将北黄海海域划分为辽东-海洋岛隆起区、北黄海盆地和胶北．刘公岛隆起区等3个一级构造单元，其中北黄海盆地包括6个二级构造单元和24个三级构造单元；盆地褶皱、断裂构造十分发育，褶皱构造可划分为区域挤压型、局部伴生型和披盖型等三类，断裂构造主要可见近EW—NE向、NW向和NNE向三组，其中近EW—NE向和NNE向断裂比较发育，控制着盆地隆、坳分布格局和沉积特征。     

Tetrahedral Plots of the Phase Relations for Basalts

The phase relations of quaternary systems are generally represented by projections onto ternary compositional planes. Such projections often obscure relationships that would only be evident in a three-dimensional tetrahedral plot. The tetrahedral plot requires that compositions of the minerals and melts be transformed into Cartesian coordinates. It is shown here how this transformation is carried out. The application is demonstrated by tetrahedral plots of experimental melt compositions of partially molten lherzolite. Furthermore, the plot can be used to evaluate whether or not a particular basaltic composition represents a primary melt. The methods are applicable to any four-component system.     

浓硫酸钠水溶液中的离子对

不同浓度的Na2SO4水溶液的拉曼光谱显示了SO42-的四个拉曼活性带:980 cm-1处的SO42-的对称伸缩振动模式v1带,1 106 cm-1处的反对称伸缩振动模式v3带,448 cm-1处的变形振动模式v2带和617 cm-1处的变形振动模式v4带。482 cm-1处的肩膀峰是由于NaSO4-离子对的形成对448 cm-1的v2带的影响而形成的SO42-的一个新的振动峰。浓Na2SO4水溶液中,水共享离子对[Na+.H2O.SO42-]-是主要的离子对物种。随着Na2SO4水溶液浓度的增加,Na+和SO42-的相互作用增强,NaSO4-离子对所占的摩尔分数增加。