1993年中甸M5.8地震前后区域尾波衰减研究

以Aki,K和Chouet^[1]提出的地方震尾波散射理论为基础，利用1993年7月17日中甸MS5．8地震的前震和余震资料，研究了该次地震前后的尾波振幅衰减率β和QC^-1值的时空变化。结果表明，主震前后区域尾波振幅衰减率β和QC^-1值发生了明显的变化。主震前，区域平均β值为0．0122s^-1，相应的QC值为111；主震后，区域平均β值为0．023s^-1，相应的QC值为60。主震前后的QC值变化为1．85倍，表明在以主震为中心，半径约50km的小范围内主震前后的介质背景发生了明显变化。用释放的地震应变能ε（t)的空间分布特点分析，表明主震前高QC值地区与高应变能释放地区是相一致的。中甸地震序列的尾波振幅衰减β和QC值显示了具有前兆意义地空变化的过程，并以力学观点分析解释了产生这种变化的成因。     

X线侧位片与高分辨率CT对鼻骨骨折的对比研究

目的　通过86例鼻骨骨折的鼻骨X线侧位片与高分辨率CT(HRCT）对比研究，确定HRCT检查对鼻骨骨折的诊断价值。材料与方祛　86例鼻外伤或/和He、面外伤的患者均进行了鼻骨X线侧位摄影、HRCT扫描检查，经集体讨论，由有经验的放射医师对全部影像资料进行分析并进行统计学处理。结果HRCT显示所有的86例鼻骨骨折，但在此86例骨折中X线平片只显示了35例阳性，包括15例鼻骨汇合部骨折，7例双侧鼻骨骨折，3例复合骨折(鼻骨汇合部及双侧鼻骨骨折)，l0例鼻区骨折。X线平片显示5l例为阴性。结论　对鼻骨骨折的诊断，HRCT明显优于鼻骨X线侧位片，HRCT扫描检查可提高X线隐性鼻骨骨折的诊断，并可明确鼻骨骨折的类型、范围和程度，为临床诊断和治疗提供可靠的依据。     

西安翠华山山崩地质遗迹资源保护

文论述了西安翠华山山崩地质遗迹资源保护的目的，进行了保护分区，将其分为核心保护区、缓冲区和视域保护区三个区，重点分析了核心保护区的保护现状，并在此基础上提出了相应的保护内容和对策，以实现山崩地质遗迹资源的可持续利用和发展。     

岫岩-海城5.4级地震前小震震源机制解与记录特征分析

采用Pn、Pg初始波初动符号，利用乌尔夫网上半球投影，用作图方法求解了岫岩－海城震区（1999年1月－1999年11月29日）主震前辽宁数字地震台网记录（ML≥2.5)的41个小震的震源机制参数。结合前震记录的某些特征，对主震前应力方向的时空变化，震源错动性质进行分析和讨论。     

TDP-0844地震前兆数据综合采集器的研制

介绍了TDP—0844型地震前兆数据综合采集器采用的设计方案及工作原理，及各个功能模块的设计准则，并列出了采集器实现的功能。文章还给出了采集器的部分应用图例，证明该采集器能够满足地震前兆观测需要。     

Study of crustal structure with S—wave data from Maqen—Jingbian profile

2-D crustal velocity structure and vp/vs are obtained by processing and interpretation of S-wave data from Maqen-Jingbian deep seismic sounding(DSS)profile.The result shows that there exist obvious differences in 2-D S-wave velocity structure and vp/vs ratio structure along the profile.The S-wave velocities are low and vp/vs ration is high for the westem section of the profile and Haiyuan region,while they are normal for the middle and eastern sections.The changes in lithologic characters of two major anomalous zones are discussed according to lateral variation of S-wave velocity structure and vp/vs ratio structure.It is concluded that the development and occurrence of the Haiyuan strong earthquake is not only related to tectonic activities,but also to lithologic characters of the region.     

Re-discussion on the Jiaochang Arcuate Structure, Sichuan Province, and the Seismogenic Structure for Diexi Earthquake in 19331

The Jiaocbang arcuate structure is one of the numerous arcuate structural belts in Sichuan. The present paper gives a further argument about the characteristics of that arcuate structure and the new activity of the Songpinggou fault and affirms that the Songpinggou fault is an active fault in the Holocene epoch. The Diexi M7.5 earthquake took place in 1933 on the west wing of that arcuate structure, near the apex of the arc. Many authors have given quite different opinions about the genetic structure of that earthquake. The authors have made on-the-spot investigations time and again over recent years. Besides this, the authors have also further studied the shape of intensity contour lines, the distribution characteristics of ground surface seismic hazards, the left-lateral dislocation of buildings along the Songpinggou fault, the NWtrending ground fissures that developed on the ground surface after earthquake, and so on. On this basis, it is still considered that the seismogenic fault of the 1933 Diexi M7.5 earthquake was the Songpinggou fault on the west wing of the Jiaochang arcuate structure.     

西藏南部郎杰学群碎屑物质来源的古水流证据

新近对西藏山南琼果和贡嘎地区(特提斯喜马拉雅北亚带)弱变质的上三叠统深海—半深海沉积地层——郎杰学群地质填图调查,在出露槽模沉积构造的37个古水流点获得了43组数据。赤平投影数据恢复后发现,这一地区主力古水流有南东140°～160°和南西190°～210°两个方向。这一分析结果为郎杰学群沉积物来自北边(未知块体)而非印度次大陆的观点提供了有力证据。     

Determination of silica sand stiffness

Site investigation and evaluation of properties of soil or rock are important aspects of geotechnical design. Determination of the ground stiffness is one of the important parameters in geotechnical engineering. Since the measurement of shear modulus is very sensitive to soil disturbance, especially for sand, determination of the stiffness of soil in the field is more reliable than in laboratory tests on sampled specimens. Measurement of shear modulus is one of the most common applications of self-boring pressuremeter testing. As an in situ device, the pressuremeter provides a unique method for assessing directly the in situ shear modulus of a soil. This paper describes a laboratory study of silica sand stiffness, which varies with stress level and strain amplitude. The results show that the elastic shear modulus value is mainly dependent on the value of the mean effective stress and relative density.