仙女山-九畹溪断裂带附近地区地震活动性与静态库仑应力变化研究     

常婷  张丽芬  王秋良  何超枫 《大地测量与地球动力学》2020,40(10):1044-1048

基于仙女山-九畹溪断裂带附近地区地质构造,讨论三峡水库蓄水前后该断裂带附近地区的地震活动特征,同时分析该区域2014-03 M4.5与M4.7地震间的触发关系及2次地震对后续小震的影响。结果表明：1）M4.7地震可能由M4.5地震与库水渗流产生的较大孔隙压力共同触发。2）M4.5与M4.7两次地震的应力扰动导致研究区内地震活动增加,后续地震中约66.9%的地震发生于库仑应力增强区。3）2次地震产生的静态库仑应力变化导致仙女山断裂带附近地区地震活动增加,后续地震活动水平将处于背景地震活动水平之上;九畹溪断裂带活动性相对较弱,略小于背景地震活动水平,且处于应力积累阶段。  相似文献   

基于包络检波和STFT谱分析的探地雷达土壤分层信息识别     

李俐  付雪  崔佳  张超  朱德海  吴克宁 《地球信息科学学报》2020,22(2):316-327

土壤分层信息,特别是表土层结构,对土地生产力具有重要影响,是评价土壤质量的一个重要指标。为了快速、准确地获取土壤分层信息,本文利用探地雷达对分层土壤进行了回波信号采集,并分别在时域和频域分析土壤层位置和层厚信息。首先在信号预处理的基础上,借助包络检波方法确定在土壤分层界面在时域上的位置;然后获取电磁波速度,得到土壤分层厚度。考虑到土壤介电常数与电磁波在土壤中传播速度的相关性,采用短时傅里叶变换方法（Short-time Fourier Transform,STFT）获取各土壤层时频域特征值,并利用回归分析建立特征值与介电常数之间的数学关系,实现对各土壤层的介电常数估算,从而计算出电磁波传播速度,进而确定土壤各层厚度。为验证算法的有效性,分别对理想模拟实验环境和农田环境进行了探地雷达实验,结果表明利用包络检波对探地雷达回波信息进行分析,土壤层检出率达到94.5%,借助STFT谱分析进行探地雷达回波速度估计,对于70 cm深度以上土层厚度计算误差大都保持在10%以下,但随着土壤深度的增加,误差变大。总体来说,本方法能有效识别浅层土壤的分层信息,可应用于实际生产中耕层厚度的估测。  相似文献   

青藏高原西部及邻区构造应力场反演和断层滑动趋势分析     

杨颖  解朝娣  徐彦  相传芳  刘本玉 《大地测量与地球动力学》2022,42(7):694-699

基于Global CMT提供的1976-01-01~2015-12-31期间1 255个M_W≥3.5地震的震源机制解,利用FMSI方法对青藏高原西部及邻区（新疆西部地区）应力场进行反演,得到区域应力场特征,并分析西昆仑断裂带及阿尔金断裂带的断层滑动趋势。结果表明,青藏高原西部及邻区的最大主压应力轴σ1整体呈NNE-SSW向,自西向东顺时针旋转;最小主压应力轴σ3整体呈NWW-SEE向。最大主压应力轴σ1倾角大小约为5°~9°,说明该地区的构造应力场以水平运动为主。西昆仑断裂带及阿尔金断裂带具有较强的滑动趋势（T_s≥0.5）,说明西昆仑断裂带及阿尔金断裂带未来失稳滑动的可能性较大。  相似文献   

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陈连旺  詹自敏 《大地测量与地球动力学》2011,31(6):1-5

?????????????????????????????????????ó???????????????????????仯??????1???????????仯????????????????NNW-SSE??????????3~9 kPa a^-1???????????仯???????????????NEE-SWW??????????1~6 kPa a^-1?????????????????????????????????????￡?2???????????仯????????????????NNW????????????????,??????????????????????????????????仯???????????????NEE????????λ?????????????????????仯????????????????????????????????????????????п????????Щ???????????????????3?????????????????????????????????з???????????-???ε???????????????????6 kPa a^-1?????-?????ε???????????????????5 kPa a^-1???????κ??????媲????ε????????????????????3~4 kPa a^-1??  相似文献   

鲁北平原深层地下水基本特征与水环境问题          下载免费PDF全文

刘桂仪 《山东国土资源》2001,17(5):43-47

鲁北平原因超量开采地下水而引发了诸多水环境问题.本文对其分布规律和演化趋势进行了分析,并提出了对策建议.  相似文献   

麻痹性贝毒对肝脏和肾脏氧化损伤的影响     

陈雪  程金平  张鉴达  宋玉玲  王文华  于金莲 《海洋科学》2010,34(12):93-95

为了探讨麻痹性贝毒(PSP)对肝脏和肾脏损伤的机制,采用膝沟藻毒素GTX-1,4对小鼠进行急性暴露,剂量为1μg/kg,时间分别为60、90、120min。结果发现,与对照组相比,肝脏染毒组中的还原型谷胱甘肽(GSH)含量没有显著变化;在肾脏中,60 min时染毒组GSH含量没有明显变化,90、120 min时GSH含量降低;两器官中抗氧化酶(GSH-Px、SOD)活性与对照组相比均无显著变化(P0.05)。从而推断,GSH参与了PSP对肾脏损害的毒性过程;肾中GSH含量有可能作为PSP早期检测的敏感指标。  相似文献   

海涂围垦工程中悬挂式爆破挤淤基础处理技术探讨   总被引：1，自引：0，他引：1  

王文杰  赵微人  郭加根 《海岸工程》2010,29(3):51-56

沿海软土地基围涂工程中悬挂式爆破挤淤基础处理断面结构设计中遇到的最大难题是对腰宽的处理,腰宽太窄则工后沉降大,反之,则断面石方量增大,投资增加,因此,试图通过工程实例说明悬挂式爆破挤淤基础处理断面设计及工程实施过程中遇到的问题及对策措施。  相似文献   

GENETIC TYPES AND CHARACTERISTICS OF GROUND ICE IN NORTHEAST CHINA     

刘福涛  王春鹤  宋长春 《中国地理科学(英文版)》1999,9(2):166-171

１ＧＥＮＥＴＩＣＴＹＰＥＳＯＦＧＲＯＵＮＤＩＣＥＩＮＣＨＩＮＡＧｒｏｕｎｄｉｃｅｉｓｗｅｌｄｅｖｅｌｏｐｅｄｉｎｔｈｅｖｉｃｉｎｉｔｙｏｆｔｈｅｓｏｕｔｈｅｒｎｐｅｒｍａｆｒｏｓｔｌｉｍｉｔｉｎｔｈｅＥｕｒａｓｉａｎｃｏｎｔｉｎｅｎｔ，ｉｎｔｈｅｎ...  相似文献   

A virtual experiment technique on the elementary behaviour of granular materials with discrete element method     

Xia Li  Hai‐Sui Yu  Xiang‐Song Li 《国际地质力学数值与分析法杂志》2013,37(1):75-96

Multi‐scale investigations aided by the discrete element method (DEM) play a vital role for current state‐of‐the‐art research on the elementary behaviour of granular materials. Similar to laboratory tests, there are three important aspects to be considered carefully, which are the proper stress/strain definition and measurement, the application of target loading paths and the designed experiment setup, to be addressed in the present paper. Considering the volume sensitive characteristics of granular materials, in the proposed technique, the deformation of the tested specimen is controlled and measured by deformation gradient tensor involving both the undeformed configuration and the current configuration. Definitions of Biot strain and Cauchy stress are adopted. The expressions of them in terms of contact forces and particle displacements, respectively, are derived. The boundary of the tested specimen consists of rigid massless planar units. It is suggested that the representative element uses a convex polyhedral (polygonal) shape to minimize possible boundary arching effects. General loading paths are described by directly specifying the changes in the stress/strain invariants or directions. Loading can be applied in the strain‐controlled mode by specifying the translations and rotations of the boundary units, or in the stress‐controlled mode by using a servo‐control mechanism, or in the combination of the two methods to realize mixed boundary conditions. Taking the simulation results as the natural consequences originated from a complex system, virtual experiments provide particle‐scale information database to conduct multi‐scale investigations for better understanding in granular material behaviours and possible development of the constitutive theories provided the qualitative similarity between the simulation results from virtual experiments and observations on real material behaviour. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Tectonic Movement and Global Climate Change     

Yang Xuexiang  Chen Dianyou 《世界地质(英文版)》2000,3(2)

Glaciation between northern hemisphere and southern hemisphere were synchronous, the ice age occurred not in high but in low value of the eccentricity of the earth's orbit. Such facts went against the precession principle of the astronomical theory of ice age. The inhomogeneous distribution of climate consisted with the inhomogeneous distribution of ocean and continent. The north/south antisymmetry may be attributed to southward deviation of the thermal center and northward deviation of the mass center within the mantle demonstrated by seismic tomography. The core - mantle angular momentum makes rotational energy into thermal energy and mantle plumes erupt in the ocean bottom. The earth's deformation by tidal force makes the eruption of mantle plumes strong. They are the reason that glaciation between the Northern Hemisphere and Southern Hemisphere are synchronous and the ice age occurred in low value of the eccentricity of the earth' s orbit. The tectonic movement is playing a most important part in global climate change.  相似文献