祁连造山带特征及其构造演化   总被引：39，自引：0，他引：39  

赵生贵 《甘肃地质》1996,5(1):16-29

祁连造山带的范围及构造单元经重新厘定和划分，其南界扩展至昆中断裂；解体了走廊过渡带；扩大了中祁连，相应缩小了南祁连范围；新划出乌兰大坂—拉脊山和柴达木周缘南北链状断陷带；确定北祁连属于柴达木—中祁连地块与阿拉善地块间的陆间裂谷。并运用断块学说对其多旋回构造演化作了分析，本区始生代—古生代属于塔里木—中朝地块南部大陆边缘断陷—焊接造山作用体制。中新生代，在古亚洲构造域、特提斯—喜马拉雅构造域和滨太平洋构造域“品”字型动力体系作用下（尤以前二者为主），转化为陆内浅层断（拗）陷—逆掩叠覆造山作用体制。应力作用方式从早到晚由顺时针直扭向旋扭转化。二者既有继承又有新生。挽近时期，在印度地块挤压动力体制下卷入青藏高原陆内汇聚作用，产生大幅度断块隆升、盆地沉陷，造就了现今高原盆岭景观  相似文献   

Smoothed particle hydrodynamics pore-scale simulations of unstable immiscible flow in porous media     

《Advances in water resources》2013

We have conducted a series of high-resolution numerical experiments using the Pair-Wise Force Smoothed Particle Hydrodynamics (PF-SPH) multiphase flow model. First, we derived analytical expressions relating parameters in the PF-SPH model to the surface tension and static contact angle. Next, we used the model to study viscous fingering, capillary fingering, and stable displacement of immiscible fluids in porous media for a wide range of capillary numbers and viscosity ratios. We demonstrated that the steady state saturation profiles and the boundaries of viscous fingering, capillary fingering, and stable displacement regions compare favorably with micromodel laboratory experimental results. For a displacing fluid with low viscosity, we observed that the displacement pattern changes from viscous fingering to stable displacement with increasing injection rate. When a high viscosity fluid is injected, transition behavior from capillary fingering to stable displacement occurred as the flow rate was increased. These observations are also in agreement with the results of the micromodel laboratory experiments.  相似文献   

利用跨断层形变资料研究近期唐山断裂活动性   总被引：2，自引：0，他引：2  

周海涛  周伟  杜雪松  余敏  夏峰 《地震研究》2013,36(3)

采用1999年1月～2012年9月唐山台跨断层基线和水准数据资料,计算出唐山断裂水平和垂直形变及断层活动速率.并求解了唐山台站的应变特征和主应变方向,研究了唐山断裂的活动特征,并探讨了唐山断裂活动与地震活动的关系.结果表明,较远区域的大震和本地区中强地震对唐山断裂的水平向张压运动和垂向运动都可能有一定的影响.2003年可能是唐山断裂周边应力场发生较大改变的一年.  相似文献   

基于性能抗震设计中的等效线性模型研究     

周道传  董作超  王林 《地震工程与工程振动》2013,33(3)

对6种等效线性化方法等效模型进行分析和总结,研究等效线性化方法应用于桥梁结构基于位移抗震设计的可行性及计算过程.以箍筋体积配箍率和桥梁结构承载能力为评价因素,对钢筋混凝土桥梁墩柱采用不同等效线性化方法进行基于位移的抗震设计,研究了等效线性化方法及阻尼调整系数对抗震设计结果的影响.研究表明,各种等效线性化方法应用于基于位移的抗震设计其计算结果存在较大差异,等效阻尼比对基于位移的抗震设计结果影响显著,不同的阻尼调整系数得到的计算结果也不同.在所研究的6种等效线性化方法中,Kowalsky方法、Iwan方法和欧进萍方法计算误差较小,随着位移延性系数的增大,Kowalsky方法的计算误差减小.应用Eurocode8规范提供的阻尼调整系数计算得到的结果与真实值较为接近.建议采用Eurocode8规范提供的阻尼调整系数和Kowalsky方法进行基于位移的抗震设计.  相似文献   

河源台地电专用电源和外线路故障查修方法     

陈智群  刘吉平  李敬 《华南地震》2013,33(2)

对C-ATS地电仪专用观测电源的原理和特点进行了简要介绍,并对其供电电源和外线路故障的查修方法作了较详细的阐述,列举故障实例,逐一说明检查维修过程.最后指出地电台站工作人员掌握一定的故障排查维护经验非常必要,对仪器的安全运行,及其产出数据的可靠性和连续性都有积极意义.  相似文献   

2008年汶川地震中断坡-滑脱断层破裂: 龙门山挤压隆升的大地测量证据          下载免费PDF全文

谭凯  杨少敏  乔学军  许才军  王琪 《地球物理学报》2013,56(5):1506-1516

青藏高原东缘龙门山构造隆升一直存在挤压造山模式和下地壳层流模式之争.下地壳层流模型认为,龙门山隆升与水平缩短关系不大,山前断层只是高原、盆地间差异性垂直运动的结果,高原之下无需挤压模式中的大规模水平滑脱层.本文利用近场密集的同震形变数据,约束汶川地震破裂几何特征及同震滑动分布.反演结果显示汶川地震撕裂龙门山中南段近水平滑脱层, 宽度达到60～80 km,释放能量约占总标量地震矩的12%,在16～21 km深度出现两三个滑动量高达6～7 m的破裂区.深部低角度破裂往上转为高角度逆冲,沿龙门山中央断裂以约55°倾角出露地表.汶川地震破裂的几何产状和滑移幅度表明龙门山冲断带发育大规模的近水平滑脱层,是青藏高原东缘地壳缩短增厚、龙门山挤压隆升的重要证据.  相似文献   

利用InSAR资料反演缅甸M_w6.8地震断层滑动分布          下载免费PDF全文

周辉  冯光财  李志伟  许兵  雷广渊 《地球物理学报》2013,56(9):3011-3021

2011年3月24日缅甸东北部发生M_w6.8级地震.本文利用覆盖该地区的升降轨ALOS PALSAR数据,获取了该次地震的同震形变场,并采用灰度配准技术获取了其地表破裂位移.针对影像中因轨道不精确造成的非线性长波长误差,本文采用二次多项式曲面法予以去除,获取了更为精确的同震形变场.最后,基于弹性半空间形变模型反演了该地震的断层滑动分布.结果表明,该地震断层滑动以左旋走滑为主,兼具少许的倾滑运动分量,断层滑动主要集中分布在断层面0~10 km深度范围,最大滑动量达5 m,位于地表以下5 km深处.反演获得的地震标量矩为2.49×10¹⁹N·m,震级约为M_w6.8级.  相似文献   

Getting Globalized: Urban Policy and Industrial Displacement in Williamsburg,Brooklyn     

《Urban geography》2013,34(6):461-482

We hypothesize that as the "global city" label becomes ever more central to a city's identity, local urban government policy increasingly supports those economic sectors that city leaders see as being congruent with the global and increasingly undermines sectors that serve primarily local markets. Through an in-depth study of small-scale manufacturers in the Williamsburg neighborhood of Brooklyn, in New York City, we examine the extent to which and the ways in which local policy undermines otherwise healthy locally oriented businesses. We find that the City's assumption that urban manufacturing is a dying breed becomes a self-fulfilling prophecy, largely via the City's own treatment of its manufacturing businesses. Through a lack of enforcement of zoning codes, zoning variances and rezoning initiatives, and more quotidian policies of harassment over noise and other quality of life complaints, the City is making it more difficult to do business for small-scale manufacturers. These policies then create a conventional wisdom that sees the City as a difficult place to start and grow a business.  相似文献   

A vector field model to handle the displacement of multiple conflicts in building generalization     

Tinghua Ai  Xiang Zhang  Qi Zhou  Min Yang 《International journal of geographical information science》2013,27(8):1310-1331

In map generalization, the displacement operation attempts to resolve proximity conflicts to guarantee map legibility. Owing to the limited representation space, conflicts may occur between both the same and different features under different contexts. A successful displacement should settle multiple conflicts, suppress the generation of secondary conflicts after moving some objects, and preserve the distribution patterns. The effect of displacement can be understood as a force that pushes related objects away with properties of propagation and distance decay. This study borrows the idea of vector fields from physics discipline and establishes a vector field model to handle the displacement of multiple conflicts in building generalization. A scalar field is first constructed based on a Delaunay triangulation skeleton to partition the buildings being examined (e.g., a street block). Then, we build a vector field to conduct displacement measurements through the detection of conflicts from multiple sources. The direction and magnitude of the displacement force are computed based on an iso-line model of vector field. The experiment shows that this global method can settle multiple conflicts and preserve the spatial relations and important building patterns.  相似文献   

Impact of the displacement damage in channel and source/drain regions on the DC characteristics degradation in deep-submicron MOSFETs after heavy ion irradiation     

薛守斌  黄如  黄德涛  王思浩  谭斐  王健  安霞  张兴 《海洋学报(英文版)》2010,29(11)

This paper mainly reports the permanent impact of displacement damage induced by heavy-ion strikes on the deep-submicron MOSFETs. Upon the heavy ion track through the device, it can lead to displacement damage, including the vacancies and the interstitials. As the featured size of device scales down, the damage can change the dopant distribution in the channel and source/drain regions through the generation of radiation-induced defects and thus have significant impacts on their electrical characteristics. The measured results show that the radiation-induced damage can cause DC characteristics degradations including the threshold voltage, subthreshold swing, saturation drain current, transconductance, etc. The radiation-induced displacement damage may become the dominant issue while it was the secondary concern for the traditional devices after the heavy ion irradiation. The samples are also irradiated by Co-60 gamma ray for comparison with the heavy ion irradiation results. Corresponding explanations and analysis are discussed.  相似文献