同震阶变异常的特征与机制分析     

李兰生  刘建华 《大地测量与地球动力学》1992,(3)

本文对徐州地震台JB—72水平摆倾斜仪1988年11月至1989年5月间所记录到的24次同震阶变进行了深入分析,认为:a.造成同震阶变的原因是多方面的,而反应了地球应变场准静态调整的同震阶变才是有价值的价变异常;b.多观测手段的地震台站,同震阶变应该在不止一台仪器上得到响应。  相似文献   

Studies on flow characteristics of coal–oil–water slurry system     

Subrata Kumar Majumder  Kamal ChandnaDhiren Sankar De  Gautam Kundu 《International Journal of Mineral Processing》2006

Experiments were carried out to investigate the rheological properties of coal–oil–water suspension containing solids of different sizes. Two different coal samples with mean particle sizes of 120 mesh, 175 mesh and 220 mesh were used. The coal concentration was varied from 5% to 25% by weight. Sodium silicate has been used as an additive to study the behavior of the variation of average viscosity of the suspension. A generalized correlation has been developed to predict the average viscosity of suspension in terms of particle diameter of the coal, concentration of coal, viscosity of the suspending medium and the concentration of water. Experimental investigations revealed that coal–oil–water suspensions show an increase in the viscosity with decrease in coal size but with the addition of an additive, the average viscosity tends to decrease initially up to a certain optimum dosages and thereafter it increases with further addition of additives. Two empirical correlations are proposed for average viscosity of the coal–oil–water suspension, μ_sL in terms of physical properties of the solid and viscosity of the suspending medium with and without additives.  相似文献   

Experimental and numerical studies of rock salt strain hardening     

M. Hamami 《Geotechnical and Geological Engineering》2006,24(5):1271-1292

The work presented in this paper comes as part of a research program dealing with the thermomechanical behaviour of rock salt. It aims to study laboratory and in-situ long-term behaviour by means of creep tests with deviator and temperature changes. The laboratory results, using a triaxial multi-stages creep tests, highlighted the strain hardening character of rock salt. Furthermore, the in-situ results, using a borehole dilatometer multi-step creep test, have shown that the drilling is carried out in a weakly stressed pillar. The interpretation of the laboratory results, using the J.LEMAITRE law, did not indicate full agreement with all the test results. As a result a ‘double’ J.LEMAITRE model, which takes into account a double strain hardening variable, has been put forward. The validation of this model on the laboratory creep tests is very satisfactory. Furthermore, the activation energy seems satisfactory to represent the influence of the temperature. The in-situ behaviour modelling is clearly more complex than the modelization based on laboratory tests. In fact, it seems that if the rock salt behaviour is maintained by J.LEMAITRE law, it is necessary to vary with the stress, at least, one of the parameters assumed constant in the basic law.  相似文献   

热幔柱的启动动力   总被引：4，自引：1，他引：4  

杨学祥  张玺云 《世界地质》1996,15(2):68-74

科氏力是地球各圈层差异旋转的原因。在重力分异过程中，随着地球质量不断向地心集中，地球自转动能也不断向地核集中，从而产生圈层分化和差异旋转。  相似文献   

Elastoplastic model with loading memory surfaces (LMS) for monotonic and cyclic behaviour of geomaterials     

Hervé di Benedetto  Matthieu Blanc  Samir Tiouajni  Alan Ezaoui 《国际地质力学数值与分析法杂志》2014,38(14):1477-1502

A new elastoplastic model called loading memory surface based on the critical state concept and the multi‐surface framework is proposed for geomaterials. The model uses a hypoelastic formulation and two plastic mechanisms. The formulations of the model are made in three‐dimensional stress–strain space and work under both monotonic and cyclic loadings. A newly introduced formalism makes it possible to obtain the cyclic response directly from the monotonic loading one. This formalism gives a three‐dimensional generalization of the well‐known Masing rule. The model has been validated against test results of Hostun sand under several conditions: monotonic and cyclic, drained and undrained, tests in compression and in extension, and at different confining pressures and different densities. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

有限圈闭复杂沥青质稠油层钻井难点与对策          下载免费PDF全文

鲍洪志  肖超  赵向阳  何青水  杨顺辉  王朝明 《探矿工程》2016,43(12):18-22

中东YD油田为海相碳酸盐岩地层,Kazh地层分布着活跃的非均质沥青质稠油,高压并含有酸性气体,为非目的层,需要钻穿并封隔该层后对下部产层进行开发。由于沥青质稠油层分布不均,孔隙压力不确定,对钻井工程造成了极大的挑战。在一期施工中,3口井由于沥青质稠油的侵入被迫工程弃井,未能实现工程目的。针对此世界性难点问题,开展了沥青质稠油侵入机理实验研究、固化剂研制、控压钻井技术应用等一系列配套工艺技术研究,提出了复杂沥青质稠油层安全钻井技术对策,现场应用取得较好的效果。  相似文献   

深孔用高钢级绳索取心钻杆分区热处理工艺试验研究          下载免费PDF全文

彭莉  梁健  蔡纪雄  杨金东  孙环平  孙建华 《探矿工程》2016,43(9):14-19

为改善绳索取心钻杆受力工况,延长钻杆使用寿命,满足深孔及特深孔钻探施工要求,开展了对绳索取心钻杆体进行分区热处理工艺的试验研究。试验选用高钢级薄壁管材,通过对钻杆两端300 mm左右的区间内进行盐浴淬火及高温回火处理,保证了调质区域的机械性能,硬度和金相组织均匀性良好,同时热处理过渡带影响区域小。试制加工的特深孔绳索取心钻杆具有两端部螺纹连接段刚性强、杆体中部韧性好的特点。该钻杆在山东莱州西岭村矿区完成了2845.55 m深孔的钻进施工,使用情况良好。  相似文献   

北大西洋地区气候准20年周期的观测和模拟分析          下载免费PDF全文

傅心雨  陶丽 《大气科学学报》2021,44(6):938-944

北大西洋地区除了存在约70 a周期的AMO（Atlantic Multidecadal Oscillation,北大西洋年代际振荡）之外,历史长期气候记录中英格兰温度（Central England Temperature,CET）与格陵兰冰芯净雪累计率还存在显著的20 a周期波动。本研究利用CCSM4（Community Climate System Model version 4）耦合模式工业革命前控制试验（piControl）结果中的海表面温度（Sea Surface Temperature,SST）,通过10～50 a带通滤波与扩展经验正交函数（Extended Empirical Orthogonal Function,EEOF）分解,得到在北大西洋副极地海区存在准20 a振荡的逆时针旋转模态。此周期与其临近地区的CET、格陵兰冰芯净雪累计率的准20 a振荡周期相吻合,说明这种北大西洋副极地海区准20 a振荡的海洋模态与其临近地区的大气准20 a振荡之间可能存在相应的联系。进一步利用CAM4（the Community Atmosphere Model version4）大气模式,以北大西洋副极地海区准20 a振荡SST旋转模态为强迫场进行敏感性试验,进一步验证了这种联系。  相似文献   

差分法计算地震动旋转分量          下载免费PDF全文

李栋青  王赟  孙丽霞 《地球科学》2021,46(1):369-380

旋转地震学是一门研究由地震、爆破以及工程振动等引起的地球介质运动的新兴学科.旋转运动的研究由来已久,但是由于缺少高精度的旋转分量地震仪,所以旋转运动的研究大多仅限于理论方面.差分法作为利用平动分量获取旋转分量的一种计算方法,在理论研究方面较为成熟,但是缺乏实际数据的验证.通过在对旋转运动研究现状充分调研的基础上,利用模拟数据和实测的爆炸源数据,对差分法进行了测试和分析.通过对比差分法计算的旋转分量和实测旋转分量的波形图、振幅谱和相位谱等,得出了在一定的误差允许范围内,差分法可以作为求取水平旋转分量（R_X,R_Y）的替代方法的结论;同时,针对爆炸源的高频特性以及密集台阵观测的特点,对现有的差分法进行了改进,提出了一种精度更高的求取旋转分量的差分法.   相似文献   

Kinetic energy budget and moisture flux convergence analysis during interaction between two cyclonic systems: Case study     

《Dynamics of Atmospheres and Oceans》2019

An analysis of the kinetic energy budget during a case of interaction between middle latitude and extratropical cyclones has been made in this work. Horizontal flux convergence constitutes a major energy sink. Generation of kinetic energy via cross-contour flow is a persistent source throughout the growth and decay periods. Dissipation of kinetic energy from subgrid to grid scales is an important source during the pre-storm period; it acts as a sink during the growth and decay periods. The major contribution to kinetic energy comes from a persistent upper tropospheric jet stream activity throughout the period of the cyclone development. The characteristics of moisture-flux components (divergent and rotational) along with precipitable water content for different tropospheric layers throughout the life cycle of our cyclone are also studied in this work. It is found that most of required humidity for our cyclone are initiated from Arabian Sea and then to some extent are reinforced over Gulf of Aden and east of central Africa and then by passing over Red sea enter to the south and south east of Mediterranean Sea. The rotational component of the moisture transport brings moisture from two regions; the first which is considered the main region is the Indian Ocean, Arabian Sea, Gulf of Aden and north east of Sudan. The second source region is the Atlantic and Mediterranean Sea. In the middle troposphere, the primary moisture source is found over central Africa, which in turn is traced to the Atlantic Ocean, the Indian Ocean, and the Arabian Sea. The upper-level moisture fluxes are weak and play a minor role over the area of interaction between two cyclones.  相似文献