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561.
During the summer of 1926, when visiting some of the mountain rang-es of the Southwestern Shansi, we noticed, in two localities, some interestingfacts concerning the basal beds of the Sinian or the Cambrian, and their rela-tions with the underlying ctystalline rocks.  相似文献   
562.
本文通过对比试验和生产实践的总结,分析了钻探工艺、取土方法和取土器结构对勘探质量和不扰动土样取土质量的影响,并提出了保证勘探、原状取土、标准贯入试验质量的一些具体设想和方法。  相似文献   
563.
Ditch recharge is a method used for raising a water table. However, if the aquifer lies above a leaky layer, then the leaky bed will have an effect on the height of the water table. This paper attempts to provide an analytical solution of the transient state to the linearized Boussinesq equation. The solution proposed in this paper is intended for a generalized form of the leaky layer, with the boundary condition of the water level moving according to an exponential form. The results of theoretical analysis and experimental studies can provide a much better explanation of ditch recharge on an inclined leaky layer. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
564.
Cruziana-localities in China. The fossil animal trails known as Bilobites have been found for the firsttime in China by A.F.Legendre in 1910 at the surface of a sandstone forma-tion near the village Tapishan,NE of Paimakou (白马口),Luchuan-  相似文献   
565.
对复式河道漫滩水流进行了研究,建立了摩阻因子与一维明渠流摩阻因子的关系,揭示出滩地的量纲为一涡粘性系数随着摩阻因子的增加而增加,并将二次流的影响表达成与雷诺切应力相同的形式,从而将其归入表观切应力中,由量纲为一表观涡粘性系数确定,后者可通过量纲为一表观涡粘性系数与摩阻因子之间的一个关系加以计算,该关系类似于量纲为一涡粘性系数与摩阻因子之间的关系。对光滑边界上对称的漫滩水流进行了计算,计算结果与实验资料吻合良好。  相似文献   
566.
The Tjörnes Fracture Zone separates Iceland's North Volcanic Zone from Kolbeinsey-Ridge (Greenland-Sea). Seismicity mainly occurs in swarms, often 100 and more per day, with similar waveforms and frequently offshore.We analysed three earthquake swarms between June and September 2004, recorded by 35 stations, i.e. the permanent Icelandic SIL network and a temporary setup of land and ocean-bottom-seismometers, and 5 swarms of the years 1994-1997 only using the sparser SIL network. Events occurring in the same swarm often show similar waveforms at the same station. We cross-correlated these time series by using a new approach of three component cross-correlation in order to relocate the hypocenters relative within the swarms and to precisely determine the direction and velocity of migration. Our method delivered good relocations with small spatial and temporal errors. This allows the interpretation and characterisation of the observed earthquake swarms. We try to classify observed migration velocities by comparing them to typical fluid- and crack-propagation velocities and determine focal-mechanisms and orientation of the best fitting plane through the hypocenter distribution.We separate the investigated events into two types of earthquake swarms, supposedly dike-induced and hydrothermally- or gas-induced swarms, by pointing out typical characteristics of both types and by comparing them to similar events of other volcanic regions. Based on different migration velocities, we will discuss possible mechanisms and their triggers of all single clusters within a swarm. Hypothetic models will be established, trying to explain the processes during the swarm episodes and to derive possible pre-eruptive patterns from the character of seismicity.  相似文献   
567.
油气储层研究所面临的挑战与新动向   总被引:4,自引:0,他引:4  
本文通过野外与室内详细的观察与测试分析,深入系统地研究了鄂尔多斯地区下古生界主力气层准同生白云岩的岩石学特征,并配合阴极发光、微量元素、电子探针、氧碳同位素及扫描电镜等多种测试手段,研究其形成机理,进一步将之划分为云坪型准同生白云岩、膏盐湖型和受改造型准同生白云岩,并分别论述了它们的油气储集性。  相似文献   
568.
In this study, laboratory rainfall simulation in an extensive area was used to study the infiltration, and interception and storage from surface runoff in points with different stone cover percentages (0, 10, 20 and 30%) and slopes (5°, 10° and 20°). The experimental results of this study showed that the interrelationships among the slope, stone cover percentage, groundwater level, surface runoff amount, and interception and storage of the ponds were varied and irregular. No systematic patterns were detected for the change in the groundwater level, surface runoff amount, and interception and storage of the ponds with different stone cover percentages at different slopes and no threshold values were apparent. For a 5° slope, if the stone cover percentage was increased, the amount of surface runoff was reduced, the infiltration and the groundwater level experienced no significant change, and the interception and storage of the ponds increased. For a 10° slope, if the stone cover percentage was increased, the amount of surface runoff increased, the infiltration decreased, the groundwater level experienced no significant change or decreased slightly at certain points, and the interception and storage of the ponds increased. For a 20° slope, if the stone cover percentage was increased, the amount of runoff increased, the infiltration decreased, the groundwater level experienced no significant change or decreased slightly at certain points, and the interception and storage of the ponds increased. With or without stone cover, when the hydraulic conductivity of the top material is close to that of fine sand or laterite, an increase in the slope gradient decreased the amount of surface runoff and increased the storage amount of the ponds. As for the stone distribution, an interlaced style showed better performance in the interception and storage of ponds than that of a regular style. There was no significant change in the groundwater level. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
569.
570.
Stochastic Environmental Research and Risk Assessment - A sediment particle in a flow not only follows the flow direction but also randomly diffuses through the surrounding fluid, because of the...  相似文献   
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