地壳介质弹性和电性各向异性研究的新进展

分析了地壳介质各向异性研究的现状，指出了弹性和电性各向异性研究中存在的问题，提出了联合利用弹性和电性各向异性研究地球介质特征及提取物性参数的正反演方法．理论研究和地震过程的实际资料表明，将弹性和电性结合起来研究地壳介质各向异性具有清晰明确的物理意义，是各向异性研究的一个非常有发展前景的新领域。     

Hydrology and geomorphology of the Upper White Nile lakes and their relevance for water resources management in the Nile basin

Remote sensing data and digital elevation models were utilized to extract the catchment hydrological parameters and to delineate storage areas for the Ugandan Equatorial Lakes region. Available rainfall/discharge data are integrated with these morphometric data to construct a hydrological model that simulates the water balance of the different interconnected basins and enables the impact of potential management options to be examined. The total annual discharges of the basins are generally very low (less than 7% of the total annual rainfall). The basin of the shallow (5 m deep) Lake Kioga makes only a minor hydrological contribution compared with other Equatorial Lakes, because most of the overflow from Lake Victoria basin into Lake Kioga is lost by evaporation and evapotranspiration. The discharge from Lake Kioga could be significantly increased by draining the swamps through dredging and deepening certain channel reaches. Development of hydropower dams on the Equatorial Lakes will have an adverse impact on the annual water discharge downstream, including the occasional reduction of flow required for filling up to designed storage capacities and permanently increasing the surface areas of water that is exposed to evaporation. On the basis of modelling studies, alternative sites are proposed for hydropower development and water storage schemes. Copyright © 2012 John Wiley & Sons, Ltd.     

Numerical assessment of tsunami attack on a rubble mound breakwater using OpenFOAM®

A numerical assessment study of tsunami attack on the rubble mound breakwater of Haydarpasa Port, located at the southern entrance of the Istanbul Bosphorus Strait in the Sea of Marmara, Turkey, is carried out in this study using a Volume-Averaged Reynolds-Averaged Navier-Stokes solver, IHFOAM, developed in OpenFOAM^® environment. The numerical model is calibrated with and validated against the data from solitary wave and tsunami overflow experiments representing tsunami attack. Furthermore, attack of a potential tsunami near Haydarpasa Port is simulated to investigate effects of a more realistic tsunami that cannot be generated in a wave flume with the present state of the art technology. Discussions on practical engineering applications of this type of numerical modeling studies are given focusing on pressure distributions around the crown-wall of the rubble mound breakwater, and the forces acting on the single stone located behind the crown-wall at the rear side of the breakwater. Numerical modeling of stability/failure mechanism of the overall cross-section is studied throughout the paper.The present study shows that hydrodynamics along the wave flume and over the breakwater can be simulated properly for both solitary wave and tsunami overflow experiments. Stability of the overall cross-section can only be simulated qualitatively for solitary wave cases; on the other hand, the effect of the time elapsed during tsunami overflow cannot be reflected in the simulations using the present numerical tool. However, the stability of the overall cross-section under tsunami overflow is assessed by evaluating forces acting on the rear side armor unit supporting the crown-wall of the rubble mound breakwater as a practical engineering application in the present paper. Furthermore, two non-dimensional parameters are derived to discuss the stability of this armor unit; and thus, the stability condition of the overall cross-section. Approximate threshold values for these non-dimensional parameters are presented comparing experimental and numerical results as a starting point for engineers in practice. Finally, investigations on the solitary wave and tsunami overflow experiments/simulations are extended to the potential tsunami simulation in the scope of both representation of a realistic tsunami in a wave flume and stability of the rubble mound breakwater.     

GPS和GLONASS系统下RAIM空洞预报

接收机自主完好性监测（RAIM）是卫星导航系统完好性监测的方法之一。一定时空条件下的RAIM可用性,可以通过RAIM空洞直观的反映出来,可以为飞行提供预警;利用不同期GPS、GLONASS实际星座,仿真分析了单星座以及GPS／GLONASS组合星座RAIM可用性,绘制了RAIM空洞图,具有一定的参考价值。     

A coupled discrete element model for the simulation of soil and water flow through an orifice

Soil erosion around defective underground pipes can cause ground collapses and sinkholes in urban areas. Most of these soil erosion events are caused by fluidization of the surrounding soil with subsequent washing into defective sewer pipes. In this study, this soil erosion process is simplified as the gradual washout of sand particles mixed with water through an orifice. The discrete element method is used to simulate the large deformation behavior of the sand particles, and the Darcy fluid model is coupled with this approach to simulate fluid flow through porous sand media. A coupled 3D discrete element model is developed and implemented based on this scheme. To simulate previous experiments using this coupled model considering the current computing capacity, we incorporated a ‘supply layer’ to study the continuous erosion process. The coupled model can predict the erosion flow rates of sand and water and the shape of erosion void. Thus, the model can be used as an effective and efficient tool to investigate the soil erosion process around defective pipes. Copyright © 2017 John Wiley & Sons, Ltd.     

SEDIMENT TRANSPORT OF LOW CONCENTRATION IN PIPES

The study of Sediment transport of low concentration in pipes bas been applied in the design of a self-cleansing storm sewer. An alternative criterion is suggested as op- posed to the widely used single flow velocity approach. A conceptual model which simu- lates the condition in a storm sewer is developed and tested against experimental data. The results proved that the volumetric sediment concentration, pipe diameter and sedi- ment size have to be taken into consideration to produce a self-cleansing storm sewer. It also shows that the slope obtained by this alternative criterion is lower than the single flow velocity approach.     

顺便伽玛测量在水化普查中的找铀效果

在铀矿普查中,伽玛测量具有经济、快速、轻便、连续测量的特点。在水化普查中作顺便伽玛测量,投资少、收效快,并可直接发现供详查揭露的矿化点。在生产布置上与水化测量相互适应。通过一遍工作之后,可取得2套各具特点的资料。在资料解释及运用上,二者可互为补充。对无水地段,水化测量为空白区,可用伽玛测量补其不足。伽玛测量可为水化异常解释提供资料,水化异常的规模及浓度的高低又是推测深部矿化情况的依据。从统计结果证实,比例尺为上1:2.5万的顺便伽玛测量与1:1万的正规伽玛测量比较,发现异常机率可达60％。可见将顺便伽玛测量资料在测量精度上降一级使用,是可以满足精度要求的。     

矿山排供结合探讨

本文解决大水矿床排供结合问题是国民经济建设中具有实际意义的重要课题。本文较系统地论述了解决排供矛盾和排供结合的办法。着重从地质一水文地质条件,从矿山排水前后矿床地下水的补给、迳流、排泄条件来论证对排供结合方案的选择,并以一个典型的矿床作为实例加以阐明。     

空间网联合处理中地壳运动参数的引入

本文阐述了空间大地网联合处理中的地壳运动模型的建立方法，并在此基础上提出了非均匀形变，均匀形变，体应变和刚体转动的识别方法，文中以我国现有空间大地网的模拟数据，结合中国大陆地壳构造进行了试算。