三李煤矿突水因素分析及堵水工艺探讨     

宋佩德  李公明 《中国煤田地质》2002,14(3):46-47,84

根据三李煤矿矿井地质及水文地质条件的分析，三李煤矿矿井突水水源应该是来自二1煤直接底板太原组上段L7－8灰岩岩溶溶裂隙含水层。为探明突水通道，采用“先探后堵，探堵结合，堵源为主”的治理方案，查明了该次突水的主要通道是：“通过煤层而未经任何材料封闭的钻孔^[1]。经对此处实施了钻孔注浆后，恢复了矿井生产。  相似文献   

小波域多时相干涉SAR数据融合     

岳焕印  郭华东  王长林  廖静娟  阎福礼 《遥感学报》2002,6(6):501-506

大气因素和高斯白噪声对由星载干涉SAR系统获取的干涉图相位有很大的影响，可能会极大地降低结果DEM的精度，提出了一种对多时相干涉SAR数据生成的独立DEM进行权重融合的方法，该算法在小波域当中估计了大气和高斯噪声的误差功率，并对多时相DEM进行权重融合。用河北省尚义县地区的ERS-1和ERS-2数据的研究表明，此算法可以很好地提高由干涉SAR获取的DEM的精度。  相似文献   

Nonlinear surface ground analysis via statistical approach     

Izuru Takewaki  Nobuyoshi Fujii  Koji Uetani 《Soil Dynamics and Earthquake Engineering》2002,22(6)

A statistical approach is proposed for nonlinear surface ground analysis. In contrast to the conventional method which deals with only a single ground motion for equivalent linearization of soil properties, a design response spectrum defined at the upper level (bottom of the surface ground) of an engineering bedrock can be handled as the target design earthquake in the present paper. The effective shear strain in each soil layer is evaluated by means of a statistical procedure in which the mean peak shear strain is computed in terms of its standard deviation and the corresponding peak factor. The stiffness and damping ratio of each soil layer are obtained iteratively from the nonlinear relation of stiffness reduction factors and damping ratios with respect to the strain level. After the evaluation of the equivalent stiffness and damping ratio of every soil layer, the ground surface response spectrum is transformed from the design response spectrum defined at the upper level of the engineering bedrock via the one-dimensional wave propagation theory. The reliability and accuracy of the proposed analysis method is examined through the comparison with the results by the conventional method (represented by the program) for many simulated spectrum-compatible ground motions.  相似文献   

Towards a more ecologically relevant assessment of the impact of heavy metals on the photosynthesis of the seagrass, Zostera capricorni     

Catriona M. O. Macinnis-Ng  Peter J. Ralph 《Marine pollution bulletin》2002,45(1-12)

This in situ study used photosynthetic activity (measured as chlorophyll a fluorescence) and photosynthetic pigment concentrations to assess the effect of copper, cadmium, lead and zinc on the seagrass Zostera capricorni. Custom-made portable in situ exposure (PIE) chambers were developed so seagrasses could be dosed within the meadow. Z. capricorni was exposed to 0.1 and 1 mg l⁻¹ of metal solutions for 10 h. During this time and for the subsequent four-day recovery period, the effective quantum yield of photosystem II (PS II) (ΔF/Fm^′) was measured. While the results were variable, copper and zinc exposed samples had a depressed ΔF/Fm^′ during the exposure period. Samples exposed to zinc recovered to pre-exposure levels but those exposed to copper did not. Cadmium and lead did not impact on the chlorophyll a fluorescence and the chlorophyll pigment data supported these findings. This study presents an innovative new application of chlorophyll a fluorescence stress assessment.  相似文献   

Influences of a Microcystis aeruginosa Kützing bloom on zooplankton populations in Jacarepaguá Lagoon (Rio de Janeiro, Brazil)     

Aloysio S. Ferro-Filho  Patricia Domingos  Sandra M.F.O. Azevedo 《Limnologica》2002,32(4)

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瞬变电磁法在黔西北猫猫厂铅锌矿区找矿中的应用   总被引：10，自引：3，他引：10  

金中国  邹林等 《地质与勘探》2002,38(6):48-50

简述了瞬变电磁法的基本原理及在黔西北猫猫厂铅锌矿区的工作方法及找矿效果。在Ⅰ矿段通过工作获得5个TEM异常，选择3个异常进行工程验证，均在深部见矿，说明这种方法在高阻围岩条件下，寻找深部隐伏金属矿体是十分有效的。此外，该方法还能较准确地确定断裂构造的位置，在第四系厚沉积物覆盖区，可为地质填图提供较好依据。  相似文献   

Effects of wave passage on the relevant dynamic properties of structures with flexible foundation     

Javier Avils  Martha Surez  Francisco J. Snchez‐Sesma 《地震工程与结构动力学》2002,31(1):139-159

An evaluation of the wave passage effects on the relevant dynamic properties of structures with flexible foundation is presented. A simple soil–structure system similar to that used in practice to take into account the inertial interaction effects by the soil flexibility is studied. The kinematic interaction effects due to non‐vertically incident P, SV and Rayleigh waves are accounted for in this model. The effective period and damping of the system are obtained by establishing an equivalence between the interacting system excited by the foundation input motion and a replacement oscillator excited by the free‐field ground motion. In this way, the maximum structural response could be estimated from standard free‐field response spectra using the period and damping of the building modified by both the soil flexibility and the travelling wave effects. Also, an approximate solution for the travelling wave problem is examined over wide ranges of the main parameters involved. Numerical results are computed for a number of soil–structure systems to identify under which conditions the effects of wave passage are important. It comes out that these effects are generally negligible for the system period, but they may significantly change the system damping since the energy dissipation within the soil depends on both the wave radiation and the diffraction and scattering of the incident waves by the foundation. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

无机盐类对干酪根生烃过程的影响   总被引：16，自引：2，他引：16  

李术元  林世静  郭绍辉  刘洛夫 《地球化学》2002,31(1):15-20

利用岩石热解评价仪（Rock-Eval）和热解气相色谱仪（Py-GC)，对采自东营凹陷和松辽盆地的烃源岩干酪根进行了热模拟实验，探讨了地层水中所存在的无机盐类对生烃过程的影响，求得了不同盐类作用下的反应动力学参数。结果表明，无机盐类对干酪根的热解生烃过程具有不同的影响。其中，氯化盐类具有一定程度的反催化作用，其他盐类表现出正的催化作用。这种催化作用是通过降低热解反应的表观活化能或提高反应的频率因子而表现出来的。最后，对无机盐类的催化作用机制进行了初步探讨，认为电子诱导效应理论可以初步解释无机盐类的催化作用。  相似文献   

Modelling electromagnetic responses of 2-D structures due to spatially non-uniform inducing fields. Analysis of magnetotelluric source effects at coastlines     

Patricia Martinelli  Ana Osella 《Geophysical Journal International》2003,155(2):623-640

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Impact of a Saturation-Dependent Dissipation Source Function on Operational Hindcasts of Wind-Waves in the Australian Region     

Jose Henrique G. M. Alves  Diana J. M. Greenslade  Michael L. Banner 《Journal of Atmospheric & Ocean Science》2002,8(4):239-267

The impact of a modified parametric form of the dissipation source function S ds on the skill of an operational spectral wind-wave model is investigated. Numerical experiments are made with a version of the WAM model presently used operationally by the Australian Bureau of Meteorology to produce sea-state forecasts within the Australian region. Performances of wave hindcasts obtained using several alternative forms of this newly proposed dissipation source function are compared to those produced with forms of S ds commonly used operationally. A new ad hoc technique to compare modelled and observed wave spectra is introduced to assess the quality of calculated one-dimensional frequency spectra.

Our results indicate that wave model performance in terms of integral spectral parameters, such as the significant wave height H s , may benefit from improved parameterisations of the dissipation source term S ds . On the other hand, we also found that model performance was relatively poor in terms of predictions of the one-dimensional frequency spectrum, regardless of the chosen form of S ds . These results suggest that further refinements of the dissipation source term are strongly dependent on improved parametrisations of the nonlinear interactions source term S nl .  相似文献