小面元三维地震勘探技术在西山屯兰矿南五采区的应用

屯兰矿南五采区地形复杂,最大高差达271m,地表大面积为第四系黄土覆盖,激发困难。为探索研究小面元三维地震勘探技术的应用效果。在常规三维地震勘区域内划出1km^2,采用5m×5m小面元进行采集。在地震数据采集过程中,采取了加大激发井深、提高覆盖次数、减小CMP面元网格和加大接收排列等技术措施,做到“四小三高、二中一深、两个等高面”。通过插值、抽线及扩大面元处理。获得2．5m×2．5m×1ms、5m×5m×1ms、5m×10m×1ms、10m×10m×1ms以及不同叠加次数的三维数据体。资料解释工作主要是在5m×5m×1ms、2．5m×2．5m×1ms两个数据体上进行,解释落差大于或等于5m的断层6条,落差3～5m的断层8条;查明长轴直径20～30m的陷落柱4个。30～100m的陷落柱1个,大于100m的陷落柱3个。与相邻区常规三维地震比较,小面元三维地震勘探有利于对小陷落柱、小断层的控制和解释。     

试论我国城市发展方针

在执行重重工业的发展战略和城乡分割体制的计划经济背景下,我国制定了“控制大城市规模,合理发展中等城市,积极发展小城市”的城市建设方针。但是分析表明,这一方针不能适应市场经济和对外开放形势的需要,也不符合我国人多地少、农村剩余劳动力多的国情,必须调整现有的城市发展方针,选择适宜的城市化发展道路。因此,本文就适度发展大中城市,提高城市现代化水平;加速乡村城市化,积极合理发展小城镇;以及根据不同地区的具体情况,因地制宜地指定城市化途径等方面作了探讨。     

Estimation of statistical parameters for censored lognormal hydraulic conductivity measurements

Field tests of hydraulic conductivity (e.g., injection test, pumping test, etc.) in low permeability formations are subject to censoring due to the detection limit of the instruments used. An iterative method of estimating the mean and variance of hydraulic conductivity data with a presumed log-normal distribution function is presented. This method accounts for the data that are actually below the lower detection limit (called truncated data) and thus gives distribution parameters that are more representative for the underlying distribution. The proposed method is then tested on two simulated normally distributed random datasets having different variances. The results show that the means and variances estimated by the proposed method are very accurate. Finally, the method is used to estimate the mean and variance of hydraulic conductivity data from single hole water injection tests in a fractured geological formation.     

肯尼亚Anza盆地东南部重力场及构造特征

肯尼亚Anza盆地东南部地处东非裂谷系，发育了巨厚的中—新生界沉积盖层。然而，该区域勘探程度较低，制约了对其构造体系的认识及油气勘探潜力的评价。文章基于研究区的重力异常数据，针对其构造特征的认识进行了数据处理及解释。研究结果表明，受中非剪切带右旋剪切应力的影响，研究区发育规模较大的北西向基底断裂和规模较小的北东向盖层断裂，且北东向断裂切断北西向断裂；基底深度差异大，总体呈"两凹夹一隆"的特征，凹陷区沉积了巨厚的中—新生界盖层；受北西向拉张断裂和沿构造软弱带发育的北东向断裂的控制，研究区划分为东部凹陷、中部凸起、南部隆起和西部凹陷4个构造单元，呈现"东西分带、南北分块"的构造格局。      

On the spatial characteristic of the short term and imminent anomalies of underground water behaviors before strong earthquake

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泥晶灰岩地层孔壁坍塌掉块现象及处理

在灰岩地区钻探施工过程中，常见孔壁坍塌、掉块现象，尤其在含泥晶灰岩地层分布区钻进过程中，这种现象尤为突出，轻则影响钻探施工效率，重则造成钻探孔内事故。针对孔内坍塌、掉块现象的征兆及特点，提出了相对应的处理办法。     

复合土钉墙支护技术在某大型软土基坑围护中的应用

根据拟建建筑基坑的工程地质条件、周边环境条件、基坑开挖深度等特点综合考虑，对基坑分段采用超前微型桩支护加土钉墙、放坡加土钉墙2种复合支护方案。实践证明，该工程所采用的多种复合式支护实施方案，技术安全可靠，经济合理。     

Adsorption of aluminium by a latosol as affected by phosphate and glutamic acid

The effect of phosphate and glutamic acid on adsorption of aluminium onto a latosol was investigated as a function of pH and ligand concentrations through batch equilibrium experiments. The results showed that adsorption of aluminium by the soil was enhanced after addition of phosphate at low pH, and this promotive effect was gradually eliminated with the increase in pH. The positive effect of phosphate on aluminium adsorption onto latosol was attributed to phosphate-induced surface negative charge and formation of ternary surface complexes involving aluminium and phosphate. While using silica as adsorbent, the inactive surfaces for phosphate, promotion of adsorption of aluminium by phosphate was also found. Then it was proposed that additional aluminium might bind to the phosphate adsorbed onto the silica in the form of surface complexes silica–aluminium–phosphate again, and the mechanism might operate in the soil systems as well. Glutamic acid exhibited no influence on the adsorption of aluminium by the soil at low pH. After increasing the pH, adsorption of aluminium was inhibited especially with the highest addition of glutamic acid, probably owing to weak affinity of complexes between glutamic acid and aluminium to the soil.     

山丘平原过渡区土壤重金属污染特征及评价——以四川省五通桥区为例

采集和分析了五通桥区不同功能区和乡镇73个土壤样品，以了解山丘平原过渡区土壤重金属的含量和污染特征。结果表明，重金属的平均含量为Pb32．18mg／kg、Cd0．82mg／kg、Cu28．61mg／kg、Zn108．08mg／kg、Ni32．66mg／kg、Cr72．44mg／kg；与四川土壤背景值相比，Cu、Ni、Cr的含量与之持平，Pb增加了0．11倍，Zn增加了0．32倍，Cd的积累较为严重，比背景值增加了10倍。污染评价结果显示该过渡区存在一定程度的重金属污染问题，不同功能区的污染程度排序为工业区〉生活区〉农业区。Cd在六种元素的土壤污染分担率中占55．46％，是最主要的污染元素；土壤Cd含量与Pb和Zn存在较高的相关性（相关系数为0．525和0．500），表明存在Pb—Cd和Zn—Cd的复合污染。