埋藏基岩地形对地震波动影响的模拟研究

本文以超声地震模型试验为基础,着重从地震波的强度方面来阐明埋藏基岩地形对地震波动的影响,提出了利用振动能量分析地震动问题的重要性,理论分析及实验结果表明,埋藏基岩地形对地震波动的影响表现为:一方面基岩面凹凸不平,致使基岩面上不同部位接收能量大小不同;另一方面,基岩的凹凸面对地震波产生汇聚与发散作用,这两方面共同作用的结果使得地表不同地点表现出不同的地震动强度。     

蓝藻聚铁作用的模拟实验

实验模拟前寒武纪大气的高二氧化碳分压(P_CO2),低氧浓度条件下,加入较低浓度(6μg/g)铁的Zarronk培养液培养蓝藻Spirulina platensis,观察铁的沉淀与凝聚。藻在生长过程中不断改变环境的离子平衡系统以及pH,Eh等,造成铁的氧化、还原、络合和Fe³⁺沉淀。实验组与未加蓝藻的对照组有显著差别。实验证实藻在聚铁和铁矿形成中起重要作用。     

吉木萨尔县帐篷沟膨润土矿矿石性能及工业应用试验

该矿为钠基膨润土,由硬质矿块与软质胶结物组成。主要矿物为蒙脱石,平均含量72.85％,其次为石英、方英石及少量石盐、赤铁矿。阳离子交换容量75.95mmol/100g胶质价93ml/15g,湿态抗压强度4.41×10~4～5.79×10~4Pa,20％HCl活化土脱色力110.4～332.5,原矿造浆率5.78m~3/t～12.2m~3/t。浇注铸件质量优良,表面光滑。     

Bayes判别分析法与地震短临预测

建立了一套完整的Bayes判别分析方法,并提出了明确的衡量综合预测结果所冒风险大小的风险代价比Kdn该方法可用于不同时间尺度的地震综合预测。选取云南地区1994～1996年的水氡观测资料,采用X2统计检验法识别前兆异常,利用Bayes判别分析方法对云南地区的强震活动性进行了内符检验和外推预测。在风险代价比Kdn取4的情况下,内符检验的R值可达0．54,外推时空占有率0．07,获得了满意的效果。     

LSQRD及解的分辨分析

较详细地介绍了ＬＳＱＲＤ（Ｌｅａｓｔ Ｓｑｕａｒｅ ＱＲ Ｄｅｃｏｍｐｏｓｉｔｉｏｎ） 反演方法以及“检测版”分辨分析方法,并举实例检验其应用。对于大型稀疏方程组的求解,ＬＳＱＲＤ 是一种内存需求小、计算效率高和抗噪能力较强的算法。“检测版”试验表明,ＬＳＱＲＤ也可以对迭代解进行有效的可靠性估计,以指导对反演结果的利用。     

Estimating Petroleum Resources Using Geo-Anchored Method--A Sensitivity Study

The Geo-anchored method, based on a moment-type estimator, has been developed for estimating parent population properties from a successive sample of discoveries. By substituting the expectation of the waiting time z _(n+1) of the (n + 1) ^th discovery to occurrence for an unknown parameter in the anchored method, the Geo-anchored method allows estimation of inclusion probabilities directly from observed data, thus eliminating the need for a priori selection of a value of N, R, or some other feature of the parent population. Because direct estimation of N and R requires an ordered sample, the Geo-anchored method is more sensitive to the data-generating process than the anchored method. This paper presents a sensitivity study on the Geo-anchored method. The test is based on simulated discovery sequences with different assumptions regarding discovery efficiency, exploration maturity, and the shape of the parent field size distribution. As a reference for comparison, estimates from the Horvitz–Thompson estimator also are presented.     

红外测距在信阳市燃气混气站场区断层水平位移监测中的应用

结合红外精密测距在信阳市燃气混气站场区稳定性研究中的应用,探讨了大气对红外测距的影响;在数据处理中采用了验后方差估计的自由网平差模型,使结果获得了亚毫米级的精度,并将F检验方法应用于变形分析中,得到了同观测结果相一致的结论,从而提高了工程岩土体稳定性定量评价的可信度。     

System identification of a concrete arch dam and calibration of its finite element model

A magnitude 4.3 earthquake occurred near Pacoima Dam on 13 January 2001. An accelerometer array that had been upgraded after the Northridge earthquake recorded the motion with 17 channels on the dam and the dam–foundation interface. Using this data, properties of the first two modes are found from a system identification study. Modal properties are also determined from a forced vibration experiment performed in 2002 and indicate a significantly stiffer system than is estimated from the 2001 earthquake records. The 2001 earthquake, although small, must have induced temporary nonlinearity. This has implications for structural health monitoring. The source of the nonlinear behaviour is believed to be loss of stiffness in the foundation rock. A finite element model of Pacoima Dam is constructed and calibrated to match modal properties determined from the system identification study. A dynamic simulation of the 2001 earthquake response produces computed motions that agree fairly well with the recorded ones. Copyright © 2006 John Wiley & Sons, Ltd.     

Pre‐ and post‐test mathematical modelling of a plan‐asymmetric reinforced concrete frame building

Pre‐ and post‐test analyses of the structural response of a three‐storey asymmetric reinforced concrete frame building were performed, aimed at supporting test preparation and performance as well as studying mathematical modelling. The building was designed for gravity loads only. Full‐scale pseudo‐dynamic tests were performed in the ELSA laboratory in Ispra. In the paper the results of initial parametric studies, of the blind pre‐test predictions, and of the post‐test analysis are summarized. In all studies a simple mathematical model, with one‐component member models with concentrated plasticity was employed. The pre‐test analyses were performed using the CANNY program. After the test results became available, the mathematical model was improved using an approach based on a displacement‐controlled analysis. Basically, the same mathematical model was used as in pre‐test analyses, except that the values of some of the parameters were changed. The OpenSees program was employed. Fair agreement between the test and numerical results was obtained. The results prove that relatively simple mathematical models are able to adequately simulate the detailed seismic response of reinforced concrete frame structures to a known ground motion, provided that the input parameters are properly determined. Copyright © 2006 John Wiley & Sons, Ltd.     

利用抽水试验资料确定水文地质参数

本文根据抽水试验取得的数据,分别采用稳定流公式法、降深-距离配线法、漏斗疏干法和直线解析法四种方法,计算了黄河侧渗补给浅层地下水的各项水文地质参数,最后对试验成果的合理性进行了分析评价并确定了各项水文地质参数.