The inversion of anelastic coefficient,source parameters and site respond using genetic algorithm

It gradually becomes a common work using large seismic wave data to obtain source parameters, such as seismic moment, break radius, stress drop, with completingof digital seismic network in China (Hough, et al, 1999; Bindi, et al, 2001). These parameters are useful on earthquake prediction and seismic hazard analysis.Although the computation methods of source parameters are simple in principle and the many research works have been done, it is not easy to obtain the parameters accurately. There are two factors affecting the stability of computation results. The first one is the effect of spread path and site respond on signal. According to the research results, there are different geometrical spreading coefficients on different epicenter distance. The better method is to introduce trilinear geometrical spreading model (Atkinson, Mereu, 1992; Atkinson, Boore, 1995; WONG, et al, 2002). In addition, traditional site respond is estimated by comparing with rock station, such as linear inversion method (Andrews, 1982), but the comparative estimation will introduce some errors when selecting different stations. Some recent research results show that site respond is not flat for rock station (Moya, et al, 2000; ZHANG,. et al, 2001; JIN, et al, 2000; Dutta, et al, 2001). The second factor is to obtain low-frequency level and corner frequency fromdisplacement spectrum. Because the source spectrum model is nonlinear function,these values are obtained by eye. The subjectivity is strong. The small change of corner frequency will affect significantly the result of stress drop.     

Calibration of an oscillating nozzle‐type rainfall simulator

Nozzle‐type rainfall simulators are commonly used in hydrologic and soil erosion research. Simulated rainfall intensity, originating from the nozzle, increases as the distance between the point of measurement and the source is decreased. Hence, rainfall measured using rain gauges would systematically overestimate the rainfall received at the ground level. A simple model was developed to adjust rainfall measured anywhere under the simulator to plot‐wide average rainfall at the ground level. Nozzle height, plot width, gauge diameter and height, and gauge location are required to compute this adjustment factor. Results from 15 runs at different rain intensities and durations, and with different rain gauge layouts, showed that a simple average of measured rain would overestimate the plot‐wide rain by about 20 per cent. Using the adjustment factor to convert measured rainfall for individual gauges before averaging improved the estimate of plot‐wide rainfall considerably. For the 15 runs considered, overall discrepancy between actual and measured rain is reduced to less than 1 per cent with a standard error of 0·97 mm. This model can be easily tested in the ?eld by comparing rainfall depths of different sized gauges. With the adjustment factor they should all give very similar values. Copyright © 2003 John Wiley & Sons, Ltd.     

关联度分析法在确定土地定级因素权重中的应用

从关联度分析法的基本原理入手，介绍了应用关联度分析法确定土地定级因素权重的具体方法，探讨了关联度分析法运用于土地定级因素权重确定的可行性。     

西南三江地区矿产资源遥感综合预测方法

详细阐述了矿产资源遥感综合预测方法的工作程序、控矿要素的数字化分析与遥感找矿模型的建立,以及遥感矿产的综合分析评价方法与应用等,并以西南三江中段遥感综合预测成果佐证了矿产资源遥感综合预测方法在矿产资源预测中能使野外调查工作更具预见性和目的性,从而大大缩短了矿产资源调查的工作周期。     

多因素复杂系统最佳因素权重确定的一种新思路——以深港西部通道工程深圳湾公路大桥为例

为了客观地反映各因素对目标问题的影响程度,本文首次提出了最佳因素权重概念。定义最佳因素权重为研究区域内系统质量处于极限状态时的各因素权重之组合。结合深港西部通道工程深圳湾公路大桥桥址比选方案,详细说明了本方法的研究思路及其确定方法。通过最佳因素权重方法,能客观地、定量地确定出多因素复杂系统中的最优场址。     

岩质边坡稳定性分析的探讨

通过最大剪应力等值线来确定边坡的滑动面,并与其结构面抗剪强度相比较,给出了确定边坡的稳定系数的方法。     

日照市短时冰雹定时-定点-定量预报

利用1960～2000年青岛、射阳、徐州3站08时探空资料及日照站08时地面气象资料，分析了日照地区出现的16次降雹天气的时空分布特征，在对降雹天气分型的基础上利用积云数值模式计算降雹因子，用降雹因子和单站要素因子建立历史降雹因子个例库，用历史实况资料建立实况个例库，用距离相似法实现日照地区短时冰雹定时、定点、定量的客观预报。     

脑卒中与气象要素关系的探讨

1994年1月至2000年12月北京地区若干社区脑卒中发病人数与同期气象资料分析结果表明：北京地区脑卒中发病有明显的季节性，冬春季高发，夏秋季低发；出血性脑卒中发病是春秋季高发，夏季低发；缺血性脑卒中发病是夏季高，秋季低。脑卒中发病与气温、气压和相对湿度有密切关系；寒冷与高温，气温、气压的剧烈变化等，可能是诱发脑卒中的重要气象因素。     

威特DI2002测距仪实测精度分析

通过对威特ＤＩ２００２测距仪的实测资料的分析，认为（１）ＤＩ２００２测距仪实测精度较高，与ＭＥ－３０００测距仪具有同等的实测精度，（２）ＤＩ２００２仪器性能稳定，加、乘常数变化幅度小，频率变化也很小，其频率的稳定性远比ＭＥ－３０００测距仪匹配的测频仪高。（３）ＤＩ２００２与ＭＥ－３０００测距成果有很好的一致性。在ＭＥ－３０００测距仪老化的情况下，可以用ＤＩ２００２替代ＭＥ－３０００用于跨断层水平形     

7月份降雨分布型的预报方法

综述了我国７月份雨型的划分方法，各种雨型的多雨特点及环流特征，总结了各类雨型的预报判据，着眼于赤道东太平洋海温（ＳＳＴ），冬季（１－３月）５００ｈＰａ环流，春季（３－５月）西太平洋副热带高压，夏季（６－８月）赤道平流层纬向风准两年振荡（ＱＢＯ）等方面，分析了与７月雨型的关联。该方法对业务预报有很好的指导意义。