基于GIS与ANN耦合技术的地裂缝灾情非线性模拟预测系统——以山西榆次地裂缝灾害为例

现代地裂缝在世界许多国家普遍存在 ,已成为当今世界范围内的主要地质灾害之一。本文在详尽分析了山西榆次地裂缝的各个致灾因子的基础上 ,利用GIS技术建立了地质学意义上的专题层 ;然后采用人工神经网络技术构建出了地裂缝灾害活动性的评价模型 ,并建立了地裂缝活动性的评价系统 ,对榆次地裂缝进行了灾害活动性评价 ,为榆次市城建和国土规划等部门的正确决策提供了重要的科学依据     

河南豫北地震台网地区波速的探讨

为了解决河南豫北地区地震的定位问题 ,对豫北台网内的 10个典型地震 ,使用了 7个地震台站的资料 ,用波速比求出横波速度 ;用和达定位法 (有的同时使用高桥法 )进行了精确定位 ,求出震源深度 ;测量了震中至各台的震中距 ,以此反算出了纵波速度。通过计算 ,确定出了较为适合河南豫北地震台网地区的波速。     

河流水质风险评价的灰色-随机风险率方法

提出了量化影响河流水质的随机不确定性与灰色不确定性的水质超标灰色－随机风险率概念，建立了水质超标灰色－随机风险率评价模型。在水质单项参数评价模型中，将河流污染物浓度变量的分布处理成灰色概率分布，将污染物浓度超过水质类别标准值的风险率处理成灰色概率，即水质超标灰色－随机风险率。在水质综合评价模型中，河流水环境系统被考虑为担任某一使用可能的可靠性系统，而任意一种水质参数超标意味着河流水体使用功能不能得到应有的保证，也即表明水体综合评价超标，最后借鉴系统可靠性分析的理论和方法计算水质综合超标率。该方法应用于黄河花园口断面重金属污染风险评价。     

安徽铜陵冬瓜山热液叠加改造型铜矿床流体包裹体地球化学特征

研究了安徽冬瓜山热液叠加改造型铜矿床流体包裹体地球化学特征（包裹体均一温度、盐度、压力、成分、流体的H，O，C和Cu同位素），探讨了成矿流体的性质及其来源。认为该矿床是在岩浆水和后期少量大气水的加入而形成的混合热液共同作用下，活化碳酸盐岩地层和石英闪长岩中的铜等成矿元素，形成含矿热液，并以铜的氯络合物方式运移，在弱还原性条件下使原始沉积矿胚层加厚变富。     

岩石受压破裂的ULF和LF电磁前兆信号

实验观测到了4类岩性、18块样品在单轴压力下直至破裂发生全过程中的ULF和LF电磁前兆信号。这些不同频率的信号是零散出现的，其形态为一组组脉冲，宽度为4ms～16ms，幅度为0．1mV～1．4mV。实验发现具同一谐振频率的天线收到的信号频次与其相对于裂缝的位置和方位有关。结果还表明，电磁前兆信号的频度与岩样强度有关，抗压强度高的岩样电磁前兆信号多。微破裂可能产生了偶电层，在破裂过程中向外辐射，产生了LF频段的磁信号，ULF磁信号则主要由压磁效应产生。     

System identification of the Vincent Thomas suspension bridge using earthquake records

The Vincent Thomas Bridge in the Los Angeles metropolitan area, is a critical artery for commercial traffic flow in and out of the Los Angeles Harbor, and is at risk in the seismically active Southern California region, particularly because it straddles the Palos Verdes fault zone. A combination of linear and non‐linear system identification techniques is employed to obtain a complete reduced‐order, multi‐input–multi‐output (MIMO) dynamic model of the Vincent Thomas Bridge based on the dynamic response of the structure to the 1987 Whittier and 1994 Northridge earthquakes. Starting with the available acceleration measurements (which consists of 15 accelerometers on the bridge structure and 10 accelerometers at various locations on its base), an efficient least‐squares‐based time‐domain identification procedure is applied to the data set to develop a reduced‐order, equivalent linear, multi‐degree‐of‐freedom model. Although not the main focus of this study, the linear system identification method is also combined with a non‐parametric identification technique, to generate a reduced‐order non‐linear mathematical model suitable for use in subsequent studies to predict, with good fidelity, the total response of the bridge under arbitrary dynamic environments. Results of this study yield measurements of the equivalent linear modal properties (frequencies, mode shapes and non‐proportional damping) as well as quantitative measures of the extent and nature of non‐linear interaction forces arising from strong ground shaking. It is shown that, for the particular subset of observations used in the identification procedure, the apparent non‐linearities in the system restoring forces are quite significant, and they contribute substantially to the improved fidelity of the model. Also shown is the potential of the identification technique under discussion to detect slight changes in the structure's influence coefficients, which may be indicators of damage and degradation in the structure being monitored. Difficulties associated with accurately estimating damping for lightly damped long‐span structures from their earthquake response are discussed. The technical issues raised in this paper indicate the need for added spatial resolution in sensor instrumentation to obtain identified mathematical models of structural systems with the broadest range of validity. Copyright © 2003 John Wiley & Sons, Ltd.     

Spatial Database Management System of China Geological Survey Extent

The spatial database management system of China geological survey extent is a social service system. Its aim is to help the government and the whole social public to expediently use the spatial database, such as querying, indexing, mapping and product outputting. The management system has been developed based on MAPGIS6. x SDK and Visual C , considering the spatial database contents and structure and the requirements of users. This paper introduces the software structure, the data flow chart and some key techniques of software development.     

猝死与气象条件的关系

通过调查1999年1～12月上海市医疗救护中心急救的839例院外猝死病例，并与同期气象资料进行分析，发现院外猝死男性多于女性，高发年龄为60～84岁，院外猝死在年内的高峰期为冬季，在昼夜中的高峰点为早晨07时，既往有心血管病史是院外猝死的主要原因。总猝死数与相对湿度、平均气压呈正相关，与最低气温、平均气温呈负相关，心血管猝死数除与以上气象要素相关外，还与气压变化、最低气温变化、日照时数变化等呈正相关。冠心病和其他心脏病与平均风速呈负相关，高血压病与平均气压呈正相关。