龙滩水电工程地震台网设计与建设

龙滩水电工程在我国规模仅次于三峡水电工程。本文论述了在龙滩大坝和库区周边建设地震监测台网的作用及意义,分别介绍了龙滩数字遥测地震台网和强震动台网的设计与建设情况,以及所取得的建设成果及投资效益。     

Two new species of Sellaphora (Bacillariophyta) from a deep oligotrophic plateau lake, Lake Fuxian in subtropical China

We describe two new species of Sellaphora from Lake Fuxian, Yunnan Plateau, China. Based on both light and scanning electron microscopy, these species are described as S. yunnanensis sp. nov. and S. sinensis sp. nov. The primary features of S. yunnanensis are: elliptical to linear-elliptical valves with broadly rounded ends, straight filiform raphe, almost straight central endings and small, slightly expanding central pores, small central area, symmetrical or slightly asymmetrical central nodule. The primary features of S. sinensis are: elliptical valves, obtusely rounded ends, similar raphe and axial area, transapically less expanded central area, larger, elliptical central nodule. We compare these species to those of a similar shape and morphology.     

兰州-天水地区三维重力反演及其地质解释

本文利用重力资料对兰州－天水地区的深部构造进行了研究。在计算中，采用Ｐａｒｋｅｒ－Ｏｌｄｅｎｂａｒｇ三维位场反演方法，反演前对重力资料进行了地形改和中新生低沉积层校正。根据反演结构，综合反演结果，综合分析了有关资料，认为该区为青藏块体过渡带，并且并且提出了陇中盆地为断块型构造盆地的新认识。     

城市避震疏散能力评价方法研究

综合考虑人口、建筑、绿地、道路、疏散场所和重大危险源等各类影响因素,提出了街区疏散能力综合评价指数CEIEC,用层次分析法(AHP)通过各因素权重,对街区避震疏散能力进行了量化表达,能够给出各研究单元的避震疏散能力的相对水平,从而对城市社区避震疏散能力进行综合评价。本方法有利于揭示城市内避震疏散的薄弱环节,对城市规划等部门的工作,尤其对城市防灾规划的编制具有明显的指导性意义。     

Dual inexact fuzzy chance-constrained programming for planning waste management systems

This study develops a dual inexact fuzzy chance-constrained programming (DIFCCP) method for planning municipal solid waste (MSW) management systems. The concept of random boundary interval (RBI) is introduced to address the high uncertain parameters in the studied system. Fuzzy flexible programming and chance-constrained programming are also introduced to take into account the uncertainties of RBIs and various uncertainties in MSW management system. Compared with the existing methods, the developed method could deal with the uncertainty without simplification and thus is more robust. Moreover, the potential system-failure risks in MSW management system due to the existing uncertainties could be quantified by means of violation levels and satisfaction levels in DIFCCP. The developed method then is applied to a MSW management system. The obtained solutions could be used for generating efficient management schemes. The values of violation and satisfaction levels could help decision makers understand the tradeoffs between system cost and system-failure risk, and identify desired strategy according to the practical economic and environmental situation.     

地面核磁共振信号相位求取电阻率

椭圆极化现象是电磁场在导电介质中传播时产生的,为得到准确的相位信息,在计算激发磁场时应考虑椭圆极化。本文研究了地面核磁共振(SNMR)信号相位求取电阻率的基本方法,利用SNMR信号通过广义逆反演法得到电阻率未知情况下的含水率及层位分布,作为相位反演电阻率的先验值,通过模拟退火法实现对电阻率的反演。对SNMR的研究解决了通过相位对电阻率的求取,有利于进一步利用相位信息提高含水层和含水率反演的精度。      

气枪震源资料反褶积方法及处理流程研究

不同工作条件下气枪震源产生的信号会存在细微差异,反褶积方法能在一定程度上消除由震源变化引起的记录信号变化。为了去除气枪震源子波信号,获取气枪源到台站之间的格林函数,通常需要选取一种恰当的方法对地震波形数据进行反褶积处理。频率域水准反褶积和时间域迭代反褶积是在接收函数等领域已被广泛使用的2种反褶积方法。本文以云南宾川主动源资料为例,对比了利用这2种方法处理气枪震源信号的效果,结果表明,在计算效率方面,频率域水准反褶积方法更具优势;在处理结果的信噪比方面,时间域迭代反褶积方法表现更好,P波初至也更清晰。此外,进一步讨论了在多炮资料的处理过程中反褶积和叠加等操作的顺序问题,最后提出了从气枪震源资料中提取气枪源到台站之间的格林函数的一般流程。     

基于长江安徽段气枪主动源实验庐江台阵的台站对双差地震速度成像

针对气枪主动源监测中相位加权叠加数据绝对到时拾取可能存在较大误差的问题,提出基于台站之间叠加信号波形的相似性,利用台站对波形的互相关得到更准确到时差的策略。在此基础上,将台站对双差地震速度成像方法直接用于台站对到时差数据,以确定地下介质的速度异常。本文利用长江安徽段气枪实验在庐江临时地震台阵接收到的数据进行了测试,发现基于波形互相关得到的到时差数据比绝对到时数据更准确。最后,采用台站对双差地震成像的方法,得到了庐江台阵覆盖区域的地壳三维速度异常模型,继而确定了该地区较大尺度的地下结构分布。     

大岗山库区主动震源探测系统性能及其影响因素

利用大岗山水库地震监测台网,在大岗山库区建立了主动震源探测系统。主动震源设备为10t精密控制机械震源,接收台站包括大岗山水库地震台网的8个固定台站、2个加密流动台站和1个震源接收台。本文介绍了大岗山库区主动震源探测系统的基本情况、震源与地基的耦合特征、系统的性能及其影响因素等,并通过初步数据处理获取了大岗山库区地壳波速的相对变化。     

3D modeling of geological anomalies based on segmentation of multiattribute fusion

3D modeling of geological bodies based on 3D seismic data is used to define the shape and volume of the bodies, which then can be directly applied to reservoir prediction, reserve estimation, and exploration. However, multiattributes are not effectively used in 3D modeling. To solve this problem, we propose a novel method for building of 3D model of geological anomalies based on the segmentation of multiattribute fusion. First, we divide the seismic attributes into edge- and region-based seismic attributes. Then, the segmentation model incorporating the edge- and region-based models is constructed within the levelset-based framework. Finally, the marching cubes algorithm is adopted to extract the zero level set based on the segmentation results and build the 3D model of the geological anomaly. Combining the edge-and region-based attributes to build the segmentation model, we satisfy the independence requirement and avoid the problem of insufficient data of single seismic attribute in capturing the boundaries of geological anomalies. We apply the proposed method to seismic data from the Sichuan Basin in southwestern China and obtain 3D models of caves and channels. Compared with 3D models obtained based on single seismic attributes, the results are better agreement with reality.