湖北地区地震震源参数研究     

申学林  魏贵春  丁文秀  戴苗 《中国地震》2018,34(4):781-787

为了研究湖北地区地震震源参数特征,本文基于湖北数字地震台网记录到的S波观测振幅谱,通过遗传算法获得湖北地区的介质品质因子和台站场地响应,并在此基础上计算了湖北地区地震震源参数。结果显示,湖北地区介质品质因子Q值随频率f变化的关系式为Q(f)=501.8·f~(0.309);对于大部分台站获得了与其岩石基底相符的场地响应,没有出现明显放大效应;地震震级与地震矩对数间呈线性关系,即lg M_0=10.06+1.093M_L;震源半径与应力降间呈双对数线性关系,即lgΔσ=10.52-2.01lgr;地震矩与拐角频率间整体上呈反相关;地震矩与应力降间关系不显著。  相似文献   

Die neue EG‐Wasserrahmenrichtlinie: Bewertung der chemischen und ökologischen Qualität von Oberflächengewässern     

U. Irmer 《洁净——土壤、空气、水》2000,28(1):7-14

The New EC Framework Water Directive: Assessment of the Chemical and Ecological Status of Surface Waters The main objective of the draft EC Framework Water Directive is the good quality of all surface waters. The directive provides for an assessment of the chemical status of surface waters (EU‐wide valid environmental quality standards for approximately 30 priority substances) and a five‐stage ecological classification of waters, comprising the stages high, good, moderate, poor, and bad. The starting point for the assessment are the reference conditions, which are defined as corresponding to high water quality and characterising a water status with no significant anthropogenic impact. The reference sites in the various water body types are to be selected using hydromorphological and physico‐chemical parameters and subsequently characterised by means of biological parameters. For surface waters, three groups of characteristics are provided for, namely: 1. with priority the biology – in the case of surface waters – with the four elements phytoplankton, macrophytes/phytobenthos, benthic invertebrate fauna, and fish fauna; 2. supporting the hydromorphology, e.g. flowing waters with the three elements hydrological regime, river continuity, and morphological conditions and 3. supporting the physico‐chemical conditions with the three elements general conditions, specific synthetic pollutants, and specific non synthetic pollutants (other than the priority substances of the chemical status).  相似文献   

WHCORS系统在武汉市第二次土地调查中的应用     

苏恒  王朝辉 《测绘信息与工程》2010,35(1):15-16

介绍了WHCORS系统的原理和工作流程,分析了其在地籍测量中的广泛应用,验证了其测量精度的质量可靠性。  相似文献   

基于深度卷积神经网络的剪切波分裂质量检测     

张彭达  戴志阳  查显杰 《中国地震》2020,36(3):539-549

剪切波分裂是分析地震各向异性的一种重要手段,常规方法是利用网格搜索获取分裂参数,再通过不同方法的测量结果对比测量结果进行质量检测,这一过程会耗费大量计算时间。本文针对这一问题提出了一种利用深度卷积神经网络对剪切波分裂进行质量检测的新方法,对使用了Resnet残差结构的深度神经网络进行训练,直接对二分量剪切波波形数据的质量进行分类。整个过程为:神经网络通过卷积层提取波形特征,计算损失函数后反向传播训练模型参数,完成迭代训练后的模型对输入波形数据正向计算自动输出类型。本文利用川西台站接收到的实际数据以及随机生成的合成数据分别对该网络进行训练,均可以获得准确的分类结果。相比于通过多种剪切波分裂方法对比测量结果的质量检测方法,基于神经网络的方法可以省略网格搜索的计算过程直接判断质量类型,在运算速度上的优势明显,并可继续通过训练提高模型的精度,为提升剪切波分裂方法在数据处理过程中的操作效率提供帮助。  相似文献   

Clean quartz matters for cosmogenic nuclide analyses: An exploration of the importance of sample purity using the CRONUS-N reference material     

《Quaternary Geochronology》2022

Reference materials are key for assessing inter-laboratory variability and measurement quality, and for placing analytical uncertainty bounds on sample analyses. Here, we investigate four years of data resulting from repeated processing of the CRONUS-N reference material for cosmogenic ¹⁰Be and ²⁶Al analyses. At University of Vermont, we prepared a CRONUS-N aliquot with most of our sample batches from 2013 to 2017; these reference material samples were then distributed to four different accelerator mass spectrometry facilities, yielding 73 ¹⁰Be analyses and 58 ²⁶Al analyses. We determine CRONUS-N ¹⁰Be concentrations of (2.26 ± 0.14) x 10⁵ atoms g⁻¹ (n = 73, mean, 1 SD) and ²⁶Al concentrations of (1.00 ± 0.08) x 10⁶ atoms g⁻¹ (n = 58, mean, 1 SD). We find a reproducibility of 6.3% for ¹⁰Be and 7.7% for ²⁶Al (relative standard deviations). We also document highly variable ²⁷Al and Mg concentrations and a ¹⁰Be dispersion twice as large as the mean AMS analytic uncertainty. Analyses of the CRONUS-N material with and without density separation demonstrate that non-quartz minerals are present in the material and have a large impact on measured concentrations of ²⁷Al, ¹⁰Be, and impurities; these non-quartz minerals represent only a very small portion of the total mass (0.6–0.8%) but have a disproportionally large effect on the resulting data. Our results highlight the importance of completely removing all non-quartz mineral phases from samples prior to Be/Al extraction for the determination of in situ cosmogenic ¹⁰Be and ²⁶Al concentrations.  相似文献   

《地震工程与工程振动》的办刊理念及质量控制     

康丽君  徐文杰 《山西地震》2014,(4):27-29

总结《地震工程与工程振动》32年来的办刊经验,分析期刊服务范畴,围绕期刊办刊理念定位。阐述了提高期刊质量的具体方法,要掌握学科前沿的发展,提高论文的时效性,保证文章创新,把好学术质量关,对科研特色人才群体进行追踪,积极组织约稿等,为学术交流搭建快捷、高效的平台。  相似文献   

基于Leica ADS80系统的航空遥感影像成果质量控制研究     

张桂英 《测绘通报》2014,(10):89-91

通过对“辽宁省农村集体土地确权登记发证”项目0.2m分辨率航空遥感影像成果的检查验收,阐述了应用Leica ADS80系统生产航空遥感影像成果的检查内容、检查方法及质量控制的关键点,进而提出了航空遥感影像成果检查的技术核心。本文对于其它生产单位应用Leica ADS80系统生产的高分辨率航空遥感影像成果的检查验收提供了可以借鉴的经验。  相似文献   

六种不同煤阶煤的品质因子特征   总被引：4，自引：3，他引：1       下载免费PDF全文

许小凯  王赟  孟召平 《地球物理学报》2014,57(2):644-650

通过6种不同煤阶煤的弹性测试,分析了煤岩变质程度（以镜质组最大反射率表示）与煤岩品质因子之间的关系;在此基础上,进一步分析了煤岩速度与品质因子之间的关系及纵波与横波品质因子的各向异性特征.研究发现：煤岩镜质组最大反射率与纵波、横波品质因子均存在良好的线性相关性;垂直层理方向的波速与品质因子存在良好的线性关系,好于走向与倾向方向;垂直层理方向的纵波与横波品质因子线性相关,相关系数可达93.5%;煤岩的三方向品质因子存在各向异性,且强于速度的各向异性.通过横波品质因子与纵波品质因子间相互换算的理论公式计算结果与实验室实测结果的对比,证明了该理论公式的可靠性,误差小于10%,为多分量转换波的吸收衰减补偿提供了理论依据.  相似文献   

A numerical study of tropospheric ozone in the springtime in East Asia   总被引：11，自引：0，他引：11  

ZHANG Meigen  XU Yongfu  Itsushi UNO  Hajime AKIMOTO 《大气科学进展》2004,21(2):163-170

The Models-3 Community Multi-scale Air Quality modeling system (CMAQ)coupled with the Regional Atmospheric Modeling System (RAMS)is applied to East Asia to study the transport and photochemical transformation of tropospheric ozone in March 1998．The calculated mixing ratios of ozone and carbon monoxide are compared with ground 1evel observations at three remote sites in Japan and it is found that the model reproduces the observed features very well．Examination of several high episodes of ozone and carbon monoxide indicates that these elevated levels are found in association with continental outflow,demonstrating the critical role of the rapid transport of carbon monoxide and other ozone precursors from the continental boundary layer．In comparison with available ozonesonde data,it is found that the model-calculated ozone concentrations are generally in good agreement with the measurements,and the stratospheric contribution to surface ozone mixing ratios is quite limited．  相似文献   

SD法在湖北大冶鸡冠嘴铜金矿床资源储量核实中的应用   总被引：4，自引：0，他引：4  

朱志祥  晏玖德 《地质与勘探》2004,40(4):82-84

SD法是一种全新的储量计算和审定方法,是我国使用的三大储量计算方法(传统法、克里格法和SD法)之一.根据国土资源部的指示和要求,湖北三鑫金铜股份有限公司和北京恩地科技发展有限责任公司共同对矿区的13条勘探线、20个矿体、16个中段的资源储量运用SD法进行了全面的复核计算,成功地确定了鸡冠嘴铜金矿矿床-160～-170 m、-170～-470 m、-470 m以下铜和金的保有储量.  相似文献