Active source monitoring at the Wenchuan fault zone: coseismic velocity change associated with aftershock event and its implication          下载免费PDF全文

Wei Yang  Hongkui Ge  Baoshan Wang  Jiupeng Hu  Songyong Yuan  Sen Qiao 《地震科学（英文版）》2014,27(6):599-606

With the improvement of seismic observation system, more and more observations indicate that earthquakes may cause seismic velocity change. However, the amplitude and spatial distribution of the velocity variation remains a controversial issue. Recent active source monitoring carried out adjacent to Wenchuan Fault Scientific Drilling (WFSD) revealed unambiguous coseismic velocity change associated with a local M_s5.5 earthquake. Here, we carry out forward modeling using two-dimensional spectral element method to further investigate the amplitude and spatial distribution of observed velocity change. The model is well constrained by results from seismic reflection and WFSD coring. Our model strongly suggests that the observed coseismic velocity change is localized within the fault zone with width of ~120 m rather than dynamic strong ground shaking. And a velocity decrease of ~2.0 % within the fault zone is required to fit the observed travel time delay distribution, which coincides with rock mechanical experiment and theoretical modeling.  相似文献   

用于单幅影像匀光的Wallis算法     

曹彬才  朱宝山  李润生  杨信能  莫德林 《测绘科学技术学报》2012,(5):373-377

匀光处理是消除光学遥感影像中亮度和色彩分布不均匀现象的过程。经典的Wallis算法仅用于保持两幅或多幅影像间的色调和亮度一致性。这里提出了一种用于单幅影像匀光的Wallis算法,讨论了从待处理影像中选择校正标准的方法;同时利用以像点为中心的局部参数统计值代替分块参数值,有效地避免了"分块效应"。通过实验并与现有Retinex匀光算法进行比较,结果表明改进后的Wallis算法能够有效减小图像反差,取得更好的匀光效果。  相似文献   

The characteristics of dissolution of fluoride and aluminum from brick tea     

LIU Xiaojing 《中国地球化学学报》2005,24(4):382-385

Four experiments have been done on the influence of times of infusion, temperature, time and ratio of tea to water on the dissolving characteristics of fluoride and aluminum in brick tea. According to the results, the behaviors of F and Al which found their way into tea liquor were analyzed and the conclusions have been drawn： the dissolution of F and Al is not synchronous and after the elements find their way into tea liquor respectively, they will be reset to form complexes of F and Al.  相似文献   

地下巷道的三维建模及C++实现   总被引：19，自引：0，他引：19  

魏占营  王宝山  李青元 《武汉大学学报(信息科学版)》2005,30(7):650-653

仿照弧段节点的拓扑数据结构思想,把巷道分为巷道体和巷道间节点,分别对它们进行三维建模,并且构建了巷道间的拓扑关系。同时按照面向对象的编程思想,给出了C 实现,并给出了实验结果。实验证明,巷道的建模方法和系统的实现方法是可行的。  相似文献   

用下降曲线估算废弃矿井煤层气资源量   总被引：1，自引：0，他引：1  

韩保山李健武  董敏涛 《中国煤田地质》2005,17(5):37-39,46

国外的最新研究成果,认为废弃矿井的甲烷涌出速度对时间的曲线是一条双曲线,而通过对西安分院大量的煤层气钻孔煤心样的解吸数据的分析,发现甲烷的解吸速度与时间的曲线也是一条双曲线.用钻孔煤心现场解吸数据可以近似得到废弃矿井甲烷涌出速度对时间的下降曲线.对废弃矿井甲烷涌出速度对时间的曲线按时间积分到无穷大,可以得到计算时刻的废弃矿井资源量.  相似文献   

双评分准则逐步回归法   总被引：1，自引：0，他引：1  

牛保山  曹鸿兴  刘生长 《气象》1993,19(8):18-21

阐明了以双评分准则(CSC)作逐步回归的基本原理,通过实例给出了计算方法与步骤。用此法所建模型能同时报好预报对象的数量和类别。  相似文献   

小秦岭金矿田中的两种罕见矿物—碲铅铋矿和自然碲   总被引：2，自引：0，他引：2  

朱惠娟  杨宝善 《矿物学报》1989,9(1):37-41

碲铅铋矿和自然碲产于河南省小秦岭含金石英脉矿床中。碲铅铋矿化学成分平均值(%)为:Te44.06,Bi40.24,Pb14.23,并含有微量的Ag、Au、Hg、Fe、Ni、Cu等元素。理论化学式为(Bi,Pb)_3Te_4,其中Bi>Pb。共生矿物有自然金、碲金矿、破银矿、碲铅矿、碲金银矿、碲铋矿;方铅矿、闪锌矿、黄铁矿、黄铜矿等。 自然碲反射色为纯白微带乳色,非均质性清楚,偏光色为蓝灰-棕灰色。显微硬度为H_v=85.1kg/mm~2(25g)。共生矿物有碲金银矿、碲银矿、黄铜矿等。化学成分中碲含量达98.44％,并含Ag、Cu、W、Fe、Pt等微量元素。  相似文献   

Grassland degradation in Northern Tibet based on remote sensing data     

GAO Qingzhu  LI Yu&rsquo  e  WAN Yunfan  LIN Erda  XIONG Wei  JIANGCUN Wangzha  WANG Baoshan  LI Wenfu 《地理学报》2006,16(2):165-173

This study selected vegetation cover as the main evaluation index, calculated the grassland degradation index (GDI) and established the remote sensing monitoring and evaluation system for grassland degradation in Northern Tibet, according to the National Standard (GB19377-2003), based on the remote sensing data such as NDVI data derived from NOAA/AVHRR with a spatial resolution of 8 km of 1981-2000, from SPOT/VGT with a spatial resolution of 1 km of 2001 and from MODIS with a spatial resolution of 0.25 km of 2002-2004 respectively in this area, in combination with the actual condition of grassland degradation. The grassland degradation processes and their responses to climate change during 1981-2004 were discussed and analyzed in this paper. The result indicated that grassland degradation in Northern Tibet is very serious, and the mean value of GDI in recent 20 years is 2.54 which belongs to the serious degradation grade. From 1981 to 2004, the GDI fluctuated distinctly with great interannual variations in the proportion of degradation degree and GDI but the general tendency turned to severe-grade during this period with the grassland degradation grade changed from light degraded to serious degraded in Northern Tibet. The extremely serious degraded and serious degraded grassland occupied 1.7% and 8.0% of the study area, the moderate and light degraded grassland accounted for 13.2% and 27.9% respectively, and un-degraded grassland occupied 49.2% of the total grassland area in 2004. The grassland degradation was serious, especially in the conjunctive area of Naqu, Biru and Jiali counties, the headstream of the Yangtze River lying in the Galadandong snow mountain and glaciers, the area along the Qinghai-Tibet highway and railway, and areas around the Tanggula and Nianqingtanggula snow mountains and glaciers. So the snow mountains and glaciers as well as their adjacent areas in Northern Tibet were sensitive to climate change and the areas along the vital communication line with frequent human activities experienced relatively serious grassland degradation.  相似文献   

下一代地球物理观测技术     

王喜珍  王宝善  马洁美  张东宁  滕云田 《国际地震动态》2007,(9):44-58

地球物理观测技术所要解决的问题是观测什么、用什么来观测、怎样观测。下一代地球物理观测技术的发展是以解决上述问题为基础。论文详细论述了观测设备、观测系统以及地球外行星体结构探测等发展动态,并对下一代地球物理观测技术的发展方向进行了分析。  相似文献   

A study on shear wave splitting of local earthquakes based on the Array of BinChuan (ABC), Yunnan     

Hui Dou  Baoshan Wang  Yihe Xu  Weitao Wang 《《地质学报》英文版》2018,92(Z1):149-150

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