2003年民乐MS6.1级地震前的重力变化研究   总被引：5，自引：1，他引：4  

梁伟锋  祝意青  徐云马  刘练  王继英 《地震研究》2004,27(4):334-338

以河西地区的流动重力监测资料为基础,分析了2003年10月25日民乐Ms6．1级地震前的重力场变化,认为在空间分布上,地震发生前观测区出现了区域性的重力异常变化及与构造活动断裂走向基本一致的重力变化高梯度带,并在震中或邻区产生局部重力变化异常区。在时间序列上,地震发生前,重力段差和重力测点先是增强,然后反向减弱,并在反向过程中发震。  相似文献   

CaO对钙矾石固化/稳定化重金属铅污染土的影响     

章定文  项莲  曹智国 《岩土力学》2018,39(1):29-35

为研究CaO的赋存形态及含量对钙矾石固化/稳定化重金属铅污染土效果的影响,采用高铝水泥提供AlO2-,纯石膏或磷石膏提供SO42-,高铝水泥、石膏、普通硅酸盐水泥或生石灰提供CaO,制备不同组分固化剂配比的固化土,测试试样强度和孔隙溶液pH值等宏观物理力学指标,通过醋酸缓冲溶液法测试试样的铅溶出量,对比分析不同固化剂固化土的矿物成分与微观结构特征。结果表明,钙矾石固化/稳定化重金属铅污染土效果显著;钙矾石对孔隙的填充作用带来的增强效果不能代替水化硅酸钙胶结土颗粒的胶结作用,普通硅酸盐水泥对试样的强度更有利,但其后期强度增幅不大,而生石灰有利于固化土强度的持续增长;生石灰较普通硅酸盐水泥对钙矾石的形成、稳定和重金属Pb2+的固化/稳定化更有利;磷石膏和纯石膏对试样的pH值、无侧限抗压强度及钙矾石固化/稳定化重金属Pb2+的效果影响较小;固化土体微观结构特征表明,CaO含量对钙矾石生成形态及作用效果影响显著。当CaO含量较低时,早期生成的钙矾石将向单硫型硫铝酸钙转化。研究成果可丰富重金属污染场地原位处理技术,具有重要的理论意义和工程应用价值。  相似文献   

碳酸盐岩孔隙结构参数构建与储层参数反演(英文)   总被引：3，自引：0，他引：3  

蒋炼  文晓涛  周东红  贺振华  贺锡雷 《应用地球物理》2012,9(2):223-232

碳酸盐岩储层孔隙结构相对碎屑岩更复杂,常用的岩石物理模型不能较好的描述其孔隙结构的变化规律,且岩石孔隙结构的差异较大程度上会影响岩石的弹性性质。本文首先利用岩石薄片分析了碳酸盐岩的微观孔隙结构。然后基于Gassmann方程和Eshelby-Walsh椭球包体裂缝理论,在合理的假设前提下给出了一种新的岩石物理建模方法,并且从中提取了一个参数来表征孔隙结构的变化规律。最后,基于全波列测井数据,我们利用该方法计算了单井的孔隙度,并与用常规方法预测的结果进行了比较,同时进行了地震储层参数反演。研究结果表明,孔隙结构对岩石的弹性性质的影响较大,且新的建模方法预测的孔隙度误差仅为0.74%。因此,该方法可有效的减小孔隙结构对计算各岩石弹性参数的影响并提高孔隙度的预测精度。  相似文献   

青藏高原近期气候变化研究进展   总被引：1，自引：0，他引：1  

余莲  封彩云 《高原山地气象研究》2012,32(3):84-88

本文对近期关于青藏高原地区气候变化的研究进行了回顾。结果表明,在过去的几十年间,青藏高原地区的气候发生了明显的变化。主要表现为:1)温度呈上升趋势;降水和积雪呈增加趋势,多年冻土呈退化状态;温度和降水的变化不仅有季节性的差异,还存在区域性的差异。2)区域气候模式RegCM对青藏高原地区温度和降水有一定的模拟能力,但存在系统性的误差。文中还对在青藏高原气候变化方面的研究不足进行了讨论。   相似文献   

Assessment of total suspended sediment concentrations in Poyang Lake using HJ-1A/1B CCD imagery   总被引：1，自引：0，他引：1  

于之锋  陈晓玲  周斌  田礼乔  袁小红  冯炼 《中国海洋湖沼学报》2012,30(2):295-304

We explored the potential of the environment and disaster monitoring and forecasting small satellite constellations (HJ-1A/1B satellites) charge-coupled device (CCD) imagery (spatial resolution of 30 m, revisit time of 2 days) in the monitoring of total suspended sediment (TSS) concentrations in dynamic water bodies using Poyang Lake, the largest freshwater lake in China, as an example. Field surveys conducted during October 17-26, 2009 showed a wide range of TSS concentration (3-524 mg/L). Atmospheric correction was implemented using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) module in ENVI with the aid of aerosol information retrieved from concurrent Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) surveys, which worked well at the CCD bands with relatively high reflectance. A practical exponential retrieval algorithm was created between satellite remote sensing reflectance and in-situ measured TSS concentration. The retrieved results for the whole water area matched the in-situ data well at most stations. The retrieval errors may be related to the problem of scale matching and mixed pixel. In three selected subregions of Poyang Lake, the distribution trend of retrieved TSS was consistent with that of the field investigation. It was shown that HJ-1A/1B CCD imagery can be used to estimate TSS concentrations in Poyang Lake over synoptic scales after applying an appropriate atmospheric correction method and retrieval algorithm.  相似文献   

Climate Change and Its Impacts on Grain Production in Jilin Province   总被引：1，自引：0，他引：1  

Lian Yi  Gao Zongting  Shen Baizhu  Ren Hongling  Tang Xiaoling  Liu Yuying 《气候变化研究进展》2008,4(00):56-59

 The climate observation data, reanalysis data, and grain/soybean yields per unit area were used to analyze and interpret the impact of climate change on grain production. The results show that Jilin Province was located in a remarkable increase area of temperature during the growing season (May-September) from 1948 in the middle latitudes of the Northern Hemisphere. The mid-west and south of Jilin Province and Liaoning Province were located in a clear linear decrease tendency area of annual precipitation, wherein a warm/dry tendency of climate change dominated, while the east of Jilin Province lay in a clear linear decrease tendency area of annual precipitation. The climate warming played an important role in continuous increase in the grain yield per unit area since the1980's in the main grain production areas of Jilin Province, however, from the end of the 20th century to the beginning of the 21st century, the beneficial effect seemed to be not obvious any longer, the grain yield per unit area fluctuated with annual precipitation.  相似文献   

一种改进的锥束螺旋CT单层重排重建算法     

陈炼  吴志芳  周立业 《CT理论与应用研究》2008,17(1):7-13

多层螺旋CT中,采用大螺距可以大大提高扫描速度,在工业和医学中颇受青睐。但在给定探测器尺寸条件下,螺距过大会出现明显的伪影。Noo等1999年提出的单层重排算法（SSRB）能够适应较大的螺距,且有较高的重建图像质量。本文采用新的重排方法对SSRB算法进行了改进,理论分析及仿真实验表明,相同探测器大小时,改进的SSRB算法（ISSRB）可适用的螺距是SSRB的（1＋tan^2δ）倍（δ射线源半张角）,且有相近或更高的图像质量。  相似文献   

Effects of mineral-organic fertilizer on the biomass of green Chinese cabbage and potential carbon sequestration ability in karst areas of Southwest China     

Sun  Qibiao  Ruan  Yulong  Chen  Ping  Wang  Shijie  Liu  Xiuming  Lian  Bin 《中国地球化学学报》2019,38(3):430-439

Acta Geochimica - The karst mountain areas of Southwest China contain barren farmland soils and suffer from nutritional and water deficiencies that affect crop productivity. Hence, it is imperative...  相似文献   

Ten Major Scientific and Technological Progresses of theChinese Geological Survey in 2018     

HUANG Min  HAO Ziguo  LIU Lian  LIU Zhiqiang  ZHANG Yuxu  ZHOU Jian  FEI Hongcai  LI Man  LIU Meng 《《地质学报》英文版》2019,93(2):502-504

正The China Geological Survey has annually invested tens of billions of yuan in China's geological surveys in order to set up ten major plans, 60 programs and more than 400 projects, which will deliver hundreds of geological survey results every year. In early 2019, the China Geological Survey organized relevant experts to select ten major achievements among the completed projects of 2018,which were awarded the"Ten Major  相似文献   

China’s Geological Science and Technology Has Made New Progress during 2018     

LIU Lian  LIU Zhiqiang  HUANG Min  FEI Hongcai  ZHOU Jian  ZHANG Yuxu  HAO Ziguo 《《地质学报》英文版》2019,93(3):785-786

正(1) Major scientific and technological innovations have been made in the Deep Continental Scientific Drilling Project of the Songliao Basin Well Songke 2 has a drilling depth of 7018 m. The large-bore coring technology system for ultra-deep wells has overcome major technical problems in deep exploration of the earth, such as ultra-high temperature drilling technology, and has created four world records. Two kinds  相似文献