超声提取-固相萃取小柱净化-气相色谱法测定土壤中14种有机氯农药   总被引：7，自引：7，他引：0  

刘文长  陶文靖  程丽娅  余兴  田旻  黄勤  李胜生 《岩矿测试》2009,28(6):541-544

对土壤中14种有机氯农药的超声提取技术和磺化、固相萃取小柱两种净化方法进行系统研究。结果表明,超声提取节省提取时间,提高分析效率;磺化法和固相萃取小柱法都有净化作用,但磺化法使样品中的艾氏剂、狄氏剂和异狄氏剂全部损失;固相萃取小柱净化当丙酮-正己烷淋洗液体积比为1∶9、淋洗液收集8 mL时回收率>90%,干扰最小。方法检出限为0.63~2.59μg/kg,精密度(RSD,n=7)为1.17%~14.66%,基体加标平均回收率为82.78%~106.94%。方法用于生态地球化学调查评价批量土壤样品的实际分析,检测结果满足评价工作需要。  相似文献   

电感耦合等离子体质谱法测定岩石样品中的锆铌铪钽两种预处理方法的比较   总被引：9，自引：8，他引：1  

时晓露  刘洪青  孙月婷  章勇  刘文长 《岩矿测试》2009,28(5):427-430

研究了微波消解酸溶和过氧化钠碱熔两种测定岩石样品中锆、铌、铪、钽前处理方法,利用电感耦合等离子体质谱法进行测定。对所选用不同种类的岩石国家标准物质样品进行了条件实验,结果表明:采用过氧化钠碱熔法处理岩石样品后,锆、铌、铪、钽的测量值准确度高,且相对标准偏差(RSD,n=10)小于6%,该方法更适用于岩石样品中锆、铌、铪、钽的测定。  相似文献   

Holocene environmental change inferred from the loess–palaeosol sequences adjacent to the floodplain of the Yellow River, China     

Chun Chang Huang  Jiangli Pang  Hongxia Su  Shengli Li  Benwei Ge 《Quaternary Science Reviews》2009,28(25-26):2633-2646

Chinese loess deposits are generally considered to be the product of dust storms and dust falls from the central Asia arid zones that were transported across China by the northwesterly continental monsoon. In contrast, the Zhengzhou Loess found southeast of the Loess Plateau, adjacent to the floodplain of the Yellow River, records a different eolian regime and dust source. The Zhengzhou Loess was investigated by field observations, measurements of magnetic susceptibility, particle-size distribution, loss-on-ignition, CaCO₃ and chemical contents. Both field observations and the laboratory results indicate that, during the last glacial, the Zhengzhou Loess was supplied by two different eolian regimes and dust sources, one was from the fresh flood deposits of the Yellow River driven by the northeast winds from the low-lying floodplain, and the other was from the dust storms and dust falls that traveled across the Loess Plateau driven by the northwesterly continental monsoon from the central Asian arid lands. The early Holocene, 11,500–8500 a BP, was a transition during the change in eolian regime and dust source because of the weakened northwesterly monsoon along with the global climatic amelioration. Following the retreat of the northwesterly monsoon from the onset of the mid-Holocene Climatic Optimum at 8500 a BP, dust supply from the drifting sand zone on the Yellow River floodplain became dominant because of the intensified strength of the northeast winds from the Bohai Sea. From 3100 a BP onwards, climatic aridity and extensive human disturbance have resulted in intensive eolian processes causing the incursion of the drifting sand into the Zhengzhou Loess zone. These results show that loess accumulation is more complex than traditionally assumed. The origin of loess deposits elsewhere outside the Loess Plateau may be related to dust sources derived from alluvial sediments of major river systems.  相似文献   

松辽盆地北部安达断陷营城组火山岩岩相的地震识别   总被引：4，自引：0，他引：4       下载免费PDF全文

于晶  刘大锰  文瑞霞  金圣爱 《地质科学》2009,44(2):595-604

安达断陷营城组的火山岩岩相分为火山通道相、爆发相、溢流相、次火山岩相和火山-沉积相,每种火山岩岩相的地震特征各不相同.根据各种岩相的地震反射特征,逐条测线解释出火山岩相,结合相干体技术和振幅属性预测了安达断陷内研究区的火山岩岩相分布,圈出3个爆发相发育区.据此讨论了地震识别方法在识别火山岩岩相和火山岩储层物性中的应用.  相似文献   

塔中地区志留系碎屑锆石测年及其地质意义   总被引：1，自引：0，他引：1       下载免费PDF全文

邬光辉  张宝收  苏文  汪海  席勤 《地质科学》2009,44(3):1025-1035

志留系是塔里木盆地第一套砂岩储层广泛分布的沉积盖层,其沉积来源与成因对志留纪构造演化及周边造山带的研究具有重要意义。塔中地区3个志留系样品的碎屑锆石LA?ICP?MS U?Pb定年研究表明,志留系具有比较集中的二期物源年龄：南华纪中期、古元古代中期。碎屑锆石测定的年龄表明塔中志留系物源均来自前寒武纪,塔中东部源区方向的塔南隆起基底在奥陶纪已隆升成为蚀源区。大量的新元古代中期锆石年龄表明塔里木板块在新元古代时期可能与Rodinia超大陆具有相似的聚合与裂解演化史。  相似文献   

Incoherent scatter spectrum of ionospheric plasma with an anisotropic temperature ion distribution     

Bao-Ke Ma  Li-Xin Guo  Hong-Tao Su  Bei-Chen Zhang  Hong-Qiao Hu 《Astrophysics and Space Science》2012,340(2):237-243

The expression of anisotropic temperature ion distribution function under the 13-moment approximation is obtained by solving a set of moment equations based on the Boltzmann equation for a relaxation collision model and with consideration of the anisotropic temperature ion distribution. And the incoherent scatter spectrum with an anisotropic temperature ion distribution is simulated in different directions based on the electromagnetic radiation theory of Sheffield. The effects of different electrical field strengths, ratios of electron temperature to ion temperature, and ion-neutral collision frequencies on the incoherent scatter spectrum are all discussed. Finally, the value of theoretical simulation is compared with the measured value of incoherent scattering spectrum. The result show that the incoherent scatter spectrum of ions seriously deviates from the form of the Maxwellian distribution in the equilibrium state. This phenomenon can be attributed to the effects of anisotropic temperature ion distribution, the larger convection electric field, and other factors in high latitude ionosphere.  相似文献   

Global-Scale Coupling Characteristics between Geomagnetic Storms and Ionospheric Disturbances     

Nisong Pei  Wu  Yong  Su  Rui  Li  Jianfeng  Wang  Yongqian  Li  Xueling  Wu  Zhenghao 《Geomagnetism and Aeronomy》2021,61(4):632-646

Geomagnetism and Aeronomy - To explore the global-scale coupling characteristics between ionospheric disturbances and geomagnetic storms, and research the near-Earth space environment, the time...  相似文献   

地震应急信息速报视图自动发布系统的设计与实现     

郑通彦  文鑫涛  李华玥  林向洋 《中国地震》2021,37(1):206-215

基于地震应急基础数据和网络震后灾害信息获取技术的相关研究,利用数据挖掘、大数据分析等理论方法,根据地震应急不同阶段的信息需求,挖掘信息时空属性,建立震情、灾情可视化信息图展现形式,开展对地震数据的整合汇聚、精准服务,创新表达方式,利用高维多元可视化处理技术,构建面向震后信息服务的自媒体可视化产品,并开发“速报视图自动发布系统”。该系统作为地震信息可视化交互服务平台,可实现桌面端和移动端H5页面的可视化发布任务,为今后进一步拓展和充实地震应急信息的可视化工作提供了基础平台和创新思路,在应用示范的基础上,完善系统运行功能,实现大震应急信息可视化服务。  相似文献   

《中国大陆现代垂直形变图集的编制与资料整编》项目数据集     

陈欣  薄万举  郑智江  宋雯  董运洪  刘文龙  张立成  万文妮  杜雪松  马青  李林 《地震地磁观测与研究》2021,42(4):183-190

2015—2019年,由中国地震局第一监测中心牵头,自然资源部大地测量数据处理中心和武汉大学等单位共同完成科技部科技基础性工作重点专项,系统拯救、整编和共享20世纪50年代以来全国垂直形变测量数据,编制不同时空尺度的地壳垂直形变图,为强震中长期预测、地壳动力学研究、地形变灾害研究与防控及相关的国民经济建设服务。本文介绍中国大陆20世纪60年代—21世纪10年代不同时段1:400万和1:2 400万垂直形变图,其活动构造相关的地理要素、形变信息的清晰度更好,分辨率更高。还有典型沉降区垂直形变图、典型构造活动区（带）垂直形变图和强震同震形变图将在后续文章详细介绍。  相似文献   

Three-dimensional tomographic inversion of the seismic velocity structure of the crust and upper mantle of northwestern Nicaragua     

Domínguez  Jaime  Suárez  Gerardo  Gorbatov  Alexei  Segura  Fabio 《Journal of Seismology》2021,25(6):1427-1439

Journal of Seismology - A three-dimensional tomographic image of the seismic velocity structure in the crust and upper mantle of northwestern Nicaragua was performed using the back-projection...  相似文献