大炮检距优化6次NMO校正   总被引：1，自引：0，他引：1  

张栋  杜清怀  许孝坤 《西北地质》2004,37(4):117-120

常规2次NMO动校是假定炮检距与深度比值小，并且射线为直线。计算的旅行时精度随着炮检距与深度比值的增加而大大降低，NMO校正能通过高次(4次、6次)项逼近得到改善。因此，在大炮检距情况下，若直接忽略高次项，则计算旅行时会产生很大误差。所以在大炮检距条件下进行2次NMO近似不利于速度分析、AVO研究和CMP道集动校叠加。笔者引入了一个更精确的旅行时近似计算，称为优化6次NMO动校方程式，因为截断误差较小，故其精确度高于泰勒6次展开式。通过模型和实际数据的试验，证明大炮检距优化6次NMO方程精度高，更具有实际应用意义。  相似文献   

第29届IASPEI大会概况及其主要专题讨论会和研讨会内容汇编     

Members of the SSB Delegation 《国际地震动态》1998,(6)

国际地震学与地球内部物理学协会（ＩＡＳＰＥＩ）第２９届大会于１９９７年８月１８～２８日在希腊塞萨洛尼基举行。来自６２个国家和地区的１０５１位科学家参加了这次大会。国家地震局有近２０位科学家出席了会议。本届大会共安排了４６个学术专题报告会和研讨会,会上宣读论文７１６篇,张贴展示论文６９５篇。本届ＩＡＳＰＥＩ大会的学术报告涉及广泛的地震学和地球内部物理学研究的问题,内容包括：地震预测;地球内部构造和地球动力学;不同构造区的强地面运动;地震孕育过程：定量模型和假设检验;岩石圈结构、动力学过程和各向异性;火山地震学;地震早期预警系统;地震危险性与地震危害;地震危险性和地震危害评估中的新的地学信息技术;触发／诱发地震;与构造过程有关的电磁信号;岩石圈结构的长周期研究和工程地震学;估计地震大小的新方法;地球的结构和演化：地球物理观测、实验约束和模似;地震成核、动力破裂及其终止：观测和物理模拟;今后的地震仪器的发展;地震灾害与危害的公众教育,等等。  相似文献   

东居延海易溶盐沉积与古气候环境变化   总被引：9，自引：5，他引：9  

张洪  靳鹤龄  肖洪浪  陈月红 《中国沙漠》2004,24(4):409-415

通过对黑河尾闾东居延海湖相沉积物易溶盐类K^ 、Na^ 、Ca^2 、Mg^2 、SO4^2 、CO3^2-、HCO3^-、Cl^-八大离子含量和其他相关指标的分析，依据它们在地层中的变化特征，结合地层^14C年代测定结果，把东居延海湖泊变化划分为：隋唐湖泊面积较大时期、宋辽湖泊缩小时期、中世纪暖期湖泊扩张时期、小冰期湖泊缩小时期及20世纪湖泊干涸期等几个阶段。考虑近1500a来该流域气候变化和人类活动对湖泊的影响，得出了以下几个结论：近1500a来，东居延海湖区气候以干旱为主，湖泊逐渐萎缩；在干旱背景下存在气候波动，并与全球变化具有一致性；湖泊的盛衰演变受到气候变化和人类活动的双重影响，前期以自然变化为主，明清以来特别是清代以后，人类活动的影响加剧，成为主控因子。  相似文献   

埕岛复式含油气系统研究及评价   总被引：1，自引：0，他引：1  

杨凤丽  周祖翼  张善文 《高校地质学报》2002,8(2):180-189

针对渤海湾南部埕岛地区的油气成藏特征和较高勘探程度的特点，对埕岛复式含油气系统（composite petroleum system)，含油气系统，亚油气系统和子系统进行了四个不同勘探级次的划分，描述，以及各含油气系统之间相互关系的讨论，从油气的生成，运移，聚集，保存和破坏有机联系的四个方面18种要素，对不同级次的系统用多级模型综合评判的数学方法，进行了综合定量评价，并在此基础上优选出下一步的有利勘探目标。  相似文献   

The Photogrammetric Society: 1952–2001     

K. B. Atkinson  & I. Newton 《The Photogrammetric Record》2002,17(100):577-600

A scholarly account of the formative discussions, the founding and the first 20 years of the Photogrammetric Society was published in 1971 and republished in 1974. This present review concentrates on the latter years of the life of the Photogrammetric Society prior to its merger with the Remote Sensing Society in 2001.
The authors joined the Photogrammetric Society in 1960 and were conspicuous in its affairs for many years. Although both occupied the Society's presidential chair, they also fulfilled several other roles in its efficient management. Atkinson's first contribution to the Photogrammetric Record was published in 1968 and Newton's in 1971.  相似文献   

以海泛面进行垂向流动单元划分的方法——以琼东南盆地崖13-1气田陵三段为例   总被引：2，自引：0，他引：2  

姜平  李胜利  李茂文  李茂  黄国政  黄月银 《地学前缘》2008,15(1):154-159

以层序地层划分为基础,把崖13-1气田主力产层陵三段划分为8个四级层序,并以四级层序的海泛面为控制边界,在气田南区与北II区划分出8个垂向流动单元,而在北I区划分为7个垂向流动单元。崖13-1气田东南部广海海泛对南部地区影响更大,使南区与北II区多沉积了一套海泛面泥岩隔层,导致这两个区块垂向流动单元比北I区多出一个。这一流动单元划分方案得到了气田压力测试的验证,对今后气田开发有指导作用。  相似文献   

Potential forest fire danger over Northern Eurasia: Changes during the 20th century   总被引：4，自引：1，他引：3  

Pavel Ya. Groisman  Boris G. Sherstyukov  Vyacheslav N. Razuvaev  Richard W. Knight  Jesse G. Enloe  Nina S. Stroumentova  Paul H. Whitfield  Eirik Frland  Inger Hannsen-Bauer  Heikki Tuomenvirta  Hans Aleksandersson  Anna V. Mescherskaya  Thomas R. Karl 《Global and Planetary Change》2007,56(3-4):371

Significant climatic changes over Northern Eurasia during the 20th century have been reflected in numerous variables of economic, social, and ecological interest, including the natural frequency of forest fires. For the former USSR, we are now using the Global Daily Climatology Network and a new Global Synoptic Data Network archive, GSDN, created jointly by U.S. National Climatic Data Center and Russian Research Institute for Hydrometeorological Information. Data from these archives (approximately 1500 of them having sufficiently long meteorological time series suitable for participation in our analyses) are employed to estimate systematic changes in indices used in the United States and Russia to assess potential forest fire danger. We use four indices: (1) Keetch–Byram Drought Index, (KBDI; this index was developed and widely used in the United States); (2) Nesterov, (3) Modified Nesterov, and (4) Zhdanko Indices (these indices were developed and widely used in Russia). Analyses show that after calibration, time series of the days with increased potential forest fire danger constructed using each of these three indices (a) are well correlated and (b) deliver similar conclusions about systematic changes in the weather conditions conducive to forest fires. Specifically, over the Eastern half of Northern Eurasia (Siberia and the Russian Far East) statistically significant increases in indices that characterize the weather conditions conducive to forest fires were found. These areas coincide with the areas of most significant warming during the past several decades south of the Arctic Circle. West of the Ural Mountains, the same indices show a steady decrease in the frequency of “dry weather summer days” during the past 60 yr. This study is corroborated with available statistics of forest fires and with observed changes in drought statistics in agricultural regions of Northern Eurasia.  相似文献   

从第29届IASPEI大会看国际地震预测研究动向   总被引：2，自引：0，他引：2  

朱传镇 《国际地震动态》1998,(4):1-4

第２９届ＩＡＳＰＥＩ大会于１９９７年８月１８～２８日在希腊塞萨洛尼基召开，来自世界６２个国家的１０５０人出席了这次大会。提交大会的论文共１４１１篇，其中口头报告７１６篇，张贴报告６９５篇。该文根据提交大会的有关论文，介绍了国际地震预测研究情况与研究动向。  相似文献   

Efficient expression of green fluorescent protein （GFP） mediated by a chimeric promoter in Chlamydomonas reinhardtii     

吴锦霞  胡章立  王潮岗  黎双飞  雷安平 《中国海洋湖沼学报》2008,26(3):242-247

To improve the expression efficiency of exogenous genes in Chlamydomonas reinhardtii, a high efficient expression vector was constructed. Green fluorescent protein （GFP） was expressed in C. reinhardtii under the control of promoters： RBCS2 and HSP70A-RBCS2. Efficiency of transformation and expression were compared between two transgenic algae： RBCS2 mediated strain Tran-Ⅰ and HSP70A-RBCS2 mediated strain Tran-Ⅱ. Results show that HSP70A-RBCS2 could improve greatly the transformation efficiency by approximately eightfold of RBCS2, and the expression efficiency of GFP in Tran-Ⅱ was at least double of that in Tran-Ⅰ. In addition, a threefold increase of GFP in Tran-Ⅱ was induced by heat shock at 40℃. All of the results demonstrated that HSP70A-RBCS2 was more efficient than RBCS2 in expressing exogenous gene in C. reinhardtii.  相似文献   

连结过去、现在和未来的遗迹组构研究:第13届国际遗迹组构专题研讨会综述   总被引：1，自引：1，他引：0       下载免费PDF全文

张立军  胡斌  齐永安  宋慧波  郑伟  牛永斌  邢智峰  范若颖 《古地理学报》2015,17(5):611-615

第13届国际遗迹组构专题研讨会于2015年5月14日—21日在日本高知大学召开。从会议报告、展板和野外地质考察可以看出:(1)遗迹化石的演化古生态学和复杂遗迹化石的古生态学、埋藏学精细分析将是未来遗迹学的研究热点;(2)遗迹化石的正确分类命名及其形态功能和古环境分析依然是遗迹学的基础和主要内容;(3)新遗迹学展示了巨大的生命力,成为了将今论古的重要钥匙;(4)三维动画模拟未来将推动遗迹学、生态学的科学普及;(5)遗迹组构在油气勘探应用中已取得了重大的成果。学科交叉和高新技术测试方法、跨越多学科的思维路线将是遗迹学发展的重要推动力。  相似文献