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101.
102.
塔里木盆地塔中沙漠区高分辨率地震勘探效果 总被引:1,自引:0,他引:1
塔中沙漠区地表被北东—南西向条带状沙层所覆盖,地形起伏剧烈,松散沙层厚度变化巨大,给地震资料采集、处理、解释带来了很大的困难。通过联合攻关,从地震波激发能量下传和反射波接收的研究入手,实现了全部潜水面以下激发,因地制宜、避高就低埋置检波器优化观测系统;针对该区石炭系和志留系低幅度构造、薄储层圈闭难以落实,奥陶系内幕地震资料反射波能量弱、信噪比低、叠加成像困难等问题,开展了沙丘对地震波吸收衰减分析和补偿技术、地表一致性处理技术、多域迭代静校正技术、精细速度场模型确立和偏移成像等配套技术的研究开发与应用。从而极大地改善了塔中沙漠区地震资料的品质,使中深层的石炭系、志留系、奥陶系对应的地震剖面主频从18~20Hz提高到36~40Hz;形成了塔中沙漠区油气勘探技术系列,精细刻画了塔中Ⅰ号带,锁定了油气勘探目标,推动了台盆区油气勘探再掀新高潮。 相似文献
103.
本文导出了线性波浪作用于上部可渗透的直立刚性圆柱体上的水动力的解析解。在线性有势流的假定下,用特征函数展开方法求出了内部和外部流场的解。给出了不同波浪要素及结构尺寸参数下的数值结果。由结果可知,提高可渗透性可以有效消减波幅。 相似文献
104.
Thomas M. Burton Craig A. Stricker Donald G. Uzarski 《Lakes & Reservoirs: Research and Management》2002,7(3):255-269
Invertebrate communities from different coastal marsh‐plant communities were compared along wave‐exposure gradients using data from 1994, 1998 and 1999. Data were subjected to correspondence analyses to search for patterns in invertebrate communities in relation to plant‐community structure and wave exposure. In 1994, quantitative plant‐ and sediment‐invertebrate samples were taken from nine habitats: four from inland, subsurface‐connected marshes and five from littoral, emergent marshes. In 1998, sweep‐net samples were taken from 13 plant communities: six on the exposed and seven on the protected side of an island. In 1999, 2–3 plant communities/sites were sampled with sweep nets from four sites around the Bay so that intersite differences between inner, less‐exposed and outer, more‐exposed habitats could be examined. In all three studies, correspondence analyses separated inland, protected or inner sites from littoral, exposed or outer sites, suggesting differences in invertebrate‐community structure. For example, Hydracarina and Asellidae occurred in large numbers in inland sites, but were less common or absent from exposed, littoral sites. Littoral marshes also separated along an exposure gradient with Tanytarsini and Orthocladiinae collectors of organic particles occurring in very high numbers in outer, exposed areas where organic particles from the pelagic zone entered the marsh. Certain plant‐community types clustered together (e.g. wet meadow and Scirpus) while others, such as Typha, stands clustered according to exposure to waves suggesting the importance of both plant‐community structure and wave exposure in determining invertebrate‐community structure. We present a conceptual model that suggests that invertebrates in Great Lakes' marshes are distributed along gradients of decreased mixing of pelagic water and increases in sediment organic matter from outer to inner marsh and between littoral and adjacent inland marshes. Some invertebrates do best on one end of these gradients, while the majority are generalists found across habitat types. 相似文献
105.
MV2000T智能变送器 总被引:1,自引:0,他引:1
较全面地介绍了ABB公司MV2 0 0 0T智能变送器的市场开发背景、工作原理、技术规格、性能特点及设计选型要点 相似文献
106.
评述了二极管泵浦内腔倍频激光技术的发展现状,对解决中小功率下‘绿光问题’的理论及实验方案进行了比较分析,对高功率内腔倍频系统亦进行了初步探讨。 相似文献
107.
In this letter, an integrated application of the prediction for radio wave propagation with the Geographic Information System (GIS) is presented and a real prediction system based on GIS is implemented. 相似文献
108.
Meng Jun min Ocean University of Qingdao Qingdao China Zhang Zi li Zhao Jun sheng First Institute of Oceanography State Oceanic Administration Qingdao China Zhang Jie Key Laboratory of Marine Science Numerical Modelling 《水动力学研究与进展(B辑)》2001,(3)
1 . INTRODUCTIONOceaninternalwaveisakindofgravitywavegeneratedinthestratifiedocean .Itproducebytheinteractionoftidecurrentandtopography ,seaquakeandmovingshipwhenthestrong ,shallowpycnoclineis present.Theinternalwavesinthecontinentalshelfarealmosttideprod… 相似文献
109.
Shu-Chu Ren Nelson N. Hsu Donald G. Eitzen 《Journal of research of the National Institute of Standards and Technology》2002,107(5):445-473
Pulsed ultrasonic techniques can be and have been used to examine the interface conditions of a bonded structure. To provide a theoretical basis for such testing techniques we model the structure as a layer on top of a half-space, both of different elastic properties, with various interface bonding conditions. The exact dynamic Green’s tensor for such a structure is explicitly derived from the three-dimensional equations of motion. The final solution is a series. Each term of the series corresponds to a successive arrival of a “generalized ray” and each is a definite line integral along a fixed path which can be easily computed numerically. Willis’ method is used in the derivation. A new scheme of automatic generation of the arrivals and ray paths using combinatorial analysis, along with the summation of the corresponding products of reflection coefficients is presented. A FORTRAN code is developed for computation of the Green’s tensor when both the source and the detector are located on the top surface. The Green’s tensor is then used to simulate displacements due to pulsed ultrasonic point sources of known time waveform. Results show that the interface bonding conditions have a great influence on the transient displacements. For example, when the interface bonding conditions vary, some of the first few head waves and regular reflected rays change polarities and amplitudes. This phenomenon can be used to infer the quality of the interface bond of materials in ultrasonic nondestructive evaluation. In addition the results are useful in the study of acoustic microscopy probes, coatings, and geo-exploration. 相似文献
110.
在介绍推进波作用下底泥起动特点的基础上,将上层水体作为粘性流体,底泥作为粘弹性体,推导了推进波作用下泥床面剪应力的表达式,并根据试验结果,给出了推进波作用下底泥起动时的床面剪应力与底泥流变参数的关系。 相似文献