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滩浅海两栖地区油气地震勘探激发接收技术研究 总被引:6,自引:2,他引:4
针对海陆两栖地区地震勘探激发、接收中存在的问题,通过改造炸药震源的装药结构和起爆方式,研制出了一种新型激发震源,提高了激发信号的品质,减小了与气枪震源之闻的信号差异;在接收技术上,研制了新型压电检波器以代替常规的沼泽机电检波器,提高了接收地震信号的频率,实现了水陆相同感应机理的检波器同时接收地震信号,消除了两种不同检波器造成的信号差异;通过对两种新技术的试验分析,认为明显提高了地震资料的分辨率和信噪比,促进了海陆两栖地区地震勘探技术的发展. 相似文献
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本文分两个部分。第一部分从理论上探讨了全息成象应用于探测时的特点,提出了“全息探测成象”的概念。指出对地层介质使用弹性波或电磁波时,关键问题是纵向分辨力低。作者从信息论和天线阵理论的观点探讨了单频全息成象,研究全息成象和相关检测、匹配滤波以及相控阵之间的联系,提出了多频合成全息探测成象作为解决纵向分辨力的一个方法。探讨了它的原理,指出了它和“脉冲全息成象”的关系,导出了纵向分辨力公式,并给出了二维理论模型计算的结果,以说明方法的可行性和应用前景。 第二部分为实验部分,叙述了多频合成微波全息探测成象的试验。采用二维干涉型全息图做了简单模型的水槽试验,由计算机成象的结果证实了多频合成法的高分辨力和良好的成象质量。 相似文献
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考虑刚度及边界条件的短索索力求解与试验研究 总被引:1,自引:1,他引:0
建立了一个非齐次边界拉索力学模型,基于拉索线性振动理论,推导了考虑拉索抗弯刚度及边界条件的拉索频率方程;根据双曲函数的数理特性对频率方程进行了合理简化,得到了实用的频率简化方程,提出了逆过程求解索力的方法和步骤,并探讨了不同支承刚度对索力的影响。设计了室内拉索试验模型并进行了27种工况索力试验,比较了不同工况下的计算索力与实际索力,验证了本文提出的频率简化方程和逆过程求解方法的实用可靠性。 相似文献
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台站资料在我国地磁学基础研究中的应用 总被引:3,自引:1,他引:3
台站观测资料包含了上至太阳活动、星际空间、磁层、电离层活动,下至地壳构造、地震活动、地球深部导电特征,乃至地核活动的各种丰富的信息。中国学者利用台站资料广泛开展地磁学的基础研究,在研制中国地磁场模型,研究地磁场长期变化规律、地下的导电率结构及震磁关系等方面取得了许多成果。文章介绍了台站资料在中国地磁学基础研究中的应用。 相似文献
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Because of its direct influence on the amount of unfrozen water and on the strength of intergranular ice in a frozen soil, temperature has a significant effect on all aspects of the mechanical behavior of the active layer in which temperature fluctuates above and below 0 °C. Hence seismic responses of engineering structures such as embankment on a sloping ground in permafrost regions exhibit obvious differences with seasonal alternation. To explore the distinctive seismic characteristics of a railway embankment on the sloping ground in permafrost regions, a coupled water-heat-dynamics model is built based on theories of heat transfer, soil moisture dynamics, frozen soil mechanics, soil dynamics, and so on. A well-monitored railway embankment on a sloping ground in Qinghai–Tibet Plateau is taken as an example to simulate seismic responses in four typical seasons in the 25th service year. The numerical results show that seismic acceleration, velocity and displacement responses are significantly different in four typical seasons, and the responses on October 15 are much higher among the four seasons. When the earthquake is over, there are still permanent differential deformations in the embankment and even severe damages on the left slope on October 15. Therefore, this position should be monitored closely and repaired timely to ensure safe operation. In addition, the numerical model and results may be a reference for maintenance, design and study on other embankments in permafrost regions. 相似文献
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在地震地下流体动态研究中发现有多种干扰,特别是地下水资源开发的干扰较为普遍,地下热水开发的干扰较为严重,影响地下流体动态监测的效果,因此需要关注、调查与研究地下水开采对地下流体动态的影响问题。作者在研究京北地热田区水文地质条件及热水开采的历史与现状的基础上,重点分析了热水开采对不同水文地质条件与离开采井距离不等的观测井地下流体动态的影响及这种影响在不同测项上表现的差异。研究结果表明,在京北地热田区热水开采对地下流体动态的影响距离为5km,对位于导水断裂带附近的观测井动态影响最为明显;就测项而言,对水位与水温动态的影响最为明显,其次是逸出气(Rn,Hg)动态的影响,对土壤气(CO2)动态的影响不明显 相似文献
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Hydrogeomorphic processes and vegetation: disturbance,process histories,dependencies and interactions 总被引:1,自引:0,他引:1
Riparian vegetation and hydrogeomorphic processes are intimately connected parts of upland catchment and fan environments. Trees, shrubs and grasses and hydrogeomorphic processes interact and depend on each other in complex ways on the hillslopes, channels and cone‐shaped fans of torrential watersheds. While the presence and density of vegetation have a profound influence on hydrogeomorphic processes, the occurrence of the latter will also exert control on the presence, vitality, species, and age distribution of vegetation. This contribution aims at providing a review of foundational and more recent work on the dependencies and interactions between hydrogeomorphic processes and vegetation. In particular, we address the role of vegetation in the initiation of hydrogeomorphic processes and its impact on stream morphology as well as immediate and long‐term effects of hydrogeomorphic disturbance on vegetation. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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本文介绍一种新的位场延拓方法——积分-迭代法.将起伏面上的实测位场值,垂直投影至起伏面下部的一个水平面上,作为该水平面上的位场初始值.根据该水平面上的初始值,用积分方法计算起伏面上的位场值.用起伏面上的实测值与计算值的差值,对水平面上的位场值进行校正.如此反复迭代,直至起伏面上的实测值与计算值的差值小到可以忽略.有了水平面上的位场值后,就可以用积分的方法或其他方法计算水平面以上的任意曲面或水平面的位场值.该方法原理简单,不用解线性代数方程组,有较高的计算速度.它特别适用于位场向下延拓,有良好的延拓效果.本文还介绍了积分迭代法的应用实例. 相似文献
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相邻地形对地震动特性的影响分析 总被引:1,自引:0,他引:1
基于采用透射人工边界的显式动力有限元方法,研究了相邻凸起地形对地震动反应谱特性的影响,分析了相邻凸起之间距离的变化对地形效应的影响。研究结果表明:1)与单一凸起地形对地震动的放大效应相比,相邻地形的存在对地震动反应谱谱比曲线的形状影响不大,但是却对谱比的值具有较大影响,而且其影响程度的大小与地表观测点的位置有关;2)相邻凸起地形的存在对凸起平台段中点地震动高频成分的放大效应具有较大影响,随着相邻凸起之间距离的增大,该影响效应逐渐减弱,多个相邻凸起构成的组合地形对地震动的放大效应逐渐接近单一凸起地形。 相似文献
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Based on the precipitation data obtained through GEWEX Asian Monsoon Experiment–Tibet fieldwork from May to September 1998, this study investigated the features of the summer monsoon precipitation on the northern and southern slopes of the huge Tanggula Mountains in the Qinghai–Xizang (Tibetan) Plateau. The results show that the precipitation on the southern slope is about 50% higher than on the northern slope, whereas the frequency and diurnal pattern of the precipitation are very similar. The mean precipitation intensity on the southern slope is larger than on the northern slope. In most cases, the daily precipitation showed similar variation on both slopes, demonstrating that the precipitation processes might be similar. In the summer monsoon period, the local convective precipitation contributed to the total precipitation on both slopes and such a contribution on the southern slope is larger. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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