地震测深中的地震波衰减          下载免费PDF全文

孙克忠  滕吉文  姚虹  程立芳 《地震工程学报》1985,7(1):86-93

基于在河南、湖北、江苏、安徽等省和西藏自治区进行的人工地震测深工作,详细分析了不同爆炸方式(水中爆炸、井中组合爆炸、矿山和洞室爆炸),不同炸药量(1.2～500吨)和不同观测距离(5～500公里)的实测资料,讨论了爆炸方式与衰减的关系。结果表明,水中爆炸的弹性波转换系数最大,并以组合爆炸方式获得最佳的效果。本文提出地震测深中的地震波衰减遵循关系式:V_m=β(R/W~1/3)-r式中,V_m 为地表运动最大速度,(R/W~1/3) 为折合距离,r 为衰减系数。(r=1.5～1.6)。文中简要讨论了地壳厚度与地震波衰减的关系。  相似文献   

利用PS反射波研究西藏雅鲁藏布江北侧局部地区深部地壳结构   总被引：1，自引：0，他引：1       下载免费PDF全文

姚虹  孙克忠  滕吉文  程立芳 《地震工程学报》1982,4(4):57-62

本文利用PS反射波探测了雅鲁藏布江北侧局部地区莫霍面的深度和起伏。在亚东—当雄测线的径向方向上记录到一个尚为清楚的PS反射波,视速度为8.35±0.28公里/秒,在同一莫霍面部分使用了PS和PP震相的走时,求得下地壳结构。莫霍面的倾角为-0.83°～0.84°,该面的深度为68～69公里左右,从结果表明该地区莫霍面起伏不大,地壳基本上是水平的。作者认为利用PS反射波测定莫霍面起伏状态是很有用的,值得进一步探讨。  相似文献   

Three-dimensional elastic wave scattering and diffraction due to a rigid cylinder embedded in an elastic medium by a point source     

Long-Far Hwang  John T. Kuo  Yu-Chiung Teng 《Pure and Applied Geophysics》1982,120(3):548-576

The formal solutions of displacement field to the problem of elastic wave scattering and diffraction due to an infinitely long rigid cylinder embedded in an infinite elastic medium by an impulsive point source have been obtained in the integral form. The integrals for the reflected and the diffracted waves both in the shadow zone and in the illuminated zone are evaluated asymptotically for the early time motion by the Reisdue-Cagniard method and the Saddle-point-Cagniard method.Numerical results of the diffractedP, S andPS waves at a fixed circum-distance from the surface of the rigid cylinder show noticeably that (1) the energy partition for the diffractedS wave is small in comparison with that for the diffractedP wave, (2) the wave form of the diffractedS wave is broader and more diffused than that of the diffractedP wave, (3) the direction of the radial motions of the diffractedP andS waves varies as a function of the observational point, and (4) the energy partition for the diffractedP wave is much smaller than that for the direct or the reflectedP waves.This paper has been presented at the 46th Annual International Meeting of Society of Exploration Geophysicists in Houston, Texas, Oct. 28, 1976.  相似文献   

中国地壳与上地幔结构的地球物理研究   总被引：1，自引：0，他引：1       下载免费PDF全文

滕吉文  魏斯禹  刘桂英  宋仲和  张少泉 《地震工程学报》1983,5(4):70-85

地壳与上地幔是人类居住与获取各种资源、能源,改造和利用自然的重要场所,是地球科学的基础与生长点,六十年代以来发展迅猛。中国大陆、海域和过渡带地区的地壳和上地幔物理探索,在全球板块构造和驱动机制的研究具有特殊地位,文中分别就1)青藏高原地区的地壳结构,2)青海、甘肃地区地壳结构和地壳中的高速块层,3)中原地区的地壳与上地幔结构,4)京津及外围地区的地壳结构,5)隋县—南京—启东和隋县—安阳人工地震探测面的观测,6)利用面波和远震P波确定中国地壳和上地幔结构,7)中国地壳结构的基本轮廓等方面进行了讨论。  相似文献   

三维地理信息数据在移动通信网络规划和优化系统中的应用     

滕艳敏 《中国地名》2007,(4)

随着移动通信的迅猛发展,网络规模不断扩大,借助数字地图,尤其是三维地理信息数据进行网络规划和优化已变得越来越重要。本文主要介绍三维地理信息数据在建立移动通信网络规划和优化系统中的应用。  相似文献   

昌化鸡血石的成矿构造背景及成因探讨   总被引：1，自引：0，他引：1  

滕瑛  廖宗廷 《上海国土资源》2001,(3):43-48

通过应用地球化学方法对昌化鸡血石的成矿构造背景进行了分析研究，并在此基础上对成因进行了初步探讨，进而指出找矿的方向和找矿标志。  相似文献   

Characterization of soil lead by comparing sequential Gaussian simulation, simulated annealing simulation and kriging methods   总被引：4，自引：0，他引：4  

Yu-Pin Lin  Tsun-Kuo Chang  Tung-Po Teng 《Environmental Geology》2001,41(1-2):189-199

  相似文献   

Environmental Geochemistry of Mining Activities in Panzhihua Region, Southwestern China   总被引：4，自引：0，他引：4  

Teng Yanguo Institute of Environmental Sciences  State Key Laboratory of Water Environmental Simulation  Beijing Normal University  Beijing Tuo Xianguo Department of Nuclear Resources  Technology  Chengdu University of Technology  Chengdu 《中国地质大学学报(英文版)》2001,12(4)

INTRODUCTIONMining activlties have significant envi ronmenta1 inll)ac'l ssuch as visual intrusions, dust, noise, blasting, trafflc and h}'drology (Kwolek, l999; Ripley et al., l996 ). The l)rot'csst'sof mineral extraction, processing, smelting and refinlng;1rt'never approximate to the environmental neutrality, but tht' affected areas can be ameliorated (KwoIek, l999; Klukanov;1;llltlRapant, 1999). The regions, where mining activities are I,r('sent or continuous for a long tlme, are pote…  相似文献   

某城地下水地表水联合优化调度管理模型实例     

金为芝  张志辉 《上海国土资源》1992,(2):46-52

本文阐述了利用响应矩阵法建立地下水、地表水优化调度管理模型的约束条件、并用目标规划法进行管理模型计算的一个实例。这是一个位于黄河之滨的城市,市内有许多名泉。近年来大量开采地下水已使泉水干涸,而黄河水在某些月份含沙量很大,不宜全年开采。本计算求得了这个城市几个水源地与黄河水在一个枯水年(或丰水年)内各月份的优化开采量分配方案,使之既可保证泉水全年喷涌;叉可提供所需水量。  相似文献   

Managing rice pests with less chemicals     

K. L. Heong  P. S. Teng  K. Moody 《GeoJournal》1995,35(3):337-349

Losses caused by pests remain an important constraint to achieving high rice yields. Potentials of protecting these losses have stimulated innovations in pesticide development. Today the rice pesticide market is valued at US $ 3.0 billion per year. With reducing land available for rice production and increasing demand for food production, attention is turning towards intensification through higher fertilizer inputs and cropping. Such intensifications may in turn increase pest intensities and demand for more pesticides.A large proportion of insecticide sprays administered by rice farmers in Asia is influenced by misperceptions and overestimations of damages. Most farmers apply their first sprays in the first 40 days after crop establishment to control leaf feeding insects. However, these pests do not occur in sufficiently high densities to cause yield loss. Instead, such early season sprays may contribute towards development of secondary pests, such as the brown planthopper. Strategies to reduce insecticide use need to focus on enhancing naturally occurring biological control and understanding farmers' decision making behavior.Most fungicides used in rice are in the sub-tropical countries, like Japan, Korea, Taiwan and Vietnam. An important strategy towards reduction in fungicide use is through host plant resistance and gene deployment strategies. With biotechnology, tools may be used to characterize population structures in order to enhance these strategies. Cultural practices, such as rotations, cultivar mixtures, crop mosaics and planting times are being investigated.As cost of labor increases, farmers are likely to resort to using herbicides. The best way to accomplish weed control is the simultanous application of a variety of practices. These will include cultural, mechanical and chemical methods. The potentials of using naturally occurring enemies, such as plant pathogens, and the use of allelopathy are also being explored.  相似文献