地震勘探数据处理的一种算法——分布参数系统最优理论的应用   总被引：2，自引：3，他引：2       下载免费PDF全文

黄光远  许闻天  傅国华  邱忠坊  杨宝哲 《地球物理学报》1985,28(1):74-84

本文将根据地震数据识别地层结构问题归结为分布参数系统的最优化问题,利用脉冲变分原理给出了一个新的算法,此算法与文献[4]中算法相比较,计算效率要高。  相似文献   

等离子体湍流对电子的加速          下载免费PDF全文

刘振兴  黄迎雷 《地球物理学报》1984,27(3):209-219

本文讨论了等离子体湍流对电子加速的两种模型:（1）假定在空间中存在一个空间均匀的等离子体湍流区,当具有一定初始分布的电子束通过此湍流区时,研究湍流场对电子束的加速过程;（2）在某一封闭的区域中,存在着具有一定初始分布和空间均匀的等离子体,当某种类型的等离子体波突然传入此等离子体区,然后考察此区中电子的加速过程。在这两种模型中,可能存在着某种电子消失机制。假定湍谱是幂指数形式,我们给出了不同类型湍流扩散系数的普遍形式。利用较简单的数学方法,求解了包括消失过程的一维准线性动力学方程,对于给定的初始分布,得出了分布函数的解析解,并给出了平均能量时间关系的表达式。另外,对于特定的湍谱指数,解出了当平行电场和湍流同时存在时的分布函数。最后,对所得结果进行了数值分析和讨论。  相似文献   

北半球夏季全球热带和副热带200hPa平均辐散环流的研究   总被引：7，自引：5，他引：7  

丁一汇  赵深铭  张键 《气象学报》1987,45(1):120-127

大气的运动场或风场包括两部分:一是旋转部分,另一是辐散部分。虽然旋转部分的方差占总运动场方差的大部分(约占80％),但与辐散风相联系的垂直环流对于天气系统的发展是重要的。Krishna-murti等人最早研究了全球热带的辐散环流。最近他的研究表明,辐散风场的大部分是属于纬向的行星尺度垂直环流的水平分支,这意味着行星尺度系统总是热力直接环流,并且以纬向环流为主。Van der Boogard计算了7月多年平均的速度势场,发现对流层上层最强的辐散中心在中南半岛上空。  相似文献   

由多个小震推断的青甘和川滇地区地壳应力场的方向特征   总被引：49，自引：7，他引：49       下载免费PDF全文

许忠淮  汪素云  黄雨蕊  高阿甲  金小锋  常向东 《地球物理学报》1987,30(5):476-486

本文根据1975-1984年期间发生的多个小地震的P波初动方向数据,推断了青、甘、川、滇地区平均主应力轴的方向。结果表明,该地区压应力轴（P轴）和张应力轴（T轴）方向皆水平,但其方位由北到南呈现规则转动的趋势,即主压应力轴在北部青甘地区大致取NE-SW方向,到中部川西北地区转为近E-W方向,再到南部云南地区转为NNW-SSE或近N-S方向。形成应力轴方向这样特定分布图象的原因,可用印度板块向北对青藏高原的推挤和缅甸中源地震带地区下沉物质对云南地区的拖曳作用来解释。  相似文献   

武昌电离层E-F谷区白天变化形态   总被引：2，自引：0，他引：2       下载免费PDF全文

苏元智  黄信榆 《地球物理学报》1987,30(6):555-559

本文利用文献[4]的分析程序对武昌地区三年共300多张频高图作了剖面换算和统计分析,得出白天E-F谷区电离的基本形态并发现一些新的变化特征;对分析结果的可能原因提出了讨论。  相似文献   

下辽河盆地大地热流   总被引：10，自引：1，他引：10       下载免费PDF全文

汪集旸  汪缉安  王永玲  张忠义 《地质科学》1986,(1):16-29

下辽河盆地属华北地堑系的一部分,是一个在前中生代基底上发育起来的中、新生代断陷盆地(张文佑等,1981;马杏垣等,1983;朱夏等,1983),解政文等(1980)曾报道过一个异常高的热流值,引起了各方面的不同反响。近年来,我们于辽河油田开展系统地热研究的同时,取得了一大批实测地温资料和岩石热物理性质参数,在此基础上计算出下辽河盆地大地热流值,并对盆地深部热状况作出相应评价。  相似文献   

Probability of received-power fluctuation of an optical system in the turbulent atmosphere     

Wang Junbo  Wu Jian  Feng Zhichao 《大气科学进展》1986,3(3):371-378

The probability of received-power fluctuation in the turbulent atmosphere is discussed with a simple and yet reasonable model for a direct-detection optical system. Good agreement was found between the theore-tical results and the field experiment. Thus the analysis in this paper may be taken as a guide for the design of atmospheric optical system.  相似文献   

航空甚低频电磁异常在胶东牟乳地区构造填图中的应用     

侯俊胜  线纪安 《地质与勘探》1995,31(1):40-43,37

通过对胶东牟平－乳山地区１：２．５万航空甚低频电磁异常的分析研究，并结合航磁，航放、遥感以及区域构造地质资料，进行了构造地质填图，首次进一步证实了被前人所忽视的近东西向断裂构造的存在，并给予了准确定位。在此基础上进行了金矿成矿远景预测，取得了比较满意的效果。  相似文献   

Magnetostratieraphy of the Red Beds in the Hengyang Basin     

Hsu Vindell  A.Baksi 《《地质学报》英文版》1995,69(2)

This paper discusses the Cretaceous-Tertiary magnetic polarity sequence of the the Hengyang Basin on the basis of magnetostratigraphic study. The age of each stratigraphic unit has been determined with the magnetic polarity time scale combined with 39Ar/40Ar dating, thus providing evidence for determining the geological ages of different formations. The authors assign the age of the Dongjing Formation of the Hengyang Basin to Early Cretaceous, the Shenhuangshan Formation to Early-Late Cretaceous, the Daijiaping Formation to Late Cretaceous, and the Dongtang and Xialiushi formations to Palaeocene.  相似文献   

The Madden-Julian oscillation in the Canadian Climate Centre general circulation model     

Jian Sheng 《Climate Dynamics》1995,12(2):125-140

The Madden-Julian oscillation (MJO) simulated by the Canadian Climate Centre general circulation model (CCC GCM) is identified by a principal oscillation pattern (POP) analysis and compared with that observed in the real atmosphere. The results are based upon two integrations of the CCC GCM, one with a parameterization of penetrative cumulus convection (EXP1) and the other with a moist convective adjustment scheme (EXP2). The signal of MJO can be detected in both integrations as the first POP of the 200 hPa velocity potential along the equator. The disturbances show a distinctive wave number one structure with the strongest local amplitude found in the longitudes corresponding to the region of the Asian monsoon. The phase speed of the eastward wave propagation is higher in the eastern Pacific and lower in the monsoon region where the convective activities are strongest. These features are in good agreement with the observations. The energy spectrum of the velocity potential peaks at the frequency corresponding to a period of about 38 days for EXP1, which is somewhat shorter compared to the observed periods of 40–50 days. On the other hand, two spectral peaks can be clearly identified for EXP2, one with a period of 24 days and the other with a much longer period, somewhere near 112 days. Both peaks appear statistically significant at 95% level. Long term data of the observed atmosphere show little indication of such spectral separation. The horizontal patterns identified by the POP analysis resemble to some extent the baroclinic response of tropical flow to a heat source travelling with the speed of MJO. At the upper level, Rossby wave energy propagates westward with winds generally following the height contours, whereas Kelvin wave energy propagates to the east from the heat source with strong cross-contour flow near the equator. At the lower level, the patterns are essentially reversed. The model-generated precipitation and diabatic heating are examined by compositing against the moving MJO. It is found in EXP2 that the composite heating distribution is coherent with the flow pattern only in a certain sector of the equator, depending on whether the fast or slow mode is used to determine the reference point. The composite vertical heating profile of a slower mode tends to have a maximum found at a lower level. The sensitivity of simulated MJO to the cumulus convection scheme in the model is discussed. Received: 19 December 1994 / Accepted: 11 July 1995  相似文献