应用δ函数计算云层反射率的改进     

朱迅 《大气科学》1987,11(1):108-111

本文在运算量不变的前提下,对计算云层反射率的一个模式作了改进,提高了计算精度。  相似文献   

DISCONTINUOUS OSCILLATION IN THE ATMOSPHERIC CIRCULATION AND INDEX CYCLE          下载免费PDF全文

Jin Feifei  Zhu Baozhen 《Acta Meteorologica Sinica》1987,1(2):133-142

By using a low-order,two-layer baroclinic quasi-geostrophic model,a nonlinear system including the interaction between a thermal forced wave,a transient wave and zonal flow is studied. Under the conditions of near-resonance and weak baroclinic instability,the features of solution in phase space are discussed with the analytical methods of multiple scale and discontinuous oscillation.The results show that the dynamic coupling between forced wave and transient wave is responsible for the physical mechanism of the non-uniform index cycle of the atmospheric circulation.  相似文献   

The Rapid Inversion of 3-D Potential Field and Program Design   总被引：1，自引：0，他引：1  

Feng Rui  Yan Huifen  Zhang Ruoshui 《《地质学报》英文版》1986,60(4):83-96

The application of three-dimensional inversion of gravity and magnetic fields is very important not only in geophysical researches, but also in the study of geological structures. A formula of potential field in frequency-domain, developed by Parker in 1973, can be used as a rapid and effective algorithm in gravity and magnetic inversion. The technique has been improved then by Oldenburg, Sprenke, Feng and others.In addition to a brief introduction of Parker's algorithm and its applications, this paper includes the following five parts: basic computational techniques, inversion of single layer, convergence and constraints, simultaneous inversion for density and topography as well as inversion of multilayers. The authors present relevant practical iterative formulas and its varieties when density distribution varies with depth in linear or exponential relation. In order to maintain computation stability and speed up iteration convergence, some approaches are taken in the program design, for instance shifting lower interface of the studied layer, inverting corrections of topography, reducing grid boundary effects and utilizing low-pass filter. With the consideration of the nonuniqueness of the inversion, a method of using seismic data to constrain the range ofpossible models is discussed. It is pointed out that the density variation generates less effects than those of topography on the spectrum of gravity anomaly in second order. Therefore density contrast and topography can be inverted simultaneously by an alternative weighting iteration. By analogy, the inversion of multilayer model can be done in the above procedure. An approach of model decomposition is useful in the computation of multilayer model. The techniques discussed in the present paper for gravitational field are also valid for magnetic field.  相似文献   

A study of circulation differences between East-Asian and Indian summer monsoons with their interaction   总被引：17，自引：0，他引：17  

Zhu Qiangen  He Jinhai  Wang Panxing 《大气科学进展》1986,3(4):466-477

Primarily based on the 1979 FGGE data an analysis is made of the circulation differences between the East-Asian and Indian summer monsoons together with their oscillation features and also the interplay be-tween various monsoon systems originating from the fact that the Asian monsoon area is divided into the East-Asian and Indian regions, of which the former is demarcated into the Nanhai (the South China Sea) and the Mainland subregions.  相似文献   

A STUDY ON THE RELATIONSHIP BETWEEN THE ROTATION OF BINARY TYPHOONS AND STEERING CURRENT   总被引：1，自引：0，他引：1  

Bao Chenglan  Ruan Junshi  Zhu Yaojian 《大气科学进展》1986,3(1):115-124

Many studies show that, within a certain distance (ca. 700－800 n mi), two typhoons forming a binary typhoon (BT) system would rotate as a whole and attract each other, which is known as “Fuji-whara Effect” (FE). This paper indicates that only 30.3% of BTs has experienced remarkable cyclonic rotation with a 12-hr angle ≥+10° when two components are less than 20° lat apart, and that the probability is much higher with the eastern, component in the NE than in the SE quadrant for the western one, implying the steering effect of the environmental flow field (EFF) on them.47 observations from 13 BTs are separately used for calculating the angular velocity due to FE and EFF and the results are compared. The conclusion can be stated as follows: FE is dominant with the centers of two elements below 7° lat apart; the EFF steering current plays a major role when they are in the range of 7－15° and for a distance above 15° the principle of FE holds no longer.  相似文献   

Mercury, arsenic, antimony, bismuth and boron as geochemical indicators for geothermal areas     

Zhu Bingqiu  Zhang Jinmao  Zhu Lixin  Zheng Yaxin 《Journal of Geochemical Exploration》1986,25(3)

From 1982 to 1983, 131 soil samples were collected within an area of 60 km² in known geothermal field and their vicinities in Tengchong, Yunnan Province. Distinct anomalies of Hg, As, Sb and Bi were found on the known geothermal fields. The contour of the multiplicative anomaly of Hg × As × Sb encircled the two known geothermal fields, Reshuitang and Rehai, within its extent, disclosing the interrelation between these two fields, and enlarging their future prospects. The B anomaly is related to structural features. Significant correlations among Hg, As and Sb are shown by correlation analysis. It was concluded that a geochemical survey with a density of two samples per km² could be carried out effectively to delineate promising targets of geothermal resources.  相似文献   

The Chemical Composition of Global Subducting Sediments and Its Geological Significance     

Renjie Zhao  Quanshu Yan  Haitao Zhang  Yili Guan  Zhenmin Ge  Long Yuan  Shishuai Yan 《地球科学进展》1986,35(8):789-803

Subducted sediments play an important role in crust-mantle interaction and deep mantle processes, especially for subduction zone magmatism and mantle geochemistry. The current rate of Global Subducting Sediments (GLOSS) is 0.5~0.7 km³/a. The GLOSS are composed of terrigenous material(76 wt.%), calcium carbonate(7 wt.%), opal(10 wt.%) and mineral-bound H₂O⁺(7 wt.%). The chemical compositions of GLOSS are similar to those of upper continental crust which is mainly controlled by the terrigenous materials, and yet the materials formed by marine processes will dilute the terrigenous materials. The components of subducted sediments are different among trenches. In the accretionary margin, the components of subducted sediments are similar to those of the upper crust, while in the non-accretionary margin the components are terrigenous materials plus those produced by marine processes. During subduction, subducted sediments will released fluids, melt or supercritical fluid to affect island arc/back-arc basin magmatism by means of aqueous fluid or sediment melt. In addition, a part of subducted sediments, together with underlying altered oceanic crust/lithosphere, recycle into the mantle and contribute to the mantle heterogeneity. Geochemical tracers indicate that subducted sediments play variable contributions to the magmatic processes in different tectonic setting. Thus, subducted sediments play an important role in two relatively independent dynamics systems (plate tectonics and mantle plume), as well as related mantle evolution models. As a result, by accurately calculating the compositions of subduction sediments and using various geochemical indicators, we can further limit the input and output fluxes of various elements or isotopes, and then obtain more accurately residual subducted components, which can provide us some important clues for geodynamic process.  相似文献   

齐依求金矿中微球粒特征     

王之峰  马生明 《黄金地质》1995,1(2):76-79,T001

首次报道齐依求金矿中微球粒的发现，对微球粒形态特征、表面及断面结构、物理特性、矿物组成、化学成分进行分析测试，并就其成因作了初步探讨，认为属宇宙成因。  相似文献   

河北平原地下水动力环境演化规律及影响因素   总被引：5，自引：0，他引：5       下载免费PDF全文

朱延华  郭永海 《地球科学》1995,20(4):433-437

通过河北平原多年地下水位长期观测资料的整理，统计和分析，探讨了地下水动力环境演化规律，并选择典型地区，采用灰色关联度分析方法，论证了地下水位变化与开采量、降水量之间的内在联系，从而揭示了地下水动力环境演化机制。  相似文献   

塔里木盆地北部构造样式   总被引：10，自引：0，他引：10       下载免费PDF全文

严俊君  黄太柱 《地球科学》1995,20(3):264-270

塔里木盆地北部发育５种典型的构造样式；基底卷入型压性逆冲构造组成、盖层滑脱型逆冲－褶皱构造组合、隐刺穿刺底檗同幅度褶皱构造组合及张性正断层组合，无论是构造变形时间还是组合分布，在塔北均呈现规律变化，其变形特征及发布受如下３个地质因素控制：（１）区域挤压作用；（２）岩性条件的差异：（２）先期构造格局。  相似文献