南天山中央地块的厘定与古气候事件

古气候变化与地质构造演化有着一定联系 ,构造活动的结果将引起地球表面海陆分布、陆地古纬度、火山活动、山脉形成以及地形地貌的巨大变化 ,是直接影响古气候的重要因素。根据志留—泥盆纪构造古地理再造、深部层次变形、基底时代、深部构造特征、构造混杂带研究 ,在确定南天山中央地块构造演化的基础上 ,探讨泥盆纪南天山构造火山作用与古气候及层孔虫绝灭事件的关系     

天山西段岩石圈深部结构及其与南北盆地构造关系

根据深部地球物理资料 ,将天山造山带划分为三个不同的构造单元 ,各构造区岩石圈结构表现各异。天山西段岩石圈深部广泛存在低速 (高导 )层 ,它是构成天山地壳“扇状”构造样式的物理基础。天山的软流圈深度浅于南北两侧 ,它具有较高密度的上地幔物质和较深山根。它与南北盆地的深部构造关系为陆内俯冲关系 ,天山岩石圈的深部结构特征 ,与其所处地球动力学环境和中亚地壳组成不均一性有关     

Improved bora wind simulation using a nested Eta Model

Summary In connection with a number of recent publications on anomalous (excessive) absorption of shortwave radiation (SWR) by clouds, the data of aircraft observations of spectral and total SWR vertical profiles in the troposphere obtained within the CAENEX, GAAREX and FGGE programmes have been discussed. These data demonstrated persuasively the existence of substantial SWR absorption by clouds in the visible wavelength region. In this context, the results of simulation numerical medelling of the SWR transfer in clouds have been considered. These show a significant enhancement of the SWR absorption by clouds due to an increase of the mean free path of photons under an impact of multiple scattering in clouds. Another important consideration may be the impact of SWR-absorbing pollutants in clouds, especially soot aerosols.With 4 Figures     

On some new statistical characteristics of the wind “Koshava”

Summary Koshava is a gusty wind of moderate to strong intensity, blowing from the south-eastern direction, over the area of the Republic of Serbia. It is caused by the interaction between the synoptic circulation and the orography of the Carpathian and the Balkan mountains. The Koshava wind can damage buildings, factories and industrial plants or city infrastructure. Therefore it is important to estimate its gust and the gustiness factor on the basis of the measured data.This paper discusses a statistical analysis of wind data in the maximum influence area of the Koshava wind in the periods of maximum duration of Koshava. The focus of the paper is the examination of urban and suburban effects on Koshava wind and the correlation between the instantaneous maximum wind speed and the hourly mean wind speed. The best fitting with various empirical distributions is proposed.With 10 Figures     

弱固结砂岩气藏水力压裂裂缝延伸规律研究

针对我国疏松砂岩层出砂严重需要进行压裂以填防砂的情况，对疏松砂岩压裂裂缝启裂有延伸规律进行了数值模拟计算，并重点对地应力、储层强度、射孔地裂缝扩展延伸的影响规律进行了分析计算。结果表明：用螺旋射孔方式完井在疏松砂岩储层中难以获得大而平整的裂缝，防砂效果不理想，定向射孔可得到较为理想的人工裂缝。研究结果对疏松砂岩储压裂充填防砂设计具有较大的指导意义。     

Probabilistic Horizontal Stress Ratios in Rock

Prior to excavation, any point in a rock mass is subjected to stress, which has to be considered in the overall stress distribution after the excavation work is completed. Over the past three decades, empirical, analytical, and field studies have shown that the ratio of average horizontal stress to vertical stress plays a dominant role in engineering structure design. Notationally, this ratio is referred to as the coefficient of lateral stress K, which is a dimensionless positive quantity. The intent of this paper was to bring out the intrinsic characteristic of K with the use of probabilistic and statistical techniques, which have not been considered extensively in any previous context.     

Theoretical seismograms for block structures

Summary In constructing theoretical seismograms for large models with block structures, approximate methods are particularly efficient. For example, in treating Earth's crust block models, the ray method with various modifications for including diffracted waves can be used. Smaller block structures, of dimensions comparable to a wavelength, are efficiently treated by direct numerical methods. In this way practically important problems of engineering seismology, seismic microzoning, etc., can be solved. The method of so-called conservative diference schemes combines effectively the advantageous features of both the standard finite element and finite difference methods. The basic properties of the method, as well as some features of the corresponding Fortran IV program LATER, are explained on a computational example. The example concerns a highly simplified evaluation of the seismic response of the earth fill. In the frequency range under study two resonance frequencies are identified. Moving along the surface of the fill, from the base to the peak, the predominant frequency decreases. Some prospects of direct numerical methods in seismology are briefly discussed in concluding section.Presented at the Workshop on Seismic waves in laterally inhomogeneous media, Liblice (Czechoslovakia), 27. 2–3. 3. 1978.     

A wave-front curvature approach to computing ray amplitudes in inhomogeneous media with curved interfaces

Summary A system of three ordinary non-linear first order differential equations is proposed for the computation of the geometrical spreading of the wave front of a seismic body wave in a three-dimensional medium. The variables of the system are the parameters which provide a second order approximation of the wave front.     

Rock mass mechanical characteristics in an opencut at bor copper mine

SummaryRock Mass Mechanical Characteristics in an Opencut at Bor Copper Mine Preliminary testing for the design of the new opencut, which will go to a depth of about 300 m, included testing rock mechanical characteristics. The character of the preliminary testing demanded by an engineering undertaking of this scale and the fundamental structural and physical properties of rock masses (fissuring, anisotropy, heterogeneity, natural stresses) are discussed and it is emphatically concluded that priority should go to in situ testing. Results are presented of determinations of the velocity of propagation of longitudinal elastic waves, elasticity modulus, coefficient of damage and shear strength parameters.With 7 Figures