STUDY OF NONLINEAR ROSSBY WAVES IN THE ATMOSPHERE UNDER SEMI-GEOSTROPHIC APPROXIMATION*

Under semi-geostrophic approximation the nonlinear ordinary differential equations are obtained for the motion in the barotropic and baroclinic atmospheres with the effects of zonal shear basic flow and topographic forcing included.Two constraints are acquired of finite-amplitude periodic and solitary waves in the original model with the aid of the phase-plane geometric qualitative theory of a dynamic system defined by the differential equation.The explicit solution of the nonlinear waves is found by means of the approximation method and some significant results are achieved.     

不同类型基性层状侵入体的成因

论述了不同类型基性层状侵入体的成因。根据母岩浆特征划分出玄武岩浆侵入体和拉斑玄武岩浆侵入体两大类。     

岩体结构面强度的 Mohr—Coulomb破坏判据与 Barton破坏判据的试验对比

岩体结构面强度是工程岩体稳定性设计中的重要参数,目前工程上常用的两个强度判据,即Mohr-Coulomb准则和Barton准则有各自适用条件。本文在对七组具不同岩性、不同粗糙度及起伏度红层样品进行试验的基础上,探讨了在试验过程中所揭示的强度周期性变化现象,同时基于两准则试验数据,分析了它们之间的区别,获得一些重要结论.即JRC、JCS越大,两准则差别越大;在低法向应力下两准则较接近,在高法向应力时,MC准则偏于危险。     

条带煤柱的抗滑稳定性分析

本文给出了走向条带开采条带煤柱抗滑稳定性分析的力学模型。提出了确定条带煤柱稳定性主要影响因素的敏感性分析法。通过峰峰矿务局九龙口矿的条采实例。介绍了走向条带煤柱抗滑稳定性分析的方法与步骤。     

Stress distribution near lake Jocassee,South Carolina

Seven months of seismic monitoring near Jocassee reservoir (impounded 1974) resulted in the detection of four clusters of earthquake activity. Composite fault plane solutions (CFPS) for each cluster indicate strike slip faulting for shallow earthquakes (<1.0 km) on the shores of the reservoir and normal faulting for deeper events (1–3 km) in the middle of the reservoir. The directions of the axes of maximum and minimum compression inferred from the CFPS were found to be NW and NE respectively and contrast with the NE and NW directions obtained by hydrofracture in a shallow well (230 m) at Bad Creek, about 10 km from the epicentral region.     

福建安砂水电站大坝左岸边坡稳定性分析

安砂水电站建成以来，大坝左岸边坡仍有掉块现象。文章通过分析原有资料和实地调查，对存在问题的左岸和厂房后边坡，进行地质构造、岩石结构情况研究，综合考虑其构造地貌、坡度、地下水、岩石中缓倾角断层、节理或地层层面相互作用，引入同时考虑地震力E和重力W共同作用下，岩石结构面组合稳定性图解分析等方法，对大坝左岸近坝岸坡进行地震边坡稳定性评价。分析结果认为：大坝左岸岸坡高陡岸坡的上段、中段剖面中的一些结构面及组合面存在下滑及接近下滑的危险。     

从清江流域瓦屋场滑坡复活看人类对坡体的利用

居住在山区的人们主要活动空间是斜坡。人们对斜坡利用的有效与否是由人们对斜坡认识充分与否决定的。倘若人们对斜坡认识不足，就可能遭受因斜坡失稳所带来的损失。因此，对这类斜坡的稳定状况的正确认识很有必要。以清江流域典型滑坡——瓦屋场滑坡的复活为例，通过介绍清江流域瓦屋场滑坡人类活动与该滑坡产生的变形情况，根据滑坡体工程地质条件，针对变形原因用萨尔玛法及不平衡推力法进行了稳定分析，同时对复活机制进行分析。在此基础上按照顺应性准则和协调性原则，提出相应的工程治理措施。鉴于该滑坡为该地区的典型滑坡，从灾害学角度说明人类在利用坡体前，对坡体稳定状况认识的重要性并给出人们合理利用该地区自然边坡的建议。     

In-Plane Ray Tracing with Calculation of Out-of-Plane Geometrical Spreading in Anisotropic Media

The objective is to provide, in one single paper, a complete collection of equations governing kinematic and dynamic ray tracing related to a symmetry plane of an anisotropic medium. Well known systems for kinematic ray tracing and in-plane dynamic ray tracing are reformulated for the purpose of clarity, by taking advantage of a vector representation of the Christoffel matrix elements and related quantities. A generalized formula is derived for the integrand in out-of-plane dynamic ray tracing, pertaining to a monoclinic medium. Integrands corresponding to non-tilted orthorhombic and transversely isotropic media are obtained as special cases.     

Geometric form of Haiyuan fault zone in the crustal interior and dynamics implications

Introduction The deep faults in the crust have direct relation to the occurrence of earthquakes and the dis-tribution of active seismic zones, so the researches on the geometric form and physical parametersof deep crustal faults are always an important problem in seismology. The researches are not onlysignificant to knowledge the deep tectonic background of strong earthquake and seismogenicmechanism, but also play a very important role in earthquake hazard estimation and earthquakeprevent…