非轴对称条件下用三维模式匹配法计算电阻率测井响应

采用模式匹配法研究了非轴对称条件下普通电阻率测井响应.根据非轴对称的地层模型,建立了新型的坐标系,确定在井轴与地层法线所形成的XOY平面上用数值方法,与此面垂直的方向上用解析方法.在XOY平面上的数值分析中,构建了广义特征值问题;在Z轴方向的解析部分中,人为地划分了一些介质层,并根据电磁场在层界面的连续性条件,推导出了各层之间场量的传递关系,从而摒弃了传统上二维模式匹配法中的复杂的反射阵和透射阵理论,完成了三维模式匹配理论.多种地层模型的数值结果对比表明,该方法在轴对称条件下的计算结果和二维模式匹配法的计算结果具有很好的一致性.此外,应用此算法还研究了倾斜地层等各种非轴对称的地层模型电阻率测井响应,系统地考察了井斜角对普通电阻率测井响应的影响.     

弹性板块运动模型研究进展

传统板块构造理论认为板块是一个刚体,实际上板块是可变形的.板块内部几年到几十年时间尺度的变形主要是弹性变形,因此应当用弹性模型描述板块运动.推导了板块的弹性运动方程,由空间大地测量新的观测成果建立了菲律宾海、太平洋和澳大利亚板块的弹性运动模型.发现三个板块内部都存在明显的水平形变.板内应变场的空间变化有明显的规律：板块边界附近的应变率最大,从边界向内部逐渐减小;在板块扩散边界附近,主张应变率大于主压应变率,主张应变轴基本上与边界的扩张方向一致;在俯冲边界附近,主压应变率大于主张应变率,主压应变轴基本上与板块的俯冲方向一致;在走滑兼有俯冲性质的边界附近,最大剪应变的方向与边界断裂的走向基本一致.由GPS观测得到的主压应变轴与由震源机制解得到的主压应力轴方向具有很好的一致性.板内的应力－应变场基本上遵循广义胡克定律.     

Influence of structural parameters on dynamic characteristics and wind-induced buffeting responses of a super-long-span cable-stayed bridge

A 3D finite element (FE) model for the Sutong cable-stayed bridge (SCB) is established based on ANSYS. The dynamic characteristics of the bridge are analyzed using a subspace iteration method. Based on recorded wind data, the measured spectra expression is presented using the nonlinear least-squares regression method. Turbulent winds at the bridge site are simulated based on the spectral representation method and the FFT technique. The influence of some key structural parameters and measures on the dynamic characteristics of the bridge are investigated. These parameters include dead load intensity, as well as vertical, lateral and torsional stiffness of the steel box girder. In addition, the influence of elastic stiffness of the connection device employed between the towers and the girder on the vibration mode of the steel box girder is investigated. The analysis shows that all of the vertical, lateral and torsional buffeting displacement responses reduce gradually as the dead load intensity increases. The dynamic characteristics and the structural buffeting displacement response of the SCB are only slightly affected by the vertical and torsional stiffness of the steel box girder, and the lateral and torsional buffeting displacement responses reduce gradually as the lateral stiffness increases. These results provide a reference for dynamic analysis and design of super-long-span cable-stayed bridges.     

济宁矿区BJ-54至WGS-84坐标转换模型改进及精度分析

坐标转换是GPS技术在大地测量中应用的重要内容。在用局部区域的GPS控制网数据处理求解三维坐标转换模型的转换参数时,平移参数病态问题比较严重。在介绍布尔萨模型的基础上,提出了一种改进方案,并结合济宁矿区坐标转换数据对布尔萨模型和改进模型所求七参数进行了精度分析。分析表明：该改进模型能有效改善病态问题,也对现在地方坐标系向2000国家大地坐标系进行转化提供了一个方法,具有一定的实用价值。     

TIME-HARMONIC VIBRATION OF AN INCOMPRESSIBLE LINEARLY NON-HOMOGENEOUS HALF-SPACE

In this paper, time-harmonic axisymmetric vibration of an incompressible viscoelastic half-space having shear modulus linearly increasing with depth is studied. The half-space is subjected to a vertical time-harmonic load on its surface. Numerical results concerning surface displacements due to a point force are given for the case of non-zero shear modulus at the surface. Hankel's transforms of the solutions have an infinite number of poles lying on the real axis of the complex plane in the non-dissipative case. A suitable contour of integration is used to avoid all the singularities. Calculations are performed for the dynamic as well as for the static case. In addition, vertical vibrations of a rigid disk on the considered half-space are investigated, and the influence of the non-homogeneity on the dynamic stiffness of the loaded area is demonstrated.     

城市规划管理统一信息平台

针对目前规划业务的现状,提出建设规划统一信息平台的必要性,整合已有系统资源,解决纵横两个规划方面的问题,并列出建设统一信息平台必需的技术要素。     

Vertical stability of periodic solutions around the triangular equilibrium points

The vertical stability character of the families of short and long period solutions around the triangular equilibrium points of the restricted three-body problem is examined. For three values of the mass parameter less than equal to the critical value of Routh (μ _R ) i.e. for μ = 0.000953875 (Sun-Jupiter), μ = 0.01215 (Earth-Moon) and μ = μ _R = 0.038521, it is found that all such solutions are vertically stable. For μ > (μ _R ) vertical stability is studied for a number of ‘limiting’ orbits extended to μ = 0.45. The last limiting orbit computed by Deprit for μ = 0.044 is continued to a family of periodic orbits into which the well known families of long and short period solutions merge. The stability characteristics of this family are also studied.     

Atmospheric Eclipses in Wr+o Binaries: From Kopal and Shapley to Present Days

Kopal and Shapley (1946) were the first to suggest to solve an integral equation for interpretation of atmospheric eclipses in WR+O binary systems. In our studies, this idea was developed in two ways: solution of two integral equations; development of efficient methods of solution of ill-posed problems. Application of the new method to the interpretation of the light curve of the WN5+O6 eclipsing binary V444 Cyg allowed us to determine the radius and the temperature of the WN5 star core. Some astrophysical applications of these results are presented.