解算液核自由章动常数Akpem>-Btkem>方法及其结果

地球液核旋转产生近周日晃动（NDFW）．利用周日波的液核共振效应解算液核自由章动（FCN）常数是液核研究的一个方面．1987年以来一些国家的学者相继开展了由潮汐资料解算FCN常数的研究,他们基本上都采用了5个周日波参与解算的迭积法(stackingmethod)．本文提出了一种有直观几何意义的Akp-Btk方法,仅用信噪比最高的3个周日波就可完成FCN常数的解算,并选用3个超导重力台站Cantley（北美洲）、武汉（亚洲）和布鲁塞尔（欧洲）的资料进行计算．解算的液核自由章动常数（TFCN和Q）与VLBI的观测结果基本一致,这在十几年来尚属首次．      

基于修正πHW变分的板非协调动态有限元法

本文本文讨论了基于修正πＨＷ变分的杂交应变板弯曲非协调动态有限元的分析列式,建立了四节点单元,进行了特征分析。算例表明,该单元是简单、有效的。     

基于修正πHW变分有限元板分析列式

本文讨论了基于修正πＨＷ变分的杂交应变板弯曲单元的分析模式，考察了该单元的数值性能，并分析了薄板自锁问题和板的振动问题。     

液核地球模型的自由摆动

一、引言 Poincaré模型是一个理想化的地球模型,在刚体外壳（代表地壳和地幔）内装有一个非粘滞性的、不可压缩的、匀质的扁球状液核。刚壳和液核之间是通过惯性耦合扭矩而产生相互作用的。     

液核地球模型的自由摆动

一、引言 Poincaré模型是一个理想化的地球模型,在刚体外壳（代表地壳和地幔）内装有一个非粘滞性的、不可压缩的、匀质的扁球状液核。刚壳和液核之间是通过惯性耦合扭矩而产生相互作用的。     

解算液核自由章动常数的三频谱线法

地球液核自由章动(FCN)常数是比较重要的地球物理参数. Sosao等人, Wahr和 Bergen等人给出了FCN常数的理论估值. Gwinn等人首先利用甚长基线干涉测量获得FCN常数的观测值, 同年Neuberg等人开始采用重力潮汐观测资料解算FCN常数, 并引入了此后进行类似研究的学者所普遍采用的迭积法, 其他学者的研究都基本与Neuberg等人的结果相似, 但其结果与VLBI的观测结果不吻合, FCN常数的观测值一时无定论. 现提出了有直观地球物理意义的三频谱线法, 采用3个超导重力台站的资料进行解算, 获得的FCN常数与VLBI的观测基本吻合, 这对于确定FCN常数的观测值具有较重要意义.     

三维变分资料同化中的非线性平衡约束

在三维变分资料同化的许多应用中, 平衡约束都是通过背景误差协方差矩阵B来考虑的: 首先, 要定义模式变量非平衡部分的背景误差协方差矩阵B(u)(一个块对角矩阵); 其次, 要定义一个把非平衡部分变换到模式变量的平衡算子, 再用B =KB(u)K ^T来构造B . 这种形式只适用于那些线性或线性化的平衡约束. 许多实际应用中需要考虑非线性平衡约束, 比如海洋资料同化中的温盐关系. 我们在线性形式的基础上, 导出了几种可以推广到非线性的形式, 提出了在三维变分同化中考虑非线性平衡约束的方案. 利用提出的方案, 进行了从海面动力高度来估计温、盐的资料同化数值试验. 结果表明, 考虑非线性平衡约束的方案比不考虑非线性平衡约束的方案对结果有很大改善.     

非保守弹性动力系统两类变量的广义拟变分原理及其应用

按照广义力和广义位移之间的对应关系,将弹性动力学的各基本方程分别乘上相应的虚量,然后在相应的体积域和面积域上积分,将积分式代数相加,再将代数和在时间域上积分,代入本构关系,并考虑到体积力和面积力均为伴生力,进而建立了非保守弹性动力系统的第1类两类变量的广义拟变分原理;再应用类似的方法,通过代入另一类本构关系,建立了非保守弹性动力系统的第2类两类变量广义拟变分原理.应用第1类两类变量广义拟余能原理给出同时求解1个典型的非保守弹性动力系统的固有频率、变形和内力的计算方法.最后,讨论了有关问题.     

液核地球的周日固体潮响应

本文研究了液核地球对日月引潮力位球谐函数项的变形响应,即周日固体潮。作为数值结果,计算了1066A地球模型的周日潮汐勒夫数。所建立的周日固体潮理论模型改进了Molodensky液核动力学理论模型。为了比较两者之间的差异,还根据Molodensky理论模型计算了1066A地球模型的周日潮汐勒夫数。     

电离层掩星反演的变分同化方法

电离层掩星数据反演的传统方法是Abel反演法及其改进方法,而实际电离层的非球对称给电离层电子密度反演带来误差.本文研究了在气象领域广泛应用的变分同化方法在掩星数据反演电离层电子密度廓线的可行性,利用IRI和Nequiek模型模拟掩星真值场和背景场进行数值模拟反演,并与Abel反演法反演结果进行对比.结果表明,变分同化反演方法能够有效综合模式和观测数据,使得反演结果精度较高;与Abel反演法相比,反演的电子密度廓线F2层峰值浓度误差在10％以下,而Abel反演法在20％～30％之间;而且变分同化反演法对误差扰动有较好的过滤性,因此实用性较强.     

Earth''''s deformation due to the dynamical perturbations of the fluid outer core

Introduction The fluid outer core separates the solid inner core from the solid elastic mantle, and as a result, makes the free and forced movement of this mechanical system more complicated and profuse. As the elastic mantle, the free oscillations may occur within the Earths fluid outer core (FOC) due to excitation of a strong and deep earthquake (Crossley, 1975b; Friedlander, Siegmann, 1982; Shen, 1983; Friedlander, 1985). However, compared with the oscillations of the elastic mantle, i…     

Earth’s deformation due to the dynamical perturbations of the fluid outer core

The elasto-gravitational deformation response of the Earth’s solid parts to the perturbations of the pressure and gravity on the core-mantle boundary (CMB) and the solid inner core boundary (ICB), due to the dynamical behaviors of the fluid outer core (FOC), is discussed. The internal load Love numbers, which are formulized in a general form in this study, are employed to describe the Earth’s deformation. The preliminary reference Earth model (PREM) is used as an example to calculate the internal load Love numbers on the Earth’s surface, CMB and ICB, respectively. The characteristics of the Earth’s deformation variation with the depth and the perturbation periods on the boundaries of the FOC are also investigated. The numerical results indicate that the internal load Love numbers decrease quickly with the increasing degree of the spherical harmonics of the displacement and depend strongly on the perturbation frequencies, especially on the high frequencies. The results, obtained in this work, can be used to construct the boundary conditions for the core dynamics of the long-period oscillations of the Earth’s fluid outer core. Foundation item: State Natural Science Foundation of China (40174022 and 49925411) and the Projects from Chinese Academy of Sciences (KZCX2-106 and KZ952-J1-411).     

The Co-seismic Response of Underground Fluid in Yunnan to the Nepal MS8.1 Earthquake

In this paper, statistics are taken on the co-seismic response of underground fluid in Yunnan to the Nepal M_S8.1 earthquake, and the co-seismic response characteristics of the water level and water temperature are analyzed and summarized with the digital data. The results show that the Nepal M_S8.1 earthquake had greater impact on the Yunnan region, and the macro and micro dynamics of fluids showed significant co-seismic response. The earthquake recording capacity of water level and temperature measurement is significantly higher than that of water radon and water quality to this large earthquake; the maximum amplitude and duration of co-seismic response of water level and water temperature vary greatly in different wells. The changing forms are dominated by fluctuation and step rise in water level, and a rising or falling restoration in water temperature. From the records of the main shock and the maximum strong aftershock,we can see that the greater magnitude of earthquake, the higher ratio of the occurrence of co-seismic response, and in the same well, the larger the response amplitude, as well as the longer the duration. The amplitude and duration of co-seismic response recorded by different instruments in a same well are different.Water temperature co-seismic response almost occurred in wells with water level response, indicating that the well water level and water temperature are closely related in co-seismic response, and the well water temperature seismic response was caused mainly by well water level seismic response.