关于中尺度对称运动的稳定性及其演变

本文首先建立了中尺度对称运动的Hamihon函数,并用变分原理导出了对称运动稳定的充分条件,然后再用Lagrange变分导出了缓变介质中对称运动的波作用量方程,这种波作用量方程与用WKB方法所得到的结果是相同的。同时,本文进一步讨论了中尺度对称扰动渡包的演变规律,并获得了对称运动发展的判据。     

Analytic continuation of quasi-periodic orbits from non-linear periodic modes

A new theory is formulated for the analytic continuation of quasi-periodic orbits from non-linear, periodic modes of a two degree-of-freedom system in rotating coordinates. Formal solutions of the equations of motion are developed in series expansions, with the non-linear modes as reference solutions. Conditions are determined on the existence and boundedness of the time-dependent coefficients of the velocity field. Boundedness properties of the orbits are specified by an orbit function derived from the Jacobi integral.     

Hamilton's equations of motion for non-conservative systems

This paper deals with the Hamilton equations of motion and non conservative forces. The paper will show how the Hamilton formalism may be expanded so that the auxiliary equations for any problem may be found in any set of canonical variables, regardless of the nature of the forces involved. Although the expansion does not bring us closer to an analytical solution of the problem, it's simplicity makes it worth noticing.The starting point is a conservative system (for instance a satellite orbiting an oblate planet) with a known Hamiltonian (K) and canonical variables {Q, P}. This system is placed under influence of a non-conservative force (for instance drag-force). The idea is then to use, as far as possible, the same definitions used in the conservative problem, in the process of finding the auxiliary equations for the perturbed system.     

Multiple resonance in one problem of the stability of the motion of a satellite relative to the center of mass

We investigate the stability of the periodic motion of a satellite, a rigid body, relative to the center of mass in a central Newtonian gravitational field in an elliptical orbit. The orbital eccentricity is assumed to be low. In a circular orbit, this periodic motion transforms into the well-known motion called hyperboloidal precession (the symmetry axis of the satellite occupies a fixed position in the plane perpendicular to the radius vector of the center of mass relative to the attractive center and describes a hyperboloidal surface in absolute space, with the satellite rotating around the symmetry axis at a constant angular velocity). We consider the case where the parameters of the problem are close to their values at which a multiple parametric resonance takes place (the frequencies of the small oscillations of the satellite’s symmetry axis are related by several second-order resonance relations). We have found the instability and stability regions in the first (linear) approximation at low eccentricities.     

太阳黑子运动引起的耀斑与活动区的耦合

利用紫台赣榆站太阳精细结构望远镜拍摄的色球和光球照片，研究了1990年11月6日至13日NOAA6361活动区的磁位形演化和耀斑产生区域，发现该活动区的活动主要集中在11日和12日两天还观测到新老活动区的碰撞耦合及耦合界面处小纤维（fibril）的快速变化，这些现象是由于前导黑子之一的p1黑子的连续几天的运动造成的．所有的活动也主要集中在P1黑子的周围．     

海～气耦合振荡的非绝热慢波

本文从大气能量平衡方程和海温变化方程出发,得到海～气耦合的多频振荡系统,分析此多频系统的特殊频率方程得到: 1)当大气视为非定常,海洋视为定常的情况下,得到的波动本质上是非绝热的Rossby波。 2)当大气定常,海洋非定常的情况下,得到两类性质相异的波动;一类是周期为准半年(4～9月)的非绝热慢波,另一类是周期为准两年(2～3年)的非绝热慢波;两类慢波的传播方向完全相反,准两年波比准半年波传播得更慢(两者几乎相差一个量级)。     

Mean values of particular functions in the elliptic motion

The mean values % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaamaalaaabaGaaGymaaqaaiaaikdacqaHapaCaaWaa8qCaeaacaGG% OaacbaGaa8NKbiabgkHiTiaadYgacaGGPaGaa8hiaiGacogacaGGVb% Gaai4Caiaa-bcacaWGRbGaa8NKbiaa-bcacaWGKbGaamiBaaWcbaGa% aGimaaqaaiaaikdacqaHapaCa0Gaey4kIipakiaa-bcacaqGHbGaae% OBaiaabsgacaWFGaWaaSaaaeaacaaIXaaabaGaaGOmaiabec8aWbaa% daWdXbqaaiaacIcacaWFsgGaeyOeI0IaamiBaiaacMcacaWFGaGaci% 4CaiaacMgacaGGUbGaa8hiaiaadUgacaWFsgGaa8hiaiaadsgacaWG% SbaaleaacaaIWaaabaGaaGOmaiabec8aWbqdcqGHRiI8aaaa!6BC2!\[\frac{1}{{2\pi }}\int\limits_0^{2\pi } {(f - l) \cos kf dl} {\rm{and}} \frac{1}{{2\pi }}\int\limits_0^{2\pi } {(f - l) \sin kf dl}\] (where f and l are respectively the true anomaly and the mean anomaly in the elliptic motion and k is an integer) are given in closed form.     

河外射电源光学对应体的“自行”和岁差常数

本文用有较长观测间隔的射电源光学对应体的光学观测结果，再次讨论了岁差常数值。由于现用岁差值的不精确，需把这些射电源光学对应体在不同历元的观测结果统一归化到共同参考系统Ｊ２０００．０，并对它们各自的参考星表都归化到ＦＫ５系统，即可得到这些源在ＦＫ５系统中的所谓“自行”．由所得“自行”对岁差常数的改正作了估计。本文还分别对４４颗源和２５颗源作了估算，其相应的岁差改正为－２．６７±１．３３ｍａｓ／年和－３．３１±１．６２ｍａｓ／年，将这些值和由新技术观测所得结果作了比较，两者之间符合得相当好。     

以基线长度变化率为约束估算VLBI站的垂直形变率

基于NNR-NUVEL-1A地球板块运动模型和ITRF2000地球参考架的三维VLBI站速度矢量,采用实测的VLBI基线长度变化率作为约束,重新估计了部分国际VLBI站的局部或区域性地壳的垂直形变,并与国际地球参考架ITRFs解和VLBI全球解GLB2003,VTRF2003和VTRF2005的结果进行了比较。结果表明,欧亚板块的URUMQI站和太平洋板块的KWAJAL26站,南极OHIGGINS站的垂直形变率、ITRFs解和VLBI全球解存在6-15mm/a的差异,北美YUMA站可能有15-31mm/a 的垂直形变率,而美国西部太平洋板块的San Francisco(PRESIDIO)站的垂直形变率还有待进一步的研究。此外,SC-VLBA,CRIMEA和EFLSBERG站的垂直形变率、ITRFs解和VLBI全球解的差约为1-6mm/a。用不同方法得到的VLBI站的水平形变率解有较好的一致性。     

Nonstationary frequency effect of the ground motion upon the strength levels of the shear type RC structures

In order to investigate the influence of nonstationary frequency content variations, nonlinear response analysis for origin-oriented type hysteretic model is carried out and results are presented by applying two different S_I and S_II ensembles with varied frequency contents. The theoretical background of strong motion simulation is explained briefly depending on frequency parameters of stiff soil data. Based on models and applying Monte-Carlo's simulation mean values and standard deviations of displacement ductility demands for both ensembles are calculated. Required strength levels are investigated in probabilistic sense adopting light and heavy (but controlled) damage criteria. It is concluded that the nonlinear behaviour of the structure is greatly influenced by the nonstationary frequency content deviations as being shown that larger strength requirements for the S_I type strong ground motion ensemble than the S_II, although both ensembles have almost the same acceleration response spectra.