The existence of a chaotic region due to the overlap of secular resonances ν5 and ν6     

M. Šidlichovský 《Celestial Mechanics and Dynamical Astronomy》1990,49(2):177-196

A nonlinear theory of secular resonances is developed. Both terms corresponding to secular resonances ₅ and ₆ are taken into account in the Hamiltonian. The simple overlap criterion is applied and the condition for the overlap of these resonances is found. It is shown that in given approximation the value p = (1 - e²)^1/2(1 - cosI) is an integral of motion, where the mean eccentricity e and mean inclination I are obtained by eliminating short-period perturbations as well as the nonresonant terms from the planets. The overlap criterion yields a critical value of parameter p depending on the semi-major axis a of the asteroid. For p greater than the critical value, resonance overlap occurs and chaotic motion has to be expected. A mapping is presented for fast calculation of the trajectories. The results are illustrated by level curves in surfaces of section method.  相似文献   

波浪作用下中上层浮鱼礁动力响应数值模型建立方法     

潘昀  刘灿  杨熙  施圣钤  沈良朵  桂福坤 《海洋工程》2020,38(5):61-70

人工浮鱼礁型式多样，适应水深范围广，优化锚泊方式可规模化建设浮鱼礁群，是海洋中上层生境构建的重要手段。中上层浮鱼礁投放于近海，属于海岸工程范畴，抗浪性能是其结构设计的关键。根据有限单元法和集中质量点法，详细阐述和推导了中上层浮鱼礁各构成组件连接位置处点或单元的相互耦合受力和运动处理方法，以及浮鱼礁出水条件的判别方法和水质点速度、加速度的修正方法。建立的波浪作用下三维浮鱼礁动力响应数值模型与其在波浪水槽中的物理模型试验对比，验证了数值模型的正确性。最后建立了一种新型锚泊方式的浮鱼礁动力响应数值模型，分析了浮鱼礁摆动角度、锚绳拉力、网衣系缚点总拉力的历时变化。研究结果可为中上层浮鱼礁优化结构形状和搭配浮体、配重提供判断依据。  相似文献   

3. Hydrometry     

DANIEL SCHERTZER  IOULIA TCHIGUIRINSKAIA  SHAUN LOVEJOY  PIERRE HUBERT  HOCINE BENDJOUDI  MICHELE LARCHEVÊQUE 《水文科学杂志》2013,58(1):139-148

Abstract

The derived model achieves the rainfall/discharge conversion by means of two individual equations, namely, a production function and a modulation function.  相似文献   

混沌系统的变结构同步控制     

李自强  唐功友  李娟 《中国海洋大学学报(自然科学版)》2009,39(3)

研究Lorenz混沌系统的同步控制问题,提出1种在多输入的情况下实现混沌同步的变结构控制算法.利用该算法设计的变结构同步控制律使得同步误差系统的运动在切换面上成为渐近稳定的滑动模态,从而较快的实现了混沌同步.通过对 Lorenz 混沌系统的理论分析和数值仿真,说明了该变结构同步控制策略的实用性和有效性.  相似文献   

塔里木盆地塔河油田奥陶系古风化壳储集体形成演化   总被引：2，自引：0，他引：2  

贾振远  蔡忠贤  徐微 《现代地质》2010,24(6)

塔河油田奥陶系古风化壳储集体是阿克库勒鼻状凸起长期抬升暴露并经过长达118 Ma风化剥蚀而成。塔河地区的抬升是与周边天山、塔里木地块的多期古构造运动密切相关,该区曾经历加里东中晚期、海西期运动等8次(幕)运动。地壳的不断抬升变化,使塔河地区经过多种溶蚀作用,包括地表径流溶蚀作用、渗流溶蚀作用、潜流溶蚀作用、海岸带的混合水溶蚀和局部深处热水的溶蚀作用,从而形成多期叠加的混沌网络溶洞系统。溶洞发育程度受控于基岩颗粒灰岩的溶蚀程度、古构造运动的抬升作用、各种方式的溶蚀作用以及受溶蚀时期长短等。  相似文献   

黑河日径流量混沌变化特性的研究—Ⅱ相空间嵌入维数的确定     

陈引锋  李继伟 《地下水》2010,32(6):143-144

通过对黑河日径流量变化规律的探索,重点论述相空间嵌入维数的确定方法。计算结果表明：黑河日径流量时间序列的关联维数为2.1,是低维分数;另外,采用饱和关联积分法,得到黑河日径流量序列的嵌入维数为9。  相似文献   

Nonlinear Dynamic Behavior of Moored Buoy Excited by Free Surface Waves     

常宗瑜  徐长密  李华军  唐原广  张喜超 《中国海洋工程》2009,23(3):585-592

In this paper, studied are the dynamics of a moored buoy near the surface subjected to wave excitation. According to the physical structure, submersible buoy moored by tethered line is modeled firstly. Then from the differential equations, the natural frequencies are estimated by neglecting the coupling between tangential and normal direction. By use of numerical integration method, solutions are obtained. On this basis, strange attractors and bifurcation phenomena are obtained by applying Poincare map, pha...  相似文献   

A Map for a Group of Resonant Cases in a quartic Galactic Hamiltonian     

N. D. Caranicolas 《Journal of Astrophysics and Astronomy》2001,22(4):309-319

We present a map for the study of resonant motion in a potential made up of two harmonic oscillators with quartic perturbing terms. This potential can be considered to describe motion in the central parts of non-rotating elliptical galaxies. The map is based on the averaged Hamiltonian. Adding on a semi-empirical basis suitable terms in the unperturbed averaged Hamiltonian, corresponding to the 1:1 resonant case, we are able to construct a map describing motion in several resonant cases. The map is used in order to find thex − p _x Poincare phase plane for each resonance. Comparing the results of the map, with those obtained by numerical integration of the equation of motion, we observe, that the map describes satisfactorily the broad features of orbits in all studied cases for regular motion. There are cases where the map describes satisfactorily the properties of the chaotic orbits as well.  相似文献   

Stellar Motions in Galactic Satellites     

Juan C. Muzzio  M. Marcela Vergne  Felipe C. Wachlin  Daniel D. Carpintero 《Celestial Mechanics and Dynamical Astronomy》2001,81(1-2):167-176

The study of the motions of the stars that belong to a galactic satellite (i.e. a globular cluster or a dwarf galaxy orbiting a larger one) has some similarities, as well as significant differences, with that of the restricted three-body problem of celestial mechanics. The high percentage of chaotic orbits present in some models is of particular interest because it rises, on the one hand, the question of the origin of those chaotic motions and, on the other hand, the question of whether an equilibrium stellar system can be built when the bulk of the stars that make it up behave chaotically.  相似文献   

On the successive elimination of perturbation harmonics     

Alessandro Morbidelli 《Celestial Mechanics and Dynamical Astronomy》1993,55(2):101-130

  相似文献