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Dynamical systems with nonlinear damping show interesting behavior in the periodic and chaotic phases. The Froude pendulum
with cubical and linear damping is a paradigm for such a system. In this work the driven Froude pendulum is studied by the
harmonic balancing method; the resulting nonlinear response curves are studied further for resonance and stability of symmetric
oscillations with relatively low damping. The stability analysis is carried out by transforming the system of equations to
the linear Mathieu equation. 相似文献
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Subodh R Shenoy 《Pramana》2002,58(2):385-397
We obtain the dynamics in number and phase difference, for Bose condensates that tunnel between two wells of a double-well
atomic trap, using the (nonlinear) Gross-Pitaevskii equation. The dynamical equations are of the canonical form for the two
conjugate variables, and the Hamiltonian corresponds to that of a momentum-shortened pendulum, supporting a richer set of tunneling oscillation modes than for a superconductor Josephson junction, that has a
fixed-length pendulum as a mechanical model. Novel modes include ‘inverted pendulum’ oscillations with an average angle of
π; and oscillations about a self-maintained population imbalance that we term ‘macroscopic quantum self-trapping’. Other systems
with this phase-number nonlinear dynamics include two-component (interconverting) condensates in a single harmonic trap, and
He3B superfluids in two containers connected by micropores. 相似文献
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针对带有电荷的弹簧摆施加在竖直方向的匀强磁场的背景下,通过牛顿力学的方法得到了其运动学方程,从而发现其摆动平面在不停的进行旋转.同时按照初始条件的不同,将其在水平方向上的运动学方程化简为不同的曲线方程,进而得到了其运动的轨迹特征. 相似文献
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介绍一种傅科摆模拟演示装置.该装置具有体积小、操作方便、演示效果显著、演示时间短、摆振动平面的偏转周期可人为控制以及对摆锤的运动轨迹可作永久记录等优点. 相似文献
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E-measure混沌摆的数学解析与运动方程 总被引:1,自引:1,他引:0
首先阐述了混沌摆的科学描述;其次对混沌摆进行了数学解析,分析了瞬衰解和稳态解的作用;然后构建了混沌摆的运动方程。得到了E-measure混沌摆实验必须满足的两个前提条件;加深了对混沌现象的深入了解。 相似文献
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转子耦合摆系统广泛应用于航空动力装置、矿业筛分机械和并联机器人等高速旋转设备.但是对转子耦合摆系统同步行为(稳定相位差值)研究甚少,系统同步行为通常影响系统的工作执行精度.基于这一特殊背景,提出了转子与摆耦合系统的简化物理模型.利用庞加莱法研究转子耦合摆系统的同步问题,进一步揭示了该类系统同步现象的本质机理.首先运用拉格朗日方程建立了转子同向和反向旋转的系统动力方程,随后将系统动力方程转换为无量纲方程.然后利用拉普拉斯法对无量纲方程解耦,计算出了系统各个自由度的近似稳态响应解.继而采用庞加莱法导出了系统实现同步的平衡方程和稳定准则.只有系统的物理参数同时满足系统同步平衡方程和稳定准则时,系统才能实现稳定的同步行为.通过理论研究发现,系统的同步行为主要受弹簧刚度、摆杆安装倾角和转子旋转方向的影响.同时系统同步"临界点"会造成相位差角无解,导致系统动态特性表现为混沌.最后,使用计算机模拟验证了理论计算的正确性,两者的结果相符. 相似文献
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The two-timing dynamics of a forced, weakly nonlinear system are considered. Experimental results on a roll-forced spherical pendulum verify the occurrence of slow-time, subharmonically and chaotically modulated oscillations in a frequency band near resonance; the modulatory behavior follows the occurrence of a Hopf bifurcation in the slow-time coordinates. A phase-sensitive detection method for experimentally isolating the slow-time behavior is described. A Lagrangian model for the pendulum is developed, and slow-time equations are presented. A two-thirds power scalling law relating roll angle to the appearance of the modulations is derived from the slow-time equations and tested with experimental results. 相似文献
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用三线摆对刚体薄圆盘绕不同轴转动时的转动惯量进行测量,通过实验与数据分析,验证了反映刚体转动惯量重要性质的垂直轴定理,从而实现了对刚体转动惯量实验内容的扩充. 相似文献
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Determination of the thermal noise limit in test of weak equivalence principle with a rotating torsion pendulum 下载免费PDF全文
Thermal noise is one of the most fundamental limits to the sensitivity in weak equivalence principle test with a rotating torsion pendulum. Velocity damping and internal damping are two of many contributions at the thermal noise, and which one mainly limits the torsion pendulum in low frequency is difficult to be verified by experiment. Based on the conventional method of fast Fourier transform, we propose a developed method to determine the thermal noise limit and then obtain the precise power spectrum density of the pendulum motion signal. The experiment result verifies that the thermal noise is mainly contributed by the internal damping in the fiber in the low frequency torsion pendulum experiment with a high vacuum. Quantitative data analysis shows that the basic noise level in the experiment is about one to two times of the theoretical value of internal damping thermal noise. 相似文献
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介绍一种组合式摆动实验仪,它可以将三线摆、两线摆、扭摆和单摆这四种实验仪器巧妙组合在一起,成为一种新的实验仪,具有一台实验仪测量多种摆动的功能,可以实现多种物理量的测量以及对不同摆动规律的研究,有效节约购置仪器成本。 相似文献
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依据非线性动力学混沌理论,采用受外力驱动的转动马达装置,依托PASCO系统的数据采集软件,开发了适应大学物理实验的受外力驱动的混沌摆实验。探讨了新型基于外力驱动的混沌摆实验仪在研究混沌效用上的应用,实验发现利用该装置可以直观的研究系统的初值敏感性,奇异子现象等,操作简单、直观、灵敏度高,实验除了具有实际应用价值外,同时适合在高等学校大学物理基础实验中开设出相应的实验教学内容。 相似文献
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R. J. Wiltshire 《General Relativity and Gravitation》2012,44(4):941-957
The Kerr solution for empty space-time is presented in an ellipsoidally symmetric coordinate system and it is used to produce
generalised ellipsoidal metrics appropriate for the generation of rotating interior solutions of Einstein’s equations. It
is shown that these solutions are the familiar static perfect fluid cases commonly derived in curvature coordinates but now
endowed with rotation. These are also shown to be potential fluid sources for not only Kerr but also Kerr-de Sitter empty
space-time. The approach is further discussed in the context of T-solutions of Einstein’s equations and the vacuum T-solution
outside a rotating source is presented. The interior source for these solutions is shown not to be a perfect fluid but rather
an anisotropic three component perfect fluid for which the energy momentum tensor is derived. The Schwarzschild interior solution
is given as an example of the approach. 相似文献
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