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通过对一种弹簧摆问题的动力学方程的研究,得到它的运动规律.然后借助GeoGebra软件对不同参数下的弹簧摆进行了数值模拟,得到其运动轨迹图像,从而直观地研究了弹簧摆运动. 相似文献
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《物理学报》2016,(20)
在许多精密科学实验和测试中,对地面垂直振动的有效隔离影响着实验结果和测试结果的精度.本文提出一种全新的两级摆杆结构的超低频垂直隔振系统,在原理分析的基础上,设计并实现了该系统的样机.两根水平摆杆放置在同一竖直平面,绕各自铰链旋转,上摆杆通过普通弹簧悬挂于基座,下摆杆通过零长弹簧悬挂于上摆杆.系统通过光电探测方法检测两根摆杆的夹角作为误差信号,经过闭环控制将反馈力作用于上摆杆,使两根摆杆的夹角为零.零长弹簧悬挂点的位置与系统刚度有着密切关系,通过精细地调节弹簧悬挂点的位置,合理地设置控制参数,可以实现一个本征频率低至0.01 Hz的系统.理论上,该系统相对于被动式垂直隔振系统具有更好的隔振效果和抗干扰能力,相对于传统的主动式垂直隔振系统体积更小,结构更简单,有望应用于精密物理实验和科学研究当中. 相似文献
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分析了常见物体运动微分方程的建立过程以及利用科学软件对方程数值求解的技术基础,对撒克逊碗、磁场中的弹簧摆和三摆混沌系统进行了数值求解和分析讨论,给出了解决这类问题的一般思路和方法步骤. 相似文献
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非线性振动、非线性波与Jacobi椭圆函数(续) 总被引:1,自引:1,他引:0
5 正弦戈登方程、扭结、反扭结波、呼吸孤立波正弦戈登方程 (sing -Gordon方程 ,简记为SG方程 )φxx- φtt=sin φ (38)是自然科学和应用科学中出现的另一个重要的非线性发展方程 (演化方程 ) .在晶体位错的传播、磁旋波在铁磁材料中的传播、约瑟夫森 (Josephson)结中继传输线等乃至生物物理的诸多问题中都应用了这一方程 .本文从单摆弹簧链模型这一特例引入SG方程 .考虑如图 3所示的N个相连弹簧 -单摆运动方程 (称为单摆弹簧链 ) .N个单摆悬挂在横置的诸弹簧上 ,每个摆的长度和质量均相同 ,每个螺旋弹簧的长度和劲度系数也相同 ,则第i… 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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In this paper, we give a controlled two-degree-of-freedom (TDOF) vibro-impact system based on the damping control law, and then investigate the dynamical behaviour of this system. According to numerical simulation, we find that this control scheme can suppress chaos to periodic orbit successfully. Furthermore, the feasibility and the robustness of the controller are confirmed, separately. We also find that this scheme cannot only suppress chaos, but also generate chaos in this system. 相似文献
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提出一个受控的量子确定性安全通信方案,在通信过程中,纠缠GHZ态用作量子信道,秘密信息的编码和破解是通过受控的量子纠缠交换和局域酉变换实现的.此方案是安全的.关于此方案安全性的证明和两步方案[Phys.Rev.A 68 042317]的安全性是一样的.此方案也可以推广到有多方控制者参与的情形. 相似文献
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E. Brion D. Comparat G. Harel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):381-387
We present a demonstrative application of the nonholonomic control method to a real physical system composed of two cold Cesium
atoms. In particular, we show how to implement a CNOT quantum gate in this system by means of a controlled Stark field. 相似文献
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《Photonics and Nanostructures》2009,7(1):47-55
We propose a scheme to realize controlled phase-flip gate between two single photons through a single quantum dot (QD) in a slow-light photonic crystal (PhC) waveguide. Enhanced Purcell factor and large β-factor lead to high gate fidelity over broadband frequencies compared to cavity-assisted system. The excellent physical integration of this PhC waveguide system provides tremendous potential for large-scale quantum information processing. Then we generalize to a multi-atom controlled phase-flip gate based on waveguide system in Sagnac interferometer. Through the Sagnac interferometer, the single photon adds the phase-flip operation on the atomic state without changing the photonic state. The controlled phase-flip gate on the atoms can be successfully constructed with high fidelity in one step, even without detecting the photon. 相似文献
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《Physica A》2004,331(1-2):140-172
We propose an information-theoretic framework for analyzing control systems based on the close relationship of controllers to communication channels. A communication channel takes an input state and transforms it into an output state. A controller, similarly, takes the initial state of a system to be controlled and transforms it into a target state. In this sense, a controller can be thought of as an actuation channel that acts on inputs to produce desired outputs. In this transformation process, two different control strategies can be adopted: (i) the controller applies an actuation dynamics that is independent of the state of the system to be controlled (open-loop control); or (ii) the controller enacts an actuation dynamics that is based on some information about the state of the controlled system (closed-loop control). Using this communication channel model of control, we provide necessary and sufficient conditions for a system to be perfectly controllable and perfectly observable in terms of information and entropy. In addition, we derive a quantitative trade-off between the amount of information gathered by a closed-loop controller and its relative performance advantage over an open-loop controller in stabilizing a system. This work supplements earlier results (Phys. Rev. Lett. 84 (2000) 1156) by providing new derivations of the advantage afforded by closed-loop control and by proposing an information-based optimality criterion for control systems. New applications of this approach pertaining to proportional controllers, and the control of chaotic maps are also presented. 相似文献
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Das R Kumar SK Kumar A 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,177(2):318-328
Geometric phases have stimulated researchers for its potential applications in many areas of science. One of them is fault-tolerant quantum computation. A preliminary requisite of quantum computation is the implementation of controlled dynamics of qubits. In controlled dynamics, one qubit undergoes coherent evolution and acquires appropriate phase, depending on the state of other qubits. If the evolution is geometric, then the phase acquired depend only on the geometry of the path executed, and is robust against certain types of error. This phenomenon leads to an inherently fault-tolerant quantum computation. Here we suggest a technique of using non-adiabatic geometric phase for quantum computation, using selective excitation. In a two-qubit system, we selectively evolve a suitable subsystem where the control qubit is in state |1, through a closed circuit. By this evolution, the target qubit gains a phase controlled by the state of the control qubit. Using the non-adiabatic geometric phase we demonstrate implementation of Deutsch-Jozsa algorithm and Grover's search algorithm in a two-qubit system. 相似文献
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Zhisheng Lin Rongyo Chang Haitau Lin Chuhua Pan Yuliang Long 《International Journal of Infrared and Millimeter Waves》1998,19(3):569-584
An automatic slotted line system controlled with the micro-computer IBM 80486 which we have developed had been reported. In this paper, the measuring principles and the software designs of impedance, attenuation, phase shift and detection law of diode measurement to make use of this system will be described, some typical measurement results will be given. This method is adaptable for MM-Wave band and other Micro-wave band. 相似文献
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Our theoretical modelings and experimental observations illustrate that the equilibrium-state luminescence of electron-trapping materials (ETMs) can be controlled to produce either excitatory or inhibitory responses to the same optical stimulus. Because of this property, ETMs have a unique potential in optical realization of neurobiologically based parallel computations. As a classic example, we have controlled the equilibrium-state luminescence of a thin film of this stimulable storage phosphor to make it behave similarly to the receptive fields of sensory neurons in the mammalian visual system, which are responsible for early visual processing. 相似文献