交变电源作用下介观电感耦合电路中电荷与电流的量子涨落

利用量子厄米不变量理论,我们研究了交变电源作用下介观电感耦合电路的量子动力学,不仅得到了含时薛定谔方程的精确解,计算了电路中电荷与电流的量子涨落,同时也得到了介观电路的非绝热非循环几何相位的表达式.     

耦合互感电路初始值的确定

利用ｓ域０－系统,直接得出完全响应的象函数,取其拉普拉斯逆变换得到解析解,依据 语互感电路的初始值。     

非线性LC电路方程的显式精确行波解

理论上考察了具有耗散的非线性LC电路中的行波. 借助于作者最近发展的精确求解非线性偏微分方程的扩展的双曲函数方法解析地研究了模拟非线性电路中冲击波的四阶耗散非线性波动方程. 一致地获得了丰富的显式精确解析行波解, 包括精确冲击波解和奇异的行波解, 和三角函数有理形式的周期波解. 关键词： LC电路')" href="#">非线性LC电路 非线性耗散波动方程 冲击波 周期波     

基于Visua C＋＋的非线性电路实验模拟

在Visual C＋＋开发环境下,通过龙格库塔方法求解非线性电路微分方程组,得到数值解并模拟显示李萨茹图形。在相同线路参数下模拟结果与实验室实验中观察到的结果一致,同时模拟显示可以容易地得到稳定的X,Y方向上的输出波形。通过该模拟实验可以很好地观察研究非线性电路中的混沌现象。     

分段线性混沌电路的非光滑分岔分析

讨论了分段线性的电容混沌电路的动力学行为.由数值模拟得到了对称的周期解和混沌吸引子.通过引入广义Jacobian矩阵,以周期解为例,从理论上分析了系统由电容电量的分段线性而引起的非光滑分岔,并合理解释了系统动力学行为产生的机理及其演化规律,其结论与数值计算的结果大致符合.     

具有非线性控制的Chua电路的混沌同步

Chua电路是一个非光滑系统.本文通过广义哈密顿系统和观测器方法,将具有非线性控制的Chua电路的混沌同步问题转化成研究具有非线性控制的光滑系统的零解稳定性;进而利用滑模控制对该光滑系统的零解稳定性进行了研究,从而使得Chua电路达到了混沌同步.最后,将上述方法应用到具体系统,数值结果也表明其正确性.     

快Z箍缩物理过程的PSPICE电路模拟方法分析

 简单介绍了快Z箍缩概念和物理过程，以及Z箍缩物理过程不稳定性因素和简单分析。用PSPICE电路模拟方法解薄壳模型得到了箍缩时间、等离子体壳的速度、负载上的电流、电压变化规律等Z箍缩物理量。     

介观LC电路零状态响应的完全解

采用代数动力学规范变换方法,求出含时变电压源的介观LC电路量子态随时间演化算符的精确解.研究了介观LC电路的零状态响应问题,求出电荷与电流对输入电压信号的零状态响应的完全解,结果表明介观LC电路系统具有线性时不变特性,且电荷与电流的零状态响应与宏观LC电路的结果相同.     

基于非线性振荡和混沌分析的单相AC-DC变流电路的摄动解析

针对单相交直流全桥变流电路,推导出其在脉宽调制下的连续等效摄动解析模型.首先通过研究非线性振荡过程得到其连续微分方程,该方程含有控制参数和摄动参数.随后通过数学理论证明正则摄动方法能够求出其近似解.求解后对比PSCAD/EMTDC的仿真结果从而验证了解析的正确性.该方法在大规模计算中具有优势.最后分析了控制参数和摄动参数的物理意义,指出这两个参数能够影响变流器的工作状态,甚至引发倍周期混沌.该摄动建模方法不仅适用于单相变流电路,也适用于三相变流电路甚至多相变流电路.     

单周期控制三电平Boost功率因数校正变换器的慢尺度分岔分析

对单周期控制三电平Boost功率因数校正(PFC)变换器中存在的慢尺度分岔现象进行了研究, 基于Floquet乘子法分析了主要电路参数对系统稳定性的影响. 首先, 分析了该电路的工作原理, 并由输入输出功率平衡推导出电路的简化模型. 然后, 采用谐波平衡法求解出电路的周期解, 根据Floquet理论分析周期解的稳定性. 通过计算Floquet乘子, 分析了电路中电压反馈电阻R_vf 对系统慢尺度分岔行为的影响. 搭建电路仿真模型, 验证了简化模型及Floquet理论分析的正确性. 最后, 计算了电路中其他参数组成的稳定边界. 研究结果表明, 正确选择三电平Boost PFC变换器的电路参数对于其稳定运行, 提高输入侧功率因数具有重要意义.     

Flux control in networks of diffusion paths

A class of optimization problems in networks of intersecting diffusion domains of a special form of thin paths has been considered. The system of equations describing stationary solutions is equivalent to an electrical circuit built of intersecting conductors. The solution of an optimization problem has been obtained and extended to the analogous electrical circuit. The interest in this network arises from, among other applications, an application to wave-particle diffusion through resonant interactions in plasma.     

Non-smooth bifurcations in a double-scroll circuit with periodic excitation

The fast-slow effect can be observed in a typical non-smooth electric circuit with order gap between the natural frequency and the excitation frequency. Numerical simulations are employed to show complicated behaviours, especially different types of busting phenomena. The bifurcation mechanism for the bursting solutions is analysed by assuming the forms of the solutions and introducing the generalized Jacobian matrix at the non-smooth boundaries, which can also be used to account for the evolution of the complicated structures of the phase portraits with the variation of the parameter. Period-adding bifurcation has been explored through the computation of the eigenvalues related to the solutions. At the non-smooth boundaries the so-called `single crossing bifurcation' can occur, corresponding to the case where the eigenvalues jump only once across the imaginary axis, which leads the periodic burster to have a quasi-periodic oscillation.     

The premelt dynamics of an exploding conductor circuit

The system of nonlinear differential equations that model a simple exploding conductor circuit in its initial stages up to the melting point of the conductor is analyzed. Using the method of variation of parameters, approximate analytical solutions are derived that reflect the role of the circuit parameters and initial conditions in shaping the dynamics. A comparison with solutions obtained by numerical integration shows that the approximate solutions are quite accurate over the entire domain of validity of the mathematical model     

Theoretical Study of Millimeter Wave Harmonic Oscillator Stabilized with a Transmission Cavity

An equivalent circuit model of millimeter wave second harmonic oscillator stabilized with a transmission cavity has been proposed for constructing analytical formulations between performance parameters of the oscillator and parameters of the circuit. The model consists of an equivalent circuit of fundamental wave and that of second harmonic wave. Each of the circuits comprises circuit models of main cavity, transmission waveguide, and transmission cavity. Absorbing material placed between the transmission waveguide and the transmission cavity can suppress additional resonances originated from transmission cavity. The behavior of the second harmonic oscillator can be effectively described by the circuit model. Furthermore, based on this model, mechanical tuning characteristics have been studied at first, and then analytical formulas for quality factor and efficiency depending on circuit parameters have been derived. The circuit parameters can be conveniently extracted by electromagnetic field simulation. Hence the formulas exhibit both compact form and enough accuracy. Thereafter, general rules of performance parameters varying with circuit parameters have been deduced for the harmonic oscillators. Then some design considerations have been derived according to the corresponding analysis. The equivalent circuit model is useful for designing and adjusting millimeter wave second harmonic stabilizing oscillator with a transmission cavity.     

Simulation Investigation of Millimeter Wave Varactor-tuned Transmission Cavity-stabilized Oscillator

A new circuit configuration for millimeter wave varactor-tuned transmission cavity-stabilized oscillator has been proposed in this paper. Compared to conventional varactor-tuned reflection cavity-stabilized oscillator, in this configuration, a high quality factor transmission cavity directly coupled to varactor diode is employed to improve the performances of the oscillator. The operation frequency of this oscillator can be tuned by varying the resonant frequency of the transmission cavity through changing bias voltage of the varactor diode. An equivalent circuit model for the oscillator has been presented in order to theoretically investigate the performance characteristics of the oscillator. On the basis of this model, electrical tuning characteristics have been studied. Mode jumping phenomena during electrical tuning process have been analyzed for obtaining stable operations of the oscillator. The analytical formulae of quality factor and efficiency have been derived in terms of relevant circuit parameters. Particular emphasis has been paid on several circuit parameters which have a substantial impact on circuit performance. Some design considerations have been pointed out according to the simulation results, which are useful to the design and fabrication of this type of oscillators.     

基于protel DXP 2004的RLC电路仿真

用protel DXP 2004软件对RLC电路的暂态过程进行仿真实验分析,主要介绍了仿真电路的创建,并结合电路理论仿真了电路在欠阻尼、临界阻尼和过阻尼三种阻尼状态下的暂态过程。     

Sound absorption of a double-leaf micro-perforated panel with an air-back cavity and a rigid-back wall: Detailed analysis with a Helmholtz-Kirchhoff integral formulation

So far the electro-acoustical equivalent circuit analysis has been widely used to analyse micro-perforated panel (MPP) absorbers, however, as for the double-leaf MPP the equivalent circuit analysis inevitably includes an approximation. In this paper, the sound absorption characteristics of a double-leaf MPP absorber backed by a rigid wall are analysed by wave theory using Helmholtz-Kirchhoff integral formulation to obtain a strict solution. The present wave theory is experimentally validated with existing measured results. The theory is also compared with the equivalent circuit solutions so that the differences between the two theories appear and the effect of the approximation is clarified. The comparison shows that the difference mainly appears in the vicinity of the resonance peaks: the differences occur in the resonance frequencies and the absorption coefficient at frequencies between the two resonance peaks.     

Steady oscillatory states of a finite Josephson junction

Under the assumption that solutions have traveling-wave form, time-periodic solutions are found for the Josephson phase equation for a finite-length tunnel junction with uniform current feed and linear loss term. Exact current-voltage characteristics are found and compared with simple approximations. The complete current-velocity and mean-width-velocity curves for isolated fluxons are found. Comparison with characteristics for a finite junction shows that end effects obtained from analysis of a circuit model of the junction shows that end effects introduce lower- and upper-current thresholds.     

Circuit bounds on stochastic transport in the Lorenz equations

In turbulent Rayleigh–Bénard convection one seeks the relationship between the heat transport, captured by the Nusselt number, and the temperature drop across the convecting layer, captured by the Rayleigh number. In experiments, one measures the Nusselt number for a given Rayleigh number, and the question of how close that value is to the maximal transport is a key prediction of variational fluid mechanics in the form of an upper bound. The Lorenz equations have traditionally been studied as a simplified model of turbulent Rayleigh–Bénard convection, and hence it is natural to investigate their upper bounds, which has previously been done numerically and analytically, but they are not as easily accessible in an experimental context. Here we describe a specially built circuit that is the experimental analogue of the Lorenz equations and compare its output to the recently determined upper bounds of the stochastic Lorenz equations [1]. The circuit is substantially more efficient than computational solutions, and hence we can more easily examine the system. Because of offsets that appear naturally in the circuit, we are motivated to study unique bifurcation phenomena that arise as a result. Namely, for a given Rayleigh number, we find a reentrant behavior of the transport on noise amplitude and this varies with Rayleigh number passing from the homoclinic to the Hopf bifurcation.