Results 1 - 10 of 1673
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[en] The fundamental mode frequency of a magnetically insulated transmission line oscillator is investigated theoretically by the equivalent circuit method, and an exact theoretical formula about the fundamental mode frequency is given. The theoretical results are compared with the simulation and experimental results, which shows that the relative error, which is calculated according to the theoretical and simulation frequencies, is less than 3%, so the validity of the theoretical formula is verified.
[en] We review the present state of the study of fluxon motion in long Josephson junctions and their applications. We explain basic problems of the fluxon motion which we encounter in the case of quantitative comparison between theory and experiment. We describe the present state of experimental studies of the applications. (orig./BUD)
[en] In this paper, we present explicitly the equivalence of the time domain and frequency domain state feedbacks, as well as the dynamic state feedback and a modified frequency domain state feedback, from the closed-loop transfer function point of view. The difference of the two approaches is also shown
[en] Highlights: • Continuous-time system identification is applied in Lithium-ion battery modeling. • Continuous-time and discrete-time identification methods are compared in detail. • The instrumental variable method is employed to further improve the estimation. • Simulations and experiments validate the advantages of continuous-time methods. - Abstract: The modeling of Lithium-ion batteries usually utilizes discrete-time system identification methods to estimate parameters of discrete models. However, in real applications, there is a fundamental limitation of the discrete-time methods in dealing with sensitivity when the system is stiff and the storage resolutions are limited. To overcome this problem, this paper adopts direct continuous-time system identification methods to estimate the parameters of equivalent circuit models for Lithium-ion batteries. Compared with discrete-time system identification methods, the continuous-time system identification methods provide more accurate estimates to both fast and slow dynamics in battery systems and are less sensitive to disturbances. A case of a 2"n"d-order equivalent circuit model is studied which shows that the continuous-time estimates are more robust to high sampling rates, measurement noises and rounding errors. In addition, the estimation by the conventional continuous-time least squares method is further improved in the case of noisy output measurement by introducing the instrumental variable method. Simulation and experiment results validate the analysis and demonstrate the advantages of the continuous-time system identification methods in battery applications.
[en] A direct application of equivalent circuit concepts leads to: (1) confirmation of Perry Wilson's SLED (SLAC Linac Energy Doubler) equation; (2) an equation that applies to a SLED device with input and output waveguides of different characteristic impedances; and (3) an equation that results if we demand that no power be lost by reflection from SLED. If the incident voltage is tailored as prescribed by this equation, the cavity voltage tracks the incident voltage and the reflected voltage is zero
[en] We propose an all-graphene-dielectric tunable terahertz absorber composed of a graphene microstructure layer, a dielectric spacer layer and a metallic ground plane. The absorption performance and internal mechanism of the absorber have been comprehensively analyzed. When E f changes from 0 eV to 0.6 eV, the absorption peak changes from 0.48 THz to 1.579 THz. In addition, we present a novel equivalent circuit model to analyze the mechanism of the absorber. The numerical calculation results are basically consistent with the result of the equivalent circuit model. Our work provides a reference for the design and theoretical study of all-graphene terahertz devices. (paper)
[en] The component frequency dependences of total complex impedance are measured in 25÷10"6 Hz spectral region by impedance spectroscopy method and relaxation processes in TlGaSe_2 crystal before and after irradiation exposure by dose in 25 Mrad are investigated. The decrease of relaxation time in crystal after irradiation exposure is revealed. The obtained diagrams on complex plane (Z''-Z') are analyzed using the method of equivalent replacement circuits. It is shown that the phase transition takes place with system transition into superionic state after γ-irradiation.
[en] We study numerically the effect of the damping resistance on the characteristics of the SQUID, such as the V-Φ relation, the circulating current, the resonant current step and the noise characteristics. We also estimate the improvement of the coupling between the SQUID and the input coil when the present SQUID with large β is used. (orig./BUD)
[en] A DC-SQUID has been designed that allows the fabrication of a multichannel circuit in all-Nb single layer technology. By introducing a double loop layout with an ohmic shunt voltage-flux modulation has been obtained for a DC-SQUID with a loop area of 3 mm x 2.5 mm without a decrease in magnetic field sensitivity thus one period in the voltage-flux modulation curve corresponds to 3.4x10-10 T. The same induction can be applied to the SQUID by sending only 1 μA thorugh a close coupled thin film modulation line. (orig.)
[en] The current transport in front of an electrode of a gas discharge is described by an electrical equivalent circuit, containing bistable resistors. By a potential function competing steady states can be valued. Interaction between discharge element is resulted, giving rise to structure formation. (author)