- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Admittance of Organic LED Structures with an Emission YAK-203 Layer
摘要： The current-voltage characteristics and admittance of multilayer structures for organic LEDs based on the PEDOT:PSS/NPD/YAK-203/BCP system have been experimentally investigated in a wide range of the measurement conditions. It is shown that at voltages corresponding to the effective radiative recombination of charge carriers, a significant decrease in the differential capacitance of the structures is observed. The frequency dependences of the normalized conductance of LED structures are in good agreement with the results of numerical simulation in the framework of the equivalent circuit method. Changes in the frequency dependences of the admittance with a change in temperature are most pronounced in the temperature range of 200–300 K and less noticeable in the temperature range of 8–200 K. From the frequency dependences of the imaginary part of impedance, the charge carrier mobilities are found at various voltages and temperatures. The mobility values obtained by this method are somewhat lower than those determined by the transient electroluminescence method. The dependence of the mobility on the electric field is well approximated by a linear function. As the temperature decreases from 300 to 220 K, the mobility decreases several times.
关键词： frequency dependence of imaginary part of impedance,LED structure,current-voltage characteristic,transient electroluminescence,organic semiconductor,charge carrier mobility,method of equivalent circuits,admittance
更新于2025-11-14 17:28:48
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Monostatic GTD Model for Double Scattering due to Specular Reflections or Edge Diffractions
摘要： GTD model is a good candidate to extract the features of radar targets, which describes the frequency dependence of scattering centers for many geometries or mechanisms and can represent the attribute information of the geometrical structures. The mechanisms associated with this model have been proven to include single reflection, single diffraction and multiple reflections from dihedral and trihedral corner reflectors. However, multi-scattering mechanisms from more complex structures are not studied adequately. In this paper, we expand the GTD model to any double scattering due to specular reflections or edge diffractions, and derive the related frequency-dependence factor. Finally, a simulation validates the theory.
关键词： specular reflection,multiple scattering mechanism,frequency-dependence factor,flat surface,straight edge,doubly-curved surface,GTD model,curved edge,edge diffraction,singly-curved surface
更新于2025-09-23 15:22:29
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Intermediate Band Challenge in InAs/GaAs Quantum Dot Solar Cell at Cryogenic Temperatures
摘要： Medium voltage drives (MVDs) are commonly used in high-power applications and show significant impact on the overall system dynamics due to their large size and high power demand. Although detailed switching models for MVDs can be built using MATLAB/Simulink, such models cannot be used in large-scale simulation software for power system dynamic studies. To solve this problem, the dynamic load model for the medium voltage cascaded H-bridge multi-level inverter drive and induction motor systems, which is suitable for power system dynamic studies, is proposed in this paper. Analytical formula of the model is presented. The model includes the aggregated effect of an MVD, an induction motor, and their control system, and thus, it can accurately represent the dynamic responses of the motor drive system under disturbances. Both voltage and frequency dependence are considered in the model. The accuracy of the model is verified by a case study. A sensitivity study is conducted to evaluate the impact of the model parameter variation on dynamic response characteristics. The developed load model can be readily inserted in the large-scale power system simulation software for power system dynamic studies.
关键词： power system dynamic studies,voltage dependence,load model,Cascaded H-bridge multi-level inverter,frequency dependence,medium voltage drives (MVDs)
更新于2025-09-23 15:19:57
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Computation of Power Extraction From Photovoltaic Arrays Under Various Fault Conditions
摘要： Medium voltage drives (MVDs) are commonly used in high-power applications and show significant impact on the overall system dynamics due to their large size and high power demand. Although detailed switching models for MVDs can be built using MATLAB/Simulink, such models cannot be used in large-scale simulation software for power system dynamic studies. To solve this problem, the dynamic load model for the medium voltage cascaded H-bridge multi-level inverter drive and induction motor systems, which is suitable for power system dynamic studies, is proposed in this paper. Analytical formula of the model is presented. The model includes the aggregated effect of an MVD, an induction motor, and their control system, and thus, it can accurately represent the dynamic responses of the motor drive system under disturbances. Both voltage and frequency dependence are considered in the model. The accuracy of the model is verified by a case study. A sensitivity study is conducted to evaluate the impact of the model parameter variation on dynamic response characteristics. The developed load model can be readily inserted in the large-scale power system simulation software for power system dynamic studies.
关键词： voltage dependence,power system dynamic studies,medium voltage drives (MVDs),frequency dependence,Cascaded H-bridge multi-level inverter,load model
更新于2025-09-23 15:19:57
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Reservoir Computing using VCSEL Polarization Dynamics
摘要： Medium voltage drives (MVDs) are commonly used in high-power applications and show significant impact on the overall system dynamics due to their large size and high power demand. Although detailed switching models for MVDs can be built using MATLAB/Simulink, such models cannot be used in large-scale simulation software for power system dynamic studies. To solve this problem, the dynamic load model for the medium voltage cascaded H-bridge multi-level inverter drive and induction motor systems, which is suitable for power system dynamic studies, is proposed in this paper. Analytical formula of the model is presented. The model includes the aggregated effect of an MVD, an induction motor, and their control system, and thus, it can accurately represent the dynamic responses of the motor drive system under disturbances. Both voltage and frequency dependence are considered in the model. The accuracy of the model is verified by a case study. A sensitivity study is conducted to evaluate the impact of the model parameter variation on dynamic response characteristics. The developed load model can be readily inserted in the large-scale power system simulation software for power system dynamic studies.
关键词： voltage dependence,power system dynamic studies,medium voltage drives (MVDs),frequency dependence,Cascaded H-bridge multi-level inverter,load model
更新于2025-09-16 10:30:52
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Frequency Dependence Evaluation of CENAM Calculable Resistors
摘要： This paper presents the evaluation results of 1 k? and 10 k? CENAM calculable resistors using as reference a 1 k? METAS calculable resistor, by means of 1:1 and 10:1 ratios measurements, respectively. The measurements show an agreement better than 0.35 μ?/? through the audio-frequency range for the 10 k? CENAM resistor. An analysis of the possible reasons of the observed linear frequency dependence in the 1 k? CENAM calculable resistors is also presented.
关键词： reference standard,frequency dependence,metrology,Calculable resistor
更新于2025-09-10 09:29:36
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Dependence of Noise Temperature of Superconducting HEB Mixers on Frequency and Bath Temperature
摘要： A log-spiral antenna coupled 0.1-1.5 THz NbN superconducting HEB mixer has been characterized by measuring its double sideband (DSB) receiver noise temperature (Trec) from 0.22 THz to 1.44 THz and at 4 K-7 K bath temperatures. The measured uncorrected Trec is 800 K, 800 K, 750 K and 850 K at 0.22 THz, 0.55 THz, 0.85 THz and 1.44 THz respectively. The optimal bias voltage seems independent to the frequency and bath temperature. The bath-temperature dependence of noise temperature has also been investigated, the bath temperature has limited effect on the noise temperature when it is operated below its transition temperature. A similar frequency response of corrected mixer noise temperature has been observed at 4 K and 7 K bath temperature, which indicates the RF coupling efficiency of planar spiral antenna of HEB mixer.
关键词： frequency dependence,receiver noise temperature,bath temperature dependence,Superconducting HEB mixer
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI) - Las Vegas, NV (2018.4.8-2018.4.10)] 2018 IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI) - In-between and cross-frequency dependence-based summarization of resting-state fMRI data
摘要： Various data summarization approaches which consist of basis transformation and dimension reduction have been commonly used for information retrieval from brain imaging data including functional magnetic resonance imaging (fMRI). However, most approaches do not include frequency variation of the temporal data in the basis transformation. Here we propose a novel approach to incorporate in-between and cross-frequency dependence for summarization of resting-state fMRI data.
关键词： Cross-frequency dependence,Hilbert transform,Canonical correlation analysis
更新于2025-09-04 15:30:14