- 标题
- 摘要
- 关键词
- 实验方案
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Numerical simulation of multilayer organic light-emitting diodes with hosta??guest emissive layer: the role of defect states
摘要： In this study, a comprehensive model for the numerical simulation of electrical and optical characteristics of multilayer organic light-emitting devices (OLED) is presented. The model consists of three parts: charge carrier transport model, exciton model, and a post-processing part for calculating luminance. The defect states in the organic layers are modeled and are introduced into the equations. For demonstrating the rule of the defect states in such devices, a multilayer OLED is considered consisting of a host–guest emissive layer sandwiched between electron and hole transport layers. The current density and luminance results of the analyzed device are compared with the experimental data. We have found that by considering the defect states, there is good accordance between the simulation results and the experimental data.
关键词： Host–guest emissive layer,Luminance,Current density,OLED,Numerical simulation,Defect states
更新于2025-09-23 15:21:01
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Optical scanning holography for tumor extraction from brain magnetic resonance images
摘要： Tumor segmentation from magnetic resonance images (MRI) is an error-prone and time-absorbing process. Recently, optical methods have opened a new avenue to tack with the aforementioned problem. In this paper, we propose a novel architecture adapting the Optical Scanning Holography (OSH) to the detection of the abnormal tissue regions in MRI. The proposed method combines an o?-axis optical scan, performed by a heterodyne fringe pattern, and a MR image display ensured by a spatial light modulator. The output in-phase component of the scanned current is collected digitally. Hence, a high-precision distribution of biological tissues is extracted using this in-phase component. Its maximum position is exactly the one of the tumor. Meanwhile, this position is used in an Active Contour Model (ACM) to perform a fast segmentation of the extent corresponding to the tumors. Several images of brain tumors from BRATS database, with tumors having di?erent contrast and form, are used to test the proposed system. Parameters reverted by the optical process are used to investigate the detection performance. Further, in terms of tumor segmentation, the proposed OSH-ACM process has high performance metrics compared to some of recently published method. The underlying physics of the precision superiority, presented by the OSH-ACM, is the high-precision extraction of the abnormal tissue regions by the in-phase component of the scanned current.
关键词： Active contour,Optical Scanning Holography (OSH),Segmentation,Brain tumor detection,In-phase component of the scanned current
更新于2025-09-23 15:21:01
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<i>Ab initio</i> study of parity and time-reversal violation in laser-coolable triatomic molecules
摘要： Electronic structure enhancement factors of simultaneous parity and time-reversal violation (P, T violation) caused by an electric dipole moment of the electron (eEDM) and scalar-pseudoscalar nucleon-electron current (SPNEC) interactions are reported for various metal monohydroxides, several of which are considered laser-coolable and promising candidates for an eEDM measurement. Electronic structure enhancements are calculated ab initio within zeroth-order regular approximation (ZORA) for CaOH, SrOH, BaOH, RaOH, and YbOH. Scaling behavior with respect to nuclear charge numbers and the ratio of enhancement factors for both discussed sources of P, T violation are analyzed, which are crucial to obtaining stringent bounds on parameters for new physics from experiments.
关键词： laser-coolable molecules,electric dipole moment,ab initio calculation,scalar-pseudoscalar nucleon-electron current,parity and time-reversal violation,ZORA
更新于2025-09-23 15:21:01
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Photovoltaic-Driven SiC MOSFET Circuit Breaker with Latching and Current Limiting Capability
摘要： This paper introduces a Solid State Circuit Breaker with Latching and Current Limiting capabilities for DC distribution systems. The proposed circuit uses very few electronic parts and it is fully analog. A SiC N-MOSFET driven by a photovoltaic driver and a maximum current detector circuit are the core elements of the system. This work details circuit operation under different conditions and includes experimental validation at 1 kVdc. Wide versatility, highly configurable, and very fast response, less than 1 μs in the case of short-circuit, are the most remarkable outcomes.
关键词： SiC MOSFET,Solid State Circuit Breaker (SSCB),fault current limiter,WBG semiconductors,DC power distribution
更新于2025-09-23 15:21:01
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AIP Conference Proceedings [Author(s) INTERNATIONAL WORKSHOP ON PHYSICS WITH POSITRONS AT JEFFERSON LAB - Newport News, VA, USA (12–15 September 2017)] - High current polarized electron source for future eRHIC
摘要： The high current and high bunch charge polarized electron source is essential for cost reduction of Linac-Ring (L-R) eRHIC. In the baseline design, electron beam from multiple guns (probably 4-8) will be combined using deflection plates or accumulate ring. Each gun aims to deliver electron beam with 10 mA average current and 5.3 nC bunch charge. With total 50 mA and 5.3 nC electron beam, this beam combining design could use for generating positron too. The gun has been designed, fabricated and expected to start commissioning by the mid of this year. In this paper, we will present the DC gun design parameters and beam combine schemes. Also, we will describe the details of gun design and the strategies to demonstrate high current high charge polarized electron beam from this source.
关键词： high bunch charge,eRHIC,polarized electron source,high current,beam combining
更新于2025-09-23 15:21:01
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Three-Legs Interleaved Boost Power Factor Corrector for High-Power LED Lighting Application
摘要： In this article, a three-leg interleaved boost Power Factor Corrector (IBPFC) converter for energy-efficient LED lighting systems connected to the main grid was discussed. This IBPFC circuit presented features 60 kHz of commutation frequency and up to 3 kW of power rating. The controlled rectifier front-end boost PFC supplied a DC/DC converter to drive power LEDs suitable for street lighting or a lighting system for a stadium, etc. The IBPFC operated in continuous current mode (CCM). The ripple impact of the IBPFC converter was analyzed and a novel methodology of inductance design was presented. In the proposed design approach, the derivative calculation of the current ripple peak compared with the derivative of the input current was used to define a critical inductance value to ensure the CCM condition. Experimental validation was provided on a 3kW prototype.
关键词： IGBT,continuous current mode (CCM),interleaved converters,three-phase boost converter,ripple analysis,high-power LED lighting,power factor correction (PFC)
更新于2025-09-23 15:21:01
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Computational study of stack/terminal topologies for perovskite based bifacial tandem solar cells
摘要： With the rapid progress on perovskite (PVK) and bifacial solar cells, there is a huge interest in integrating PVK with established technologies such as crystalline silicon (c-Si) and CIGS for bifacial tandem structures. Here we use self-consistent optical/electrical simulations to compare various stack/terminal configurations for bifacial tandem solar cells having PVK as the top cell. In particular, we compare a non-conventional three-terminal four-junction (3T-4J) twin bifacial tandem configuration with standard two-junction bifacial tandem structures having a monolithic two-terminal (2T-2J) or mechanically stacked four-terminal (4T-2J) integration. We show that the optimal design of 2T-2J cell is strongly albedo dependent – the cell designed for a given albedo will perform sub-optimally for other albedo due to the current-matching constraint. A mechanically stacked 4T-2J cell, on the other hand, can perform optimally for a broad range of albedo, albeit at the cost of additional processing complications. The 3T-4J twin tandem cell could offer a relatively simpler process through back-to-back bonding of two identical monolithic 2J tandem cells with superior utilization of albedo in a broad range. The potential benefit of 3T-4J cell could however be limited due to a high front reflection, hence necessitating anti-reflection approaches. We further quantify the effect of bottom subcell material on the efficiency for PVK tandem cells. Using state-of-the-art bottom subcells, efficiency of 33% and 30% respectively could be achieved at the average Earth albedo of 30%. By integrating advanced anti-reflectance techniques, the absolute cell efficiency could further be improved by 4%.
关键词： Albedo,Simulations,Current-matching,Tandem,Bifacial gain
更新于2025-09-23 15:21:01
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Robust Model Predictive Control (MPC) for large-scale PV plant based on paralleled three-phase inverters
摘要： In this contribution a robust Model Predictive Control (MPC) is proposed to enhance the power quality of a large-scale PV plant connected to the grid through Paralleled Voltage Source Inverters (PVSIs) with common AC and DC buses. Paralleling inverters allow handling high-power export and offer advantages in terms of redundancy which ensure the system reliability. However, due to the physical differences and parameter disparities between the inverters, zero sequence circulating currents will flow through it, which will disturb the performance of the system. Hence, the control goal is to regulate the currents injected into the grid, suppress the zero-sequence circulating current (ZSCC). Consequently, this study proposes an MPC algorithm that is based on optimization approach which allows minimizing circulating currents. In order to show its effectiveness and performance of the proposed control, a comparison with linear PI controller is included. In addition, design control and tuning procedure are detailed. Simulation results show the performance of the proposed controller in ensuring power quality, and suppressing circulating currents. To verify the real-time feasibility of the proposed control scheme, Hardware-In-the-Loop (HIL) setup is carried out with means of Opal-RT and dSPACE rapid prototyping systems.
关键词： Hardware-in-the-loop,Model predictive control,PV power plant,Grid-connected inverter,Circulating current,Parallel operation
更新于2025-09-23 15:21:01
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Spin-dependent tunneling of light and heavy holes with electric and magnetic fields
摘要： The spin-dependent tunneling of light holes and heavy holes was analysed in a symmetrical heterostructure with externally applied electric and magnetic fields. The effects of the applied bias voltage, magnetic field and reverse bias were discussed for the polarization efficiency of light holes and heavy holes. The current density of spin-up and spin-down light holes increases as the bias voltage increases and reaches the saturation, whereas the current density of spin-up heavy holes is almost negligible. The applied bias voltage and the magnetic field highly influence the energy of resonance polarization, polarization efficiency, and the current density of heavy holes more than for the light holes.
关键词： heterostructure,reverse bias,current density
更新于2025-09-23 15:21:01
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[IEEE 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - Erode (2018.2.15-2018.2.16)] 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - A STUDY ON MODELING AND SIMULATION OF PHOTOVOLTIC ARRAYS USING SINGLE DIODE METHOD
摘要： This paper presents a method of modeling and simulation of photovoltaic arrays. The main objective of this study is to achieve a circuit based simulation model of a photovoltaic cell and to scrutinize the results and compare them with respect to change in environmental parameters like irradiation and temperature. The proposed method of single diode model is implemented in MATLAB software based on the particular environmental condition. And on the basis of this study simulation results and ideal theoretical values are compared.
关键词： Renewable energy sources,MATLAB software,PV system,Single diode method,Open circuit current and short circuit voltage
更新于2025-09-23 15:21:01