Article
Engineering, Electrical & Electronic
Cheol-Hee Jo, Dong-Hee Kim
Summary: This paper proposes a reconfigurable LLC resonant converter for bidirectional electric-vehicle chargers. By designing the resonant inductors and the structure of the windings in the transformer, the proposed converter can achieve the monotonic voltage gain curves of a unidirectional LLC resonant converter in both charging and discharging modes. Experimental results show that the converter achieves maximum efficiencies of 96.86% and 95.95% in the charging and discharging modes, respectively.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Automation & Control Systems
Deshang Sha, Xiao Yang
Summary: The full-bridge/half-bridge (FB/HB) morphing topology is well-suited for wide input voltage range LLC dc-dc converters. To enhance dynamic performance in the face of input voltage variations, a numerical optimal trajectory control method is proposed. Simulations are conducted on the power circuit considering parasitic parameters, and the data obtained can be stored in DSP memory for later use. With the help of numerical methods, accurate gain-frequency curves for different loads can be obtained using these discrete data. The effectiveness of the proposed numerical optimal trajectory control has been verified through simulation and experimental results.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Mingxiao Li, Chang Wang, Ziwei Ouyang, Michael A. E. Andersen
Summary: This article focuses on the optimization of the transformer for an LLC resonant converter used in data centers to achieve isolation and a fixed voltage step-down ratio. The improved interleaving winding scheme reduces conduction path, lowers ac resistance, and decreases core volume compared to previous research. Ansys 3D simulation is used to design and optimize the magnetic core, and the proposed core, winding layout, and design are verified in a 30-/5-V 660-W LLC resonant converter.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2023)
Article
Automation & Control Systems
Yu Zuo, Xuewei Pan, Can Wang
Summary: This article proposes a new bidirectional isolated LLC resonant converter for ultra-wide voltage gain range applications, such as electric vehicle charging systems. The proposed topology includes an inverter and rectifier with two modes, allowing for ultrawide output voltage operation. The results are validated through experiments on a converter prototype.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Guidong Zhang, Junming Zeng, Wenxun Xiao, Samson Shenglong Yu, Bo Zhang, Yun Zhang
Summary: This article presents an advanced self-protected single-stage ac-dc LLC resonant converter, which introduces a diode for overvoltage prevention, achieving self-protection, cost reduction, and smaller size. The proposed converter also features power factor correction, soft switching, and a wide output voltage range. Detailed analysis and prototype experimentation have confirmed the effectiveness of the design.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Energy & Fuels
Jingkai Niu, Xuezhi Wu, Yue Wang, Long Jing, Weige Zhang, Yibin Tong
Summary: This paper proposes a variable duty-cycle control strategy for backward step-up mode in an LLC resonant converter, which enables bidirectional power transmission without changing the basic topology.
Article
Automation & Control Systems
Yuefeng Liao, Guo Xu, Yao Sun, Tao Peng, Mei Su, Bin Guo, Wenjing Xiong
Summary: A single-stage dual active bridge (DAB) LLC hybrid bidirectional converter based on the sigma converter structure is proposed in this article for tight voltage regulation and fully utilizing the advantages of LLC-DCX operation.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Energy & Fuels
Di Xie, Liangliang Wang, Zhi Zhang, Shoumo Wang, Longyun Kang, Jigang Yao
Summary: This paper proposes a bidirectional isolation LLC converter topology for the photovoltaic energy storage complementary system. By establishing equivalent models and closed-loop controllers, the correctness and feasibility of this topology under the proposed charging and discharging control strategy are verified.
Article
Engineering, Electrical & Electronic
Hengkai Dang, Sixing Du, Yan Zhang, Jinjun Liu
Summary: The traditional LLC converter with variable switching frequency suffers from reduced efficiency and difficult magnetic component design. A novel LLC converter is proposed, which utilizes configurable capacitors in the output stage to achieve two-times adjustment of output voltage. Compared to prior art, it reduces the output inductor, power losses, and switch capacity.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Automation & Control Systems
Xin Lou, Mohamed H. Ahmed, Virginia Li, Qiang Li
Summary: This article focuses on the crucial 48V voltage regulator modules in 48V data center power architecture. It performs small-signal analysis of the Sigma converter under different control methods and compares their performances to select the enhanced V-2 control. Furthermore, an adaptive voltage position (AVP) design based on enhanced V-2 control is proposed to improve performance and stability, and its functionality and load transient performance are verified through simulation and experimental results.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Jakub Kucka, Drazen Dujic
Summary: The bidirectional LLC resonant converter has a naturally stiff voltage ratio, low switching losses, and stable open-loop behavior, but determining the required operation direction in open-loop operation is a challenge that needs to be addressed.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Computer Science, Information Systems
Ziheng Xiao, Zhixing He, Yong Ning, Hongliang Wang, An Luo, Yandong Chen, Junling Chen
Summary: LLC resonant DC-DC converter is widely used in high power density and high efficiency applications, with pulse frequency modulation (PFM) and phase shift modulation (PSM) commonly applied. This paper presents a unified time domain operation stage trajectories (OSTs) analysis and optimization method, resulting in improved performance compared to conventional modulation methods.
Article
Engineering, Electrical & Electronic
Qinglin Zhao, Jianmeng Zhang, Yuxia Gao, Deyu Wang, Qiuxia Yang
Summary: This article proposes a multimode hybrid LLC resonant converter with a wide output voltage range. The converter can operate in three different modes: low-gain mode, medium-gain mode, and high-gain mode, by controlling the drive signals of the primary switches. Variable frequency modulation is used in each mode, allowing for a smooth transition and achieving an ultra-wide output voltage range. The prototype of the proposed converter demonstrates good efficiency performance over the entire voltage range, with a peak efficiency of 97.5%.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Xiaoquan Zhu, Kang Liu, Ke Jin, Bo Zhang
Summary: A bidirectional half-bridge (BHB) LLC resonant converter with automatic current sharing characteristics is proposed for high-power bidirectional energy storage applications. The converter achieves zero-voltage switching with the help of the magnetizing inductance of the transformer. By grouping the secondary windings of the transformer, excellent current sharing can be achieved even with resonant parameter errors.
INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS
(2023)
Article
Automation & Control Systems
Zhaoyang Zhao, Dao Zhou, Huai Wang, Pooya Davari, Frede Blaabjerg
Summary: This article discusses methods to reduce capacitance requirements while ensuring the transient performance of VRMs, proposing an auxiliary circuit scheme based on VSVS. The scheme can significantly improve the reliability of VRMs.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Biochemistry & Molecular Biology
Xiaodong Jin, Yanbei Kuang, Linying Li, Hongbin Li, Ting Zhao, Yufang He, Cuixia Di, Jian Kang, Lingyan Yuan, Boyi Yu, Qiang Li
Summary: This study discovered that p21 protein is upregulated under hypoxic conditions, enhancing the radioresistance of glioblastoma cells. The positive correlation between p21 and HIF-1 alpha creates a positive feedback loop, aggravating the cells' radioresistance.
Article
Energy & Fuels
Qiang Li, Changlin Liao, Jian Hou, Wenju Wang, Jiansheng Zhang
Summary: This paper presents a compartment packing model that can increase the solid loading of coal water slurry (CWS) by improving the packing efficiency of coal samples. The model includes important parameters such as particle size ratios and initial voidage, which influence the value and trend of packing efficiency. The model is verified through comparison with experimental data and can predict CWS with lower viscosity and optimize CWS with higher solid loading.
Article
Nanoscience & Nanotechnology
Lei Gao, Jia-Lin Sun, Qiang Li, Qingfeng Yan
Summary: Inorganic metal halide perovskites have superior environmental stability compared to their organic-inorganic counterparts, making them more promising for practical applications. This study investigates the stability of an archetypical all-inorganic CsPbBr3 single crystal and its single-carrier devices under Co-60 gamma-ray irradiation. The results reveal that the performance of the hole-only device deteriorates more than the electron-only device under high irradiation doses, suggesting different influences of gamma-ray irradiation-induced defects on hole and electron transport behaviors in CsPbBr3 single-crystal devices.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Qiang Li, Mingdi Wang, Yunhe Bai, Qifan Zhang, Haoran Zhang, Zhenhuan Tian, Yanan Guo, Jingping Zhu, Yuhuai Liu, Feng Yun, Tao Wang, Yue Hao
Summary: This study investigates the film stripping process of hexagonal boron nitride (hBN) films using liquid phase exfoliation and spin coating. The transferred hBN films demonstrate a constant resistance window and show potential for application in resistive switching devices.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Hankun Xu, Kun Lin, Wenjie Li, Qiang Li, Joerg C. Neuefeind, Jue Liu, Kenichi Kato, Jun Miao, Xianran Xing
Summary: In this study, the role of non-stoichiometry in second harmonic generation (SHG) in LiNbO3 was investigated by preparing non-stoichiometric LiNbO3 samples with different Li mole percentages. It was found that reducing the Li content to 47 mol% significantly weakened the SHG response by 50% without affecting the band gap. This effect was attributed to the introduction of anti-occupied Nb and Li vacancies, which reduced local distortions and polarizations of the octahedra, resulting in the decline of SHG response. These findings provide insights for the future design of functional materials with non-stoichiometric compositions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Hong Liu, Chao Xu, Qundong Xia, Yunbin Ying, Qiang Li, Xiaoyu Zhao, Yongjun Zhang, Shikuan Yang
Summary: In this study, a new type of structural color material is reported, which is achieved by filling polystyrene nanospheres into silver brochosomes. The color is originated from the enhanced electromagnetic resonances of the polystyrene nanospheres by the surrounding metallic nanobowls. The color can be modified by tuning the diameter of the polystyrene nanospheres through plasma etching treatment. This material exhibits promising applications in the field of structural colors due to its simple fabrication process and easy processability.
Article
Chemistry, Multidisciplinary
Shitong Wang, Lijiang Zhao, Yanhao Dong, He Zhu, Yang Yang, Haowei Xu, Baoming Wang, Yakun Yuan, Yang Ren, Xiaojing Huang, Wei Quan, Yutong Li, Yimeng Huang, Charles M. Settens, Qi He, Yongwen Sun, Hua Wang, Zunqiu Xiao, Wenjun Liu, Xianghui Xiao, Riqiang Fu, Qiang Li, Yong S. Chu, Zhongtai Zhang, Qi Liu, Andrew M. Minor, Junying Zhang, Zilong Tang, Ju Li
Summary: Wadsley-Roth oxides (WROs) with pore diameters of 2.5 angstrom < d < 2.8 angstrom allow rapid diffusion of Li+ in single-crystal particles, enabling high-rate charge cycles similar to gasoline vehicles and improving the cycle life up to 10,000 cycles.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Joseph P. Kozak, Qihao Song, Ruizhe Zhang, Yunwei Ma, Jingcun Liu, Qiang Li, Wataru Saito, Yuhao Zhang
Summary: This article presents a comparative study of the parametric shift and recovery of three mainstream GaN HEMTs in repetitive overvoltage switching. The study shows that the devices exhibit shifts in threshold voltage and saturation current during the switching process, and these shifts saturate in a short period of time. The recovery process is dominated by hole detrapping and through-gate removal, with the gate stack playing a significant role. The article also suggests effective methods for poststress recovery.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Yuanyuan Ma, Jingfang Mao, Xinguo Liu, Zhongying Dai, Hui Zhang, Xinyang Zhang, Qiang Li
Summary: This study explored a deep learning-based framework to segment iGTV rapidly and accurately in 4D CT images for lung cancers. The results showed that the proposed networks with multi-channel multi-path and convolutional GRU improved the segmentation accuracy but reduced the segmentation efficiency. Different fusion strategies also had different effects on similarity and distance metrics.
Correction
Optics
Meiyan Pan, Yifei Fu, Mengjie Zheng, Hao Chen, Yujia Zang, Huigao Duan, Qiang Li, Min Qiu, Yueqiang Hu
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Qiang Li, Yanxia Gao, Jing Chen, Hongpeng Jia
Summary: Decorating isolated nickel atoms on La2O3 surface can enhance the activity of light-driven dry reforming of methane. The atomically dispersed 0.5Ni/La2O3 catalyst exhibits high hydrogen evolution rate and resistance to carbon coking.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Optics
Jianghui Liu, Qiang Li, Junbo Liu, Song Hu, Chunchao Qi
Summary: In this work, a structure-illumination based wafer focus measuring system (SI-WFMS) was proposed, which can measure the vertical defocus distance of the exposure area with less than 0.06 μm error in a single-step sampling process. The SI-WFMS can also rapidly measure the surface profile and tilt angle of the wafer, saving measuring time and improving manufacturing efficiency.
OPTICS AND LASERS IN ENGINEERING
(2023)
Review
Chemistry, Multidisciplinary
Kun Lin, Qiang Li, Runze Yu, Jun Chen, J. Paul Attfield, Xianran Xing
Summary: Chemical pressure, a lattice internal force caused by lattice strain with chemical modifications, is a versatile and efficient method for synthesizing new compounds and tuning functional materials. It can be either positive or negative and is particularly important as a degree of freedom to manipulate material behaviors. Chemical pressure affects chemical bonding, rationalizes crystal structures, and modifies electronic structures, emerging as a general and effective synthesis method.
CHEMICAL SOCIETY REVIEWS
(2022)
Review
Materials Science, Multidisciplinary
Shan Li, Yilin Wang, Mingdi Yang, Jun Miao, Kun Lin, Qiang Li, Xin Chen, Jinxia Deng, Xianran Xing
Summary: Ferroelectric thin film materials, known for their robust spontaneous electric polarization and strong coupling with optical, electric, and magnetic fields, have been widely used in various fields. Recent breakthrough progress has been made in optimizing their performance and applications. Flexible ferroelectric thin film devices with excellent ductility and resilience have great potential for applications in intelligent robots, wearable electronic devices, and the Internet of Things.
MATERIALS ADVANCES
(2022)
Article
Materials Science, Multidisciplinary
Chang-woo Cho, Peipei Wang, Fangdong Tang, Sungkyun Park, Mingquan He, Rolf Lortz, Genda Gu, Qiang Li, Liyuan Zhang
Summary: In this study, thermal and electrical transport experiments were conducted in the three-dimensional topological semimetal ZrTe5, providing experimental evidence of hydrodynamic behavior. The results suggest the presence of hydrodynamic-like flow between the ballistic and diffusive regimes in ZrTe5.