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第35届中国控制与决策会议

作者： Bowen Zheng Dongxue Yang Huacai Lu AnHui Key Laboratory of Detection Technology and Energy Saving Devices AnHui Polytechnic University Key Laboratory of Electric Drive and Control of Anhui Province Anhui Polytechnic University

An improved adaptive torque siding mode control algorithm is proposed in this paper for a permanent magnet synchronous motor speed control ***,based on the chattering problem of traditional sliding mode control,the PID sliding surface is selected to reduce the system error,and the sliding function is used to modify the sliding mode reaching law to weaken the chattering ***,based on the premise of speed error and torque error,the backstepping control algorithm is used to obtain a new torque update law for compensation,and the asymptotic stability of the whole system is verified by Lyapunov stability ***,the simulation is carried out by MATLAB/*** experimental results show that the control algorithm improves the tracking performance of the system,weakens the chattering phenomenon of the traditional sliding mode control,and reduces the load torque interference.

关键词： sliding mode control backstepping control sliding function permanent magnet synchronous motor

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Photon energy loss and management in perovskite solar cells

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Energy Reviews 2022年第1期1卷 1-8页

作者： Yutian Lei Yongfang Li Zhiwen Jin School of Physical Science and Technology&Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou UniversityLanzhou730000China Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsInstitute of ChemistryChinese Academy of SciencesBeijing100190PR China Laboratory of Advanced Optoelectronic Materials Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and DevicesCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123 PR China

The power conversion efficiency(PCE)of perovskite solar cells(PSCs)has increased rapidly to 25.7%in *** is growing curiosity about whether it will increase further up to the PCE *** the fundamental energy loss mechanism and targeted treatment is the crux to step forward,especially the definite and management of photons in ***,we first briefly review the main modes of photon energy loss in PSCs and illustrate the significance of photon ***,historical research trials to overcome these loss mechanisms in PSCs are highlighted,including the application of anti-reflection coatings,plasmonic strategies,and the adoption of upconversion and downconversion ***,we make a brief summary and prospect about strategies that can help to improve photon management in the future.

关键词： Energy loss Photon management Light harvesting Perovskite solar cells

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Performance Study of Array Detector for Spatial Phase Compensation in Laser Heterodyne detection

SSRN

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SSRN 2024年

作者： Dong, Hongzhou Wei, Junjie Luo, Ziwen Yang, Chunping Ao, Mingwu Yang, Xianming State Key Laboratory of Electronic Thin Films and integrated Devices School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu610054 China

Abstract: Based on an array detector and autocorrelation, a new method has recently been proposed to compensate for spatial phase distortion. In this method, adopting more array elements is beneficial for strengthening signal when the distortion is severe, but doing so will introduce more circuit noise and thermal noise. Thus, a fundamental contradiction exists for the method’s application. To probe this problem, a theoretical formula for the signal-to-noise ratio (SNR) of an array detector is derived based on saturation effect model. The formula indicates that, when local oscillator light (LO) power is optimal, the maximum SNR is not affected by the increasing array number, which is confirmed by an experiment in this paper. Compared with a single detector, the array detector’s performance in the new method is experimentally examined by generating misaligned angle and simulating atmospheric turbulence. The results reveal that, even if the misaligned angle is as small as 35μrad, a SNR advantage of 17dB can be demonstrated for the array detector. In some turbulence conditions, when the detection accuracies of the single detector decrease to zero, these of the array detector can maintain between 60%~95%. These works in this paper clarify the crucial contradiction issue of the new method and confirm its effectiveness for different types of phase distortions. © 2024, The Authors. All rights reserved.

关键词： Heterodyne detection

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Perovskite light emitting diode

Perovskite light emitting diode

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International Conference on Display technology, ICDT 2020

作者： Li, Danyang Mu, Lan Yip, Hin-Lap Peng, Junbiao Institute of Polymer Optoelectronic Materials & Devices State Key Laboratory of Luminescent Materials & Devices South China University of Technology Guangzhou China

Metal halide perovskite materials occupy an increasingly important position in the field of optoelectronic materials due to their excellent light absorption properties, long carrier dispersion length and high mobility. However, the instability of perovskite materials is still a major factor constraining its development. So, it’s important to improve the stability of perovskite materials in air and even to produce high-performance LEDs in air. Here, we proposed a simple way to improve the stability of perovskite quantum dots and achieved the preparation of perovskite light-emitting diodes in air. And green PQDs-LED devices are fabricated by inkjet printing. © 2021, John Wiley and Sons Inc. All rights reserved.

关键词： Perovskite

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Lensless Light-field Imaging with Angular Resolution Improvement

Lensless Light-field Imaging with Angular Resolution Improve...

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2022 International Conference on Optical and Photonic Engineering, icOPEN 2022

作者： Mo, Chen Cai, Zewei Xi, Jiangtao Tong, Jun Liu, Xiaoli Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen518060 China School of Electrical Computer and Telecommunications Engineering University of Wollongong WollongongNSW2522 Australia School of Electronic and Optical Engineering Nanjing University of Science and Technology Jiangsu Province Nanjing210094 China

ISBN: (纸本)9781510661905

Lensless light-field imaging is the process to encode the light field information of object through an optical encoder, and then recover the light field information of object through a reconstruction algorithm. In traditional lens-based light field imaging, each microlens in microlens-array corresponds to an angular sampling, and it needs to adjust the microlens-array to alter the angular resolution. In this paper, a commercial holographic diffuser is used as an optical encoder, and a flexible overlapping segmentation method of angular sampling is proposed for the point spread function (PSF). The surface microstructures of holographic diffuser allow any region of it to encode and recover light information of object independently, corresponding to an angular sampling. Calibration of PSF for the lensless imaging system is done firstly, and encoded image of object is captured;then the PSF is divided into different regions as sub-PSFs, corresponding to different angular samplings;after that, light field images of object is reconstructed with corresponding sub-PSFs through reconstruction algorithm;with these light field images, digital refocusing can be achieved finally. Different from evenly segmentation of angular sampling in microlens-array, the overlapping segmentation method divides PSF into sub-PSFs while adjacent sub-PSFs overlap each other. This improves angular resolution of imaging system and ensures low error in reconstruction of light field images. Experiments show that, the overlapping segmentation method can guarantee the reconstruction accuracy of lensless light-field imaging system while flexibly adjusting and improving the angular resolution. © 2022 SPIE.

关键词： Optical transfer function

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Continuous terahertz omnidirectional beam steering by dual diffraction of metagratings

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Photonics Research 2023年第1期11卷 44-54页

作者： JIE-RONG CHENG YANG YANG SAI CHEN QI-YE WEN YUN-YUN JI FEI FAN SHENG-JIANG CHANG Institute of Modern Optics Nankai UniversityTianjin 300350China Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology Tianjin 300350China School of Electronic and Information Engineering Beihang UniversityBeijing 100191China State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin 300350China

Dynamic beam steering with unlimited angular range and fast speed remains a challenge in the terahertz gap,which is urgently needed for next-generation target tracking,wireless communications,and imaging *** from metasurface phased arrays with element-level phase control,here we steer the beam by globally engineering the diffraction of two cascaded metagratings during in-plane *** from large-angle diffraction and flexible on/off control of the diffraction channels,a pair of metagratings with optimized supercells and proper orientation successfully directs the incoming beam towards any arbitrary direction over the transmission half space,with the steering speed improved more than twice that of the small-angle diffractive ***-beam and dual-beam steering within the solid angle of 1.56πand elevation angle of±77°has been demonstrated with average throughput efficiency of 41.4%at 0.14 THz,which can be generalized to multiple-beam *** dual diffraction engineering scheme offers a clear physical picture for beamforming and greatly simplifies the device structure,with additional merits of large aperture and low power consumption.

关键词： beam directional globally

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Intrinsic polarization conversion and avoided-mode crossing in X-cut lithium niobate microrings

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Chinese Physics B 2024年第6期33卷 398-403页

作者：谭泽林张检发朱志宏陈伟邵铮铮刘肯秦石乔 College of Advanced Interdisciplinary Studies&Hunan Provincial Key Laboratory of Novel Nano Optoelectronic Information Materials and Devices National University of Defense TechnologyChangsha 410073China Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China School of Physics Central South UniversityChangsha 410083China

Compared with well-developed free space polarization converters, polarization conversion between TE and TM modes in the waveguide is generally considered to be caused by shape birefringence, like curvature, morphology of waveguide cross section and scattering. Here, we study the polarization conversion mechanism in 1-THz-FSR X-cut lithium niobate microrings with multiple-resonance condition, that is the conversion can be implemented by birefringence of waveguides,which will also introduce an avoided-mode crossing. In the experiment, we find that this mode crossing results in severe suppression of one sideband in local nondegenerate four-wave mixing and disrupts the cascaded four-wave mixing on this side. Simultaneously, we propose one two-dimensional method to simulate the eigenmodes(TE and TM) in X-cut microrings, and the mode crossing point. This work will provide one approach to the design of polarization converters and simulation for monolithic photonics integrated circuits, and may be helpful to the studies of missed temporal dissipative soliton formation in X-cut lithium niobate rings.

关键词： polarization conversion birefringence nondegenerate four-wave mixing

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Molecular design towards two-dimensional electron acceptors for efficient non-fullerene solar cells

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Journal of Energy Chemistry 2020年第12期29卷 190-198页

作者： Yan Liu Zixian Liu Zhicheng Hu Yuanying Liang Zhenfeng Wang Zhongxin Chen Fei Huang Yong Cao Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou 510640GuangdongChina

Non-fullerene polymer solar cells(NF-PSCs) have gained wide attention recently. Molecular design of non-fullerene electron acceptors effectively promotes the photovoltaic performance of NF-PSCs. However,molecular electron acceptors with 2-dimensional(2 D) configuration and conjugation are seldom ***, we designed and synthesized a series of novel 2 D electron acceptors for efficient NF-PSCs. With rational optimization on the conjugated moieties in both vertical and horizontal direction, these 2 D electron acceptors showed appealing properties, such as good planarity, full-spectrum absorption, high absorption extinction coefficient, and proper blend morphology with donor polymer. A high PCE of 9.76%was achieved for photovoltaic devices with PBDB-T as the donor and these 2 D electron acceptors. It was also found the charge transfer between the conjugated moieties in two directions of these 2 D molecules contributes to the utilization of absorbed photos, resulting in an exceptional EQE of 87% at 730 nm. This work presents rational design guidelines of 2 D electron acceptors, which showed great promise to achieve high-performance non-fullerene polymer solar cells.

关键词： Two-dimensional molecules Perylene diimide Electron acceptors Molecular design Non-fullerene solar cells

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Balloon Catheter with in Situ Pressure Sensing Function for Evaluating Hemodynamics 22

Balloon Catheter with in Situ Pressure Sensing Function for ...

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22nd International Conference on Solid-State Sensors, Actuators and Microsystems, Transducers 2023

作者： Wang, Yizhou Wang, Chengxu Wang, Jianrong Geng, Lei Cao, Xiangyu Chen, Xing Beihang University Beijing Advanced Innovation Center For Biomedical Engineering School Of Engineering Medicine Beijing China Tiangong University School Of Life Sciences Tianjin China Tianjin Key Laboratory Of Optoelectronic Detection Technology And Systems Tianjing China Chinese Pla General Hospital Department Of Neurology Beijing China

ISBN: (纸本)9784886864352

The balloon catheter is widely used for widening narrowed blood vessels to treat cardiovascular diseases. This paper presents a balloon catheter with an integrated MEMS pressure sensor for in situ blood pressure measurement. This multifunctional medical device enables local hemodynamic feedback along with balloon angioplasty. Both in vitro and in vivo experiments show that the developed device conforms to standard clinical procedure and its pressure measurement can evaluate the real-time efficacy of the angioplasty procedure. The study provides a paradigm for developing electronic interventional devices. © 2023 IEEJ.

关键词： balloon catheter Biomedical sensor hemodynamic evaluation pressure sensor

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Unconventional surface responses of fourfold-degenerate Dirac-nodal-line semimetals in sonic crystals

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Physical Review Applied 2023年第6期20卷 064047-064047页

作者： Chang-Yin Ji Jijie Tang Xiao-Ping Li Zheng Tang Di Zhou Yeliang Wang Feng Li Jiafang Li Yugui Yao Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems and School of Physics Beijing Institute of Technology Beijing 100081 China School of Integrated Circuits and Electronics Ministry of Industry and Information Technology (MIIT) Key Laboratory for Low-Dimensional Quantum Structure and Devices Beijing Institute of Technology Beijing 100081 China School of Physical Science and Technology Inner Mongolia University Hohhot 010021 China

Three-dimensional nodal-line semimetals (NLSMs) are of remarkable importance for both enriching topological physics and wave management. However, NLSMs realized in acoustic systems are twofold band degenerate and are called Weyl NLSMs. Here, we report on the experimental observation of Dirac NLSMs with fourfold degeneracy in sonic crystals. We reveal that the topological properties of the Dirac NLSMs are entirely different than those of the conventional Weyl NLSMs. The Berry phase related to the Dirac nodal line (DNL) is 2π, which results in surface responses of the Dirac NLSMs in two radically different situations: a torus surface state occupying the entire surface Brillouin zone (SBZ) and one without any surface state in the SBZ. We further reveal that topological surface arcs caused by the DNL can change from open to closed contours. The findings of Dirac NLSMs and their unique surface response may bring about exciting frontiers for the flexible manipulation of acoustic surface waves.

关键词： Acoustic metamaterials Edge states Geometric & topological phases Topological insulators Dirac semimetal Semimetals Weyl semimetal

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