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ⅢA-ⅡB multicomponent perovskite rare earth ferrites with promising electromagnetic wave absorption properties

journal of Rare Earths 2024年第6期42卷 1118-1127,I0005页

作者： Yanyan He Tao chen Yanyu Pan Minzhong Huang Kaixian Wang Liyan Xue Yazhu Li Fengzhi Tan Fan Yang Tongkuan Xu Heng chen School of Light Industry and Chemical Engineering Dalian Polytechnic UniversityDalian116034China Xiamen Institute of Rare EarthMaterials Haixi InstitutesChinese Academy of SciencesXiamen36021China Fujian Institute of Research on the Structure of Matter Chinese Academyof SciencesFuzhou350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China Xiamen Key-Laboratoryof Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen361021China Key Laboratory of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou3410ooChina

Perovskite-type rare-earth ferrites(REFeO_(3))are promising materials for absorbing electromagnetic(EM)wave ***,insufficient dielectric loss and poor impedance matching are key factors that limit the broader implementation of REFeO_(3).Herein,a series of multicomponent perovskite-type ferrites with strong EM wave absorption capabilities was *** the synergistic effect of chemical constitution regulation and entropy regulation,optimization of the dielectric loss and impedance matching is achieved by strengthening the structural defect mechanism,thus further adjusting the EM wave absorption *** with(LaGdSmNdBa)FeO_(3)(HE-1)and(LaGdPrSmNdBa)FeO_(3)(HE-2),(LaGdBa)FeO_(3)(ME-1)and(LaGdSmBa)FeO_(3)(ME-2)exhibit favorable performance,with optimal minimum reflection loss(RL_(min))of-56.35 dB(at 11.12 GHz)and-63.25 dB(at 7.22 GHz)and effective absorption bandwidth(EAB)of 4.46 and 4.72 GHz,*** multicomponent design provides a new strategy for the development of EM wave absorption materials.

关键词： Rare earths Multicomponent design Rare earth ferrites Entropy regulation Electromagnetic wave absorption

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Surface air temperature change in the Wuyi Mountains,southeast China

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journal of Mountain Science 2024年第6期21卷 1992-2004页

作者： QIN Yihui WEI Yuxing LU jiayi Mao jiahui chen Xingwei Gao Lu chen Ying LIU Meibing DENG Haijun Institute of Geography Fujian Normal UniversityFuzhou 350117China National Demonstration Center for Experimental Geography Education Fujian Normal UniversityFuzhou 350117China School of Geographical Science Fujian Normal UniversityFuzhou 350117China Fujian Provincial Engineering Research Center for Monitoring and Assessing Terrestrial Disasters Fujian Normal UniversityFuzhou 350117China Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education Fujian Normal UniversityFuzhou 350117China

Detecting changes in surface air temperature in mid-and low-altitude mountainous regions is essential for a comprehensive understanding of warming trend with *** use daily surface air temperature data from 64 meteorological stations in Wuyi Mountains and its adjacent regions to analyze the spatio-temporal patterns of temperature *** results show that Wuyi Mountains have experienced significant warming from 1961 to *** warming trend of the mean temperature is 0.20℃/decade,the maximum temperature is 0.17℃/decade,and the minimum temperature is 0.26℃/*** 1961-1990,more than 63%of the stations showed a decreasing trend in annual mean temperature,mainly because the maximum temperature decreased during this ***,in 1971-2000,1981-2010 and 1991-2018,the maximum,minimum and mean temperatures *** fastest increasing trend of mean temperature occurred in the southeastern coastal plains,the quickest increasing trend of maximum temperature occurred in the northwestern mountainous region,and the increase of minimum temperature occurred faster in the southeastern coastal and northwestern mountainous regions than that in the central ***,this study suggests that elevation does not affect warming in the Wuyi *** results are beneficial for understanding climate change in humid subtropical middle and low mountains.

关键词： Climate change Surface air temperature Temporal and spatial changes Mann-Kendall nonparametric test Wuyi Mountains

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Fault Estimation for a Class of Markov jump Piecewise-Affine Systems: Current Feedback Based Iterative Learning Approach

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IEEE/CAA journal of Automatica Sinica 2024年第2期11卷 418-429页

作者： Yanzheng Zhu Nuo Xu Fen Wu Xinkai chen Donghua Zhou IEEE College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China College of Mechanical Engineering and Automation Huaqiao UniversityXiamen 361021China Department of Mechanical and Aerospace Engineering North Carolina State UniversityRaleigh NC 27695 USA Department of Electronic and Information Systems Shibaura Institute of TechnologySaitama 337-8570Japan

In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuoustime Markov jump piecewise-affine(PWA) systems against actuator and sensor faults. Firstly, a novel mode-dependent PWA iterative learning observer with current feedback is designed to estimate the system states and faults, simultaneously, which contains both the previous iteration information and the current feedback mechanism. The auxiliary feedback channel optimizes the response speed of the observer, therefore the estimation error would converge to zero rapidly. Then, sufficient conditions for stochastic stability with guaranteed performance are demonstrated for the estimation error system, and the equivalence relations between the system information and the estimated information can be established via iterative accumulating ***, two illustrative examples containing a class of tunnel diode circuit systems are presented to fully demonstrate the effectiveness and superiority of the proposed iterative learning observer with current feedback.

关键词： Current feedback fault estimation iterative learning observer Markov jump piecewise-affine system

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Body-force modeling considering induced upstream effects for a transonic compressor with total temperature distortion

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Chinese journal of Aeronautics 2024年第6期37卷 7-19页

作者： jiahui QIU chen YANG Wenqiang ZHANG Min ZHANG juan DU Digital Twin Research Center Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Engineering and Science University of Chinese Academy of SciencesBeijing 100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Chinese Academy of SciencesBeijing 100190China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

To numerically study the impact of total temperature distortion on a transonic compressor with reduced computational costs,a Body-Force Model(BFM)is ***,the interactions between the distorted flow and the compressor are analyzed using full-annulus Unsteady Reynolds-Averaged Navier-Stokes(URANS)results and the orbit *** is found that the induced swirl distortion and the mass flux nonuniformity are intensified in the compressor upstream flow field.A correction factor is thus added to the BFM to account for the effect of the induced swirl,which is crucial for the accurate representation of distortion transfer in the ***,steady simulations with large-amplitude 180circumferential total temperature distortion are performed using the developed *** is shown that the distorted compressor map simulated with the BFM matches well with URANS *** circumferential phase shift of total temperature and the generation of the additional total pressure distortion across the rotor are in line with the time-averaged URANS flow *** compressor upstream effects on the distorted inflow can also be exactly *** above-mentioned results demonstrate the BFM developed in this paper can effectively capture the distorted flow features inside the compressor,and significantly reduce the computational costs by five orders of magnitude compared with URANS.

关键词： Upstream effect Orbit method Induced swirl distortion Body force model Correction factor Time-averaged URANS

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Development of a novel Eu^(3+)-doped tantalate red-emitting phosphor for w-LEDs application

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journal of Rare Earths 2024年第8期42卷 1479-1488,I0003页

作者： Fan Zeng jingjing Ru Bing Zhao Feiyun Guo jianzhong chen College of Chemistry and Materials Fujian Province University Key Laboratory of Green Energy and Environment CatalysisNingde Normal University.Ningde352100China School of Environment and Resources School of Carbon Neutral and Modern IndustryFujian Normal UniversityFuzhou350007China College of Information and Mechanical&Electrical Engineering Ningde Normal UniversityNingde352100China College of Chemistry Fuzhou UniversityFuzhou350108China

Two novel phosphors LiBa_(4(1-x))Eu_(4x)Ta_(3)O_(12)(H-LBTO:xEu^(3+)) and Li_(0.25)Ba_(1-x)Eu_(x)Ta_(0.75)O_(3)(C-LBTO:xEu^(3+))were prepared successfully by a molten salt *** transformation between these two structures was realized by changing the sintering temperature or changing the Eu^(3+) ions concentration,which was also demonstrated by the X-ray diffraction(XRD),scanning electron microscopy(SEM),diffuse reflectance spectra(DRS),and photoluminescence excitation(PLE) analyses,Both the sintering temperature and the Eu^(3+)ions doping concentration have significant impact on the formation of the crystal *** these phosphors sintered at 1023 K exhibit two major luminescence lines at 594 and 614 nm under nearUV light of 395 nm excitation,corresponding to Eu^(3+)ions typical transitions of ^(5)D_(0)→^(7)F_(1) and ^(5)D_(0)→^(7)F_(2).The optimum concentration of Eu^(3+) ions is 9 mol% for C-LBTO:xEu^(3+) samples and the quenching interaction type is the nearest-neighbor ion *** thermal stability of the C-LBTO:0.09Eu^(3+)sample was investigated in detail and the device application further suggests that C-LBTO:0.09Eu^(3+) can be used as a red phosphor for near-UV excited w-LEDs in lighting.

关键词： Phosphor Tantalate LED device Rare earths

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Carrier transport barrier in AlGaN-based deep ultraviolet LEDs on offcut sapphire substrates

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Chinese Optics Letters 2024年第2期22卷 148-158页

作者：陈秋爽陈荔陈聪高歌郭炜叶继春 Ningbo Institute of Materials Technology and Engineering Ningbo 315201China University of Chinese Academy of Sciences Beijing 100049China

AlGaN-based light-emitting diodes(LEDs)on offcut substrates enhance radiative emission via forming carrier localization centers in multiple quantum wells(MQWs).This study introduces the carrier transport barrier concept,accessing its impact on the quantum efficiency of LEDs grown on different offcut sapphire substrates.A significantly enhanced internal quantum efficiency(IQE)of 83.1%is obtained from MQWs on the 1°offcut sapphire,almost twice that of the controlled 0.2°offcut ***,1°offcut LEDs have higher turn-on voltage and weaker electroluminescence than 0.2°*** calculations demonstrate the existence of a potential barrier on the current path around the step-induced Ga-rich ***-rich stripes reduce the turn-on voltage but restrict sufficient driving current,impacting LED performance.

关键词： carrier localization step-bunching potential barrier offcut substrate DUV LEDs

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Comprehensive,Continuous,and Vertical Measurements of Seawater Constituents with Triple-Field-of-View High-Spectral-Resolution Lidar

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Research 2024年第2期2023卷 191-201页

作者： Kai Zhang Yatong chen Hongkai Zhao Zhongping Lee Emmanuel Boss Iwona Stachlewska Davide Dionisi Cedric jamet Paolo D.Girolamo Aleksey Malinka chengchong jiang Hongda Wu Lingyun Wu Feitong chen Xiaolei Zhu Nanchao Wang Chuxiao chen Qun Liu Lan Wu Yudi Zhou Weibiao chen Dong Liu Ningbo Research Institute State Key Laboratory of Modern Optical InstrumentationCollege of Optical Science and EngineeringZhejiang UniversityHangzhou 310027China ZjU-Hangzhou Global Scientific and Technological lnnovation Center Zhejang UniversityHangzhou 311200China Donghai Laboratory.Zhoushan 316021 China State Key Lab of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China School of Marine Sciences University of MaineOronoME 04469-5741USA Faculty of Physics University of WarsawWarsaw 02093Poland institute of Marine Sciences Italian National Research CouncilRome 00133Italy Universitédu Littoral Cote d'Opale CNRSUniv.LilleIRDUMR 8187-LOG-Laboratoire d'Oceanologie et de GéosciencesWimereux F-6293 Francen Institute Scuola di Ingegneria Universita della BasilicataPotenza 85100Italy Institute of Physics National Academy of Sciences of BelarusMinsk 220072Belarus Key Laboratory of Space Laser Communication and Detection Technology Shanghai lnstitute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Inteligent Optics&Photonics Research Center Jiaxing Research Institute Zhejiang UniversityJiaxing 314000China jiaxing Key Laboratory of Photonic Sensing&Intelligent Imaging Jiaxing 314000China

Measuring the characteristics of seawater constituent is in great demand for studies of marine ecosystems and ***,existing techniques based on remote sensing or in situ samplings present various tradeoffs with regard to the diversity,synchronism,temporal-spatial resolution,and depth-resolved capacity of their data ***,we demonstrate a novel oceanic triple-field-of-view(FOV)high-spectral-resolution lidar(HSRL)with an iterative retrieval *** technique provides,for the first time,comprehensive,continuous,and vertical measurements of seawater absorption coefficient,scattering coefficient,and slope of particle size distribution,which are validated by simulations and field ***,it depicts valuable application potentials in the accuracy improvement of seawater classification and the continuous estimation of depth-resolved particulate organic carbon *** triple-FOV HSRL with high performance could greatly increase the knowledge of seawater constituents and promote the understanding of marine ecosystems and biogeochemistry.

关键词： lidar Vertical seawater

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Efficient and Fast X-Ray Luminescence in Organic Phosphors Through High-Level Triplet-Singlet Reverse Intersystem Crossing

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CCS Chemistry 2024年第2期6卷 334-341页

作者： Yang Zhang Minghong chen Xiaoze Wang Miao Lin Hongyu Wang Weihong Li Fuhai chen Qing Liao Hongming chen Qiushui chen Meijin Lin Huanghao Yang Key Laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhouFujian 350116 New Cornerstone Science Laboratory MOE Key Laboratory for Analytical Science of Food Safety and BiologyCollege of ChemistryFuzhou UniversityFuzhouFujian 350108 College of Materials Science and Engineering Fuzhou UniversityFuzhouFujian 350116

Organic scintillators that efficiently generate bright triplet excitons are of critical importance for highperformance X-ray-excited luminescence in radiation ***,the nature of triplet-singlet spinforbidden transitions in these materials often result in long-lived phosphorescence,which is undesirable for ultrafast X-ray detection and *** we demonstrate that the effect of hybridized local and charge-transfer(HLCT)excited states enables organic scintillators to exhibit highly efficient and fast radioluminescence(RL)in response to X-ray *** experimental and theoretical investigation shows that the oxidized 1,8-naphthalimide-phenothiazine dyad(OMNI-PTZ 2)with HLCT-excited states has an enhanced overlap integral of the highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)on MNIπ-orbitals,and moderate donor–acceptor electron *** a result,the RL of these crystals exhibits a 61-fold increase and its monoexponential decay lifetime is three orders of magnitude faster compared to its corresponding thermally activated delayed fluorescence(TADF)molecule MNI-PTZ *** further demonstrate the practical utility of the OMNI-PTZ 2(G)in high-performance X-ray detection and imaging,achieving an X-ray dose sensitivity of 97 nGy s−1 and an exceptional spatial resolution of 20 lp/*** study provides a promising molecular design principle for utilizing triplet excitons to develop high-efficiency and fast X-ray scintillators for the development of next-generation flexible and stretchable X-ray imaging detectors.

关键词： organic scintillators X-ray imaging hybridized local and charge transfer excited state triplet-singlet reverse intersystem crossing high exciton utilization

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Rice stripe mosaic virus hijacks rice heading‐related gene to promote the overwintering of its insect vector

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journal of Integrative Plant Biology 2024年第9期66卷 2000-2016页

作者： Siping chen Xinyi Zhong Zhiyi Wang Biao chen Xiuqin Huang Sipei Xu Xin Yang Guohui Zhou Tong Zhang Guangdong Province Key Laboratory of Microbial Signals and Disease Control College of Plant ProtectionSouth China Agricultural UniversityGuangzhou 510642China State Key Laboratory of Green Pesticide South China Agricultural UniversityGuangzhou 510642China

Rice stripe mosaic virus(RSMV)is an emerging pathogen which significantly reduces rice yields in the southern region of *** is transmitted by the leafhopper Recilia dorsalis,which overwinters in rice *** field investigations revealed that RSMV infection causes delayed rice heading,resulting in a large number of green diseased plants remaining in winter rice *** creates a favorable environment for leafhoppers and viruses to overwinter,potentially contributing to the rapid spread and epidemic of the ***,we explored the mechanism by which RSMV manipulates the developmental processes of the rice plant.A rice heading‐related E3 ubiquitin ligase,Heading date Associated Factor 1(HAF1),was found to be hijacked by the RSMV‐encoded *** impairment of HAF1 function affects the ubiquitination and degradation of downstream proteins,HEADING DATE 1 and EARLY FLOWERING3,leading to a delay in rice *** results provide new insights into the development regulation‐based molecular interactions between virus and plant,and highlights the importance of understanding virus‐vector‐plant tripartite interactions for effective disease management strategies.

关键词： HAF1 heading leafhoppers overwintering RSMV

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Structural transition,electric transport,and electronic structures in the compressed trilayer nickelate La_(4)Ni_(3)O_(10)

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 9-15页

作者： jingyuan Li Cui-Qun chen Chaoxin Huang Yifeng Han Mengwu Huo Xing Huang Peiyue Ma Zhengyang Qiu junfeng chen Xunwu Hu Lan chen Tao Xie Bing Shen Hualei Sun Dao-Xin Yao Meng Wang Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China Center for Materials of the Universe School of Molecular SciencesArizona State UniversityTempe 85287USA School of Sciences Sun Yat-sen UniversityShenzhen 518107China

Atomic structure and electronic band structure are fundamental properties for understanding the mechanism of superconductivity. Motivated by the discovery of pressure-induced high-temperature superconductivity at 80 K in the bilayer Ruddlesden-Popper nickelate La_(3)Ni_(2)O_(7), the atomic structure and electronic band structure of the trilayer nickelate La_(4)Ni_(3)O_(10) under pressure up to 44.3 GPa are investigated. A structural transition from the monoclinic P2_(1)/a space group to the tetragonal I4/mmm around 12.6-13.4 GPa is identified, accompanied by a drop of resistance below 7 K. Density functional theory calculations suggest that the bonding state of Ni 3d_(z^(2)) orbital rises and crosses the Fermi level at high pressures, which may give rise to possible superconductivity observed in resistance under pressure in La_(4)Ni_(3)O_(10). The trilayer nickelate La_(4)Ni_(3)O_(10) shows some similarities with the bilayer La_(3)Ni_(2)O_(7) and has unique properties, providing a new platform to investigate the underlying mechanism of superconductivity in nickelates.

关键词： La_(4)Ni_(3)O_(10) high pressure synchrotron X-ray diffraction structural transition DFT calculations

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