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IEEE/CAA j.urnal 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 j.mp 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 j.mp piecewise-affine system

Underwater four-quadrant dual-beam circumferential scanning laser fuze using nonlinear adaptive backscatter filter based on pauseable SAF-LMS algorithm

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Defence Technology（防务技术） 2024年第7期37卷 1-13页

作者： Guangbo xu Bingting Zha Hailu Yuan Zhen Zheng He Zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjing 210094China Science and Technology on Electromechanical Dynamic Control Laboratory Beijing 100081China Shanghai Radio Equipment Research Institute Shanghai 201109China

The phenomenon of a target echo peak overlapping with the backscattered echo peak significantly undermines the detection range and precision of underwater laser *** overcome this issue,we propose a four-quadrant dual-beam circumferential scanning laser fuze to distinguish various interference signals and provide more real-time data for the backscatter filtering *** enhances the algorithm loading capability of the *** order to address the problem of insufficient filtering capacity in existing linear backscatter filtering algorithms,we develop a nonlinear backscattering adaptive filter based on the spline adaptive filter least mean square(SAF-LMS)*** also designed an algorithm pause module to retain the original trend of the target echo peak,improving the time discrimination accuracy and anti-interference capability of the ***,experiments are conducted with varying signal-to-noise ratios of the original underwater target echo *** experimental results show that the average signal-to-noise ratio before and after filtering can be improved by more than31 d B,with an increase of up to 76%in extreme detection distance.

关键词： Laser fuze Underwater laser detection Backscatter adaptive filter Spline least mean square algorithm Nonlinear filtering algorithm

Experimental study of face passive failure features of a shallow shield tunnel in coastal backfill sand

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 252-271页

作者： Weifeng QIAN Ming HUANG Bingnan WANG Chaoshui xu Yanfeng HU School of Civil Engineering Fuzhou UniversityFuzhou 350108China School of Civil Environment and Mining EngineeringUniversity of AdelaideAdelaide 5005Australia China First Highway Xiamen Engineering Co. Ltd.Xiamen 361000China

Face passive failure can severely damage existing structures and underground utilities during shallow shield tunneling,especially in coastal backfill *** this work,a series of laboratory model tests were developed and conducted to investigate such failure,for tunnels located at burial depth ratios for which C/D=0.5,0.8,1,and *** pressures,the evolution of failure processes,the failure modes,and the distribution of velocity fields were examined through model tests and numerical *** support pressure in the tests first rose rapidly to the elastic limit and then gradually increased to the maximum value in all *** maximum support pressure decreased slightly in cases where C/D=0.8,1,and 1.3,but the rebound was insignificant where C/D=*** addition,the configuration of the failure mode with C/D=0.5 showed a wedge-shaped arch,which was determined by the outcropping shear *** configuration of failure modes was composed of an arch and the inverted trapezoid when C/D=0.8,1,and 1.3,in which the mode was divided into lower and upper failure zones.

关键词： tunnel face stability passive failure model test support pressure failure mode

Deep Learning for Financial Time Series Prediction:A State-of-the-Art Review of Standalone and HybridModels

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 187-224页

作者： Weisi Chen Walayat Hussain Francesco Cauteruccio xu Zhang School of Software Engineering Xiamen University of TechnologyXiamen361024China Peter Faber Business School Australian Catholic UniversityNorth Sydney2060Australia Department of Information Engineering Polytechnic University of MarcheAncona60121Italy

Financial time series prediction,whether for classification or regression,has been a heated research topic over the last *** traditional machine learning algorithms have experienced mediocre results,deep learning has largely contributed to the elevation of the prediction ***,the most up-to-date review of advanced machine learning techniques for financial time series prediction is still lacking,making it challenging for finance domain experts and relevant practitioners to determine which model potentially performs better,what techniques and components are involved,and how themodel can be designed and *** review article provides an overview of techniques,components and frameworks for financial time series prediction,with an emphasis on state-of-the-art deep learning models in the literature from2015 to 2023,including standalonemodels like convolutional neural networks(CNN)that are capable of extracting spatial dependencies within data,and long short-term memory(LSTM)that is designed for handling temporal dependencies;and hybrid models integrating CNN,LSTM,attention mechanism(AM)and other *** illustration and comparison purposes,models proposed in recent studies are mapped to relevant elements of a generalized framework comprised of input,output,feature extraction,prediction,and related *** the state-of-the-artmodels,hybrid models like CNNLSTMand CNN-LSTM-AM in general have been reported superior in performance to stand-alone models like the CNN-only *** remaining challenges have been discussed,including non-friendliness for finance domain experts,delayed prediction,domain knowledge negligence,lack of standards,and inability of real-time and highfrequency *** principal contributions of this paper are to provide a one-stop guide for both academia and industry to review,compare and summarize technologies and recent advances in this area,to facilitate smooth and informed implementation,and t

关键词： Financial time series prediction convolutional neural network long short-term memory deep learning attention mechanism finance

Coexistence of antiferromagnetism and unconventional superconductivity in a quasi-one-dimensional flat-band system:Creutz lattice

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Chinese Physics B 2024年第3期33卷 583-588页

作者：徐峰张磊 School of Physics and Telecommunication Engineering Shaanxi University of TechnologyHanzhong 723001China

We study the coexistence of antiferromagnetism and unconventional superconductivity on the Creutz lattice which shows strictly flat bands in the noninteracting *** famous renormalized mean-field theory is used to deal with strong electron-electron repulsive Hubbard interaction in the effective low-energy t-j.model,the superfluid weight of the unconventional superconducting state has been calculated via the linear response *** unconventional superconducting state with both spin-singlet and staggered spin-triplet pairs emerges beyond a critical antiferromagnetic coupling interaction,while antiferromagnetism accompanies this *** superconducting state with only spin-singlet pairs is dominant with paramagnetic *** A phase is analogous to the pseudogap phase,which shows that electrons go to form pairs but do not cause a *** also show the superfluid behavior of the unconventional superconducting state and its critical *** is proven directly that the flat band can effectively raise the critical temperature of *** is implementable to simulate and control strongly-correlated electrons'behavior on the Creutz lattice in the ultracold atoms experiment or other artificial *** results may help the understanding of the interplay between unconventional superconductivity and magnetism.

关键词： flat-band unconventional superconductivity antiferromagnetism strong electron-electron interaction superfluid weight

Linking leaf elemental traits to biomass across forest biomes in the Himalayas

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Science China Earth Sciences 2024年第5期67卷 1518-1528页

作者： Nita DYOLA Eryuan LIANG j.sep PEÑUELAS j.j.lio CAMARERO Shalik Ram SIGDEL Sugam ARYAL Wentao LIN Xiang LIU Yongwen LIU Xingliang xu Sergio ROSSI State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Laboratoire sur lesécosystèmes terrestres boréaux Département des Sciences FondamentalesUniversitédu QuébecàChicoutimi555Boulevard de l′UniversitéChicoutimi(QC)G7H2B1Canada CSIC Global Ecology Unit CREAF-CSIC-UABBellaterraE-08193 CataloniaSpain CREAF Cerdanyola del VallèsE-08193 CataloniaSpain Instituto Pirenaico de Ecología(IPE-CSIC) Avenida Montañana 1005Zaragoza 50059Spain Friedrich-Alexander-Universität Erlangen-Nürnberg Institut für GeographieErlangen 91058Germany State Key Laboratory of Grassland Agro-Ecosystems College of EcologyLanzhou UniversityLanzhou 730000China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Plants require a number of essential elements in different proportions for ensuring their growth and *** elemental concentrations in leaves reflect the functions and adaptations of plants under specific environmental ***,less is known about how the spectrum of leaf elements associated with resource acquisition,photosynthesis and growth regulates forest biomass along broad elevational *** examined the influence of leaf element distribution and diversity on forest biomass by analyzing ten elements(C,N,P,K,Ca,Mg,Zn,Fe,Cu,and Mn)in tree communities situated every 100 meters along an extensive elevation gradient,ranging from the tropical forest(80 meters above sea level)to the alpine treeline(4200 meters above sea level)in the Kangchenj.nga Landscape in eastern Nepal *** calculated communityweighted averages(reflecting dominant traits governing biomass,i.e.,mass-ratio effect)and functional divergence(reflecting increased trait variety,i.e.,complementarity effect)for leaf elements in a total of 1,859 trees representing 116 *** increasing mass-ratio effect and decreasing complementarity in leaf elements enhance forest biomass accumulation.A combination of elements together with elevation explains biomass(52.2%of the variance)better than individual elemental trait diversity(0.05%to 21%of the variance).Elevation modulates trait diversity among plant species in biomass *** promotes biomass at lower elevations,but reduces biomass at higher elevations,demonstrating an interaction between elevation and *** interaction between elevation and mass-ratio effect produces heterogeneous effects on biomass along the elevation *** research indicates that biomass accumulation can be disproportionately affected by elevation due to interactions among trait diversities across vegetation *** higher trait variation enhances the adaptation of species to environmental changes,it reduces

关键词： Ecosystem function Elevational gradient Functional diversity Functional traits Leaf elements Niche complementarity

Aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders:progress of experimental models based on disease pathogenesis

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Neural Regeneration Research 2025年第2期20卷 354-365页

作者： Li xu Huiming xu Changyong Tang Department of Neurology The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor *** date,no effective treatment exists as the exact causative mechanism remains ***,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic *** most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets *** experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum *** this review,we summarize the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model *** addition,this review summarizes the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials.

关键词： aquaporin-4 experimental model neuromyelitis optica spectrum disorder pathogenesis

Breaking the boundaries of biological penetration depth:X-ray luminescence in light theranostics

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Science China Chemistry 2024年第4期67卷 1056-1059页

作者： Zhij.an Yang Qiaohong xu Qiushui Chen Huanghao Yang New Cornerstone Science Laboratory Key Laboratory for Analytical Science of Food Safety and Biology of Ministry of EducationCollege of ChemistryFuzhou UniversityFuzhou 350002China Fuj.an Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

Advances in luminescence materials have markedly propelled research in light theranostics,spanning luminescence biosensing[1],in vivo optical imaging[2],photodynamic therapy[3],optogenetics[4],and related fields[5-7].Nevertheless,conventional light sources have limited penetration depths within deep tissues,and the current state of light theranostics in superficial tissues does not fulfill the requirements for deep tissue treatments in clinical applications.

关键词： luminescence light spanning

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Agriculture green development in China: insights and advances

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Frontiers of Agricultural Science and Engineering 2024年第1期11卷 5-19,I0005页

作者： j.anbo SHEN Qichao ZHU Yong HOU Wen-Feng CONG Wen xu j.uliang xu Zhichao AN Xiaoqiang j.AO Kai ZHANG Tianxiang YU Lin MA Oene OENEMA William j.DAVIES Fusuo ZHANG State Key Laboratory of Nutrient Use and Management College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China Key Laboratory of Agricultural Water Resources Center for Agricultural Resources ResearchInstitute of Genetic and Developmental BiologyChinese Academy of SciencesShijiazhuang 050021China Wageningen Environmental Research Wageningen University&ResearchWageningen6700 AAthe Netherlands Lancaster Environment Centre University of LancasterLancasterLA14YQUK

Reconciling the tasks of producing adequate amounts of nutritious food for the increasing global population while preserving the environment and natural ecosystems simultaneously is an enormous challenge. The concept of agriculture green development(AGD) and the necessary governmental policies were developed to address the aforementioned challenge in China and to help achieve the related global sustainable development goals. Agriculture green development emphasizes the synergy between green and development;current agriculture has to transform from the intensive farming with high inputs, high environmental impacts and low resource-use efficiency to a more sustainable agriculture, in order to ensure an adequate supply of nutritious food while delivering environmental integrity, improved economic profitability,and social equity. A research program on AGD was established by China Agricultural University with four research themes, namely: green crop production, green integrated crop-animal production, green food and industry,and green ecological environment and ecosystem services, to provide a scientific basis for future developments and to facilitate the implementation of AGD in practice. AGD requires a multistakeholder approach, fueled by innovative and interdisciplinary research. j.int actions have to be taken by governments, farmers, supply industries, consumers, educators, extension services and researchers to support AGD. This requires strong coordination and public awareness campaigns. This review presents the progress that has been made over the past 5 years and makes recommendations for more research and development, in order to better deliver agricultural green and sustainable development on national and international scales.

关键词： Agriculture ecosystem services environmental protection food security green development multi-sectoral cooperation sustainable development

Significant annealing-induced hardening effect in nanolaminate d-nanotwinne d(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)me dium-entropy alloy by severe cold rolling

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j.urnal of Materials Science & Technology 2024年第3期170卷 156-166页

作者： Shuqing Yuan Hui Fu Lei Qian Chi Fai Cheung xu-Sheng Yang State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Due to the easy coarsening caused by poor thermal stability,the verified annealing-induced hardening in nanograined metals can only maintain at a relatively low-temperature *** this study,a nanolam-inated(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)medium-entropy alloy with an average lamellae thickness of∼20 nm embedded by thinner nanotwins was fabricated by severe cold rolling to achieve superior thermal *** with the conventional nanotwinned CrCoNi with nanotwins inside ultra-fined grains,the hier-archical nanolaminated-nanotwinned(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8) exhibits a significant annealing-induced hard-ening effect,i.e.,hardness increasing from∼250 HV in the original specimen to∼500 HV in the cold-rolled status and finally∼630 HV after annealing at 600℃for 1 *** microstructure characterizations reveal that the reduced dislocation density and formation of L1_(2)ordered domain are mainly responsible for such hardening effect,which is facilitated by the effectively suppressed coarsening with annealing temperature,i.e.,slow detwinning process and well-retained low-angle nanolamellar *** coarsening mechanisms from the cold-rolled nanolamellae to the fully recrystallized micro-equiaxed structures under the annealing temperatures ranging from 400 to 800℃ were also elucidated by atomic observations.

关键词： Annealing-induced hardening Thermal stability Nanolaminated-nanotwinned structure CrCoNi Detwinning Grain boundary migration