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Dominant woody plant species recognition with a hierarchical model based on multimodal geospatial data for subtropical forests

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Journal of Forestry Research 2024年第3期35卷 111-130页

作者： xin Chen Yujun Sun State Forestry&Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083People's Republic of China

Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable ***,the potential of GEE for forest resource management has not been fully *** extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast *** and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant *** results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source ***,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was *** terrain factors and removing spatial correlation from NFRI sample points further improved the recognition *** optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,*** high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant *** the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.

关键词： Google Earth Engine Sentinel Forest resource inventory data Dominant woody plant species Subtropics Model performance

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A two-field-scan harmonic Hall voltage analysis for fast, accurate quantification of spin-orbit torques in magnetic heterostructures

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Science China(Physics,Mechanics & Astronomy) 2024年第10期Mechanics & Astronomy) .卷 109-116页

作者： xin Lin Lijun Zhu State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences

We report on the development of a “two-field-scan” harmonic Hall voltage(HHV) analysis, which collects the second HHVas a function of a swept in-plane magnetic field at 45° and 0° relative to the excitation current, for the determination of the spin-orbit torques of transverse spins in magnetic heterostructures without significant perpendicular spins, longitudinal spins, and longitudinal/perpendicular Oersted fields. We demonstrate that this two-field-scan analysis is as accurate as the well-established but time-consuming angle-scan HHV analysis even in the presence of considerable thermoelectric effects but takes more than a factor of 7 less measurement time. We also show that the fit of the HHV data from a single field scan at 0°, which is commonly employed in the literature, is not reliable because the employment of too many free parameters in the fitting of the very slowly varying HHV signal allows erroneous conclusion about the spin-orbit torque efficiencies.

关键词： spin-orbit torque spin current spin-orbit coupling spintronics

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Dissipation-Driven Superradiant Phase Transition of a Two-Dimensional Bose-Einstein Condensate in a Double Cavity

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Chinese Physics Letters 2024年第6期41卷 44-48页

作者： Bo-Hao Wu xin-xin Yang Yu Chen Wei Zhang Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China Graduate School of China Academy of Engineering Physics Beijing 100193China Beijing Academy of Quantum Information Sciences Beijing 100193China

We study superradiant phase transitions in a hybrid system of a two-dimensional Bose–Einstein condensate of atoms and two cavities arranged with a tilt *** adjusting the loss rate of cavities,we map out the phase diagram of steady states within a mean field *** is found that when the loss rates of the two cavities are different,superradiant transitions may not occur at the same time in the two cavities.A first-order phase transition is observed between the states with only one cavity in superradiance and both in *** the case that both cavities are superradiant,a net photon current is observed flowing from the cavity with small decay rate to the one with large decay *** photon current shows a non-monotonic dependence on the loss rate difference,owing to the competition of photon number difference and cavity field phase *** findings can be realized and detected in experiments.

关键词： Einstein transitions decay

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Activation of leukotriene B_(4)receptor 1 is a prerequisite for complement receptor 3-mediated antifungal responses of neutrophils

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Cellular & Molecular Immunology 2024年第3期21卷 245-259页

作者： Yan xin Sihan Xiong Linghong Zhou xin Lin Institute for Immunology and School of Medicine Tsinghua University100084BeijingChina Tsinghua University-Peking University Center for Life Sciences 100084BeijingChina Department of Infectious Diseases Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency ResponseNational Medical Center for Infectious DiseasesHuashan HospitalFudan UniversityShanghai200040China

Invasive fungal infections are life-threatening,and neutrophils are vital cells of the innate immune system that defend against *** role of LTA4H-LTB_(4)-BLT1 axis in regulation of neutrophil responses to fungal infection remains poorly ***,we demonstrated that the LTA4H-LTB_(4)-BLT1 axis protects the host against Candida albicans and Aspergillus fumigatus,but not Cryptococcus neoformans infection,by regulating the antifungal activity of *** results show that deleting Lta4h or Blt1 substantially impairs the fungal-specific phagocytic capacity of ***,defective activation of the spleen tyrosine kinase(Syk)and extracellular signal-related kinase(ERK1/2)pathways in neutrophils accompanies this ***,BLT1 regulates CR3-mediated,β-1,3-glucan-induced neutrophil phagocytosis,while a physical interaction with CR3 with slight influence on its dynamics is *** findings thus demonstrate that the LTA4H-LTB_(4)-BLT1 axis is essential for the phagocytic function of neutrophils in host antifungal immune response against Candida albicans and Aspergillus fumigatus.

关键词： LTA4H BLT1 Phagocytosis Complement receptor 3 Fungi

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Parametric study on contact sensors for MASW measurement-based interfacial debonding detection for SCCS

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 331-344页

作者： Chen Hongbing Pang xin Gan Shiyu Li Yuanyuan Gokarna Chalise Nie xin Research Institute of Urbanization and Urban Safety School of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijing 100083China Department of Civil Engineering Tsinghua UniversityBeijing 100084China Faculty of Infrastructure Engineering Dalian University of TechnologyDalian 116081China

Steel-concrete composite structures(SCCS)have been widely used as primary load-bearing components in large-scale civil *** the basis of the co-working ability of steel plate and concrete,the bonding status plays an essential role in guaranteeing the structural performance of ***,efficient non-destructive testing(NDT)on interfacial debondings in SCCS has become a prominent research ***-channel analysis of surface waves(MASW)has been validated as an effective NDT technique for interfacial debonding detection for ***,the feasibility of MASW must be validated using experimental *** study establishes a high-frequency data synchronous acquisition system with 32 channels to perform comparative verification experiments in ***,the current sensing approaches for high-frequency vibration and stress waves are ***,three types of contact sensors,namely,piezoelectric lead-zirconate-titanate(PZT)patches,accelerometers,and ultrasonic transducers,are selected for MASW ***,the selection and optimization of the force hammer head are *** experiments are carried out for the optimal selection of ultrasonic transducers,PZT patches,and accelerometers for MASW *** addition,the influence of different pasting methods on the output signal of the sensor array is *** results indicate that optimized PZT patches,acceleration sensors,and ultrasonic transducers can provide efficient data acquisition for MASW-based non-destructive *** research findings in this study lay a solid foundation for analyzing the recognition accuracy of contact MASW measurement using different sensor arrays.

关键词： steel-concrete composite structures(SCCS) interface debonding detection multi-channel analysis of surface waves(MASW) sensor selection comparative experimental study

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Hybrid model for BOF oxygen blowing time prediction based on oxygen balance mechanism and deep neural network

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 106-117页

作者： xin Shao Qing Liu Zicheng xin Jiangshan Zhang Tao Zhou Shaoshuai Li State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Engineering Research Center of MES Technology for Iron&Steel Production Ministry of EducationBeijing 100083China Laiwu Iron and Steel Group Yinshan Section Steel Co. Ltd.Jinan 271104China

The amount of oxygen blown into the converter is one of the key parameters for the control of the converter blowing process,which directly affects the tap-to-tap time of converter. In this study, a hybrid model based on oxygen balance mechanism (OBM) and deep neural network (DNN) was established for predicting oxygen blowing time in converter. A three-step method was utilized in the hybrid model. First, the oxygen consumption volume was predicted by the OBM model and DNN model, respectively. Second, a more accurate oxygen consumption volume was obtained by integrating the OBM model and DNN model. Finally, the converter oxygen blowing time was calculated according to the oxygen consumption volume and the oxygen supply intensity of each heat. The proposed hybrid model was verified using the actual data collected from an integrated steel plant in China, and compared with multiple linear regression model, OBM model, and neural network model including extreme learning machine, back propagation neural network, and DNN. The test results indicate that the hybrid model with a network structure of 3 hidden layer layers, 32-16-8 neurons per hidden layer, and 0.1 learning rate has the best prediction accuracy and stronger generalization ability compared with other models. The predicted hit ratio of oxygen consumption volume within the error±300 m^(3)is 96.67%;determination coefficient (R^(2)) and root mean square error (RMSE) are0.6984 and 150.03 m^(3), respectively. The oxygen blow time prediction hit ratio within the error±0.6 min is 89.50%;R2and RMSE are0.9486 and 0.3592 min, respectively. As a result, the proposed model can effectively predict the oxygen consumption volume and oxygen blowing time in the converter.

关键词： basic oxygen furnace oxygen consumption oxygen blowing time oxygen balance mechanism deep neural network hybrid model

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Microstructure evolution of Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)amorphous alloy after semi-solid isothermal treatment

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China Foundry 2024年第3期21卷 287-294页

作者： xin-hua Huang Jing-wen Pu Yong-xin Luo Yue-jun Ouyang School of Material Electricity and Intelligent ManufacturingHuaihua UniversityHuaihua 330031HunanChina Hunan Renewable Aluminum Innovation Research Center Huaihua UniversityHuaihua 330031HunanChina

The as-cast amorphous Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14)composites,comprising in situ formedβ-Ti ductile crystalline precipitates,were prepared by water cooled copper mold suction ***,the semi-solid composites were obtained after the as-cast composites were treated by semi-solid isothermal *** microstructure evolution and kinetics of the composites were *** show that the microstructures of both the as-cast and semi-solid composites comprise ofβ-Ti crystal phases and amorphous matrix *** and after treatment,the crystals evolve from fine granular or fine dendritic crystals to coarse *** the treatment temperature increasing or the time prolonging,the average crystal size gradually increases and the surface morphology of the crystals gradually becomes *** studying the microstructural evolution and dynamics during the isothermal treatment process,it is found that the final morphology ofβ-Ti crystals is influenced by the isothermal treatment temperature and time(t),and theβ-Ti evolution rate increases with an increase in treatment *** addition,a linear relationship was observed between the size of cubicβ-Ti crystals(D^(3))and t;the growth kinetics factor K is 3.8μm^(3)·s^(-1).As the K value closes to 4μm^(3)·s^(-1),it is inferred the morphology evolution ofβ-Ti crystals is a coarsening behavior controlled by the diffusion of solute elements.

关键词： Ti_(48)Zr_(27)Cu_(6)Nb_(5)Be_(14) amorphous matrix composites semi-solid as-cast microstructure

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Poles Extraction Based LiDAR Localization for Autonomous Robot Systems

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Journal of Systems Science & Complexity 2024年第4期37卷 1413-1424页

作者： HONG xin DONG Yi College of Electronic and Information Engineering Tongji UniversityShanghai 201800China

With the development of intelligent technology,the problem of Li DAR-based localization has played an increasingly important role in the localization of robots in unmanned *** the dense point clouds from the environment requires a large amount of memory,specific and stable structural features,such as pole-like objects in the environment,can serve as the ideal landmarks for localization in unmanned systems,which can effectively reduce the memory usage and mitigate the effects of dynamic environment *** this paper,the authors propose a pole-like objects extraction approach and then,it is applied into the localization system of mobile *** the same experimental conditions,the proposed method can extract more pole-like objects and achieve better long-term localization accuracy than some existing methods in different urban environmental datasets.

关键词： Pole-like landmark extraction robot localization

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Space telescope set to open a new chapter in China's solar research

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National Science Review 2024年第1期11卷 225-227页

作者： Ling xin 机构不祥

One year after China launched its first dedicated space telescope to study the Sun, the Advanced Space-based Solar Observatory(ASO-S) is now fine-tuned and ready for discoveries during the activity peak of this solar cycle. ‘ASO-S has completed its in-orbit tests, and all instruments are in stable operation. Some early results are already in the pipeline,’ said the mission’s chief scientist, Gan Weiqun, as the telescope was officially delivered to his co-workers at the Purple Mountain Observatories,

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Competition of Composition Fluctuation Modes in Weakly Segregated Salt-doped Symmetric Diblock Copolymers

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Chinese Journal of Polymer Science 2024年第9期42卷 1375-1385,I0008页

作者： Yuan-xin Zhou Xian Kong South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou510640China Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou510640China

Salt-doped block copolymers have widespread applications in batteries,fuel cells,semiconductors,and various industries,where their properties crucially depend on phase separation ***,investigations into salt-doped diblock copolymers have predominantly focused on microphase separation,overlooking the segregation between ionic and polymeric *** study employs weak segregation theory to explore the interplay between phase separation dominated by the polymer-modulated mode and the salt-out-modulated mode,corresponding to microscopic and macroscopic phase separations,*** comparing diblock copolymers doped with salts to those doped with neutral solvents,we elucidate the significant role of charged species in modulating phase *** phase separation mode exhibits a transition between the polymer-modulated and salt-out-modulated modes at different *** systems doped with neutral solvents,this transition is stepwise,while in salt-ion-doped systems,it is *** a sufficiently large Flory-Huggins parameter between ions and polymers,the salt-out-modulated mode becomes dominant,promoting macrophase *** to the solvation effect of salt ions,salt-doped systems are more inclined to undergo microphase ***,we explore factors influencing the critical wavenumber of phase separation,including doping level and the Flory-Huggins parameters between two blocks and between ions and polymeric *** findings reveal that in a neutral solvent environment,these factors alter only the boundary between micro-and macro-phase separations,leaving the critical wavenumber unchanged in microphase separation ***,in a salt-doped environment,the critical wavenumber of microphase separation varies with these *** provides valuable insights into the pivotal role of electrostatics in the phase separation of salt-doped block copolymers.

关键词： Block copolymer Phase separation Field theory Salt-doped

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