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Characteristics of the SOL ion-to-electron temperature ratio on the j-TEXT tokamak with different plasma configurations

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Plasma Science and Technology 2024年第2期26卷 13-21页

作者：李存凯梁云峰江中和周松华建坤阳杰杨庆虎 Alexander KNIEPS Philipp DrEWS 徐鑫毛飞越谢伟杨雨桐郭金龙李杨波任正康陈志鹏王能超 the j-TEXT Team International joint research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China Forschungszentrum jülich GmbH Institut für Energie-und Klimaforschung—PlasmaphysikPartner of the Trilateral Euregio Cluster(TEC)Julich 52425Germany 不详

Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion *** the j-TEXT tokamak,a multi-channel retarding field analyzer(rFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor *** edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,*** is broadly consistent with what has been observed previously from various tokamak ***,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate *** the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter *** results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.

关键词： ion temperature island divertor poloidal divertor retarding field analyzer(rFA)probe

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Nearly degenerate ground states of a checkerboard antiferromagnet and their bosonic interpretation

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 84-89页

作者： Haiyuan Zou Fan yang Wei Ku Key Laboratory of Polar Materials and Devices(MOE) School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China Department of Physics Beijing Institute of TechnologyBeijing 100081China Tsung-Dao Lee Institute Shanghai 200240China Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) Shanghai 200240China Shanghai Branch Hefei National LaboratoryShanghai 201315China

The spin-1/2 model system with antiferromagnetic(AF) couplings on a j1-j2checkerboard lattice, known as the planar pyrochlore model, is strongly frustrated and associated with a two-to-one dimensional crossover. Using the Pr.j.cted Entangled Simplex States tensor network ansatz, we identify a large number of nearly degenerate states in the frustrated region(j_(1)j_(2)).Specifically, we find the long-sought crossed-dimer valence bond solid(VBS) state to be the ground state at j_(1)≤j_(2), while various 1D AF correlated states take over the rest. We verify the stability of the VBS state against nematic perturbation. The corresponding bosonic picture provides an intuitive understanding of the low-energy physics. Particularly, it predicts weaker VBS states in the easy-plane limit, which we confirm numerically. Our results clarify the most essential ground state properties of this interesting system and demonstrate the usefulness of bosonic picture in dealing with frustrated magnetism.

关键词： tensor networks frustrated magnetism dimensional crossover degenerate states

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Fine classification of rice paddy using multitemporal compact polarimetric SAr C band data based on machine learning methods

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Frontiers of Earth Science 2024年第1期18卷 30-43页

作者： Xianyu GUO junjun YIN Kun LI jian yang Huimin ZOU Fukun yang School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China Aerospace Information research Institute Chinese Academy of SciencesBeijing 100094China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China

rice is an important food crop for human *** distinguishing different varieties and sowing methods of rice on a large scale can provide more accurate information for rice growth monitoring,yield estimation,and phenological monitoring,which has significance for the development of modern *** polarimetric(CP)synthetic aperture radar(SAr)provides multichannel information and shows great potential for rice monitoring and ***,the use of machine learning methods to build classification models is a controversial *** this paper,the advantages of CP SAr data,the powerful learning ability of machine learning,and the important factors of the rice growth cycle were taken into account to achieve high-precision and fine classification of rice ***,CP SAr data were simulated by using the seven temporal rADArSAT-2 C-band data ***,20-two CP SAr parameters were extracted from each of the seven temporal CP SAr data *** addition,we fully considered the change degree of CP SAr parameters on a time scale(ΔCP_(DoY)).Six machine learning methods were employed to carry out the fine classification of rice *** results show that the classification methods of machine learning based on multitemporal CP SAr data can obtain better results in the fine classification of rice paddies by considering the parameters ofΔCP_(DoY).The overall accuracy is greater than 95.05%,and the Kappa coefficient is greater than *** them,the random forest(rF)and support vector machine(SVM)achieve the best results,with an overall accuracy reaching 97.32%and 97.37%,respectively,and Kappa coefficient values reaching 0.965 and 0.966,*** the two types of rice paddies,the average accuracy of the transplant hybrid(T-H)rice paddy is greater than 90.64%,and the highest accuracy is 95.95%.The average accuracy of direct-sown japonica(D-j)rice paddy is greater than 92.57%,and the highest accuracy is 96.13%.

关键词： compact polarimetric(CP)SAr rice paddy machine learning fine classification multitemporal

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Liquid metal compartmented by polyphenol-mediated nanointerfaces enables high-performance thermal management on electronic devices

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InfoMat 2024年第1期6卷 83-95页

作者： Chaojun Zhang yang Tang Tianyu Guo Yizhou Sang Ding Li Xiaoling Wang Orlando j.r.j.s junling Guo BMI Center for Biomass Materials and Nanointerfaces College of Biomass Science and EngineeringSichuan UniversityChengduSichuanthe People's Republic of China Bioproducts Institute Departments of Chemical and Biological EngineeringThe University of British ColumbiaVancouverBritish ColumbiaCanada Institute of Development Studies Southwestern University of Finance and EconomicsChengduSichuanthe People's Republic of China National Engineering Laboratory for Clean Technology of Leather Manufacture Sichuan UniversityChengduSichuanthe People's Republic of China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengduSichuanthe People's Republic of China

The exponentially increasing heat generation in electronic devices,induced by high power density and miniaturization,has become a dominant issue that affects carbon footprint,cost,performance,reliability,and *** metals(LMs)with high thermal conductivity are promising candidates for effective thermal management yet are facing pump-out and surface-spreading *** in the form of metallic particles can address these problems,but apparent alloying processes elevate the LM melting point,leading to severely deteriorated ***,we propose a facile and sustainable approach to address these challenges by using a biogenic supramolecular network as an effective diffusion barrier at copper particle-LM(EGaIn/Cu@TA)interfaces to achieve superior thermal *** supramolecular network promotes LM stability by reducing unfavorable alloying and fluidity *** EGaIn/Cu@TA exhibits a record-high metallic-mediated thermal conductivity(66.1 W m^(-1) K^(-1))and fluidic ***,mechanistic studies suggest the enhanced heat flow path after the incorporation of copper particles,generating heat dissipation suitable for computer central processing units,exceeding that of commercial *** results highlight the prospects of renewable macromolecules isolated from biomass for the rational design of nanointerfaces based on metallic particles and LM,paving a new and sustainable avenue for high-performance thermal management.

关键词： Electronic devices High thermal conductivity Liquid metals Natural polyphenols Thermal management

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Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony r.j.Kucernak David Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOr).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the *** electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the *** single-atom samples showed higher HOr activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating *** selective activity toward HOr arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

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Efficiency-first spraying mission arrangement optimization with multiple UAVs in heterogeneous farmland with varying pesticide requirements

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Information Processing in Agriculture 2024年第2期11卷 237-248页

作者： yang Li Yanqiang Wu Xinyu Xue Xuemei Liu yang Xu Xinghua Liu Nanjing Institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014PR China College of Mechanical&Electronic Engineering Shandong Agricultural UniversityTai'an 271018PR China Key Laboratory of Modern Agricultural Equipment Ministry of Agriculture and Rural AffairsNanjing 210014PR China Shandong Provincial Key Laboratory of Horticultural Machinery and Equipment Tai’an 271018PR China Shandong Provincial Engineering Laboratory of Agricultural Equipment Intellectualization Tai’an 271018PR China

Combining multiple crop protection Unmanned Aerial Vehicles(UAVs)as a team for a scheduled spraying mission over farmland now is a common way to significantly increase ***,given some issues such as different configurations,irregular borders,and especially varying pesticide requirements,it is more important and more complex than other multi-Agent Systems(MASs)in common *** this work,we focus on the mission arrangement of UAVs,which is the foundation of other high-level cooperations,systematically propose Efficiency-first Spraying Mission Arrangement Problem(ESMAP),and try to construct a united problem framework for the mission arrangement of crop protection ***,to characterise the differences in sub-areas,the varying pesticide requirement per unit is well considered based on Normalized Difference Vegetation Index(NDVI).Firstly,the mathematical model of multiple crop-protection UAVs is established and ESMAP is ***,an acquisition method of a farmland’s NDVI map is proposed,and the calculation method of pesticide volume based on NDVI is ***,an improved Genetic Algorithm(GA)is proposed to solve ESMAP,and a comparable combination algorithm is *** simulations for algorithm analysis are carried out within MATLAB,and it is determined that the proposed GA is more efficient and accurate than the ***,a mission arrangement tested with three UAVs was carried out to validate the effectiveness of the proposed GA in spraying *** results illustrated that it performed well,which took only 90.6%of the operation time taken by the combination algorithm.

关键词： Efficiency-first optimization Mission arrangement Multi-UAVs Heterogeneous farmland

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Europium recovery process by means of polymeric nanoparticles functionalized with acrylic acid,curcumin and fumaramide

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journal of rare Earths 2024年第10期42卷 1950-1959页

作者： P.A.Martínez-Montoya j.M.del río A.de j.Morales-ramirez M.Corea Escuela Superior de Ingeniería Química e Industrias Extractivas ESIQIE-IPNDepartamento de Ingeniería Metalúrgica UPALM S/N Col.Lindavista Escuela Superior de Ingenieria Química e Industrias Extractivas ESIQIE-IPNLaboratorio de Investigación en Polímeros y NanomaterialesUPALM S/N Col.Lindavista Centra de Investigación e Innovación Tecnológica CIITEC-IPNCda.de CECATIs/n

Polymeric nanoparticles of poly(methyl methacrylate) were obtained by emulsion polymerization techniques in a proce ss of two *** particles were functionalized with acrylic acid,curcumin,and fumaramide and three series of polymeric particles were *** incorporation of functional groups was confirmed by Fourier transform-infrared spectrosocopy(FT-Ir) and ultraviolet-visible(UV-Vis) *** spherical morphology of particles with an average diameter of 100 nm was observed by scartning electron microscopy(SEM).The polymeric materials were used for recovery of [Eu]from synthetic *** nanoparticles show excellent chelation capacity to trap rare-earth ions,because they recover more than 85% of [Eu] at pH of *** images of SEM after extraction process show arrays between particles with larger average particle sizes to 1.5 *** addition,the particles have a good stripping capacity,exceeding 50% of it,maintaining their homogeneity in morphology and good stability in dispersion for the recovery and stripping processes.A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of6.

关键词： Chelating effect Emulsion polymerization Extraction process rare earths Stripping process [Eu]recovery

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Spatiotemporal pattern of climate change in the China-Myanmar Economic Corridor from 1901 to 2018

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journal of Mountain Science 2024年第1期21卷 131-145页

作者： yang Xiaoliu LI Yungang GAO Lu Institute of Geography Fujian Normal UniversityFuzhou 350117China School of Geographical Sciences Fujian Normal UniversityFuzhou 350117China Institute of International rivers and Eco-Security Yunnan UniversityKunming 650500China Fujian Provincial Engineering research Center for Monitoring and Accessing Terrestrial Disasters Fujian Normal UniversityFuzhou 350117China Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education Fujian Normal UniversityFuzhou 350117China

The China-Myanmar Economic Corridor(CMEC) is an important part of China's Belt and road Initiative and an important area for global ecology and biodiversity. In this study, the annual and seasonal spatiotemporal patterns of temperature and precipitation in the CMEC over the past century were investigated using linear tendency estimation, the Mann-Kendall mutation test, the T-test, and wavelet analysis based on the monthly mean climatic data from 1901 to 2018 released by the Climatic research Unit(CrU) of the University of East Anglia, UK. The results show that the CMEC demonstrated a trend of warming and drying over the past 100 years, and the rate of change in Myanmar was stronger than that in Yunnan Province of China. The warming rate was 0.039 ℃/10a. Precipitation decreased at a rate of -6.1 mm/10a. From the perspective of spatial distribution, temperature was high in the central and southern, low in the north of the CMEC, and the high-temperature centers were mainly distributed in the southern plain and river valley. Precipitation decreased from west to east and from south to north of the CMEC. From the perspective of the rate of change, warming was stronger in central and northern CMEC than in southern and northeastern CMEC. The rate of precipitation decline was stronger in the central and western regions than in the eastern region. This study provides a scientific reference for the CMEC to address climate change and ensure sustainable social and economic development and ecological security.

关键词： China-Myanmar Economic Corridor CrU Air temperature Precipitation Spatiotemporal pattern

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Meticulously engineered three-dimensional-printed scaffold with microarchitecture and controlled peptide release for enhanced bone regeneration

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Biomaterials Translational 2024年第1期5卷 69-83页

作者： yang j. Fatima K. Zhou X. He C. Shanghai Engineering research Center of Nano-Biomaterials and regenerative Medicine College of Biological Science and Medical Engineering Donghua University Shanghai China

The repair of large load-bearing bone defects requires superior mechanical strength, a feat that a single hydrogel scaffold cannot achieve. The objective is to seamlessly integrate optimal microarchitecture, mechanical robustness, vascularisation, and osteoinductive biological responses to effectively address these critical load-bearing bone defects. To confront this challenge, three-dimensional (3D) printing technology was employed to prepare a polycaprolactone (PCL)-based integrated scaffold. Within the voids of 3D printed PCL scaffold, a methacrylate gelatin (GelMA)/methacrylated silk fibroin (SFMA) composite hydrogel incorporated with parathyroid hormone (PTH) peptide-loaded mesoporous silica nanoparticles (PTH@MSNs) was embedded, evolving into a porous PTH@MSNs/GelMA/SFMA/PCL (PM@GS/PCL) scaffold. The feasibility of fabricating this functional scaffold with a customised hierarchical structure was confirmed through meticulous chemical and physical characterisation. Compression testing unveiled an impressive modulus of 17.81 ± 0.83 MPa for the composite scaffold. Additionally, in vitro angiogenesis potential of PM@GS/ PCL scaffold was evaluated through Transwell and tube formation assays using human umbilical vein endothelium, revealing the superior cell migration and tube network formation. The alizarin red and alkaline phosphatase staining assays using bone marrow-derived mesenchymal stem cells clearly illustrated robust osteogenic differentiation properties within this scaffold. Furthermore, the bone repair potential of the scaffold was investigated on a rat femoral defect model using micro-computed tomography and histological examination, demonstrating enhanced osteogenic and angiogenic performance. This study presents a promising strategy for fabricating a microenvironment-matched composite scaffold for bone tissue engineering, providing a potential solution for effective bone defect repair. © 2024, Chinese Medical Multimedia Press Co Ltd. All rights reserve

关键词： angiogenesis bone regeneration methacrylated gelatin methacrylated silk fibroin osteogenesis PTH

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Thermal oxidation description methodology of thermal barrier coatings on gas turbine blades considering service characteristics

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Chinese journal of Aeronautics 2024年第6期37卷 410-424页

作者： Qiannan TAO Yanrong WANG Dasheng WEI Shun yang School of Energy and Power Engineering Beihang UniversityBeijing 100191China jiangxi research Institute of Beihang University Nanchang 330096China

Predicting the thickness of Thermally Grown Oxide(TGO)and the residual stresses induced by TGO growth in the Thermal Barrier Coatings(TBCs)is significant work in analyzing the failure of *** practical applications,the operating temperature,oxygen partial pressure,aluminium content in TBCs,and porosity of the topcoat affect the oxidation ***,a novel oxidation rate model is proposed to describe the effect of such *** parameters in the proposed model were fitted with isothermal degradation test data from prior ***,a method for calculating the residual stress in a disk-shaped specimen was developed based on the oxidized growth strain model and the oxidized ***,a variable-temperature oxidation experiment was performed to validate the new oxidation *** average error between the predicted and experimental thicknesses is approximately 10%,and the average error between the residual stresses is 30%.Under the variable-temperature condition,the error between the predicted thickness and the average experimental thickness is 3.9%.

关键词： Thermal barrier coatings Oxidation Gas turbine residual stresses Sintering

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