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Layer-by-layer epitaxy growth of thickness-controllable two-dimensional tungsten disulfide

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Science China(Information Sciences) 2024年第5期67卷 302-310页

作者： Jieyuan LIANG Zixing ZOU Junwu LIANG Di WANG Biao WANG Anshi CHU Jiali yi Cheng ZHANG Lizhen FANG tian ZHANG Huawei LIU Xiaoli zhu Dong LI Anlian PAN Key Laboratory for Micro-Nano Physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan Institute of Optoelectronic IntegrationCollege of Materials Science and Engineering School of Physics and ElectronicsHunan University School of Electronic Information and Electrical Engineering Changsha University School of Physics and Telecommunication Engineering Yulin Normal University Units Semiconductor Technology Co. Ltd. School of Physics and Electronics Hunan Normal University

Bilayer transition metal dichalcogenides（TMDs） balance the high mobility of single layers with the high state density of multilayers and therefore have promising application prospects in high-performance electronics. However, the layer-controlled growth of 2D materials is still confronted with challenges such as poor repeatability between different labs and a limited understanding of the growth mechanism at the atomic scale. Herein, we report a new carbon-assisted chemical vapor deposition process that can realize the growth of WS2sheets with high yield, precise thickness controllability, and repeatability. We show that carbon can act as a reducing agent and catalyst that preferentially reacts with the WO3precursor to form intermediate WO3-xproducts with low-valence state W. The resulting oxycarbide gas has a low surface adsorption energy when deposited on the surface of as-grown WS2, which provides nucleation sites for the subsequent layer of WS2growth and leads to the vertical growth of WS2sheets. The growth mechanism is thoroughly investigated. Electrical transport measurements show that the produced bilayer WS2possesses a high carrier mobility(up to 58 cm2·V-1·s-1) and small subthreshold swing（estimated to be 148 mV/decade）,which are among the best reported results for TMDs produced using CVD.

关键词： WS$_2$ thickness-controlled growth chemical vapor deposition additive carbon

A Non-Parametric Scheme for Identifying Data Characteristic Based on Curve Similarity Matching

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1424-1437页

作者： Quanbo Ge Yang Cheng Hong Li Ziyi Ye yi zhu Gang Yao School of Automation Nanjing University of Information Science&TechnologyJiangsu Provincial University Key Laboratory of Big Data Analysis and Intelligent SystemsNanjing University of Information Science&Technologyand the Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET)Nanjing University of Information Science&TechnologyNanjing 210044China School of Department of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China China Classification Society Nantong Office Nantong 226006China Chinese Flight Test Establishment Xi’an 710089China School of Mathematics Tsinghua UniversityBeijing 100084China School of Automation Nanjing University of Information Science&TechnologyNanjing 210044China Department of Logistics Engineering Shanghai Maritime UniversityShanghai 201306China IEEE

For accurately identifying the distribution charac-teristic of Gaussian-like noises in unmanned aerial vehicle(UAV)state estimation,this paper proposes a non-parametric scheme based on curve similarity *** the framework of the pro-posed scheme,a Parzen window(kernel density estimation,KDE)method on sliding window technology is applied for roughly esti-mating the sample probability density,a precise data probability density function(PDF)model is constructed with the least square method on K-fold cross validation,and the testing result based on evaluation method is obtained based on some data characteristic analyses of curve shape,abruptness and *** com-parison simulations with classical methods and UAV flight exper-iment shows that the proposed scheme has higher recognition accuracy than classical methods for some kinds of Gaussian-like data,which provides better reference for the design of Kalman filter(KF)in complex water environment.

关键词： Curve similarity matching Gaussian-like noise non-parametric scheme parzen window.

Application of total keratometry in ten intraocular lens power calculation formulas in highly myopic eyes

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Eye and Vision 2024年第2期10卷 22-30页

作者： Ling Wei Kaiwen Cheng Wenwen He Xiangjia zhu yi Lu Department of Ophthalmology and Eye Institute Eye and ENT Hospital of Fudan UniversityShanghai 200031China Key Laboratory of Myopia(Fudan University)Key Laboratory of MyopiaShanghai Key Laboratory of Visual Impairment and Restoration National Health CommissionChinese Academy of Medical ScienceShanghai 200031China State Key Laboratory of Medical Neurobiology Fudan UniversityShanghai 200031China

Background:The accuracy of using total keratometry(TK)value in recent IOL power calculation formulas in highly myopic eyes remained ***:Highly myopic patients who underwent uneventful cataract surgery were prospectively enrolled in this prospective comparative *** one month postoperatively,standard deviation(SD)of the prediction errors(PEs),mean and median absolute error(MedAE)of 103 highly myopic eyes were back-calculated and compared among ten formulas,including XGboost,RBF 3.0,Kane,Barrett Universal II,Emmetropia Verifying Optical 2.0,Cooke K6,Haigis,SRK/T,and Wang-Koch modifications of Haigis and SRK/T formulas,using either TK or standard keratometry(K)***:In highly myopic eyes,despite good agreement between TK and K(P>0.05),larger differences between the two were associated with smaller central corneal thickness(P0.05),which both presented smaller MedAEs than others(all P0.05),and statistically larger percentages than the other eight formulas(P<0.05).Conclusions:Highly myopic eyes with thinner corneas tend to have larger differences between TK and *** XGboost enhancement calculator and RBF 3.0 formula using TK showed the most promising outcomes in highly myopic eyes.

关键词： High myopia Total keratometry Cataract surgery IOL power calculation

Tribological properties of Al-GNP composites at elevated temperature

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Friction 2024年第5期12卷 1028-1041页

作者： Sunil POUDEL Rizwan BAJWA Yongde XIA Zakir KHAN yi ZHANG Yanqiu zhu College of Engineering Mathematics and Physical SciencesUniversity of ExeterExeterEX44QFUK European Technical Centre Daido Metal Co.Ltd.Iliminster SomersetTA199PHUK

Lighter and more powerful next generation vehicles and other rotary machinery demand bearings to operate in harsher conditions for higher efficiency,and the continuous development of advanced low-wear and friction materials is thus becoming even more important to meet these *** aluminium composites reinforced with high performance lubricate phases such as graphene nanoplatelets(GNPs)are very promising and have been vigorously *** maintaining a low coefficient of friction(COF)and offering great strength against wear due to their self-lubricating capability,the solid lubricant like GNPs protect the bearing surface from wear damage and prevent change in metallurgical properties during temperature *** paper first studies the high-temperature tribological performance of aluminium matrix composites reinforced with GNP,consolidated via powder metallurgy,then elucidates their tribological *** report that the best tribological performance is achieved by the composite containing 2.0 wt%GNP,with an extraordinarily low COF of 0.09 and a specific wear rate of 3.5×10^(−2)mm^(3)·N^(−1)·m^(−1),which represent 75%and 40%reduction respectively,against the plain aluminium consolidated under identical *** in-track and out-of-track Raman analysis have confirmed the role of GNPs in creating a tribofilm on the counterpart surface which contributed to the excellent performance.

关键词： nanocomposite graphene nanoplatelet(GNP) tribology powder metallurgy

Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19

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Advances in Atmospheric Sciences 2024年第1期41卷 84-96页

作者： Zhiding ZHANG Xu YUE Hao ZHOU Jun zhu Yadong LEI Chenguang tian Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science&Technology(NUIST)Nanjing 210044China Climate Change Research Center Institute of Atmospheric Physics(IAP)Chinese Academy of Sciences(CAS)Beijing 100029China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry of CMA Chinese Academy of Meteorological SciencesBeijing 100081China

The pan-Arctic is confronted with air pollution transported from lower *** have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less ***,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,yiBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during *** show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,*** all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic *** aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the *** contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle *** trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols *** affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.

关键词： diffuse radiation fertilization effects anthropogenic aerosols natural aerosols pan-Arctic net primary productivity

A function-based behavioral modeling method for air combat simulation

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Journal of Systems Engineering and Electronics 2024年第4期35卷 945-954页

作者： WANG Tao zhu Zhi ZHOU Xin JING tian CHEN Wei College of Systems Engineering National University of Defense TechnologyChangsha 410073China Institute of Communication and Navigation Air Force Research AcademyBeijing 100085China

Today’s air combat has reached a high level of uncertainty where continuous or discrete variables with crisp values cannot be properly represented using fuzzy sets. With a set of membership functions, fuzzy logic is well-suited to tackle such complex states and actions. However, it is not necessary to fuzzify the variables that have definite discrete ***, the aim of this study is to improve the level of model abstraction by proposing multiple levels of cascaded hierarchical structures from the perspective of function, namely, the functional decision tree. This method is developed to represent behavioral modeling of air combat systems, and its metamodel,execution mechanism, and code generation can provide a sound basis for function-based behavioral modeling. As a proof of concept, an air combat simulation is developed to validate this method and the results show that the fighter Alpha built using the proposed framework provides better performance than that using default scripts.

关键词： air combat behavioral modeling intelligent agent

Drought-Tolerant Rice at Molecular Breeding Eras:An Emerging Reality

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Rice science 2024年第2期31卷 179-189页

作者： zhu Chengqi YE Yuxuan QIU tian HUANG Yafan yiNG Jifeng SHEN Zhicheng Institute of Insect Sciences Zhejiang UniversityHangzhou 310058China Performance Plants Inc. 1287 Gardiners RoadKingstonOntario K7P 3J6Canada China National Rice Research Institute Hangzhou 310006China

Rice(Oryza sativa L.)stands as the most significantly influential food crop in the developing world,with its total production and yield stability affected by environmental *** stress impacts about 45%of the world’s rice area,affecting plants at molecular,biochemical,physiological,and phenotypic *** conventional breeding method,predominantly employing single pedigree selection,has been widely utilized in breeding numerous drought-tolerant rice varieties since the Green *** rapid progress in plant molecular biology,hundreds of drought-tolerant QTLs/genes have been identified and tested in rice crops under both indoor and field *** genes have been introgressed into elite germplasm to develop commercially accepted drought-tolerant varieties,resulting in the development of several drought-tolerant rice varieties through marker-assisted selection and genetically engineered *** review provides up-to-date information on proof-of-concept genes and breeding methods in the molecular breeding era,offering guidance for rice breeders to develop drought-tolerant rice varieties.

关键词： conventional breeding drought stress drought tolerant rice genetic engineering marker-assisted selection breeding

Spectral Index Distribution of Various Scale Components in Supernova Remnant Cassiopeia A

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Research in Astronomy and Astrophysics 2024年第5期24卷 211-217页

作者： Xianhuan Lei Hui zhu Zongyao yin Haiyan Zhang Wenwu tian Xianchuan Yu Key Laboratory of Radio Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 101408China School of Artiﬁcial Intelligence Beijing Normal UniversityBeijing 100875China

Cassiopeia A(Cas A) is a well-known candidate for studying cosmic-ray acceleration, in which compact features of various scales have attracted much attention. Based on observations by the Very Large Array of Cas A at 6 cm and 21 cm, we measure the spectral index distribution of various scale components using the observation of the 1998 epoch. We decompose its total density image into nine scale components, and map the temperature spectral index distribution of each component, which ranges from-2.48 ± 0.01 to-2.91 ± 0.05. We find that the spectral indices increase from the small scale to large scale components. A damped post-shock magnetic field model with a strength larger than ~200 μG and a damping length scale less than ~10% of the remnant radius can account for the spectral index variation naturally.

关键词： ISM supernova remnants-(ISM:)cosmic rays-radio continuum ISM

Effectiveness of urban distributed runoff model for discharge and water depth calculation in urban drainage pipe networks

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Journal of Hydrodynamics 2024年第3期36卷 582-591页

作者： Yang Zhou yi-ling Leng Peng-yu Wang Shang-hong Zhang Yu-long zhu Yu-jun yi School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing102206China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing100875China

Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense *** at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use *** Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban *** prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence *** findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence ***,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster *** these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage ***,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban ***,this methodology warrants further promotion in the field of urban re-planning.

关键词： Stormwater runoff water depth urban distributed runoff model urban drainage pipe networks urban land-use re-planning