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Rare Metals 2024年第7期43卷 3273-3285页

作者： Meng-Chen Song Fu-Ying Wu Yi-Qun jiang xiu-Zhen wang Hu Zhao Li-Xin Chen Liu-Ting Zhang School of Energy and Power Instrumental Analysis CenterJiangsu University of Science and Technology Max Planck Institute for Iron Research School of Mechanical and Aerospace Engineering Nanyang Technological University State Key Laboratory of Silicon Materials Department of Materials Science and EngineeringZhejiang University

The exploration of efficient,long-lived and cost-effective transition metal catalysts is highly desirable for the practical hydrogen storage of magnesium hydride（MgH2） in sustainable energy ***,FeCoNiCrTi high-entropy alloy（HEA） nanosheets were prepared via a facile wet chemical ball milling strategy and they were introduced into MgH2to boost the hydrogen storage *** refined HEA exhibited superior catalytic activity on *** contrast to additive-free MgH2,the initial desorption temperature of the constructed MgH2-HEA composite was reduced from 330.0 to 198.5℃ and a remarkable 51% reduction in the dehydrogenation activation energy was ***,the MgH2-HEA composite only required one-twentieth time of that consumed by pure MgH2to absorb 5.0 wt% of H2at 225℃.The synergy between the "hydrogen pumping" effect of Mg2Ni/Mg2NiH4and Mg2Co/Mg2CoH5couples,as well as the good dispersion of Fe,Cr and Ti on the surface of MgH2contributed to the enhanced de/hydrogenation performance of the MgH2-HEA *** study furnishes important steering for the design and fabrication of multiple transition metal catalysts and may push the commercial application of magnesium-based hydrides one step forward.

关键词： Hydrogen storage Magnesium hydride High-entropy alloys Catalysis

Tomato detection method using domain adaptive learning for dense planting environments

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农业工程学报 2024年第13期40卷 134-145页

作者： LI Yang HOU Wenhui YANG Huihuang RAO Yuan wang Tan jiN xiu ZHU Jun College of Information and Artificial Intelligence Anhui Agricultural UniversityHefei 230036China Key Laboratory of Agricultural Sensors Ministry of Agriculture and Rural AffairsHefei 230036China College of Engineering Anhui Agricultural UniversityHefei 230036China

This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic ***,the heavy reliance on extensive manually annotated datasets for training deep learning models still poses significant limitations to their application in real-world agricultural production *** overcome these limitations,we employed domain adaptive learning approach combined with the YOLOv5 model to develop a novel tomato detection model called as TDA-YOLO(tomato detection domain adaptation).We designated the normal illumination scenes in dense planting environments as the source domain and utilized various other illumination scenes as the target *** construct bridge mechanism between source and target domains,neural preset for color style transfer is introduced to generate a pseudo-dataset,which served to deal with domain ***,this study combines the semi-supervised learning method to enable the model to extract domain-invariant features more fully,and uses knowledge distillation to improve the model's ability to adapt to the target ***,for purpose of promoting inference speed and low computational demand,the lightweight FasterNet network was integrated into the YOLOv5's C3 module,creating a modified C3_Faster *** experimental results demonstrated that the proposed TDA-YOLO model significantly outperformed original YOLOv5s model,achieving a mAP(mean average precision)of 96.80%for tomato detection across diverse scenarios in dense planting environments,increasing by 7.19 percentage points;Compared with the latest YOLOv8 and YOLOv9,it is also 2.17 and 1.19 percentage points higher,*** model's average detection time per image was an impressive 15 milliseconds,with a FLOPs(floating point operations per second)count of 13.8 *** acceleration processing,the detection accuracy of the TDA-YOLO mo

关键词： plants models domain adaptive tomato detection illumination variation semi-supervised learning dense planting environments

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The mechanisms of enhanced thickness-dependent DC breakdown strength of EP/MWCNTs nanocomposites

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High Voltage 2024年第2期9卷 440-452页

作者： Zhen Li He Gao Longfei Zhang Shouming wang ji Liu Shengtao Li Key Laboratory of Engineering Dielectrics and Its Application Ministry of EducationHarbin University of Science and TechnologyHarbinChina State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina

Owing to advanced power electronic and electrical applications developing towards miniaturisation and integration,the thickness-dependent DC breakdown mechanism of epoxy/multiwall-carbon-nanotube nanocomposites is under *** results indicate that the breakdown strength of nanocomposites containing 0.05 wt%multiwall-carbon-nanotubes rises by~18%,and the breakdown strength falls exponentially with increasing *** clarify the microscopic mechanism,a simulation model of DC breakdown,including carriers transport and segmental dynamics,is developed,and the accordant simulation results with experimental results indicate that the thickness-dependent DC breakdown of epoxy/multiwall-carbon-nanotube nanocomposites is determined both by segment chain dynamics and charge *** to the breakdown model analysis,the effects of multiwall-carbon-nanotube on enhanced breakdown strength are caused by the increased amount of deep traps in the interfacial region,while the influence of thickness is attributed to the enlarged segment chain displacement and electric field distortion as the voltage raising time increases.

关键词： strength breakdown nanocomposites

Bicarbonate used as a buffer for controlling nutrient solution pH value during the growth of hydroponic lettuce

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 59-67页

作者： Mengxue Zhang Wenxin wang Luming Zhong Fang ji Dongxian He Key Laboratory of Agricultural Engineering in Structure and Environment of MARA College of Water Resources&Civil EngineeringChina Agricultural UniversityBeijing 100083China

Unstable pH of nutrient solution in hydroponic systems is a major obstacle to *** simplify the management of nutrient solution pH and attenuate negative effects of pH on plant growth,this study investigated the effect of different buffer salt additions on nutrient solution pH,ion uptake,growth and photosynthesis of Yamazaki lettuce,with the equivalent concentrations of macro-element *** results indicated that the pH of nutrient solution was buffered to varying degrees by the 2 mol/L HCO_(3)^(-),1 mol/L HCO_(3)^(-),and 0.33 mol/L HPO_(4)^(2-)The 0.33 mol/L HPO_(4)^(2-)treatment fluctuated most with a pH of 1.74 units,while the addition of HCO_(3)^(-)buffered nutrient solution pH was better,with higher pH values(7.2-7.7).The CK-pH control solution,1 mol/L HCO_(3)^(-)and 0.33 mol/L HPO_(4)^(2-)treatments all promoted the uptake of ion and then the growth of lettuce was better in comparison with the CK-pH no adjustment treatment,while the 2 mol/L HCO_(3)^(-)treatment inhibited K uptake and reduced the availability of Fe,the shoot and root fresh weight of lettuce decreased by 21.3%and 10.1%,*** addition,although the chlorophyll content and net photosynthetic rate under 1 mol/L HCO_(3)^(-)and 0.33 mol/L HPO_(4)^(2-)treatments were significantly lower than the CK-pH control solution treatment,there were no significant differences in leaf length and leaf number of lettuce among them,and shoot fresh weight per plant was 83.09,82.95,and 78.92 g,*** conclusion,adding 1 mol/L HCO_(3)^(-)to the nutrient solution in a single dosage not only buffered the pH of nutrient solution better but also promoted ion uptake,it had no negative effects on the growth,photosynthesis and ion uptake of hydroponic lettuce in comparison with the CK-pH control solution ***,1 mol/L HCO_(3)^(-)can be used as a buffer during the growth of hydroponic lettuce and reduce frequent addition of acids or alkalis,and then simplify the management of nut

关键词： pH buffer nutrient solution hydroponic lettuce growth ion uptake

Identifying Three New AGNs among Fermi Unidentified Gigaelectronvolt Sources

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Research in Astronomy and Astrophysics 2024年第7期24卷 260-270页

作者： Shun-Hao ji Zhong-Xiang wang Qiang-Meng Huang Ruo-Heng Yang Department of Astronomy School of Physics and AstronomyYunnan University Shanghai Astronomical Observatory Chinese Academy of Sciences

We report our identification of three gigaelectronvolt γ-ray sources, 4FGL J0502.6+0036, 4FGL J1055.9+6507,and 4FGL J1708.2+5519, as Active Galactic Nuclei(AGNs). They are listed in the latest Fermi-Large Area Telescope source catalog as unidentified ones. We find that the sources all showed γ-ray flux variations in recent years. Using different survey catalogs, we are able to find a radio source within the error circle of each source's position. Further analysis of optical sources in the fields allows us to determine the optical counterparts, which showed similar variation patterns to those seen in γ-rays. The optical counterparts have reported redshifts of 0.6,1.5, and 2.3, respectively, estimated from photometric measurements. In addition, we also obtain an X-ray spectrum of 4FGL J0502.6+0036 and a flux upper limit on the X-ray emission of 4FGL J1055.9+6507 by analyzing the archival data. The broadband spectral energy distributions of the three sources from radio to γ-rays are constructed. Comparing mainly the γ-ray properties of the three sources with those of different sub-classes of AGNs, we tentatively identify them as blazars. Followup optical spectroscopy is highly warranted for obtaining their spectral features and thus verifying the identification.

关键词： (galaxies:) BL Lacertae objects: general (galaxies:) quasars: general gamma-rays: galaxies

A strong physical unclonable function with machine learning immunity for Internet of Things application

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Science China(Information Sciences) 2024年第1期67卷 271-283页

作者： Pengpeng REN Yongkang XUE Linglin jiNG Lining ZHANG Runsheng wang Zhigang ji National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiao Tong University Department of Micro/Nano Electronics Shanghai Jiao Tong University School of Electronic and Computer Engineering Peking University School of Integrated Circuits Peking University

The physical unclonable functions(PUFs) are novel cryptographic primitives in modern hardware security *** with traditional alternatives based on digital keys and non-volatile memory(NVM),the PUF system shows great unclonability,high efficiency,and physical attack ***,the conventional PUF design suffers from weak machine learning immunity,high storage overhead,and unreliability,making it difficult to implement in the Internet of Things(Io T) and edge computing *** paper presents a new PUF design that could solve the proposed *** utilizing the emission probability of traps commonly found in nano-scaled transistors,a model-based PUF system with strong machine learning resistance could be *** PUF design,called Prob-PUF,needs fewer challengeresponse pairs(CRPs) space and reveals superior resistance to modeling attacks due to the mixture of stable/random bits in its output ***,the Prob-PUF system could reach a high level of uniqueness and robustness,making it a potential candidate for future cryptographically secured protocols within the IoT.

关键词： physical unclonable function (PUF) electron traps authentication encryption cryptography security

Multidimensional regulation of Ti-Zr-Cr-Mn hydrogen storage alloys via Y partial substitution

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Nano Research 2024年第5期17卷 4211-4220页

作者： Haixiang xiu Wanqiang Liu Dongming Yin Nan Ding Wenfeng Qiao Shaolei Zhao Long Liang Cong Liu Shaohua wang Qingshuang wang Bingbing Chen Limin wang Yong Cheng School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences(CAS)Changchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Department of Energy Science and Engineering Nanjing Tech UniversityNanjing 211816China National Engineering Research Center of Nonferrous Metals Materials and Products for New Energy GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China College of Life Science and Technology Changchun University of Science and TechnologyChangchun 130022China

High density and safe storage of hydrogen are the preconditions for the large-scale application of hydrogen ***,the hydrogen storage properties of Ti_(0.6)Zr_(0.4)Cr_(0.6)Mn_(1.4) alloys are systematically studied by introducing Y element instead of Ti element through vacuum arc *** the partial substitution of Y,a second phase of rare earth oxide is added in addition to the main suction hydrogen phase,C14 Laves *** to the unique properties of rare earth elements,the partial substitution of Y can not only improve the activation properties and plateau pressure of the alloys,but also increase the effective hydrogen storage capacity of the *** comprehensive properties of hydrogen storage alloys are improved by multidimensional regulation of rare earth *** them,Ti_(0.552)Y_(0.048)Zr_(0.4)Cr_(0.6)Mn_(1.4) has the best comprehensive *** alloy can absorb hydrogen without activation at room temperature and 5 MPa,with a maximum hydrogen storage capacity of 1.98 wt.%.At the same time,it reduces the stability of the hydride and the enthalpy change value,making it easier to release *** theoretical analysis and first-principle simulation,the results show that the substitution of Y element reduces the migration energy barrier of hydrogen and the structural stability of the system,which is conducive to hydrogen *** alloy has superior durability compared to the original alloy,and the capacity retention rate was 96.79%after 100 hydrogen absorption/desorption cycles.

关键词： AB_(2)-type hydrogen storage alloy rare earth element first-principles simulation multidimensional regulation

Research on the IL-Bagging-DHKELM Short-Term Wind Power Prediction Algorithm Based on Error AP Clustering Analysis

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Computers, Materials & Continua 2024年第6期79卷 5017-5030页

作者： jing Gao Mingxuan ji Hongjiang wang Zhongxiao Du School of Electric Power Shenyang Institute of EngineeringShenyang100083China

With the continuous advancement of China’s“peak carbon dioxide emissions and Carbon Neutrality”process,the proportion of wind power is *** the current research,aiming at the problem that the forecasting model is outdated due to the continuous updating of wind power data,a short-term wind power forecasting algorithm based on Incremental Learning-Bagging Deep Hybrid Kernel Extreme Learning Machine(IL-Bagging-DHKELM)error affinity propagation cluster analysis is *** algorithm effectively combines deep hybrid kernel extreme learning machine(DHKELM)with incremental learning(IL).Firstly,an initial wind power prediction model is trained using the Bagging-DHKELM ***,Euclidean morphological distance affinity propagation AP clustering algorithm is used to cluster and analyze the prediction error of wind power obtained from the initial training ***,the correlation between wind power prediction errors and Numerical Weather Prediction(NWP)data is introduced as incremental updates to the initial wind power prediction *** the incremental learning process,multiple error performance indicators are used to measure the overall model performance,thereby enabling incremental updates of wind power *** examples show the method proposed in this article reduces the root mean square error of the initial model by 1.9 percentage points,indicating that this method can be better adapted to the current scenario of the continuous increase in wind power penetration *** accuracy and precision of wind power generation prediction are effectively improved through the method.

关键词： Short-term wind power prediction deep hybrid kernel extreme learning machine incremental learning error clustering

Atomic-Scale Insights into Damage Mechanisms of GGr15 Bearing Steel Under Cyclic Shear Fatigue

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1265-1278页

作者： Qiao-Sheng Xia Dong-Peng Hua Qing Zhou Ye-Ran Shi Xiang-Tao Deng Kai-Ju Lu Hai-Feng wang xiu-Bing Liang Zhao-Dong wang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an710072China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Defense Innovation Institute Academy of Military ScienceBeijing100071China

Alternating shear stress is a critical factor in the accumulation of damage during rolling contact fatigue,severely limiting the service life of ***,the specific mechanisms responsible for the cyclic shear fatigue damage in bearing steel have not been fully *** the mechanical response and microstructural evolution of a model GGr15 bearing steel under cyclic shear loading are investigated through the implementation of molecular dynamics *** samples undergo 30 cycles under three different loading conditions with strains of 6.2%,9.2%,and 12.2%,*** findings indicate that severe cyclic shear deformation results in early cyclic softening and significant accumulation of plastic damage in the bearing ***,samples subjected to higher strain-controlled loading exhibit higher plastic strain energy and shorter fatigue ***,strain localization is identified as the predominant damage mechanism in cyclic shear fatigue of the bearing steel,which accumulates and ultimately results in fatigue ***,simulation results also revealed the microstructural reasons for the strain localization(e.g.,BCC phase transformation into FCC and HCP phase),which well explained the formation of white etching *** study provides fresh atomic-scale insights into the mechanisms of cyclic shear fatigue damage in bearing steels.

关键词： Cyclic shear fatigue Molecular dynamic simulation Bearing steels Plastic damage accumulation

Sedimentary architecture of submarine channel-lobe systems under different seafloor topography:Insights from the Rovuma Basin offshore East Africa

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Petroleum Science 2024年第1期21卷 125-142页

作者： Mei Chen Sheng-He Wu Rui-Feng wang jia-jia Zhang Peng-Fei Xie Min wang Xiao-Feng wang ji-Tao Yu Qi-Cong Xiong State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Faculty of Geosciences University of BremenBremen28359Germany MARUM-Center for Marine and Environmental Sciences University of BremenBremen28359Germany Research institute of Petroleum Exploration and Development PetroChinaBeijing10083China School of Geosciences Yangtze UniversityWuhan 100083HubeiChina CNODC Mozambique Ltd. Beijing 100034China

Seafloor topography plays an important role in the evolution of submarine ***,it is still not so clear how the shape of slope affects the three-dimensional(3-D)architecture of submarine *** this study,we analyze the effect of topography factors on different hierarchical lobe architectures that formed during Pliocene to Quaternary in the Rovuma Basin offshore East *** characterize the shape,size and growth pattern of different hierarchical lobe architectures using 3-D seismic *** find that the relief of the topographic slope determines the location of preferential deposition of lobe complexes and single *** the topography is irregular and presents topographic lows,lobe complexes first infill these *** lobes are deposited preferentially at positions with higher longitudinal(***-slope)slope *** the longitudinal slope becomes higher,the aspect ratio of the single lobes ***(***-slope)topography does not seem to have a strong influence on the shape of single lobe,but it seems to affect the overlap of single *** the lateral slope gradient is relatively high,the single lobes tend to have a larger overlap ***,as the average of lateral slope and longitudinal slope gets greater,the width/thickness ratio of the single lobe is smaller,*** tend to accumulate *** results demonstrate that the shape of slopes more comprehensively influences the 3-D architecture of lobes in natural deep-sea systems than previously other lobe deposits and analogue experiments,which helps us better understand the development and evolution of the distal parts of turbidite systems.

关键词： Submarine fan Seafloor topography Sedimentary architecture Slope system SW Indian ocean

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