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Missing Value Imputation for Radar-Derived Time-Series Tracks of Aerial Targets Based on Improved Self-Attention-Based Network

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Computers, Materials & Continua 2024年第3期78卷 3349-3376页

作者： Zihao Song Yan zhou Wei cheng Futai Liang Chenhao Zhang Department of Early Warning Intelligence Early Warning AcademyWuhan430019China

The frequent missing values in radar-derived time-series tracks of aerial targets(RTT-AT)lead to significant challenges in subsequent data-driven ***,the majority of imputation research focuses on random missing(RM)that differs significantly from common missing patterns of *** method for solving the RM may experience performance degradation or failure when applied to RTT-AT *** autoregressive deep learning methods are prone to error accumulation and long-term dependency *** this paper,a non-autoregressive imputation model that addresses the issue of missing value imputation for two common missing patterns in RTT-AT is *** model consists of two probabilistic sparse diagonal masking self-attention(PSDMSA)units and a weight fusion *** learns missing values by combining the representations outputted by the two units,aiming to minimize the difference between the missing values and their actual *** PSDMSA units effectively capture temporal dependencies and attribute correlations between time steps,improving imputation *** weight fusion unit automatically updates the weights of the output representations from the two units to obtain a more accurate final *** experimental results indicate that,despite varying missing rates in the two missing patterns,our model consistently outperforms other methods in imputation performance and exhibits a low frequency of deviations in estimates for specific missing *** to the state-of-the-art autoregressive deep learning imputation model Bidirectional Recurrent Imputation for Time Series(BRITS),our proposed model reduces mean absolute error(MAE)by 31%~50%.Additionally,the model attains a training speed that is 4 to 8 times faster when compared to both BRITS and a standard Transformer model when trained on the same ***,the findings from the ablation experiments demonstrate that the PSDMSA,the weight fusion unit,cascade network design

关键词： Missing value imputation time-series tracks probabilistic sparsity diagonal masking self-attention weight fusion

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The first 10 m resolution thermokarst lake and pond dataset for the Lena Basin in the 2020 thawing season

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Big Earth Data 2024年第2期8卷 302-332页

作者： Yining Yu Fengming Hui Yu zhou Chong Liu Xiao cheng School of Geospatial Engineering and Science Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)ZhuhaiChina Key Laboratory of Comprehensive Observation of Polar Environment (Sun Yat-sen University)Ministry of EducationZhuhaiChina Guangdong Provincial Key Laboratory of Geodynamics and Geohazards School of Earth Sciences and EngineeringSun Yat-sen UniversityZhuhaiChina

Climate warming rates in the Arctic are far greater than the global average,exerting stronger impacts on permafrost degradation and thermokarst landform *** lakes and ponds(TLPs),which are widely distributed in the Lena Basin in the Russian Arctic,play a vital role in altering local ***,the detailed distribution of TLPs in the Lena Basin still remains poorly *** this study,we built the first 10 m resolution TLP dataset for the Lena Basin in the 2020 thawing season by utilizing 4902 Sentinel-2 images.A robust mapping workflow was developed and implemented in the Google Earth Engine(GEE)*** accu-racy assessment demonstrates a satisfactory accuracy(93.63%),and our results exhibit a better consistency with real TLPs than global water body products.A total of 380,477 TLPs(~0.53%of the total surface area of the Lena Basin)were identified,showing an uneven distribution in the five *** TLPs were found to be mainly located within plain areas,with an active layer thickness in the range of 80-100 *** higher ground ice content and mean annual ground temperature were favorable for TLP *** dataset will be valuable for investigating the complex interac-tion between TLPs and *** will also serve as a baseline product for better incorporating thermokarst processes into perma-frostclimate models.

关键词： Thermokarst lakes and ponds Lena Basin permafrost GEE Sentinel-2

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Electrical tree degradation of MgO/epoxy resin composites at different voltage frequencies

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High Voltage 2024年第3期9卷 581-590页

作者： Yunxiao Zhang Wenxin Lin Yuanxiang zhou Weiwei Xing Jiayu cheng Chenyuan Teng College of Electrical Engineering and Automation Fuzhou UniversityFujian Key Laboratory of New Energy Generation and Power ConversionFuzhouChina State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijingChina

Electrical tree degradation is one of the main causes of insulation failure in high-frequency *** tree degradation is studied on pure epoxy resin(EP)and MgO/EP composites at frequencies ranging from 50 Hz to 130 *** results show that the tree initiation voltage of EP decreases,while the growth rate and the expansion coefficient increase with ***,the bubble phenomenon at high frequencies in EP composites is *** with trap distribution character-istics within the material,the intrinsic mechanism of epoxy composites to inhibit the growth of the electrical tree at different frequencies is *** can be concluded that more deep traps and blocking effect are introduced by doping nano-MgO into EP bulks,which can improve the electrical tree resistance performance of EP composites in a wide frequency range.

关键词： composites tree Electrical

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Study on the anti-inflammatory mechanism of moxibustion in rheumatoid arthritis in rats based on phospholipaseA2 signaling inhibition by Annexin 1

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Journal of Traditional Chinese Medicine 2024年第4期44卷 753-761页

作者： GUO Yanding LUO Kun ZHANG Linlin LU Wenting shang Yanan ZHONG Yumei HU Danhui YANG Xin zhou Haiyan Department of Acupuncture-Moxibustion and Tuina the Third Affiliated HospitalChengdu University of Traditional Chinese MedicineChengdu 610075China External Treatment Center First People's Hospital of ChengduChengdu 610095China Department of chengdu Integrated Traditional Chinese Medicine and Western Medicine Hospital Chengdu 610075China Department of Health Rehabilitation School Chengdu University of Traditional Chinese MedicineChengdu 610075China

OBJECTIVE:To determine whether moxibustion had an anti-inflammatory effect on rheumatoid arthritis(RA)by regulating Annexin 1 expression and interfering with the phospholipaseA2 signaling ***:Thirty male Sprague-Dawley rats were randomly categorized into five groups(six rats per group):blank control(CON)group,RA model(RA)group,moxibustion(MOX)group,Annexin 1 lentiviral intervention(RNAi-Anxa1)group,and Annexin 1 lentiviral intervention+moxibustion(RNAi-Anxa1+MOX)*** rats in the RNAi-Anxa1 and the RNAi-Anxa1+MOX groups were injected with the lentiviral vector-mediated RNAi-Anxa1 into the rat foot *** experimental RA rat model was established by injecting Freund's complete adjuvant(FCA)into the RA,MOX,RNAi-Anxa1,and RNAi-Anxa1+MOX *** in the MOX and RNAiAnxa1+MOX groups received moxibustion *** modeling,using moxibustion“Shenshu(BL23)”and“Zusanli(ST36)”,each point is 5 times,bilateral alternating,once a day,6 times for a course of treatment,between the courses of rest for a one day.A total of three treatment courses were *** bilateral pad thicknesses were measured using Vernier calipers on experimental days 1,7,14,21,and *** expression of cPLA2αsignaling in the synovium of diseased joints was observed using Western *** pathology of the rat ankle synovium was observed using hematoxylineosin(HE)***(IL)-1β,IL-10,prostaglandin E2(PGE2),and leukotriene B4(LTB4)were detected using enzyme-linked immunosorbent ***:Moxibustion increased the levels of Annexin 1 and decreased the inflammatory response in rats with *** increasing the expression of Annexin 1,the phosphorylated expression of cPLA2αwas inhibited,the serum levels of IL-1β,PGE2,and LTB4 decreased,and the level of IL-10 *** moxibustion treated RA rats after the Annexin 1 lentiviral intervention,the serum levels of IL-1β,PGE2,LTB4,and IL-10 were almost ***:Moxibustion enhanced the negative regulation of

关键词： annexins group IV phospholipases A2 signal transduction moxibustion arthritis,rheumatoid

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Bimetallic selenide heterostructure with directional built-in electricfield confined in N-doped carbon nanofibers for superior sodium storage with ultralong lifespan

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Journal of Energy Chemistry 2024年第4期91卷 407-416页

作者： Junying Weng Degui Zou Wenyong Yuan Pengfei zhou Minghui Ding Jin zhou Hailin Cong Fangyi cheng School of Materials Science and Engineering Shandong University of TechnologyZibo 255000ShandongChina School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000ShandongChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China

Constructing heterostructure is considered as an effective strategy to address the sluggish electronic and ionic kinetics of anode materials for sodium ion batteries(SIBs).However,realizing the orientated growth and uniform distribution of the heterostructure is still a great ***,the regulated novel CoSe_(2)/NiSe_(2)heterostructure confined in N-doped carbon nanofibers(CoSe_(2)/NiSe_(2)@N-C)are prepared by using Co/Ni-ZIF template,in which,the CoSe_(2)/NiSe_(2)heterostructures realize uniform distribution on a micro *** from the unique heterostructure and N-doped carbon nanofibers,the CoSe_(2)/NiSe_(2)@N-C deliveries superior rate capability and durable cycle lifespan with a reversible capacity of 400.5 mA h g^(-1)after 5000 cycles at 2 A g^(-1).The Na-ion full battery with CoSe_(2)/NiSe_(2)@N-C anode and layered oxide cathode displays a remarkable energy density of 563 W h kg^(-1)with 241.1 W kg^(-1)at 0.1 A g^(-1).The theoretical calculations disclose that the periodic and directional built-in electric-field along with the heterointerfaces of CoSe_(2)/NiSe_(2)@N-C can accelerate electrochemical reaction *** in(ex)situ experimental measurements reveal the reversible conversion reaction and stable structure of CoSe_(2)/NiSe_(2)@N-C during Na+insertion/*** study highlights the potential ability of precisely controlled heterostructure to stimulate the electrochemical performances of advanced anode for SIBs.

关键词： CoSe_(2)/NiSe_(2) heterostructure Built-in electric-field Rate capability Ultralong lifespan Sodium ion batteries

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Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng zhou Yu Long Yan-Liang Yi cheng Deng Lian-Xi Hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

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Berberine Inhibits Ferroptosis and Stabilizes Atherosclerotic Plaque through NRF2/SLC7A11/GPX4 Pathway

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Chinese Journal of Integrative Medicine 2024年第10期30卷 906-916页

作者： WANG Ting-ting YU Li-li ZHENG Jun-meng HAN Xin-yi JIN Bo-yuan HUA cheng-jun CHEN Yu-shan shang Sha-sha LIANG Ya-zhou WANG Jian-ru Heart Center the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou450000China

Objective:To investigate potential mechanisms of anti-atherosclerosis by berberine(BBR)using ApoE-/-***:Eight 8-week-old C57BL/6J mice were used as a blank control group(normal),and 568-week-old AopE-/-mice were fed a high-fat diet for 12 weeks,according to a completely random method,and were divided into the model group,BBR low-dose group(50 mg/kg,BBRL),BBR medium-dose group(100 mg/kg,BBRM),BBR high-dose group(150 mg/kg,BBRH),BBR+nuclear factor erythroid 2-related factor 2(NRF2)inhibitor group(100 mg/kg BBR+30 mg/kg ML385,BBRM+ML385),NRF2 inhibitor group(30 mg/kg,ML385),and positive control group(2.5 mg/kg,atorvastatin),8 in each *** 4 weeks of intragastric administration,samples were collected and serum,aorta,heart and liver tissues were *** kits were used to detect serum lipid content and the expression levels of malondialdehyde(MDA)and superoxide dismutase(SOD)in all experimental *** pathological changes of atherosclerosis(AS)were observed by aorta gross Oil Red O,aortic sinus hematoxylin-eosin(HE)and Masson *** lipopathy was observed in mice by HE *** morphology of mitochondria in aorta cells was observed under transmission electron *** cytometry was used to detect reactive oxygen species(ROS)expression in aorta of mice in each *** content of ferrous ion Fe^(2+)in serum of mice was detected by biochemical *** mRNA and protein relative expression levels of NRF2,glutathione peroxidase 4(GPX4)and recombinant solute carrier family 7 member 11(SLC7A11)were detected by quantitative real time polymerase chain reaction(RT-q PCR)and Western blot,***:BBRM and BBRH groups delayed the progression of AS and reduced the plaque area(P<0.01).The characteristic morphological changes of ferroptosis were rarely observed in BBR-treated AS mice,and the content of Fe^(2+)in BBR group was significantly lower than that in the model group(P<0.01).BBR decreased ROS and MDA levels in mouse

关键词： berberine ApoE−/− ferroptosis atherosclerosis oxidative stress NRF2/SLC7A11/GPX4 pathway

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Microstructure evolution of Al_(0.6)CoCrFeNi high entropy alloy powder prepared by high pressure gas atomization

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Transactions of Nonferrous Metals Society of China 2018年第5期28卷 939-945页

作者： shang-cheng zhou Peng ZHANG Yun-fei XUE Fu-chi WANG Lu WANG Tang-qing CAO Zhen TAN Bao-ynan cheng Ben-peng WANG School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing Institute of Technology Beijing 100081 China College of Materials Science and Engineering Beijing University of Technology Beijing 100124 China

The influence of cooling rate on the microstructure of Al0.6CoCrFeNi high entropy alloy（HEA） powders was investigated. The spherical HEA powders（D50≈78.65 μm） were prepared by high pressure gas atomization. The different cooling rates were achieved by adjusting the powder diameter. Based on the solidification model, the relationship between the cooling rate and the powder diameter was developed. The FCC phase gradually disappears as particle size decreases. Further analysis reveals that the phase structure gradually changes from FCC＋BCC dual-phase to a single BCC phase with the increase of the cooling rate. The microstructure evolves from planar crystal to equiaxed grain with the cooling rate increasing from 3.19×10^4 to 1.11×10^6 K/s.

关键词： Al0.6CoCrFeNi high entropy alloy high pressure gas atomization spherical powder microstructure cooling rate

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Elevational distribution of forests and its spatiotemporal dynamics in subtropical China from 2000 to 2019

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Science China Earth Sciences 2024年第8期67卷 2563-2582页

作者： Zhencan ZHENG Liuwen ZHUANG Guofang MIAO Han LIU Zhiqiang cheng Wenyu LI Rong shang Peng GONG Jing Ming CHEN Institute of Geography Fujian Normal University Key Laboratory of Humid Subtropical Eco-Geographical Process (Ministry of Education) Fujian Normal University School of Geographical Sciences Fujian Normal University National Land Consolidation Center Ministry of Natural Resources Key Laboratory of Land Consolidation and Rehabilitation Ministry of Natural Resources Key Laboratory of Digital Mapping and Land Information Application Ministry of Natural Resources Department of Geography & Planning University of Toronto Department of Geography The University of Hong Kong

The subtropical region of China possesses abundant forest resources and features a mountainous *** the implementation of policies such as natural forest protection,the Grain for Green Project,and other initiatives since the beginning of the 21st century,coupled with climate change,the forest resources in this region have undergone significant changes compared to historical *** addition,forest resources distributing mainly in mountainous areas also implies that these changes may vary significantly with *** explore the spatiotemporal dynamics of forest distribution in subtropical China since 2000,especially the trend of changes with elevation,we analyzed the data from two land cover products focusing on forest cover and forest *** used a hierarchical approach,in which coarse-classification forest cover data with relatively small uncertainties impose constraints on forest type data with larger uncertainties,to achieve a reasonable balance between obtaining more details and reducing data *** first divided the forest cover data into‘unchanged'and‘changed'*** the constraints by the forest cover results,we further analyzed the‘unchanged'and‘changed'forest *** results indicated that,since the implementation of ecological engineering and management policies,54%of the area in the subtropical region had maintained unchanged forest cover attributes over the past 20 years,which implied the good state of ecological *** results also showed that dynamic conversions existed in the long term between forests and lands for essential production needs like *** elevational variations of forest cover suggested that the dominant changes came from the conversion between forests and croplands in low-elevation regions below 700 m,the conversion between forests and shrublands in mid-elevation regions of 700–1500 m,and the conversion between forests and grasslands in high-elevation regions above 2000 *** the regio

关键词： Subtropical China Land cover Forest cover Forest type Elevational distribution

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Hydrophobic long-chain two-dimensional perovskite scintillators for underwater X-ray imaging

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Rare Metals 2024年第1期43卷 175-185页

作者： Jin-Xiao Zheng Zi-An zhou Tiao Feng Hui Li cheng-Hua Sun NüWang Yang Tian Yong Zhao Shu-Yun zhou Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Laboratory of Bioinspired Smart Interfacial Science and Technology of the Ministry of Education Beijing Key Laboratory of Bioinspired Energy Materials and DevicesSchool of ChemistryBeijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing 100191China Department of Engineering Physics Tsinghua University and Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China e-mail:yangt@***

The underwater X-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of X-ray imaging detection, the scintillator has been plagued by inherent moisture absorption and decomposition, and strict requirements for seamless packaging and ***, we designed a manganese-doped two-dimensional(2D) perovskite scintillator modified by hydrophobic longchain organic amine through the combination of component and doping engineering. The modified perovskites show high water repellency that can be used as an underwater X-ray scintillator. X-ray images of aquatic organisms or other objects with a high spatial resolution of10 lp·mm^(-1) at a big view field(32 mm × 32 mm) were obtained by scintillation screen. This hydrophobic perovskite scintillator based on molecular design is of great promise in underwater X-ray nondestructive testing technology development.

关键词： Two-dimensional perovskite Hydrophobic Scintillators Underwater X-ray imaging Underwater nondestructive testing technology

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