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Effects of friction stir processing and nano-hydroxyapatite on the microstructure,hardness,degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications

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Journal of Magnesium and Alloys 2024年第1期12卷 209-224页

作者： Bo Wu Farazila Yusof Fuguo Li Huan Miao A.R.Bushroa Mohd Ridha bin Muhamad Irfan Anjum Badruddin Mahmoud z.Ibrahim Department of Mechanical Engineering Faculty of EngineeringUniversiti MalayaKuala Lumpur 50603Malaysia Centre of Advanced Manufacturing and Material Processing(AMMP Centre) Universiti MalayaKuala Lumpur 50603Malaysia Center of Foundation studies in Science Universiti MalayaKuala Lumpur 50603Malaysia State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Mechanical Engineering Department College of EngineeringKing Khalid UniversityAbha 61421Saudi Arabia Design and Production Engineering Faculty of EngineeringAin Shams UniversityCairo 11517Egypt

Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural ***,the rapid degradation of magnesium alloys in biological media hinders successful *** of microstructure,as well as reinforcement particles can significantly improve the degradation *** this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were *** subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three *** resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,*** is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation *** corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n ***,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation *** wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base ***,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three *** results raise that the grain refinement by FSP and introduction of n HA partic

关键词： Friction stir processing Magnesium-based composite Nano-hydroxyapatite Corrosion behavior In-vitro bioactivity

Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter

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Research in Astronomy and Astrophysics 2024年第1期24卷 128-134页

作者： Hengjie Lin Yan Gong bin Yue Xuelei Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center for High Energy Physics Peking UniversityBeijing 100871China

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope(JWST),and it may require a high star formation ***,this will lead to large number density of ionizing photons in the epoch of reionization(EoR),so that the reionization history will be changed,which can arise tension with the current EoR *** dark matter(WDM),via the free streaming effect,can suppress the formation of small-scale structure as well as low-mass *** provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-z massive galaxies without altering the cosmic reionization *** the other hand,the constraints on the properties of WDM can be derived from the JWST *** this work,we study WDM as a possible solution to reconcile the JWST stellar mass density of high-z massive galaxies and reionization *** find that,the JWST high-z comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM *** using the observational data of other stellar mass density measurements and reionization history,we obtain that the WDM particle mass with mw=0.51_(-0.12)^(+0.22) keV and star formation efficiency parameter f_(*)^(0)> 0.39 in 2σ confidence level can match both the JWST high-z comoving cumulative stellar mass density and the reionization history.

关键词： Cosmology (cosmology:)dark matter (cosmology:)large-scale structure of universe

Learning Scalable Task Assignment with Imperative-Priori Conflict Resolution in Multi-UAV Adversarial Swarm Defense Problem

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Journal of Systems Science & Complexity 2024年第1期37卷 369-388页

作者： zHAO zhixin CHEN Jie XIN bin LI Li JIAO Keming zHENG Yifan School of Electronics and Information Engineering Tongji UniversityShanghai 201804China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Autonomous Intelligent Unmanned Systems Beijing 100081China Shanghai Institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China.

The multi-UAV adversary swarm defense(MUASD)problem is to defend a static base against an adversary UAV swarm by a defensive UAV *** the problem into task assignment and low-level interception strategies is a widely used ***-based approaches for task assignment are a promising *** studies on learning-based methods generally assume decentralized decision-making architecture,which is not beneficial for conflict *** contrast,centralized decision-making architecture is beneficial for conflict resolution while it is often detrimental to *** achieve scalability and conflict resolution simultaneously,inspired by a self-attention-based task assignment method for sensor target coverage problem,a scalable centralized assignment method based on self-attention mechanism together with a defender-attacker pairwise observation preprocessing(DAP-SelfAtt)is ***,an imperative-priori conflict resolution(IPCR)mechanism is proposed to achieve conflict-free ***,the IPCR mechanism is parallelized to enable efficient *** validate the algorithm,a variant of proximal policy optimization algorithm(PPO)is employed for training in scenarios of various *** experimental results show that the proposed algorithm not only achieves conflict-free task assignment but also maintains scalability,and significantly improve the success rate of defense.

关键词： Conflict resolution reinforcement learning scalability task assignment.

Recent progress in the research on magnesium and magnesium alloy foils:A short review

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 842-854页

作者： Qiuyan Shen Yongxing Ba Peng zhang Jiangfeng Song bin Jiang Fusheng Pan National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation coefficients,magnetic and electrical conductivities,as well as high theoretical specific ***,magnesium alloys exhibit poor deformation ability due to their hexagonal close-packed crystal *** magnesium and magnesium alloy foils with thicknesses of less than 0.1 mm is difficult because of surface oxidation and grain growth at high temperatures or severe anisotropy after cold rolling that leads to *** methods have been applied to prepare magnesium alloy *** include warm rolling,cold rolling,accumulative roll bonding,electric plastic rolling,and on-line heating *** of magnesium and magnesium alloy foils during preparation,such as edge cracks and breakage,are important factors for ***,the current status of the research on magnesium and magnesium alloy foils is summarized from the aspects of foil preparation,defect control,performance characterization,and application *** advantages and disadvantages of different preparation methods and defect(edge cracks and breakage)mechanisms in the preparation of foils are identified.

关键词： magnesium alloy foil rolling defect performance application

Experimental study on seismic reinforcement of bridge foundation on silty clay landslide with inclined interlayer

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 193-207页

作者： Lei Da Xiao Hanmo Ran Jianhua Luo bin Jiang Guanlu Xue Tianlang College of Civil Engineering Sichuan Agricultural UniversityDujiangyan 611830China Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction Dujiangyan 611830China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

A shaking table test for a bridge foundation reinforced by anti-slide piles on a silty clay landslide model with an inclined interlayer was *** deformation characteristics of the bridge foundation piles and anti-slide piles were analyzed in different loading *** dynamic response law of a silty clay landslide with an inclined interlayer was *** spacing between the rear anti-slide piles and bridge foundation should be reasonably controlled according to the seismic fortification requirements,to avoid the two peaks in the forced deformation of the bridge foundation ***“blocking effect”of the bridge foundation piles reduced the deformation of the forward anti-slide *** stress-strain response of silty clay was intensified as the vibration wave field appeared on the *** the vibration intensified,the thrust distribution of the landslide underwent a process of shifting from triangle to inverted trapezoid,the difference in the acceleration response between the bearing platform and silty clay landslide tended to decrease,and the spectrum amplitude near the natural vibration frequency *** rear anti-slide piles were able to slow down the shear deformation of the soil in front of the piles and avoid excessive acceleration response of the bridge foundation piles.

关键词： silty clay landslide inclined interlayer shaking table test anti-slide pile bridge foundation pile

Irreducible Representations of GL_(n)(C)of Minimal Gelfand-Kirillov Dimension

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Acta Mathematica Sinica,English Series 2024年第3期40卷 639-657页

作者： zhan Qiang BAI Yang Yang CHEN Dong Wen LIU bin Yong SUN School of Mathematical Sciences Soochow UniversitySuzhou 215006P.R.China School of Sciences JiangnanUniversityWui214122P.R.China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058P.R.China Institute for Advanced Study in Mathematics Zhejiang UniversityHangzhou 310058P.R.China

In this article,by studying the Bernstein degrees and Goldie rank polynomials,we es-tablish a comparison between the irreducible representations of G=GL_(n)(C)possessing the minimal Gelfand-Kirillov dimension and those induced from finite-dimensional representations of the maximal parabolic subgroup of G of type(n-1,1).We give the transition matrix between the two bases for the corresponding coherent families.

关键词： Bernstein degree coherent continuation Gelfand-Kirillov dimension

Gradient-structure-enhanced dielectric energy storage performance of flexible nanocomposites containing controlled preparation of defective TiO_(2) and ferroelectric KNbO_(3) nanosheets

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Nano Research 2024年第5期17卷 4079-4088页

作者： Yan Wang Lili zhao Ruicong Chen Wenhui zhao Dengwei Hu Haoran Wang bin Cui Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education Shaanxi Key Laboratory of Physico–Inorganic Chemistry Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China School of Information Science and Technology Northwest UniversityXi’an 710127China Engineering Research Center for Titanium Based Functional Materials and Devices in Universities of Shaanxi Province Faculty of Chemistry and Chemical EngineeringBaoji University of Arts and SciencesBaoji 721013China

Next generation power system needs dielectrics with increased dielectric energy ***,the low energy density of dielectrics limits their ***,an asymmetric trilayered nanocomposite,with a transition layer(TL),an insulation layer(IL),and a polarization layer(PL),is designed based on poly(vinylidene fluoride)-polymethyl methacrylate(PVDF-PMMA)matrix using KNbO_(3)(KN)and TiO_(2)(TO)as the *** morphology and defect control of the two-dimensional nano KN and nano TO fillers are realized via a hydrothermal method to increase the composite breakdown strength(E_(b))and the composite energy density(U_(e)).The asymmetric trilayered structure leads to a gradient electric field distribution,and the KN and TO nanosheets block charges transfer along z *** a result,the development path of the electrical trees is greatly curved,and E_(b) is effectively *** the Ue value of the nanocomposites reaches 17.79 J·cm^(-3) at 523 MV·m^(-1).On the basis,the composite Ue is further improved by defect control in TO *** nanocomposite KN/TO/PVDF-PMMA containing TO with less oxygen vacancy concentration(calcined at oxygen atmosphere)acquires a high Ue of 21.61 J·cm^(-3) at 548 MV·m^(-1).This study provides an idea for improving the energy storage performance by combining the design of the composite dielectric structure and the control of nanofillers’defect and morphology.

关键词： asymmetric trilayered structure two-dimensional energy density oxygen vacancies breakdown strength dielectric

Bipolar membrane electrodialysis integrated with in-situ CO_(2)absorption for simulated seawater concentrate utilization,carbon storage and production of sodium carbonate

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Journal of Environmental Sciences 2024年第8期142卷 21-32页

作者： Jingtao Bi Tianyi Chen Yue Xie Ruochen Shen bin Li Mengmeng Sun Xiaofu Guo Yingying zhao School of Chemical Engineering and Technology Hebei University of TechnologyTianjin 300401China Engineering Research Center of Seawater Utilization Technology of Ministry of Education School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300401China Hebei Collaborative Innovation Center of Modern Marine Chemical Technology Tianjin 300401China Tianjin Key Laboratory of Chemical Process Safety Tianjin 300130China Shandong Technology Innovation Center of Seawater and Brine Efficient Utilization Weifang 262737China

In the context of carbon capture,utilization,and storage,the high-value utilization of carbon storage presents a significant *** address this challenge,this study employed the bipolar membrane electrodialysis integrated with carbon utilization technology to prepare Na_(2)CO_(3)products using simulated seawater concentrate,achieving simultaneous saline wastewater utilization,carbon storage and high-value production of Na_(2)CO_(3).The effects of various factors,including concentration of simulated seawater concentrate,current density,CO_(2)aeration rate,and circulating flow rate of alkali chamber,on the quality of Na_(2)CO_(3)product,carbon sequestration rate,and energy consumption were *** the optimal condition,the CO_(3)^(2-)concentration in the alkaline chamber reached a maximum of 0.817 mol/L with 98 mol%*** resulting carbon fixation rate was 70.50%,with energy consumption for carbon sequestration and product production of 5.7 k Whr/m^(3)CO_(2)and1237.8 k Whr/ton Na_(2)CO_(3),*** coupling design provides a triple-win outcome promoting waste reduction and efficient utilization of resources.

关键词： Bipolar membrane electrodialysis(BMED) Carbon capture Utilization and storage(CCUS) Seawater concentrate Sodium carbonate

Genetic analysis and fine mapping of a grain size QTL in the smallgrain sterile rice line zhuo201S

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Journal of Integrative Agriculture 2024年第7期23卷 2155-2163页

作者： bin Lei Jiale Shao Feng zhang Jian Wang Yunhua Xiao zhijun Cheng Wenbang Tang Jianmin Wan College of Agronomy Hunan Agricultural UniversityChangsha 410128China National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory for Crop Genetics and Germplasm Enhancement/Jiangsu Plant Gene Engineering Research Center Nanjing Agricultural UniversityNanjing 210095China State Key Laboratory of Hybrid Rice Hunan Hybrid Rice Research CenterChangsha 410125China

The development and application of the small-grain rice sterile line zhuo201S(z201S)has demonstrated its potential for mechanized hybrid rice seed production,leading to significant cost ***,the molecular mechanism responsible for the small-grain size characteristic of z201S remains *** this study,we conducted a genetic analysis using near-isogenic lines constructed from z210S,a small-grain rice sterile line,and R2115,a normal-grain *** results revealed that the small-grain trait in z201S is governed by a single partially dominant gene which also enhances grain *** mapping,we localized the causal gene to the short arm of chromosome 2,within a 113 kb physical region delimited by the molecular markers S2-4-1 and *** analysis and gene expression assays indicated LOC_Os02g14760 as the most likely candidate gene,suggesting that the small-grain size trait of z201S is controlled by a novel locus that has not been previously identified.

关键词： rice grain size map-based cloning