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Absorption properties and mechanism of lightweight and broadband electromagnetic wave-absorbing porous carbon by the swelling treatment

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1701-1712页

作者： jianghao Wen Di Lan Yiqun Wang Lianggui Ren Ailing feng Zirui jia Guanglei Wu College of Materials and Chemistry&Chemical Engineering Chengdu University of TechnologyChengdu 610059China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China Institute of Physics&Optoelectronics Technology Baoji University of Arts and SciencesBaoji 721016China

Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental *** this study,KOH was evenly distributed on biomass Tremella using the swelling induction method,leading to the preparation of a three-dimensional network-structured hierarchical porous carbon(HPC)through *** achieved microwave absorption intensity is robust at-47.34 dB with a thin thickness of 2.1 ***,the widest effective absorption bandwidth,reaching 7.0 GHz(11–18 GHz),is attained at a matching thickness of 2.2 *** exceptional broadband and reflection loss performance are attributed to the 3D porous networks,interface effects,carbon network defects,and dipole *** has outstanding absorption characteristics due to its excellent impedance matching and high attenuation *** uniform pore structures considerably optimize the impedance-matching performance of the material,while the abundance of interfaces and defects enhances the dielectric loss,thereby improving the attenuation ***,the impact of carbonization temperature and swelling rate on microwave absorption performance was systematically *** research presents a strategy for preparing absorbing materials using biomass-derived HPC,showcasing considerable potential in the field of electromagnetic wave absorption.

关键词： biomass hierarchical porous carbon dielectric loss electromagnetic wave absorption

Effects of loneliness and isolation on cardiovascular diseases:a two sample Mendelian Randomization Study

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Journal of Geriatric Cardiology 2024年第3期21卷 340-348页

作者： jia-Yin CAI Xin WANG Cong-Yi ZHENG xue CAO Zhen HU Run-Qing GU Yi-Xin TIAN Ye TIAN Lan SHAO Lin-feng ZHANG Zeng-Wu WANG Division of Prevention and Community Health National Center for Cardiovascular DiseaseNational Clinical Research Center of Cardiovascular DiseaseState Key Laboratory of Cardiovascular DiseaseFuwai HospitalPeking Union Medical College&Chinese Academy of Medical SciencesBeijingChina

BACKGROUND Loneliness and isolation are associated with multiple cardiovascular diseases(CVDs),but there is a lack of research on whether they were causally *** conducted a Mendelian Randomization(MR)study to explore causal relationships between loneliness and isolation and multiple *** Single nucleotide polymorphisms associated with loneliness and isolation were identified from a genome-wide association study(GWAS)of 455,364 individuals of European ancestry in the IEU GWAS *** data for 15 CVDs were also obtained from the IEU GWAS *** used three MR methods including inverse variance weighting,MR-Egger,and weighted median estimation to assess the causal effect of exposure on ***'s Q test and MR-Egger intercept test were used to evaluate the heterogeneity and *** MR analysis showed that loneliness and isolation were significantly associated with essential hypertension(OR=1.07,95%CI:1.03-1.12),atherosclerotic heart disease(OR=1.04;95%CI:1.02-1.06),myocardial infarction(OR=1.02;95%CI:1-1.04)and angina(OR=1.04;95%CI=1.02-1.06).No heterogeneity and pleiotropy effects were found in this *** Causal relationship of loneliness and isolation with CVDs were found in this study.

关键词： diseases cardiovascular angina

Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

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Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie xue-yuan jiang Hai-yan Tang ·Gen Li Yu-hang Wang jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel Institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

Uncovering Microstructure-Property Relationship in Ni-Alloyed Fe-Mn-Al-C Low-Density Steel Treated by Hot-Rolling and Air-Cooling Process

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 713-725页

作者： Xiaoliang jia Guhui Gao Xiaolu Gui Chun feng R.D.K.Misra Bingzhe Bai School of Mechanical Electronicand Control EngineeringBeijing Jiaotong UniversityBeijing100044China CNPC Tubular Goods Research Institute Xi’an710077China Laboratory for Excellence in Advanced Steel Research University of Texas at El PasoEl PasoTX79968-0521USA School of Material Science and Engineering Key Laboratory of Advanced Materials of Ministry of EducationTsinghua UniversityBeijing100084China

This paper focuses on the relationship between the microstructure and tensile properties of Fe-Mn-Al-C low-density high-strength steel processes by hot-rolling and air-cooling process. The microstructure analysis reveals that the combination of hot-rolling and air-cooling results in the formation of heterogeneous structures comprising different-sized γ and B_(2) phases in the low-density steel with the addition of nickel (Ni). The addition of Ni promotes the formation of the B_(2) phase and induces the pinning of B_(2) phase particles at the γ grain boundaries. This pinning effect effectively hinders the growth of the γ grains, leading to grain refinement. The tensile test results demonstrate that LDS-5Ni (low-density steel, LDS) exhibits excellent high strength and ductility combination, e.g., a tensile strength of 1535 MPa, yield strength of 1482 MPa, and elongation of 23.3%. These remarkable mechanical properties are primarily attributed to the combined strengthening contributions of grain refinement and duplex nano-sized second-phase precipitation hardening.

关键词： Low-density steel Microstructure B_(2)phase κ-Carbide Tensile properties

A novel transcription factor FnMYB4 regulates pigments metabolism of yellow leaf mutants in Fragaria nilgerrensis

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Horticultural Plant Journal 2024年第5期10卷 1134-1150页

作者： Shu jiang Yi Ji Jingyu Yue Mingqian Wang Yumeifeng jia Li xue jiajun Lei College of Horticulture Shenyang Agricultural UniversityShenyangLiaoning 110866China

The strawberry species Fragaria nilgerrensis Schlechtendal ex ***,renowned for its distinctive white,fragrant peach-like fruits and strong disease resistance,is an exceptional research *** a previous study,an ethyl methane sulfonate(EMS)mutant library was established for this species,resulting in various yellow leaf *** yellowing materials are not only the ideal materials for basic studies on photosynthesis mechanism,chloroplast development,and molecular regulation of various pigments,but also have important utilization value in ornamental plants *** present study focused on four distinct yellow leaf mutants:mottled yellow leaf(MO),yellow green leaf(YG),light green leaf(LG),and buddha light leaf(BU).The results revealed that the flavonoid content and carotenoid-to-chlorophyll ratio exhibited a significant increase among these mutants,while experiencing a significant decrease in chlorophyll and carotenoid contents compared to the wild type(WT).To clarify the regulatory mechanisms and network relationships underlying these mutants,the RNA-seq and weighted gene coexpression network(WGCNA)analyses were *** results showed flavonoid metabolism pathway was enriched both in MO and YG mutants,while the chlorophyll biosynthesis pathway and carotenoid degradation pathway were only enriched in MO and YG mutants,***,key structural genes and transcription factors were identified on metabolic pathways of three pigments through correlation analyses and quantitative ***,a R2R3-MYB transcription factor,FnMYB4,was confirmed to be positively correlated with flavonoid synthesis through transient overexpression,virus-induced gene silencing(VIGS),and RNA interference(RNAi),accompanying by reoccurrence and attenuation of mutant ***,dual-luciferase(LUC)and yeast one-hybrid assays confirmed the binding of FnMYB4 to the FnFLS and FnF3H promoters,indicating that FnMYB4 positively regulates flavonoid sy

关键词： Fragaria nilgerrensis Mutant Leaf yellowing RNA-seq Flavonoid MYB

Swelling of Spherical Polyelectrolyte Gels

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Chinese Journal of Polymer Science 2024年第9期42卷 1386-1392,I0009页

作者： Ming-Yu Duan jia-Dong Chen Yi-Ming Liu Zhao-feng Peng Guang Chen Department of Advanced Manufacturing and Robotics College of EngineeringPeking UniversityBeijing 100871China

Polyelectrolyte(PE)gels,distinguished by their unique stimuli-responsive swelling behavior,serve as the basis of broad applications,such as artificial muscles and drug *** this work,we present a theoretical model to analyze the electrostatics and its contribution to the swelling behavior of PE gels in salt *** minimizing the free energy of PE gels,we obtain two distinct scaling regimes for the swelling ratio at equilibrium with respect to the salt *** compare our predictions for the swelling ratio with experimental measurements,which show excellent *** addition,we employ a finite element method to assess the applicability range of our theoretical model and *** anticipate that our model will also provide valuable insights into drug adsorption and release,deformation of red blood cells,4D printing and soft robotics,where the underlying mechanism of swelling remains enigmatic.

关键词： Gels Polyelectrolytes Swelling Stimuli-responsive Electrostatic interaction Cell model

Finite-temperature ductility-brittleness and electronic structures of Al_(n)Sc(n=1,2 and 3)

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Rare Metals 2024年第8期43卷 3974-3989页

作者： xue-Qian Wang Ying Zhao Hao-Xuan Liu Shu-Chen Sun Hong-Bo Yang jia-Min Zhong Gan-feng Tu Song Li Yu-Dong Zhang Claude Esling Hai-Le Yan Liang Zuo Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China Rare Earth Functional Materials(Xiong'an)Innovation Center Co. Ltd.Xiong'an 071700China Laboratoire d'étude des Microstructures et de Mécanique des Matériaux(LEM3) Unikersitéde Lorraine57045MetzFrance

Finite-temperature ductility-brittleness and electronic structures of Al_(3)Sc,Al_(2)Sc and AlSc are studied comparatively by first-principles calculations and ab initio molecular *** show that Al_(3)Sc and Al_(2)Sc are brittle at both ground state and finite temperatures,while AlSc possesses a significantly superior *** ground state,AlSc is ductile from Pugh's and Poisson's criteria,while it is brittle in Pettifor's *** ductility of all Al_(3)Sc,Al_(2)Sc and AISc improves greatly with the elevated ***,the Cauchy pressure of AlSc undergoes a transition from negative to *** T>600 K,AlSc is unequivocally classified as ductile from all criteria *** all compounds,the Al-Al bond originated from s-p and p-p orbital hybridizations,and the Al-Sc bond dominated by p-d covalent hybridization,are the first and second strongest chemical bonds,*** explain the difference in mechanical properties,the mean bond strength(MBS)is introduced in this *** weaker Al-Al bond in AlSc,leading to a smaller MBS,could be the origin of the softer elastic stiffness and superior intrinsic *** longer length of the Al-Al bond in AlSc is responsible for its weaker bond ***,the enhanced metallicity of the Al-Al bond in AlSc would also contribute to its exceptional *** longer length of the Al-Al bond in AISc is responsible for its weaker bond ***,the enhanced metallicity of the Al-Al bond in AlSc would also contribute to its exceptional ductility.

关键词： Al-Sc Target materials Intrinsic ductility Finite-temperature elastic constant First-principles calculation

Variability of urban fractional vegetation cover and its driving factors in 328 cities in China

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Science China Earth Sciences 2024年第2期67卷 466-482页

作者： Fei feng Xin YANG Baoquan jia Xiaoting LI Xianwen LI Chengyang XU Kaicun WANG Research Centre of Urban Forestry Key Laboratory for Silviculture and Forest Ecosystem of State Forestry and Grassland AdministrationBeijing Forestry UniversityBeijing100083China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing100875China Research Institute of Forestry Chinese Academy of ForestryBeijing100091China School of Architecture Tsinghua UniversityBeijing100084China College of Urban and Environmental Sciences Sino-French Institute for Earth System ScienceInstitute of Carbon NeutralityPeking UniversityBeijing100871China

Urban green space promotes the health of urban residents,enhances urban ecosystem biodiversity,mitigates environmental pollution,and attenuates urban heat island ***,urban vegetation cover is highly heterogeneous and difficult to *** this study,the variation of urban fractional vegetation cover(FVC)in 328 cities in China from 1990 to2022 was quantified based on Landsat satellite data at a 30-m *** was found that from 1990 to 2005,due to increases in building density and impervious surfaces in cities,the national mean urban vegetation cover decreased from 0.38 to ***2005,urban vegetation cover began to reverse,reaching 0.45 in *** increasing trend was most pronounced in newly built urban *** decrease in average urban vegetation cover before 2005 was mainly due to the expansion of low vegetation cover areas,while the increase in urban vegetation cover after 2005 manifested as the expansion of high vegetation cover *** reversal in the trend of urban vegetation cover change after 2004 is related to the gradual implementation of national policies requiring increased urban green space *** urban gross domestic product(GDP)showed the highest correlation with changes in urban vegetation *** large and medium-sized cities,the top three factors influencing vegetation cover were GDP,urban population,and ***,for cities in arid/semi-arid regions,changes in vegetation cover were more sensitive to climatic factors(such as precipitation).Although the urban vegetation cover in China has substantially increased in recent years,the urban green space in small-sized cities and in the old urban districts of large-sized cities still have room to improve.

关键词： Urban vegetation Urban vegetation cover Urbanization Remote sensing

Efficient nitrate electroreduction over Mn-doped Cu catalyst via regulating N-containing intermediates adsorption configuration

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Science China Chemistry 2024年第6期67卷 1969-1975页

作者： Limin Wu Shunhan jia Libing Zhang Ruhan Wang jiaqi feng Xiaofu Sun Buxing Han Beijing National Laboratory for Molecular Sciences CAS Laboratory of Colloid and Interface and ThermodynamicsCAS Research/Education Center for Excellence in Molecular SciencesCenter for Carbon Neutral ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing100049China College of Chemical Engineering and Environment China University of PetroleumBeijing102249China Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai200062China

The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch ***,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction *** this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)*** doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)*** experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of**** alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).

关键词： nitrate reduction electrocatalysis ammonia synthesis N-intermediate green chemistry