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science China Mathematics 2024年第2期67卷 237-252页

作者： Hong-Lin Liao Tao Tang Tao Zhou School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Division of science and Technology BNU-HKBU United International CollegeZhuhai 519087China SUSTech international Center for Mathematics Shenzhen 518055China NCMIS&LSEC Institute of Computational Mathematics and Scientific/Engineering ComputingAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

The positive definiteness of real quadratic forms with convolution structures plays an important rolein stability analysis for time-stepping schemes for nonlocal operators. In this work, we present a novel analysistool to handle discrete convolution kernels resulting from variable-step approximations for convolution *** precisely, for a class of discrete convolution kernels relevant to variable-step L1-type time discretizations, weshow that the associated quadratic form is positive definite under some easy-to-check algebraic conditions. Ourproof is based on an elementary constructing strategy by using the properties of discrete orthogonal convolutionkernels and discrete complementary convolution kernels. To our knowledge, this is the first general result onsimple algebraic conditions for the positive definiteness of variable-step discrete convolution kernels. Using theunified theory, we obtain the stability for some simple nonuniform time-stepping schemes straightforwardly.

关键词： discrete convolution kernels positive definiteness variable time-stepping orthogonal convolution kernels complementary convolution kernels

Enhanced ferroelectric and improved leakage of BFO-based thin films through increasing entropy strategy

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international Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2263-2273页

作者： Dongfei Lu Guoqiang Xi Hangren Li Jie Tu Xiuqiao Liu Xudong Liu Jianjun Tian Linxing Zhang institute for Advanced Materials Technology University of Science and Technology BeijingBeijing 100083China

BiFeO_(3)(BFO)has received considerable attention as a lead-free ferroelectric film due to its large theoretical remnant ***,BFO suffers from a large leakage current,resulting in poor ferroelectric ***,the sol-gel method was used to deposit a series of BFO-based thin films on fluorine-doped tin oxide substrates,and the effects of the substitution of the elements Co,Cu,Mn(B-site)and Sm,Eu,La(A-site)on the crystal structure,ferroelectricity,and leakage current of the BFO-based thin films were *** confirmed that lattice distortion by X-ray diffraction can be attributed to the substitution of individual elements in the BFO-based *** and Eu substitutions contribute to the lattice distortion in a pseudo-cubic structure,while La is biased toward *** force microscopy confirmed that reversible switching of ferroelectric domains by nearly 180°can be realized through the prepared *** ferroelectric hysteresis loops showed that the order for the polarization contribution is as follows:Cu>Co>Mn(B-site),Sm>La>Eu(A-site).The current density voltage curves indicated that the order for leakage contribution is as follows:Mn

关键词： increasing entropy synergistic ferroelectric film remnant polarization leakage current

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

Interface optimization of graphene paper-Cu composite prepared by electrodeposition

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Journal of Iron and Steel Research international 2024年第1期31卷 64-73页

作者： Jing Guo Hai-jing Wang Shuang-juan Liu Peng Zhang Jing-yu Tang Wei-yang Zhang Han-jie Guo Peng-cheng Wang Cai Meng School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Advanced Technology and Materials Co. Ltd.Beijing100083China School of Nuclear science and Technology University of Science and Technology of ChinaHefei230027AnhuiChina

A room-temperature electrodeposition method with an organic electrolyte was developed to fabricate a HNO3-pretreated graphene paper Cu(GP'-Cu)*** improve the interfacial bonding of GP'-Cu composite,magnetron sputtering technology was used to create a"sandwich"structural gradient GP'-Cu *** selection of the intermediate transition layer metal was based on two-dimensional *** electron microscopy,X-ray photoelectron spectroscopy,and other analytical methods confirmed that the addition of an intermediate transition metal(Cr,Ni)layer reduced the gap distance and enhanced the interfacial bonding of the GP'and Cu deposited *** GP'-Ni-Cu composite exhibited the largest increase in tensile strength and *** addition,it had the highest thermal diffusivity and elongation at break among the GP'-Cu,GP'-Cr-Cu and GP'-Ni-Cu composites.

关键词： Graphene paper Two-dimensional disregistry Magnetron sputtering Metal composite

Livelihood Vulnerability and Adaptation for Households Engaged in Forestry in Ecological Restoration Areas of the Chinese Loess Plateau

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Chinese Geographical science 2024年第5期34卷 849-868页

作者： YANG Qingqing CHEN Yang LI Xiaomin YANG Jie GAO Yanhui Northwest Land and Resources Research Center Global Regional and Urban Research InstituteShaanxi Normal UniversityXi’an 710119China School of Geographical science and Tourism Shaanxi Normal UniversityXi’an 710119China School of Tourism and Research institute of Human Geography Xi’an International Studies UniversityXi’an 710128China

Chinese Loess Plateau has achieved a win-win situation concerning ecological restoration and socio-economic ***,synergistic development may not be realized at the local *** areas undergoing ecological restoration,livelihood vulner-ability may be more pronounced due to the inflexibility,policy protection,and susceptibility to climate and market changes in forestry *** this issue has attracted academic interest,empirical studies are relatively *** study,centered on Jiaxian County,Shaanxi Province of China explored the households’livelihood vulnerability and coping strategies and group heterogeneity con-cerned with livelihood structures or forestry resources through field investigation,comprehensive index assessment,and nonparametric *** showed that:1)the percentage of households with high livelihood vulnerability indicator(LVI)(>0.491)reached 46.34%.2)Eight groups in livelihood structures formed by forestry,traditional agriculture,and non-farm activities were significantly different in LVI,land resources(LR),social networks(SN),livelihood strategies(LS),housing characteristics(HC),and socio-demo-graphic profile(SDP).3)The livelihood vulnerability of the groups with highly engaged/reliance on jujube(Ziziphus jujuba)forest demonstrated more prominent livelihood vulnerability due to the increased precipitation and cold market,where the low-engaged with reliance type were significantly more vulnerable in LVI,SDP,LR,and HC.4)The threshold of behavioral triggers widely varied,and farmers dependent on forestry livelihoods showed negative coping ***,the cutting behavior was strongly associated with lagged years and government subsidies,guidance,and high returns of ***,the findings can provide guidance on the dir-ection of livelihood vulnerability mitigation and adaptive government management in ecologically restored *** issue of farmers’livelihood sustainability in the context of ecologi

关键词： livelihood vulnerability forestry coping behaviors climate change market change Jiaxian County

Effect of hafnium and molybdenum addition on inclusion characteristics in Co-based dual-phase high-entropy alloys

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international Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1639-1650页

作者： Yong Wang Wei Wang Joo Hyun Park Wangzhong Mu Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education&Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Department of Materials science and Engineering KTH Royal Institute of TechnologySE-10044StockholmSweden Department of Chemical Engineering Northeast Electric Power UniversityJilin 132012China Department of Materials science and Chemical Engineering Hanyang UniversityAnsan 15588Korea Engineering Materials Division of Materials ScienceDepartment of Engineering Science and MathematicsLuleå University of Technology97187 LuleåSweden

Specific grades of high-entropy alloys(HEAs)can provide opportunities for optimizing properties toward high-temperature *** this work,the Co-based HEA with a chemical composition of Co_(47.5)Cr_(30)Fe_(7.5)Mn_(7.5)Ni_(7.5)(at%)was *** refractory metallic elements hafnium(Hf)and molybdenum(Mo)were added in small amounts(1.5at%)because of their well-known positive effects on high-temperature *** characteristics were comprehensively explored by using a two-dimensional cross-sectional method and extracted by using a three-dimensional electrolytic extraction *** results revealed that the addition of Hf can reduce Al_(2)O_(3)inclusions and lead to the formation of more stable Hf-rich inclusions as the main *** addition cannot influence the inclusion type but could influence the inclusion characteristics by affecting the physical parameters of the HEA *** calculated coagulation coefficient and collision rate of Al_(2)O_(3)inclusions were higher than those of HfO_(2)inclusions,but the inclusion amount played a larger role in the agglomeration behavior of HfO_(2)and Al_(2)O_(3)*** impurity level and active elements in HEAs were the crucial factors affecting inclusion formation.

关键词： high-entropy alloy non-metallic inclusion agglomeration thermodynamics alloying

Flux phases in the extended Hubbard model on the triangular lattice

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science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 148-153页

作者： Yuge Chen Kun Jiang Yi Zhang Jiangping Hu Beijing National Laboratory for Condensed Matter Physics and institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical sciences University of Chinese Academy of SciencesBeijing 100190China Department of Physics and institute for Quantum science and Technology Shanghai UniversityShanghai 200444China Shanghai Key Laboratory of High Temperature Superconductors and international Center of Quantum and Molecular Structures Shanghai UniversityShanghai 200444China Kavli institute of Theoretical sciences University of Chinese Academy of SciencesBeijing 100190China New Cornerstone science Laboratory Beijing 100190China

Using the unrestricted Hartree-Fock variational method,we study the extended Hubbard model in the triangular lattice at 3/4 *** to the nesting instability of the Fermi surface,various density wave states compatible with the 2×2 supercell are found as the ground state by tuning the onsite and nearest neighbor repulsions U and ***,the flux phases with complex bond order parameters are realized in a wide range of the U-V phase *** also acquire nontrivial topological properties due to the spontaneous breaking of the time-reversal *** study suggests that the flux phases can be stabilized by the interplay between short-range repulsive interactions in correlated electron systems.

关键词： flux state triangular lattice Hubbard model

Mpox(formerly monkeypox):pathogenesis,prevention,and treatment

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Signal Transduction and Targeted Therapy 2024年第1期9卷 234-248页

作者： Junjie Lu Hui Xing Chunhua Wang Mengjun Tang Changcheng Wu Fan Ye Lijuan Yin Yang Yang Wenjie Tan Liang Shen Xiangyang Central Hospital Affiliated Hospital of Hubei University of Arts and ScienceHubei ProvinceXiangyang 441021China NHC Key Laboratory of Biosafety National Institute for Viral Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China College of Biotechnology Tianjin University of Science&TechnologyTianjin 300457China Shenzhen Key Laboratory of Pathogen and Immunity National Clinical Research Center for infectious diseaseState Key Discipline of Infectious DiseaseShenzhen Third People’s HospitalSecond Hospital Affiliated to Southern University of Science and TechnologyShenzhen 518112China

In 2022,a global outbreak of Mpox(formerly monkeypox)occurred in various countries across Europe and America and rapidly spread to more than 100 countries and *** World Health Organization declared the outbreak to be a public health emergency of international concern due to the rapid spread of the Mpox ***,nations intensified their efforts to explore treatment strategies aimed at combating the infection and its ***,the available therapeutic options for Mpox virus infection remain *** far,only a few numbers of antiviral compounds have been approved by regulatory *** the high mutability of the Mpox virus,certain mutant strains have shown resistance to existing pharmaceutical *** highlights the urgent need to develop novel antiviral drugs that can combat both drug resistance and the potential threat of ***,there is a lack of comprehensive literature on the pathophysiology and treatment of *** address this issue,we conducted a review covering the physiological and pathological processes of Mpox infection,summarizing the latest progress of anti-Mpox *** analysis encompasses approved drugs currently employed in clinical settings,as well as newly identified small-molecule compounds and antibody drugs displaying potential antiviral efficacy against ***,we have gained valuable insights from the process of Mpox drug development,including strategies for repurposing drugs,the discovery of drug targets driven by artificial intelligence,and preclinical drug *** purpose of this review is to provide readers with a comprehensive overview of the current knowledge on Mpox.

关键词： prevention treatment intensified

A new class of crystalline X-ray induced photochromic materials assembled from anion-directed folding of a flexible cation

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Chinese Chemical Letters 2024年第8期35卷 554-557页

作者： Hong-Jin Liao Zhu Zhuo Qing Li Yoshihito Shiota Jonathan P.Hill Katsuhiko Ariga Zi-Xiu Lu Lu-Yao Liu Zi-Ang Nan Wei Wang You-Gui Huang CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials science Fujian Normal UniversityFuzhou 350007China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China Fujian science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China institute for Materials Chemistry and Engineering Kyushu UniversityFukuoka 819-0395Japan World Premier international(WPI)Center for Materials Nanoarchitectonics(MANA) National Institute for Materials Science(NIMS)Ibaraki 305-0044Japan

Electron-deficient viologens are widely used as ligands or structure-directing agents(SDAs)to synthesize crystalline X-ray induced photochromic ***,a new rational strategy of anion-directed fold-ing a flexible cation(H_(2)imb)^(2+)((H_(2)imb)^(2+)=di-protonated 2,3-bis(imidazolin-2-yl)-2,3-dimethylbutane)has been ***-donating Cl−and(ZnCl4)2−are used to direct folding a flexible electron-deficient(H_(2)imb)^(2+)*** complexes(H_(2)imb)(NO_(3))2(1),(H_(2)imb)Cl2·H_(2)O(2),and(H_(2)imb)ZnCl4(3)have been synthesized in which(H_(2)imb)^(2+)crystallize in an anti-conformation,88.8°-gauche,and 51.8°-gauche,*** contrary to X-ray silent complex 1,X-ray induced photochromism has been achieved in both complex 2 and *** intermolecular charge-transfer mechanism has been elucidated and the anion directed folding of(H_(2)imb)^(2+)has been validated to be critical to yield colored long-lived charge-separated states.

关键词： Supramolecular Photochromic X-ray induced Anion-directed folding Electron-deficient viologens

An alfalfa MYB-like transcriptional factor MsMYBH positively regulates alfalfa seedling drought resistance and undergoes MsWAV3-mediated degradation

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Journal of Integrative Plant Biology 2024年第4期66卷 683-699页

作者： Kun Shi Jia Liu Huan Liang Hongbin Dong Jinli Zhang Yuanhong Wei Le Zhou Shaopeng Wang Jiahao Zhu Mingshu Cao Chris S.Jones Dongmei Ma Zan Wang College of Grassland science and Technology China Agricultural UniversityBeijing 100193China institute of Animal sciences Chinese Academy of Agricultural SciencesBeijing 100193China AgResearch Grasslands Research Centre Palmerston North 4442New Zealand international Livestock Research institute Nairobi 00100Kenya School of Ecology and Environment Ningxia UniversityYinchuan 750021China

Drought is a major threat to alfalfa(Medicago sativa L.)*** discovery of important alfalfa genes regulating drought response will facilitate breeding for drought-resistant alfalfa ***,we report a genome-wide association study of drought resistance in *** identified and functionally characterized an MYB-like transcription factor gene(MsMYBH),which increases the drought resistance in *** with the wild-types,the biomass and forage quality were enhanced in MsMYBH overexpressed *** RNA-seq,proteomics and chromatin immunoprecipitation analysis showed that MsMYBH can directly bind to the promoters of MsMCP1,MsMCP2,MsPRX1A and MsCARCAB to improve their *** outcomes of such interactions include better water balance,high photosynthetic efficiency and scavenge excess H_(2)O_(2)in response to ***,an E3 ubiquitin ligase(MsWAV3)was found to induce MsMYBH degradation under long-term drought,via the 26S proteasome ***,variable-number tandem repeats in MsMYBH promoter were characterized among a collection of germplasms,and the variation is associated with promoter ***,our findings shed light on the functions of MsMYBH and provide a pivotal gene that could be leveraged for breeding drought-resistant *** discovery also offers new insights into the mechanisms of drought resistance in alfalfa.

关键词： alfalfa drought resistance E3 ubiquitin ligase MsMYBH MsWAV3 MYB-like transcriptional factor