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Progress on the antiferromagnetic topological insulator MnBi2Te4

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National Science Review 2024年第2期11卷 33-49页

作者： Shuai Li Tianyu liu Chang liu Yayu Wang hai-zhou Lu X.C.Xie Department of Physics Harbin Institute of Technology Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen Key Laboratory of Quantum Science and Engineering International Quantum Academy Beijing Academy of Quantum Information Sciences Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-Nano Devices Department of Physics Renmin University of China State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University Frontier Science Center for Quantum Information Hefei National Laboratory International Center for Quantum Materials School of Physics Peking University Institute for Nanoelectronic Devices and Quantum Computing Fudan University

Topological materials, which feature robust surface and/or edge states, have now been a research focus in condensed maTher physics. They represent a new class of materials exhibiting nontrivial topological phases,and provide a platform for exploring exotic transport phenomena, such as the quantum anomalous Hall effect and the quantum spin Hall effect. Recently, magnetic topological materials have attracted considerable interests due to the possibility to study the interplay between topological and magnetic *** particular, the quantum anomalous Hall and axion insulator phases can be realized in topological insulators with magnetic order. MnBi2Te4, as the first intrinsic antiferromagnetic topological insulator discovered, allows the examination of existing theoretical predictions; it has been extensively studied, and many new discoveries have been made. Here we review the progress made on MnBi2Te4from both experimental and theoretical aspects. The bulk crystal and magnetic structures are surveyed first, followed by a review of theoretical calculations and experimental probes on the band structure and surface states, and a discussion of various exotic phases that can be realized in MnBi2Te4. The properties of MnBi2Te4thin films and the corresponding transport studies are then reviewed, with an emphasis on the edge state transport. Possible future research directions in this field are also discussed.

关键词： MnBi2Te4 magnetic topological insulator antiferromagnetic quantum anomalous Hall effect axion insulator

Ultrafast investigation of room temperature valley polarization in“optical bilayer”WS_(2)

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Science China(Technological Sciences) 2024年第1期67卷 91-97页

作者： ZHAO LeYi WANG hai liu TianYu LI FangFei zhou Qiang WANG haiYu Synergetic Extreme Condition High-Pressure Science Center State Key Laboratory of Superhard MaterialsCollege of PhysicsJilin UniversityChangchun 130012China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

Monolayer transition metal dichalcogenides(TMDCs)have become a promising platform in valleytronics due to possessing the regulatable valley degrees of ***,as a result of the rapid intervalley scattering,it is difficult to measure the PL valley polarization of monolayer TMDCs at room temperature,which limits their application in valleytronics ***,we report a room temperature photoluminescence(PL)valley polarization up to 3.73%in an“optical bilayer”WS_(2)formed by transferring monolayer WS_(2)onto flat Ag ***,in the transient absorption(TA)measurements,a remarkably long valley depolarization lifetime is ***,we demonstrate the valley properties of such“optical bilayer”WS_(2)resemble actual bilayer WS_(2),in which the robust valley polarization can be attributed to the phonons depletion effect and the blocked interlayer hopping *** peculiar valley features in“optical bilayer”WS_(2)provide a particularly simple method to enhance valley control at room temperature.

关键词： valleytronics optical bilayer transient absorption tungsten disulfide

Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators

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National Science Review 2024年第2期11卷 15-23页

作者： Rui Chen hai-Peng Sun Mingqiang Gu Chun-Bo Hua Qihang liu hai-zhou Lu X.C.Xie Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) International Quantum Academy Institute for Theoretical Physics and Astrophysics University of Würzburg School of Electronic and Information Engineering Hubei University of Science and Technology Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Shenzhen Key Laboratory of Quantum Science and Engineering International Center for Quantum Materials School of PhysicsPeking University Collaborative Innovation Center of Quantum Matter CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.

关键词： layerHall effect hidden Berry curvature antiferromagnetic insulator axion insulator, quantum transport

Consensus on glycemic management for patients with coronary heart disease and type 2 diabetes

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Journal of Geriatric Cardiology 2024年第7期21卷 689-702页

作者： Li-Nong JI Yun-Dai CHEN Jing liu Xiang-hai zhou Cardiovascular Subcommittee of Chinese International Exchange and Promotion Association for Medical and Healthcare Peking University People's Hospital Chinese PLA General Hospital

The prevalence of patients with coronary heart disease(CHD)and diabetes mellitus is notably high,posing sig-nificant residual cardiovascular risks even after routine interventions such as antihypertensive,lipid-lowering,and antithrombot-ic *** studies have demonstrated that certain glucose-lowering medications confer cardiovascular benefits for pa-tients with type 2 ***,a survey indicates that cardiologists may not be fully acquainted with the optimal screen-ing timing,indicators,and diagnostic criteria for type 2 diabetes,and there is insufficient awareness and a low rate of prescrip-tion of novel glucose-lowering medications with proven cardiovascular efficacy,such as glucagon-like peptide-1 receptor agon-ists(GLP-1 RAs)and sodium-glucose co-transporter-2 inhibitors(SGLT-2i).In this context,based on domestic and international guidelines or consensus and the latest evidence-based evidence,this consensus aims to standardize the glycemic management for patients with acute coronary syndrome,chronic coronary syndrome,and perioperative management for percutaneous coronary *** highlights the key points of screening and diagnosis of type 2 diabetes,and the comprehensive management of cardiovascular risk in patients with *** consensus elaborates on the principles and algorithms of glycemic management for CHD patients,without involving acute complications of diabetes,clarifies the clinical practice of glucose-lowering medications with cardiovascular benefits,and promotes the standardized use of these medications in cardiovascular and other related spe-cialty ***,it addresses the glucose-lowering treatment to comprehensively reduce cardiovascular risks.

关键词： coronary patients routine

Towards the insights into the deactivation behavior of acetylene hydrogenation catalyst

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Petroleum Science 2024年第2期21卷 1405-1414页

作者： hai-Xia Su Yang Jiao Jian-Gong Shi Zhi-Wei Yuan Di Zhang Xu-Peng Wang Jing Ren Dan liu Jian-zhou Gui hai-Yang Gao Xiao-Li Xu State Key Laboratory of Separation Membranes&Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of Material Science and EngineeringTiangong UniversityTianjin300387China Institute of Engineering Technology Sinopec Catalyst Co.LtdBeijing101100China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of ChemistryTiangong UniversityTianjin300387China

A series of model catalysts were obtained by treating commercial fresh and spent catalysts unloaded from the factory with different methods, including green oil dipping, extraction and high-temperature regeneration;finally, the deactivation behavior of the commercial catalyst for acetylene hydrogenation were studied. The influence of various possible deactivation factors on the catalytic performance was elucidated via detailed structural characterization, surface composition analysis, and activity *** results showed that green oil, carbon deposit and sintering of active metal were the main reasons for deactivation, among which green oil and carbon deposit led to rapid deactivation, while the activity could be recovered after regeneration by high-temperature calcination. The sintering of active metal components was attributed to the high-temperature regeneration in hydrothermal conditions, which was slow but irreversible and accounted for permanent deactivation. Thus, optimizing the regeneration is expected to extend the service life of the commercial catalyst.

关键词： Acetylene Hydrogenation Green oil Carbon deposit Sintering Catalyst deactivation

Ancient mitochondrial genome depicts sheep maternal dispersal and migration in Eastern Asia

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Journal of Genetics and Genomics 2024年第1期51卷 87-95页

作者： liu Yang Xing Zhang Yaning Hu Piao Zhu Hua Li Zhenyu Peng hai Xiang Xinying zhou Xingbo Zhao National Engineering Laboratory for Animal Breeding Key Laboratory of AnimalGeneticsBreeding and ReproductionMinistry of Agriculture and Rural AffairsCollege of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding School of Life Science and EngineeringFoshan UniversityFoshanGuangdong 528225China State Key Laboratory of Agricultural Genomics BGI-ShenzhenShenzhenGuangdong 518083China Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China

Sheep have been one of the most important groups of animals since ancient ***,the knowledge of their migration routes and genetic relationships is still poorly *** investigate sheep maternal migration histories alongside Eurasian communications routes,in this study,we obtain mitochondrial genomes(mitogenomes)from 17 sheep remains in 6 Chinese sites and 1 Uzbekistan site dated 4429–3100 years before present(BP).By obtaining the mitogenomes from the sheep(4429–3556 BP)found in the Tongtian Cave site in Xinjiang,Altai region of northwest China,our results support the emergence of haplogroup C sheep in Xinjiang as early as 4429–3556 *** combined phylogenetic analyses with extant ancient and modern sheep mitogenomes suggest that the Uzbekistan-Altai region may have been a migration hub for early sheep in eastern *** least two migration events have taken place for sheep crossing Eurasia to China,one passing by Uzbekistan and Northwest China to the middle and lower reaches of the Yellow River at approximately 4000 BP and another following the Altai region to middle Inner Mongolia from 4429 BP to 2500 ***,this study provides further evidence for early sheep utilization and migration patterns in Eastern Asia.

关键词： Sheep Ancient DNA Eastern Asia Mitochondrial genome Migration Altai

Southern Hemisphere Volcanism Triggered Multi-year La Niñas during the Last Millennium

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Advances in Atmospheric Sciences 2024年第4期41卷 587-592页

作者： Shangrong zhou Fei liu School of Atmospheric Sciences Sun Yat-Sen University Key Laboratory of Tropical Atmosphere-Ocean System Ministry of Educationand Southern Marine Science and Engineering Guangdong LaboratoryZhuhai 519082China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science and TechnologyNanjing 210044China

To explain the recent three-year La Niña event from 2020 to 2022,which has caused catastrophic weather events worldwide,Fasullo et al.(2023)demonstrated that the increase in biomass aerosol resulting from the 2019-20 Australian wildfire season could have triggered this multi-year La Niñ***,we present compelling evidence from paleo-proxies,utilizing a substantial sample size of 26 volcanic eruptions in the Southern Hemisphere(SH),to support the hypothesis that ocean cooling in the SH can lead to a multi-year La Niña *** research highlights the importance of focusing on the Southern Ocean,as current climate models struggle to accurately simulate the Pacific response driven by the Southern Ocean.

关键词： volcanic eruptions multi-year La Niñas Australian wildfire southern ocean cooling

Design and synthesis of thiol-terminated imidothioether oligomer as thermally latent hardener and modifier for high-performance epoxy/thiol thermosets

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Science China Chemistry 2024年第2期67卷 632-641页

作者： Xing liu Jianjun zhou Shumei liu Jianqing Zhao School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Key Lab Guangdong High Property&Functional Polymer Materials Key Laboratory of Polymer Processing EngineeringMinistry of EducationGuangzhou510640China

Conventional base-catalyzed epoxy/aliphatic thiol systems have a poor storage stability,and are impossible to be one-pot systems.A widely accepted solution is to use the latent catalysts,which are usually insoluble anionic initiators sensitive to impurities and moisture,and have many limitations in practical *** this work,a soluble thiol-terminated imidothioether oligomer(TPI) was synthesized and used as a latent hardener and modifier to prepare one-pot epoxy/thiol systems without the latent *** latent behavior and curing mechanism of epoxy systems(EP/TPI series),consisted of bisphenol A diglycidyl ether(DGEBA),pentaerythritol tetrakis(mercaptoacetate)(PETMP) and TPI,were *** thiol exchange reaction between TPI and PETMP preceded the curing reaction of DGEBA,and produced aromatic thiols,which were unreactive at ambient conditions and reacted with DGEBA to form the thermosets at temperatures above 130 ℃.At the loading of 24.4 wt%TPI,the epoxy system(EP/TPI-3) had a shelf life of 13 days and was completely cured within 20 min at 180 ℃.Meanwhile,the catalyst-free curing process of EP/TPI-3 system was insensitive to impurities and ***,the thermal and mechanical properties of EP/TPI-3 thermoset were simultaneously improved,thereinto,the glass transition temperature,Young's modulus and ultimate tensile strength were increased by 16.7 ℃,12.9%,and 13.6%,respectively,compared with those of the commercial DGEBA/PETMP *** work shows that TPI has the potential to be a powerful alternative to commercial latent catalysts,and EP/TPI thermosets with high performance have broad application prospects.

关键词： thiol-terminated imidothioether oligomer epoxy systems thiol exchange reaction thermal latency high performance

Critical current degradation in an epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)coated conductor caused by damage during a quench

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1557-1572页

作者： Donghui liu Huadong YONG Youhe zhou Institute of Superconductor Mechanics Lanzhou UniversityLanzhou 730000China Department of Mechanics and Engineering Sciences College of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education of ChinaLanzhou UniversityLanzhou 730000China

High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field ***,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical *** this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a *** temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the *** delamination of the REBCO CC predicted by the numerical model is consistent with the experimental *** numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO *** premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO ***,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also *** results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.

关键词： epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductor(CC) quench damage critical current degradation shear stress