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Stabilizing n-type cubic AgBiSe_(2) thermoelectric materials through alloying with PbS

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Journal of Materiomics 2024年第1期10卷 70-77页

作者： Lai Zhang Weixia Shen Zhuangfei Zhang Chao Fang Qianqian Wang Biao Wan Liangchao Chen Yuewen Zhang Xiaopeng Jia Key Laboratory of Material physics of Ministry of Education School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou450052China

Phase transition generates rapid changes of transport parameters and poor mechanical property,and thus restricts the application of thermoelectric ***_(2) exhibits cubic phase at above 580 K with high-symmetry structure and low lattice thermal conductivity,indicating the potentiality of high thermoelectric *** this work,the cubic structure of AgBiSe_(2) was achieved at ambient conditions by alloying with PbS,enhancing the configurational entropy at both cationic and anionic *** cubic structure was rather stable after several measurement *** substitution at cationic sites effectively reduced band gap,and increased both carrier concentration and effective *** samples exhibited relatively low lattice thermal conductivity(0.68-0.34 W/(m·K))in the temperature range of 300-773 K,due to the nanoscale inhomogeneity and the random distribution of multiple species at some atomic sites.A maximum zT of 0.65 at 773 K was obtained for(Ag_(0.99)Nb_(0.01)BiSe_(2))_(0.8)(PbS)_(0.2) *** entropy-driven structural stabilization is a promising strategy to achieve stable structure for practical thermoelectric applications.

关键词： Thermoelectric AgBiSe_(2) Configurational entropy Phase transition

A family of quantum von Neumann architecture

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Chinese physics B 2024年第8期33卷 56-61页

作者：王东升 CAS Key Laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

We develop universal quantum computing models that form a family of quantum von Neumann architectures,with modular units of memory,control,CPU,and internet,besides input and *** family contains three generations characterized by dynamical quantum resource theory,and it also circumvents no-go theorems on quantum programming and *** universality,such a family satisfies other desirable engineering requirements on system and algorithm design,such as modularity and programmability,hence serves as a unique approach to building universal quantum computers.

关键词： von Neumann architecture quantum resource theory quantum computing

An effective gauge field theory of the nucleon interactions

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Communications in Theoretical physics 2024年第10期76卷 78-86页

作者： Eduard Boos Skobeltsyn Institute of Nuclear physics Lomonosov Moscow State University Faculty of physics Lomonosov Moscow State University

We discuss the possibility of constructing an effective gauge field theory of the nucleon interactions based on the ideas of isotopic invariance as well as hypercharge invariance as a local gauge symmetry and spontaneous breaking of this symmetry. The constructed effective field theory predicts the structure of interactions of protons and neutrons with ρ- and σ-mesons, and with pi-mesons and photons, as well as interactions of these particles with each other. The Lagrangian of the theory consists of several parts involving dimension 4 and 5 gauge invariant operators. Feynman rules for physical degrees of freedom that follow on from the Lagrangian define the structure of diagrams for one-boson exchanges between nucleons, predicting the internucleon one-boson-exchange potential as well as nucleon scattering amplitudes. The range of applicability of the effective theory is discussed and estimates are made of the resulting coupling constants. The theory predicts the mass of the neutral ρ0-meson to be about 1 MeV larger than the mass of the charged mesons ρ±. The vector ω-meson, which is a sterile particle with respect to the considered gauge group SUI（2） × UY（1）, can be added to the scheme via a gauge-invariant operator of dimension 5, as shown in the appendix.

关键词： gauge invariance nucleon interactions spontaneous symmetry breaking

Microwave diagnostics of pulsed atmospheric discharge with electrolytic electrode and long-lived luminous formation in its afterglow

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High Voltage 2024年第1期9卷 127-136页

作者： Shixin Zhao Xingbao Lyu Aleksandr Astafiev Chengxun Yuan Lin Miao Jingfeng Yao Ying Wang Anatoly Kudryavtsev Aleksandr Chirtsov Gennadii Shabanov Zhongxiang Zhou School of physics Harbin Institute of TechnologyHarbinChina physics Department Saint Petersburg Electrotechnical University“LETI”St.PetersburgRussia Heilongjiang Provincial Key Laboratory of Plasma physics and Application Technology HarbinChina physics Department St.Petersburg State UniversitySt.PetersburgRussia Konstantinov Petersburg Nuclear physics Institute National Research Centre“Kurchatov Institute”GatchinaRussia

The Gatchina discharge phenomenon holds significant promise as a laboratory model for simulating ball ***,crucial aspects concerning the plasma components of the resulting afterglow remain ***,the measurement of the electron density,a critical parameter,has not been fully achieved thus *** this study,microwave diagnostics and video recording were employed during a pulsed Gatchina discharge,along with synchronous measurement of discharge current and *** antennas were positioned at different heights to enable separate diagnosis of the discharge and the ensuing long-lived *** findings revealed that during the active phase of the Gatchina discharge,the plasma density was substantial enough to cause reflection of an electromagnetic wave with a frequency of 20 GHz from this highly conductive *** the afterglow,the signal experienced only a moderate weakening of 10–20 percent,facilitating the determination of the time dependence of average electron density during the afterglow's passage between the two *** measurements verified the unusually slow plasma decay in the afterglow of the Gatchina discharge,suggesting the potential significance of chemi-ionisation processes involving long-lived(metastable)particles.

关键词： holds luminous electrolytic

Molecular components in J/ψandρ-πpuzzle

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Chinese physics C 2024年第5期48卷 141-150页

作者：郭星导陈殿勇李学潜苑仲元桑士晶 College of physics and New Energy Xuzhou University of TechnologyXuzhou 221111China School of physics Southeast UniversityNanjing 211189China Department of physics Nankai UniversityTianjin 300071China Lanzhou Center for Theoretical physics Lanzhou UniversityLanzhou 730000China

Motivated by the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕand the light exotic candidates,we found that there may exist molecular states composed of f0(1710)ωand f0(1710)ϕ,which correspond to X(2440)and X(2680)observed a few decades *** branching fractions of X(2440)and X(2680)to various PV and KKω(ϕ)channels were estimated in the molecular *** addition,the large branching fractions of J/ψ→f0(1710)ω/f0(1710)ϕindicate sizable molecular components in the J/ψ***,we consider J/ψas the superposition of thecc¯(1S),f0(1710)ω,and f0(1710)ϕmolecular *** molecular components have a significant impact on the light hadron decays of J/ψ,which may elucidate the long standingρ−πpuzzle.

关键词： ρ-πpuzzle J/ψ molecular state

Reconstruction of poloidal magnetic field profiles in field-reversed configurations with machine learning in laser-driven ion-beam trace probe

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Plasma Science and Technology 2024年第3期26卷 83-87页

作者：徐栩涛徐田超肖池阶张祖煜何任川袁瑞鑫许平 State Key Laboratory of Nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871People's Republic of China School of physics Xihua UniversityChengdu 610039People's Republic of China

The diagnostic of poloidal magnetic field(B_(p))in field-reversed configuration(FRC),promising for achieving efficient plasma confinement due to its highβ,is a huge challenge because B_(p)is small and reverses around the core *** laser-driven ion-beam trace probe(LITP)has been proven to diagnose the B_(p)profile in FRCs recently,whereas the existing iterative reconstruction approach cannot handle the measurement errors *** this work,the machine learning approach,a fast-growing and powerful technology in automation and control,is applied to B_(p)reconstruction in FRCs based on LITP principles and it has a better performance than the previous *** machine learning approach achieves a more accurate reconstruction of B_(p)profile when 20%detector errors are considered,15%B_(p)fluctuation is introduced and the size of the detector is remarkably ***,machine learning could be a powerful support for LITP diagnosis of the magnetic field in magnetic confinement fusion devices.

关键词： FRC LITP poloidal magnetic field diagnostics machine learning

Band structures of strained kagome lattices

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Chinese physics B 2024年第2期33卷 456-463页

作者：徐露婷杨帆 Center for Joint Quantum Studies and Department of physics School of ScienceTianjin UniversityTianjin 300354China Tianjin Key Laboratory of Low Dimensional Materials physics and Preparing Technology Department of PhysicsTianjin UniversityTianjin 300354China

Materials with kagome lattices have attracted significant research attention due to their nontrivial features in energy *** theoretically investigate the evolution of electronic band structures of kagome lattices in response to uniaxial strain using both a tight-binding model and an antidot model based on a periodic muffin-tin *** is found that the Dirac points move with applied ***,the flat band of unstrained kagome lattices is found to develop into a highly anisotropic shape under a stretching strain along y direction,forming a partially flat band with a region dispersionless along ky direction while dispersive along kx *** results shed light on the possibility of engineering the electronic band structures of kagome materials by mechanical strain.

关键词： kagome lattice strain band structure engineering

Recent progress of in-situ characterization of LiNi_(1−x−y)Co_(x)Mn_(y)O_(2) cathodes for lithium metal batteries: A mini review

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Nano Research 2024年第3期17卷 1384-1401页

作者： Huanzhu Lv Xiaoqi Zhu Jun Mei Yuanhua Xia Bin Wang Institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 611731China Chengdu Development Center of Science and Technology China Academy of Engineering PhysicsChengdu 610200China Key Laboratory of Neutron physics and Institute of Nuclear physics and Chemistry China Academy of Engineering Physics(CAEP)Mianyang 621999China

In the context of the gradual popularity of electric vehicles(EVs),the development of lithium battery systems with high energy density and power density is regarded as the foremost way to improve the range of ***_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathodes have been the focus of researchers due to their high energy density,excellent power performance,and low-temperature ***,the elaboration of the decay mechanism of NCM cathode based on lithium metal batteries(LMBs)is still being restricted to the primary *** the past decades,the development and application of advanced in-situ characterization tools have facilitated researchers'understanding of the internal operation mechanism of batteries during charging and *** this minireview,the latest progress of in-situ observation of the NCM cathode by X-ray diffraction(XRD),fourier transform infrared(FT-IR)spectroscopy,Raman spectroscopy,atomic force microscopy(AFM),transmission electron microscope(TEM),optical microscope,and other characterization tools is *** mechanisms of structural degradation,cathode-electrolyte interfaces(CEIs)composition,and dynamic changes of NCM,electrolyte breakdown,and gas production are ***,based on the existing research progress,the opportunities and challenges for future in-situ characterization technology in the study of the mechanism of LMBs are discussed in ***,the purpose of this minireview is to summarize recent work that focuses on the outstanding application of in-situ characterization techniques in the mechanistic study of LMBs,and pointing the way to the future development of high energy density and power density LMBs systems.

关键词： lithium metal batteries(LMBs) In-situ characterization LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)

Even-odd layer-dependent multiferroic in freestanding rare-earth orthorhombic perovskite

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Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 151-157页

作者： Shaowen Xu Fanhao Jia Ning Dai School of physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Department of physics College of ScienceHangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Infrared physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

Freestanding oxide perovskites possess strong interlayer coupling between adjacent atomic layers,thus exerting a determinative effect on the magnetism and ferroelectricity of these atomic-scale ***,we propose an effective strategy to manipulate magnetism and ferroelectricity in freestanding rare-earth orthorhombic perovskite via modulation of layer *** performing first-principles calculations,an even-odd oscillation is demonstrated in few-layer GdAlO_(3)perovskite(GAP).Specifically,odd-layer systems with charged atomic layers are ferromagnetic polar metals,while even-layer systems are antiferromagnetic ferroelectric *** thickness-dependent magnetic phase transition originates from carrier doping,as rationalized by the Stoner ***,we demonstrate the promotion of in-plane ferroelectricity via the concurrent application of two distinct antiferrodistortive displacements,each driven by formation and breaking of *** multiferroic phases may emerge in other transition metal oxide perovskites supporting multiple valence states,e.g.,few-layer Gd MO_(3)(M=V,Cr,Mn,and Ni).This work puts forward a strategy for layer thickness engineering of magnetism and ferroelectricity in 2D oxide perovskite multiferroic materials.

关键词： few-layer rare-earth perovskite multiferroicity size effect first principles calculations