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Breaking efficiency limit of thermal concentrators by conductivity couplings

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Science China(Physics,Mechanics & Astronomy) 2022年第11期65卷 68-77页

作者： pengfei zhuang Liujun Xu Peng Tan Xiaoping Ouyang Jiping Huang Department of Physics State Key Laboratory of Surface Physicsand Key Laboratory of Micro and Nano Photonic Structures(MOE)FudanUniversityShanghai200438China Department of Physics and State Key Laboratory of Surface Physics Fudan UniversityShanghai 200438China School of Materials Scienceand Engineering Xiangtan UniversityXiangtan 411105China

The concentrating efficiency of a thermal concentrator can be reflected in the ratio of its interior to exterior temperature gradients,which, however, has an upper limit in existing schemes. Here, we manage to break this upper limit by considering the couplings of thermal conductivities and improve the concentrating efficiency of thermal concentrators. For this purpose, we first discuss a monolayer scheme with an isotropic thermal conductivity, which can break the upper limit but is still restricted by its geometric configuration. To go further, we explore another degree of freedom by considering the monolayer scheme with an anisotropic thermal conductivity or by adding the second shell with an isotropic thermal conductivity, thereby making the concentrating efficiency completely free from the geometric configuration. Nevertheless, apparent negative thermal conductivities are required, and we resort to external heat sources realizing the same effect without violating the second law of thermodynamics. Finite-element simulations are performed to confirm the theoretical predictions, and experimental suggestions are also provided to improve feasibility. These results may have potential applications for thermal camouflage and provide guidance to other diffusive systems such as static magnetic fields and dc current fields for achieving similar behaviors.

关键词： thermal concentrator concentrating efficiency conductivity coupling apparent negative conductivity

Equal-time kinetic equations in a rotational field

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Chinese Physics C 2022年第2期46卷 149-159页

作者：陈诗乐王梓岳庄鹏飞 Physics Department Tsinghua UniversityBeijing 100084China

We investigate quantum kinetic theory for a massive fermion system under a rotational *** theDirac equation in rotating frame we derive the complete set of kinetic equations for the spin components of the 8-and 7-dimensional Wigner *** the particles are no longer on a mass shell in the general case due to therotation-spin coupling,there are always only two independent components,which can be taken as the number andspin *** help from the off-shell constraint we obtain the closed transport equations for the two independent components in the classical limit and at the quantum *** classical rotation-orbital coupling controls thedynamical evolution of the number density,but the quantum rotation-spin coupling explicitly changes the spin density.

关键词： equal-time transport rotation field kinetic theory

UA(1)symmetry restoration at high baryon density

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Chinese Physics C 2023年第10期47卷 120-129页

作者：李嘉宁桂进庄鹏飞 Department of Physics Tsinghua UniversityBeijing 100084China

We study the relation between chiral and UA(1)symmetries in the quark-meson *** quarks and mesons are described in mean field approximation,the topological susceptibility characterizing the UA(1)breaking comprises two components:one controlled by the condensate and the other by the meson *** UA(1)restoration is governed by the competition of these *** a hot medium,the condensates ***,the fluctuation is ***,the UA(1)symmetry cannot be solely restored via the temperature ***,the baryon density reduces the condensates and fluctuation,and thereby,the UA(1)symmetry can only be restored in a dense or dense and hot *** strange condensate plays a weak role in the susceptibility,and the chiral and UA(1)symmetry restorations occur almost at the same critical point.

关键词： UA(1)symmetry chiral phase transition finite temperature field theory

Synthesis, structure, and magnetic properties of a cyanide-bridged Fe(Ⅲ)-Cu(Ⅱ) bimetallic double-zigzag chain with slow relaxation of the magnetization

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Science China Chemistry 2012年第6期55卷 1018-1021页

作者： DONG DaPeng ZHENG Hui ZHAO Liang zhuang pengfei LIU Tao HE Cheng DUAN ChunYing State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 China

Using Bu4N[Fe(Tp*)(CN)3]- (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) as the building block to react with CuII and N-methylimidazole, we obtained a one-dimensional (1D) heterobimetallic cyano-bridged chain, [Fe(Tp*)(CN)3]2Cu(N-methylimidazole)2·2H2O (1). The crystal structures and magnetic studies demonstrate that complex 1 exhibits slow relaxation of the magnetization due to strong intrachain ferromagnetic coupling and weak interchain interactions.

关键词：铁磁耦合晶体结构磁性能桥链磁化松弛双金属氰化物

Synthesis, structure, and magnetic properties of a cyanide-bridged Fe(Ⅲ)-Cu(Ⅱ) bimetallic double-zigzag chain with slow relaxation of the magnetization

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中国科学:化学 2012年第6期42卷 918-919页

作者： DONG DaPeng ZHENG Hui ZHAO Liang zhuang pengfei LIU Tao HE Cheng DUAN ChunYing State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116012Chin

Using Bu4N[Fe(Tp*)(CN)3]- (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) as the building block to react with CuII and N-methylimidazole, we obtained a one-dimensional (1D) heterobimetallic cyano-bridged chain, [Fe(Tp*)(CN)3]2Cu(N- methylimidazole)2·2H2O (1). The crystal structures and magnetic studies demonstrate that complex 1 exhibits slow relaxation of the magnetization due to strong intrachain ferromagnetic coupling and weak interchain interactions.

关键词：铁磁耦合晶体结构磁学性质磁化松弛氰化物双金属 N-甲基咪唑

Color Superconductivity beyond Mean Field

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Color Superconductivity beyond Mean Field

Formation and growth of nanophase iron particles on the surface of Mercury revealed by experimental study

CCAST“研究禁闭与退禁闭相变的连续场论途径”研讨会

作者： zhuang pengfei

＜正＞1)CSC2)Gapless CSC3)CSC in RPA

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Acta Geochimica 2024年第4期43卷 774-784页

作者： Ronghua Pang Yang Li Chen Li pengfei Zhang zhuang Guo Sizhe Zhao Han Yu Li Wang Chenxi Zhu Shuangyu Wang Kairui Tai Qinwei Zhang Yuanyun Wen Rui Li Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyangChina University of Chinese Academy of Sciences BeijingChina Center for Excellence in Comparative Planetology Chinese Academy of SciencesHefeiChina Institute of Remote Sensing and Geographical Information System School of Earth and Space SciencesPeking UniversityBeijingChina State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacaoChina Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunmingChina State Key Laboratory of High Performance Ceramics and Superfi ne Microstructures Shanghai Institute of CeramicsChinese Academy of SciencesShanghaiChina Laboratory for Space Environment and Physical Sciences Harbin Institute of TechnologyHarbinChina Research Center for Planetary Science College of Earth ScienceChengdu University of TechnologyChengduChina Key Laboratory of Planetary Sciences Purple Mountain ObservatoryChinese Academy of SciencesNanjingChina

Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless ***,current research on space weathering focuses mainly on the Moon and certain types of *** particular,the impacts of meteoroids and micrometeoroids,radiation from solar wind/solar flares/cosmic rays,and thermal fatigue due to temperature variations are being *** weathering produces various transformation products such as melted glass,amorphous layers,iron particles,vesicles,and solar wind *** in turn lead to soil maturation,changes in visible and near-infrared reflectance spectra(weakening of characteristic absorption peaks,decreased reflectance,increased near-infrared slope),and alterations in magnetism(related to small iron particles),collectively termed the“lunar model”of space weathering *** to the Moon and asteroids,Mercury has unique spatial environmental characteristics,including more intense meteoroid impacts and solar thermal radiation,as well as a weaker particle radiation environment due to the global distribution of its magnetic ***,the lunar model of space weathering may not apply to *** studies have extensively explored the eff ects of micrometeoroid ***,this work focuses on the eff ects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar *** the utilization of highvalence state,heavy ion implantation,and vacuum heating simulation experiments,this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite,pyroxene,and olivine on Mercury’s surface and compares them to the weathering transformation model of the *** experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe^(0)directly but

关键词： Mercury Space weathering Np-Fe^(0) Solar thermal radiation Solar wind

Heavy flavor dissociation in framework of multi-body Dirac equations

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Chinese Physics C 2020年第8期44卷 115-124页

作者：施舒哲赵佳星庄鹏飞 Physics Department Tsinghua UniversityBeijing 100084China Department of Physics McGill UniversityMontrealQC H3A 2T8Canada

We study heavy flavor properties at finite temperature in the framework of a relativistic potential *** an improved method to solve the three-body Dirac equation,we determine a universal set of model parameters for both mesons and baryons by fitting heavy flavor masses in *** heavy quark potential from lattice QCD simulations in hot medium,we systematically calculate heavy flavor binding energies and averaged sizes as functions of the *** meson and baryons are separately sequentially dissociated in the quark-gluon plasma,and the mesons can survive at higher temperatures owing to the stronger potential between quark-antiquark pairs than that between quark-quark pairs.

关键词： heavy flavor hadron dissociation relativistic heavy-ion collision heavy flavor baryon

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高温高密度时的新物质形态

科学通报 2018年第24期63卷 2465-2473页

作者：姜寅马永亮庄鹏飞北京航空航天大学物理科学与核能工程学院清华大学物理系吉林大学物理学院

在高温高密条件下,夸克将解除禁闭形成全新的物质形态——夸克物质.本文从核物质的基本相互作用——量子色动力学(QCD)的基本对称性出发,首先简单介绍研究QCD相变的各种方法,阐述相变发生的物理机制和条件,然后着重讨论实现QCD相变的两... 详细信息

在高温高密条件下,夸克将解除禁闭形成全新的物质形态——夸克物质.本文从核物质的基本相互作用——量子色动力学(QCD)的基本对称性出发,首先简单介绍研究QCD相变的各种方法,阐述相变发生的物理机制和条件,然后着重讨论实现QCD相变的两种物理系统,即相对论重离子碰撞和致密星体.相对论重离子碰撞是制造高温环境的重要手段,核物质将形成全新的夸克胶子等离子体相(QGP).文中介绍了探测QGP的实验信号和高温环境特有的新奇物理现象.致密天体中的高密区则展现了极其丰富多彩的相结构.理论预示了与颜色和味道等自由度相联系的各类超导、超流态存在的可能性.相信在未来更大范围的束流能量扫描和对致密星体的精确观测中,我们将会对高温高密核物质的物态性质有着更加深入的认识.

关键词：量子色动力学相图相对论重离子碰撞致密星体对称性高温高密