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An internal ballistic model of electromagnetic railgun based on PFN coupled with multi-physical field and experimental validation

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Defence Technology（防务技术） 2024年第2期32卷 254-261页

作者： Benfeng Gu Haiyuan Li Baoming Li National key laboratory of Transient physics Nanjing University of Science and TechnologyNanjing 210094China

To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore *** this paper,a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun,and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network(PFN)is carried *** test methods such as spectrometer,fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity,transient magnetic field strength and stress-strain of *** the simulation results and experimental data,the damage condition of the contact surface is analyzed.

关键词： Internal ballistic modeling Electromagnetic rail gun Multi-physics field coupling Experimental validation PFN

Thermodynamic nature of black holes in coexistence region

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Science China(physics,Mechanics & Astronomy) 2024年第5期67卷 27-32页

作者： Shao-Wen Wei Yu-Xiao Liu Lanzhou Center for Theoretical physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of Mo ELanzhou UniversityLanzhou 730000China Institute of Theoretical physics&Research Center of Gravitation Lanzhou UniversityLanzhou 730000China

Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic ***,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of *** at these coexistence states,in this work,we develop a general approach by introducing two new ratio *** first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule *** demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase *** study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and *** results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.

关键词： transition. state. thermodynamic

Semiclassical approach to spin dynamics of a ferromagnetic S = 1 chain

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Chinese physics B 2024年第6期33卷 95-100页

作者：李承晨崔祎于伟强俞榕 Department of physics and Beijing key laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China key laboratory of Quantum state Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

Motivated by recent experimental progress on the quasi-one-dimensional quantum magnet Ni Nb2O6, we study the spin dynamics of an S = 1 ferromagnetic Heisenberg chain with single-ion anisotropy by using a semiclassical molecular dynamics approach. This system undergoes a quantum phase transition from a ferromagnetic to a paramagnetic state under a transverse magnetic field, and the magnetic response reflecting this transition is well described by our semiclassical *** show that at low temperature the transverse component of the dynamical structure factor depicts clearly the magnon dispersion, and the longitudinal component exhibits two continua associated with single-and two-magnon excitations,respectively. These spin excitation spectra show interesting temperature dependence as effects of magnon interactions. Our findings shed light on the experimental detection of spin excitations in a large class of quasi-one-dimensional magnets.

关键词： one-dimensional ferromagnetism spin dynamics magnon excitation molecular dynamics

Finding Ordered state in a Disordered Jungle

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Chinese physics Letters 2024年第4期41卷 124-125页

作者：周晓东沈健 state key laboratory of surface physics and Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Zhangjiang Fudan International Innovation Center Fudan UniversityShanghai 201210China Shanghai Research Center for Quantum Sciences Shanghai 201315China

A rich portfolio of emergent phenomena has been discovered in twisted two-dimensional(2D)moirésystems,including strongly correlated insulators,[1]superconductivity,[2]integer and fractional Chern insulators(ChIs),[3-... 详细信息

关键词： integer twisted ferroelectric

Insights into the role of oxygen-containing functional groups on carbon surface in water–electricity generation

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Nano Research 2024年第7期17卷 6645-6653页

作者： Wan Xue Zongbin Zhao Honghui Bi Bolun Zhang Xuzhen Wang Jieshan Qiu state key laboratory of Fine Chemicals Liaoning Key Laboratory for Energy Materials and Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 116024China state key laboratory of Fine Chemicals Liaoning Key Laboratory for Energy Materials and Chemical EngineeringSchool of ChemistryDalian University of TechnologyDalian 116024China state key laboratory of Chemical Resource Engineering College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029China

A deep understanding of the electricity generation mechanism from the interaction between water molecules and carbon material surfaces is attractive for next-generation water-based energy conversion and storage ***,an asymmetric generator was assembled based on functionalized carbon nanotubes films to investigate the relative contribution from various oxygen functional groups on carbon surface to the water-electrical *** and calculations demonstrate that the electricity mainly originates from the water molecule adsorption by carboxyl groups and dissociation of functional groups on carbon surface,which leads to the formation of electrical double layers at *** device allows the electricity generation with a variety of water sources,such as deionized water,tap water,as well as *** particular,the generator based on carboxyl carbon nanotubes can induce a voltage of over 200 mV spontaneously in natural seawater with the power density of about 0.11 mW·g^(−1).High voltages can be achieved easily through the series-connection strategy to power electronic products such as a liquid crystal *** work reveals the dominant role of carboxyl groups in carbon-based water–electricity conversion and is expected to offer inspiration for the preparation of carbon materials with high electrical performance.

关键词： electricity generation water adsorption dissociation carboxyl groups carbon nanotubes

Single thiolate replacement of metal nanoclusters

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Science China Chemistry 2024年第2期67卷 523-528页

作者： Ambreen Ambreen Yue Zhou Wanmiao Gu Qing You Liang Fang Guoqing Bian Nan Yan Nan Xia Zhikun Wu key laboratory of Materials physics Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

surface thiolates play important roles in evincing the structures and properties of thiolated metal nanoclusters—one type of recently emerging inorganic-organic hybrids,and thus the thiolate substitution,especially single thiolate substitution,is highly desirable for subtly tailoring the structures and properties of metal ***,such a single-thiolate substituting is challenging,and its influence on the metal-metal and metal-sulfur bonds remains mysterious due to the absence of the singlethiolate-substituted ***,we developed a combined method,concurrently synthesized the single-thiolate-substituted nanocluster and its parent nanocluster,and successfully resolved their structures by single crystal X-ray crystallography,which reveals that the single thiolate substitute has an obvious influence on the metal-metal and metal-sulfur bond lengths although it has no effect on the absorption ***,the metal-metal and metal-sulfur bonds show various thermal extensibility and even the negative thermal expansion phenomena of the Au–S bond were observed in the single-thiolate-substituted *** bond length-related stability was also ***,this study highlights a novel synthesis method and offers novel structural insights and an in-depth structure-property correlation of thiolated metal nanoclusters.

关键词： metal nanoclusters single thiolate replacement thermal expansion stability intercluster interaction

Nanostructured lubricant additives for titanium alloy:Lubrication by the solid-liquid interface with Coulomb repulsion

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Friction 2024年第7期12卷 1564-1579页

作者： Linlin DUAN Dan JIA Jian LI Jianfang LIU Haitao DUAN state key laboratory of Special surface Protection Materials and Application Technology Wuhan Research Institute of Materials ProtectionWuhan 430030China Hubei Longzhong laboratory Xiangyang 441000China College of Life Science and Technology Wuhan Polytechnic UniversityWuhan 430030China

In this work,the advantage of Coulomb repulsion in the intermolecular forces experienced by molecules on the solid–liquid nanosized contact interface is taken,and the superior friction-reducing property of Cu_(3)(PO_(4))2·3H_(2)O(CuP)oil-based additives has been confirmed for titanium ***-dimensional(3D)CuP nanoflowers(CuP-Fs)with a strong capillary absorption effect are prepared to achieve the homogeneous mixing of solid CuP and lubricating *** by CuP-Fs additives for titanium alloy,friction coefficient(COF)can be reduced by 73.68%,and wear rate(WR)reduced by 99.69%.It is demonstrated that the extraordinary friction-reducing property is due to the repulsive solid–liquid interface with low viscous shear force originating from Coulomb repulsion between polar water molecules in CuP and non-polar oil ***,any steric hindrance or connection between this repulsive solid–liquid interface will trigger the adhesion and increase the viscous shear force,for example,dispersant,hydrogen bondings,and shaky adsorbed water ***,the lamellar thickness of CuP and the molecular size of lubricant both have a great influence on tribological *** the lubrication mechanism based on interface Coulomb repulsion is proposed that may help broaden the scope of the exploration in low-friction nanomaterial design and new lubricant systems.

关键词： lubrication nanomaterial additive solid-liquid interface wear

Unveiling the pressure-driven metal–semiconductor–metal transition in the doped TiS_(2)

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Chinese physics B 2024年第6期33卷 63-67页

作者：陈佳骏吕心邓李思敏但雅倩黄艳萍崔田 Institute of High Pressure physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China state key laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

Conventional theories expect that materials under pressure exhibit expanded valence and conduction bands,leading to increased electrical ***,we report the electrical properties of the doped 1T-TiS_(2) under high pressure by electrical resistance investigations,synchrotron x-ray diffraction,Raman scattering and theoretical *** to 70 GPa,an unusual metal-semiconductor-metal transition *** first-principles calculations suggest that the observed anti-Wilson transition from metal to semiconductor at 17 GPa is due to the electron localization induced by the intercalated Ti *** electron localization is attributed to the strengthened coupling between the doped Ti atoms and S atoms,and the Anderson localization arising from the disordered *** pressures exceeding 30.5 GPa,the doped TiS_(2) undergoes a re-metallization transition initiated by a crystal structure phase *** assign the most probable space group as P2_(1)2_(1)2_(1).Our findings suggest that materials probably will eventually undergo the Wilson transition when subjected to sufficient pressure.

关键词： high pressure transition metal dichalcogenides doped TiS_(2) electronic phase transition

Heralded entanglement between error-protected logical qubits for fault-tolerant distributed quantum computing

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Science China(physics,Mechanics & Astronomy) 2024年第2期67卷 25-33页

作者： Jialun Li Zhihao Xie Yachen Li Yansen Liang Zhenhua Li Tao Li MIIT key laboratory of Semiconductor Microstructure and Quantum Sensing School of PhysicsNanjing University of Science and TechnologyNanjing 210094China National laboratory of Solid state Microstructures Nanjing UniversityNanjing 210093China

Quantum error correction is essential for achieving reliable quantum information processing tasks,as it can mitigate the detrimental effects of noise by encoding single-qubit information into a larger quantum ***,the generation of distributed entanglement between logical qubits located within two spatially separated nodes presents a significant resource-intensive challenge that has yet to be *** we present a heralded protocol for generating distributed entanglement between two nonlocal error-protected logical qubits.A high-dimensional single photon can evolve physical qubits into a logical qubit that entangles with the photon and then converts logical qubit-photon entanglement into entanglement between two logical qubits,when the photon state is properly tuned and an effective photon-spin interface between single photons and individual spins is ***,the success of the entanglement generation is heralded by the detection of the photon,and the corresponding efficiency can,in principle,approach *** distinguished features make our protocol highly appealing for future large-scale quantum technologies.

关键词： quantum networks distributed entanglement error-protected logical qubits high-dimensional photons