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Chinese physics B 2024年第9期33卷 576-580页

作者： Xing-Feng Zhang Li-Bin Liu Yu-Qing Li Dong-Tao Zhang Wei-Qiang Liu Ming Yue college of materials Science and engineering Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

The Sm–Zr–Fe–Co–Ti quinary-alloys with ThMn12 structure has attracted wide attention for ultra-high intrinsic magnetic properties,showing potentiality to be developed into rare-earth permanent *** Ti element in alloys is crucial for phase stability and magnetic properties,and lower Ti content can increase intrinsic magnetic properties but reduce phase *** this study,the 1:12 single-phase melt-spun ribbons with low Ti content was successfully prepared using a rapid solidification non-equilibrium method for the Sm1.1Zr_(0.2)Fe_(9.2)Co_(2.3)Ti_(0.5) ***,this non-equilibrium ribbon did not achieve good magnetic hardening due to the uneven microstructure and ***,annealing was carried out to eliminate micro-strain and homogenize microstructure,therefore,remanence and coercivity were significantly improved even the precipitation of a small amount of a-Fe phase which were not conducive to *** remanence of 86.1 emu/g and coercivity of 151 kA/m was achieved when annealing at 850℃ for 45 *** hot pressing,under the action of high temperature and pressure,a small portion of ThMn12 phases in the magnet decompose into Sm-rich phases and a-Fe,while remanence of 4.02 kGs(1 Gs=10^(-4) T),and coercivity of 1.12 kOe(1 Oe=79.5775 A·m^(-1))were still *** findings can provide reference for exploring practical permanent magnets made of 1:12 type quinary-alloys.

关键词： magnetic materials (Sm,Zr)(Fe,Co,Ti)_(12) magnets nanocrystalline magnet microstructure

Doping suppresses lattice distortion of vacant quadruple perovskites to activate self-trapped excitons emission

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Nano Research 2024年第4期17卷 3068-3078页

作者： Zhipeng Chen Fei Zhang Dongwen Yang Huifang Ji Xu Chen Di Wu Xinjian Li Yu Zhang Zhifeng Shi Key laboratory of materials physics of ministry of education School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China State Key laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

The vacancy-ordered quadruple perovskite Cs_(4)CdBi_(2)Cl_(12),as a newly-emerging lead-free perovskite system,has attracted great research interest due to its excellent stability and direct band ***,the poor luminescence performance limits its application in light-emitting diodes(LEDs)and other ***,for the first time,an Ag^(+)ion doping strategy was proposed to greatly improve the emission performance of Cs_(4)CdBi_(2)Cl_(12) synthesized by hydrothermal *** functional theory calculations combined with experimental results evidence that the weak orange emission from Cs_(4)CdBi_(2)Cl_(12) is attributed to the phonon scattering and energy level crossing due to the large lattice distortion under excited ***,Ag^(+)ion doping breaks the intrinsic crystal field environment of Cs_(4)CdBi_(2)Cl_(12),suppresses the crossover between ground and excited states,and reduces the energy loss in the form of nonradiative *** a critical doping amount of 0.8%,the emission intensity of Cs_(4)CdBi_(2)Cl_(12):Ag^(+)reaches the maximum,about eight times that of the pristine ***,the doped Cs_(4)CdBi_(2)Cl_(12) still maintains excellent stability against heat,ultraviolet irradiation,and environmental oxygen/*** above advantages make it possible for this material to be used as solid-state phosphors for white LEDs applications,and the Commission International de I’Eclairage color coordinates of(0.31,0.34)and high color rendering index of 90.6 were *** importantly,the white LED demonstrates remarkable operation stability in air ambient,showing almost no emission decay after a long working time for 48 *** believe that this study puts forward an effective ion-doping strategy for emission enhancement of vacancy-ordered quadruple perovskite Cs_(4)CdBi_(2)Cl_(12),highlighting its great potential as efficient emitter compatible for practical applications.

关键词： Cs_(4)CdBi_(2)Cl_(12) self-trapped excitons ion doping emission enhancement stability

Revealing the atomic mechanism of diamond–iron interfacial reaction

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Carbon Energy 2024年第3期6卷 255-263页

作者： Yalun Ku Kun Xu Longbin Yan Kuikui Zhang Dongsheng Song Xing Li Shunfang Li Shaobo Cheng Chongxin Shan Henan Key laboratory of Diamond Optoelectronic materials and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhouChina Department of Mechanical engineering Stanford UniversityStanfordCaliforniaUSA Information materials and Intelligent Sensing laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefeiChina Institute of Quantum materials and physics Henan Academy of SciencesZhengzhouChina

Diamond,with ultrahigh hardness,high wear resistance,high thermal conductivity,and so forth,has attracted worldwide ***,researchers found emergent reactions at the interfaces between diamond and ferrous materials,which significantly affects the performance of diamond-based ***,combing experiments and theoretical calculations,taking diamond–iron(Fe)interface as a prototype,the counter-diffusion mechanism of Fe/carbon atoms has been ***,it is identified that Fe and diamond first form a coherent interface,and then Fe atoms diffuse into diamond and prefer the carbon vacancies ***,the relaxed carbon atoms diffuse into the Fe lattice,forming Fe_(3)***,graphite is observed at the Fe_(3)C surface when Fe_(3)C is over-saturated by carbon *** present findings are expected to offer new insights into the atomic mechanism for diamondferrous material's interfacial reactions,benefiting diamond-based device applications.

关键词： coherent interface counter-diffusion diamond iron phase transition

Asymmetric Zn-N4 atomic sites embedded hollow fibers as stable Zn anode for high-performance Zn-ion hybrid capacitor

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Journal of Energy Chemistry 2024年第10期97卷 460-469页

作者： Yukun Liu Bing Li Jin Wang Caiyun Li Hongrui Yang Yang Song Sen Zhang Chao Deng Key laboratory for Photonic and Electronic Bandgap materials Ministry of Education College of Physics and Electronic Engineering Harbin Normal University college of Material Science and Chemical engineering Harbin Engineering University

Zn based electrochemical energy storage systems（EES） have attracted tremendous interests owing to their low cost and high intrinsic ***,the uncontrolled growth of Zn dendrites and the side reactions of Zn metal anodes（ZMAs） severely restrict their *** address these issues,we design the asymmetric Zn-N4atomic sites embedded hollow fibers（AS-IHF） as the flexible host for stable *** introducing different nitrogen resources in the synthesis,two kinds of coordination,i,***-N（pyridinic） and Zn-N（pyrrolic）,are introduced in the Zn-N4atomic module *** asymmetric Zn-N4module with regulated micro-environment facilitates the superior zincophilic features and promotes the Zn ***,the highly porous structure of the hollow fiber effectively reduces local current density,homogenize Zn ion flux,and alleviate structure *** the advantages endow the high efficiency and good stability for Zn plating/*** theoretical and experimental results demonstrate the high reversibility,low nucleation overpotential,and dendritefree behavior of the AS-IHF@Zn anode,which afford the high stability in high-rate and long-term ***,the solid-state Zn-ion hybrid capacitor（ZIHC） based on AS-IHF@Zn anode shows the high flexibility,reliability,and superior long-term cycling capability in a wide-range of temperatures（-20-25℃）.Therefore,the present work not only gives a new strategy for modulating local environments of single atomic sites,but also propels the development of flexible power sources for diverse electronics.

关键词： Asymmetric coordination Dendrite free behavior Single atomic sites Zincophilic sites Zn-ion hybrid capacitor

Power transfer efficiency in an air-breathing radio frequency ion thruster

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Chinese physics B 2024年第7期33卷 430-438页

作者：黄高煌李宏高飞王友年 Key laboratory of materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China college of physical Science and Technology Dalian UniversityDalian 116622China

Due to a series of challenges such as low-orbit maintenance of satellites, the air-breathing electric propulsion has got widespread attention. Commonly, the radio frequency ion thruster is favored by low-orbit missions due to its high specific impulse and efficiency. In this paper, the power transfer efficiency of the radio frequency ion thruster with different gas compositions is studied experimentally, which is obtained by measuring the radio frequency power and current of the antenna coil with and without discharge operation. The results show that increasing the turns of antenna coils can effectively improve the radio frequency power transfer efficiency, which is due to the improvement of Q factor. In pure N_2 discharge,with the increase of radio frequency power, the radio frequency power transfer efficiency first rises rapidly and then exhibits a less steep increasing trend. The radio frequency power transfer efficiency increases with the increase of gas pressure at relatively high power, while declines rapidly at relatively low power. In N_(2)/O_(2) discharge, increasing the N_(2) content at high power can improve the radio frequency power transfer efficiency, but the opposite was observed at low power. In order to give a better understanding of these trends, an analytic solution in limit cases is utilized, and a Langmuir probe was employed to measure the electron density. It is found that the evolution of radio frequency power transfer efficiency can be well explained by the variation of plasma resistance, which is related to the electron density and the effective electron collision frequency.

关键词： radio frequency ion thruster inductively coupled plasma power transfer efficiency analytic solution

Integrated multi-scale approach combining global homogenization and local refinement for multi-field analysis of high-temperature superconducting composite magnets

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 747-762页

作者： Hanxiao GUO Peifeng GAO Xingzhe WANG Key laboratory of Mechanics on Western Disaster and Environment of ministry of education Key Laboratory of Special Function Materials and Structure Design of Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting *** respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic *** numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally ***,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake *** approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic *** then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic *** results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and *** proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.

关键词： epoxy-impregnated high-temperature superconducting(HTS)magnet multi-scale method global homogenization(GH) local refinement(LR) multi-field analysis

Exploring precursor effect in in-situ reconstruction of Bi metal organic-frameworks during CO_(2)electroreduction reaction to tailor formate selectivity towards 100%

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Science china Chemistry 2024年第7期67卷 2190-2198页

作者： Zhida Liu Qikui Fan Hang Huo Fanglei Yao Xiaoping Gao Jin Wang college of materials Science and engineering Shenzhen UniversityShenzhen 518071China college of physics and Optoelectronic engineering Shenzhen UniversityShenzhen 518060China Key laboratory of Functional Molecular Solids Ministry of EducationCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China Hefei National Research Center for physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Bi-based metal-organic frameworks(Bi-MOFs)as efficient catalysts for the CO_(2)electroreduction reaction(CRR)have been extensively *** has been established that Bi-MOFs usually undergo in-situ transformation during the CRR,ultimately converting into Bi ***,the effect of the MOF precursors on the structure of the derived Bi catalysts and consequently on their electrocatalytic properties has not been clearly *** this work,we prepared four variants of a novel Bi-MOF with different morphologies and dimensions,and explored the effects of the precursors on the resulting Bi catalysts and their CRR performance.A precursor-dependent in-situ transformation and its profound impact on tuning the CO_(2)-formate FE towards~100%have been *** the four examined variants,Bi-MOF with nanocube-like morphology(BiMOF-NC)is transformed into thin and flat Bi nanosheets capable of successfully enveloping the fibers of carbon paper(working electrode),while the other three variants with increased size and dodecahedral/octahedral geometry have been transformed into Bi nanoflowers,exposing a fair portion of the carbon fibers in the working ***,the transformation rate was found to be dependent on the precursors and BiMOF-NC exhibited the highest rate of reconstruction compared with other ***,the Bi catalyst derived from BiMOF-NC delivered a selectivity for the formate product of nearly 100%at-1.2 V(*** hydrogen electrode(RHE))and of over 95%in a wide potential range due to efficient suppression of the competing hydrogen evolution reaction(HER)over carbon *** in-situ transformed BiMOFNC also demonstrated equivalently high formate selectivity at large current densities(≥100 mA cm^(-2))in flow cell reactors as that in H-type reactors,underscoring its potential for industrial *** work highlights the necessity of finely tuning the structural features of MOF precursors to achieve optim

关键词： Bi-MOFs precursor effect in-situ transformation Bi nanosheets CO_(2)-to-formate

Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of Polymer Science 2024年第5期42卷 636-642,I0008页

作者： Xiao-Lin Lyu Shi-Chu Yang An-Qi Xiao Ping-Ping Hou Wei Zhang Hong-Bing Pan Zhi-Hao Shen Xing-He Fan Qi-Feng Zhou Beijing National laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key laboratory of Advanced materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent ***,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing ***,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network *** reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD *** resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing *** results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid

Designing highly transparent cerium doped Y_(2)O_(3) ceramics with high mechanical and thermal properties for UV-shielding in extreme conditions

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Journal of Advanced Ceramics 2024年第7期13卷 1032-1042页

作者： Cong Zhang Jianqi Qi Xiaolan Zhou Zhonghua Lu Tiecheng Lu college of physics Sichuan UniversityChengdu 610064China Key laboratory of High Energy Density physics of ministry of education Sichuan UniversityChengdu 610064China Key laboratory of Radiation physics and Technology of the ministry of education Sichuan UniversityChengdu 610064China

Ultraviolet(UV)radiation poses risks to both human health and *** response to the urgent demand for UV-shielding across various applications,extensive endeavors have been dedicated to developing UV-shielding materials spanning from wide-bandgap semiconductors to organo-inorganic composite ***,existing UV shielding materials,though suitable for daily use,cannot meet the demands of extreme *** this work,we incorporated CeO_(2)as a UV absorber into Y_(2)O_(3)transparent ceramics for *** effect of CeO_(2)concentration on the optical,mechanical,and thermal properties of Y_(2)O_(3)ceramics was systematically *** findings indicate that CeO_(2)serves not only as a UV absorber but also as an effective sintering aid for Y_(2)O_(3)transparent *** 5 at%Ce-doped Y_(2)O_(3)transparent ceramics exhibit the optimal optical quality,with in-line transmittance of~77%at 800 *** introduction of Ce shifted the UV cutoff edge of Y_(2)O_(3)transparent ceramics from 250 to 375 nm,which was attributed to the visible band absorption of Ce^(4+).This shift grants UV shielding capabilities to Y_(2)O_(3)transparent ceramics,resulting in 100%shielding for ultraviolet C(UVC,100-280 nm)and ultraviolet B(UVB,280-320 nm)and~95%shielding for ultraviolet A(UVA,320-400 nm).The service stability(optical properties)under various corrosive conditions(acid,alkali,UV irradiation,and high temperature)was investigated,confirming the excellent stability of this transparent ceramic UV-shielding material.A comparison of the performance parameters of transparent ceramics with those of traditional UV shielding materials such as glasses,films,and coatings was *** work provides innovative design concepts and an effective solution for UVshielding materials for extreme conditions.

关键词： ultraviolet(UV)-shielding transparent ceramics bandgap engineering thermal properties optical properties

Reliable calculations of nuclear binding energies by the Gaussian process of machine learning

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Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： Zi-Yi Yuan Dong Bai Zhen Wang Zhong-Zhou Ren School of physics Science and engineering Tongji UniversityShanghai 200092China college of Science Hohai UniversityNanjing 211100China Key laboratory of Advanced Micro-Structure materials Ministry of EducationShanghai 200092China

Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.

关键词： Nuclear binding energies decay Machine learning Gaussian process