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Journal of Advanced Ceramics 2024年第5期13卷 689-698页

作者： Qingyi Kong Lei Chen Sijia Huo Kunxuan Li Wenyu Lu Yujin Wang Yu Zhou institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced structure‒function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

To address the relatively mediocre mechanical properties of single-phase multi-component carbide ceramics,a phase transition from a single phase to multiple phases was proposed to achieve superior mechanical properties.A series of(TiZrV_(x)Nb)C_(0.8) ceramics with different V contents were fabricated by spark plasma sintering(SPS).The influence of the V content on the phase composition,microstructural evolution,and mechanical properties was investigated in *** transition behavior from a single phase to multiple phases is discovered and *** formation of the Zr-rich phase and Zr-poor phase can be attributed to the increase in lattice distortion and mixed enthalpy caused by the addition of V.A nanometer lamellar structure with a semi-coherent interface obtained via in situ decomposition is reported for the first time in multi-component carbide *** semi-coherent interfaces with high dislocation density and strain concentration effectively improve the mechanical properties,grain refinement,and multi-phase *** optimal comprehensive mechanical properties of the Vickers hardness(26.3 GPa),flexural strength(369 MPa),and fracture toughness(3.1 MPa·m^(1/2))were achieved for the sample with 20 mol%V.

关键词： multi-component ceramics multiple phases microstructure evolution phase decomposition mechanical properties

High-frequency magnetic properties of biphase Ce_(2)Fe_(17)N_(3)/α-Fe microflakes with easy-plane anisotropy

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Journal of Rare Earths 2024年第1期42卷 110-115,I0004页

作者： Ke Wang Hang Zhang Yuandong Huang Zhibiao Xu Fashen Li Tao Wang Key Laboratory for Magnetism and Magnetic Materials of MOE Lanzhou UniversityLanzhou730000China Key Laboratory of Special function Materials and structure Design Ministry of EducationLanzhou UniversityLanzhou730000China

Soft magnetic composites(SMCs)are effective as magnetic powder cores in an *** to high saturation magnetization,large magnetocrystalline anisotropy and high operating frequency of M(metal)-RE(rear earth)soft magnetic composites,it is possible to miniaturize inductor cores by reducing total loss,especially eddy current loss and excess loss at high *** this article,the characteristics of Ce_(2)Fe_(17)N_(3)/α-Fe(CFN/F)loss per volume and effective permeability reaching a high frequency of 3 MHz are *** biphase CFN/F composite exhibits a high permeability of 16 at 70 MHz,which is two times greater than that of pure Ce_(2)Fe_(17)N_(3)(CFN)*** total loss is as low as 545 mW/cm^(3)at 3 MHz and 6 *** direct current(DC)-bias properties have a percent of permeability exceeding 65% at H=7960 A/*** phenomenon indicates that our material has a higher working frequency and lower core loss than other materials;the biphase CFN/F structure is a promising and efficient approach for developing the miniaturized radio frequency(RF)inductor core.

关键词： High frequency Soft magnetic composites Easy-plane anisotropy Permeability spectra Core loss Rare earths

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

Transcatheter aortic valve replacement:A journey of two decades and beyond

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Chinese Medical Journal 2024年第9期137卷 1012-1015页

作者： Tianyuan Xiong Mao Chen Department of Cardiology West China HospitalSichuan UniversityChengduSichuan 610041China Laboratory of Cardiac structure and function Institute of Cardiovascular DiseasesWest China HospitalSichuan UniversityChengduSichuan 610041China

The number of patients with calcic aortic stenosis(AS)is 9.4 million according to 2019 Global Disease Burden estimates,which will continue to increase as the population ages.[1]For the treatment of symptomatic severe AS,transcatheter aortic valve replacement(TAVR)has evolved to be a well-established option across all risk spectra,with a rapid growth of procedures *** rise of TAVR initiates the revolution of the management of valvular heart diseases,from patient surveillance,the staging of disease,the use of multimodality imaging,the concept of the Heart Team,new designs and iterations of devices to technical innovations and the discovery of unmet clinical *** a consequence of the global adoption of TAVR,geographical differences in the epidemiology of AS and patient characteristics have also been further identi*** examination of the changing patient population,current applications and breakthroughs,and remaining challenges are crucial for the future of this ***,we discuss the temporal utilization of TAVR,the accumulation of evidence and progress of devices,the selection of patients,and some ongoing topics concerning the improvement of TAVR.

关键词： epidemiology breakthrough beyond

Pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy for activating water and urea oxidation

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Green Energy & Environment 2024年第4期9卷 684-694页

作者： Guangfu Qian Wei Chen Jinli Chen Li Yong Gan Tianqi Yu Miaojing Pan Xiaoyan Zhuo Shibin Yin Guangxi Key Laboratory of Electrochemical Energy Materials College of Chemistry and Chemical EngineeringState Key Laboratory of Processing for Non-Ferrous Metal and Featured MaterialsGuangxi University100 Daxue RoadNanning530004China institute for structure and function and Department of Physics Chongqing UniversityChongqing400030China

Exploitation of oxygen evolution reaction(OER)and urea oxidation reaction(UOR)catalysts with high activity and stability at large current density is a major challenge for energy-saving H_(2) production in water ***,we use the pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy activated by NiFe_(2)O_(4)(FeNi/NiFe_(2)O_(4)@NC)for efficiently increasing the performance of water and urea *** to the tensile strain effect on FeNi/NiFe_(2)O_(4)@NC,it provides a favorable modulation on the electronic properties of the active center,thus enabling amazing OER(η_(100)=196 mV)and UOR(E_(10)=1.32 V)intrinsic ***,the carbon-coated layers can be used as armor to prevent FeNi alloy from being corroded by the electrolyte for enhancing the OER/UOR stability at large current density,showing high industrial *** work thus provides a simple way to prepare high-efficiency catalyst for activating water and urea oxidation.

关键词： Carbon-encapsulated Tensile strain Catalyst Oxygen evolution reaction Urea oxidation reaction

Phase transition of multi-component(TiZrVNb)C ceramics—Part I:Phase decomposition induced by carbon content

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Journal of Advanced Ceramics 2024年第5期13卷 679-688页

作者： Qingyi Kong Rao Zhang Lei Chen Sijia Huo Wenyu Lu Yujin Wang Boxin Wei Yu Zhou institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced structure‒function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150001China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

Phase decomposition can effectively enhance the mechanical properties of carbide ceramics and can overcome the difficulty of enhancing the mechanical properties of single-phase multicomponent carbide *** this work,a series of nonstoichiometric(TiZrVNb)Cx ceramics were prepared by spark plasma sintering(SPS)at different *** effects of the carbon content on the phase composition,microstructure evolution,and mechanical properties were investigated in *** decomposition occurred with decreasing carbon *** different solid solutions of(Ti,V)-rich and Zr-rich phases formed from the decomposition of equimolar single-phase solid solutions,namely,the Zr-poor phase and Zr-rich phase,*** distribution of Nb element is relatively *** semicoherent interfaces between the Zr-poor phase and the Zr-rich phase can harden and strengthen effectively under the synergistic effect of grain *** with phase decomposition structures have apparent advantages compared to single-phase high-entropy *** work provides an important train of thought for the microstructure tailoring and properties optimization of multi-component carbide ceramics.

关键词： multicomponent ceramics nontoichiometry microstructure evolution phase decomposition mechanical properties

Co/N co-doped flower-like carbon-based phase change materials toward solar energy harvesting

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Aggregate 2024年第1期5卷 321-330页

作者： Xiao Chen Lei Wang Yan Gao Yang Li Xiaowei Zhang Yu Jiang Ge Wang institute of Advanced Materials Beijing Normal UniversityBeijingChina Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory of Function Materials for Molecule and Structure ConstructionSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijingChina

The photothermal conversion capacity of pristine organic phase change materials(PCMs)is inherently insufficient in solar energy *** upgrade their photothermal conversion capacity,we developed bimetallic zeolitic imidazolate framework(ZIF)derived Co/N co-doped flower-like carbon(Co/N-FLC)-based composite PCMs toward solar energy harvesting.3D interconnected carbon framework with low interfacial thermal resistance,abundant carbon defects and high content of nitrogen doping,excellent localized surface plasmon resonance(LSPR)effect of Co nanoparticles,and light absorber Co_(3)ZnC in Co/N-FLC synergistically upgrade the photothermal capacity of(polyethylene glycol)PEG@Co/N-FLC composite PCMs with an ultrahigh photothermal conversion efficiency of 94.8%under 0.16 W/cm^(2).Uniformly anchored Co and Co_(3)ZnC nanoparticles in carbon framework guarantee excellent photon capture *** carbon nanotubes(CNTs)in 2D carbon nanosheets further accelerate the rapid transport of phonons by constructing cross-connected heat transfer ***,PEG@Co/N-FLC exhibits a thermal energy storage density of 100.69 J/g and excellent thermal stability and durable ***,PEG@Co/N-FLC composite PCMs are promising candidates to accelerate the efficient utilization of solar energy.

关键词： bimetallic ZIF Co/N co-doped carbon phase change materials photothermal conversion thermal energy storage

Defect engineering of W^(6+)-doped NiO for high-performance black smart windows

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Nano Research 2024年第4期17卷 3043-3052页

作者： Yingjun Xiao Xiang Zhang Dukang Yan Jianbo Deng Mingjun Chen Hulin Zhang Wenhai Sun Jiupeng Zhao Yao Li School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China Center for Composite Materials and structure Harbin Institute of TechnologyHarbin 150001China

In this report,W^(6+)doping as a defect engineering strategy has been proposed to improve the electrochromic properties of NiO *** research was conducted to explore the electrochromic properties and the modified mechanism of W-doped NiO *** to the pure NiO,W-doped NiO film exhibits improved electrochromic properties with significant optical modulation(61.56%at 550 nm),fast switching speed(4.42 s/1.40 s for coloring/bleaching),high coloration efficiency(45.41 cm^(2)·C-1)and outstanding cycling stability(no significant attenuation after 2000 cycles)in Li-based *** functional theory(DFT)calculations combined with the experimental results indicate that the improved electrochromic properties were due to enhanced the electronic conductivity and ion conductivity after the introduction of W^(6+).The charge capacity of W-doped NiO has also been improved,and it can function with WO_(3) to achieve a high performance black electrochromic smart window(ECSW)by balancing *** work could advance the fundamental understanding of defect engineering as an effective strategy to boost the electrochromic properties of NiO anodic material,manifesting a significant development as a candidate counter electrode in high-performance black smart windows.

关键词： NiO defect engineering charge balance black electrochromic windows

Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 137-154页

作者： Pan WANG Xiangcheng HAN Weibin WEN Baolin WANG Jun LIANG School of Civil Engineering Central South UniversityChangsha 410083China institute of Advanced structure Technology Beijing Institute of TechnologyBeijing 100081China School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2D) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative *** results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations.

关键词： anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)

Exploring centimeter-sized crystals of bismuth-iodide perovskite toward highly sensitive X-ray detection

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Chinese Chemical Letters 2024年第6期35卷 185-188页

作者： Xin Dong Jing Liang Zhijin Xu Huajie Wu Lei Wang Shihai You Junhua Luo Lina Li College of Chemistry Fuzhou UniversityFuzhou 350116China State Key Laboratory of structure Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

Lead-halide perovskites exhibit outstanding performance in X-ray detection due to their intrinsic features such as high charge carrier mobility,large atomic number,and long carrier lifetime,but the toxicity of lead is regarded as the major factor hindering their ***,we introduce organic molecule(R)-(-)-2-methylpiperazine(R-MPz)into the bismuth-based structure to synthesize lead-free(R)-(H_(2)MPz)BiI_(5)(R-MBI).The high-quality centimeter-sized single crystals have been obtained,which show a low dark current and superior environmental ***,the single-crystal device of R-MBI exhibits a highμτproduct up to 1.88×10^(-4)cm^(2)/V and a low trap density of 1.21×10^(10)cm^(-3).Further,the detector displays excellent detection sensitivity of 263.58μC Gy_(air)^(-1)cm^(-2)and a favorable low detection limit of 4.35μGyair/s,both of which meet the requirement for medical *** findings shed light on the exploration of innovative bismuth-based hybrid perovskites for high-performance X-ray detection.

关键词： Perovskite Lead-free Bismuth-based X-ray detection Sensitivity