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In-situ synthesized SiC/TiC/SiTiOC hybrid nanofiber mats for broad-range temperature microwave absorption

science China Technological sciences 2025年第6期68卷 183-196页

作者： Yashan HUO Yuetong QIAN Minshan ZHAO Lei ZHANG Yujia TAN Zhihui HE Peng MIAO Fuchun ZHANG Wei CUI Renchao CHE School of Physics and Electronic Information Yan'an University Shaanxi Key Laboratory of Intelligent Processing for Big Energy Data Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative Materials Academy for Engineering &Technology Advanced Coatings Research Center of Ministry of Education of China Fudan University School of Materials and Chemical Engineering Xi'an Technological University School of Materials Science & Engineering Tongji University College of Physics Donghua University

Efficient, temperature-insensitive electromagnetic attenuation materials are critical for high microwave absorption at high temperatures. This study presents SiC/TiC/SiTiOC hybrid nanofiber mats constructed using an in-situ synthesis method;these mats incorporate SiC/TiC as the microwave loss unit and SiTiOC as the antioxidant unit, offering an innovative approach to high-temperature microwave absorption. The introduction of high-conductivity TiC not only optimizes the dielectric constant and impedance matching of the material but also enhances its thermal cycling stability. This design ensures steady electromagnetic attenuation, enabling the hybrid nanofiber mats to maintain robust absorption performance in the X-band, even at high temperatures. At 873 K, the material demonstrates an effective absorption bandwidth of 3.6 GHz and a minimum reflection loss of-45.55 dB. Compared to single-system absorbers, such as SiC/C nanofiber materials, with a single system, the multicomponent SiC/TiC/SiTiOC hybrid nanofiber mats deliver reliable absorption performance in the temperature range of 293–873 K. This study confirms that highly conductive titanium-based ceramic materials used for dielectric property regulation effectively address the challenges of poor temperature stability and limited reusability in high-temperature carbon-ceramic absorbing materials, providing valuable insights and guidance for designing efficient microwave absorbers that can operate across a wide temperature range.

关键词： electrospinning SiC/TiC/SiTiOC hybrid nanofiber mats high-temperature microwave absorption dielectric properties thermal stability

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Insight into Ca Addition on Phase Transformation in CGHAZ of Mg Deoxidized Shipbuilding Steel Plates with In-situ Observation

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Metallurgical and materials Transactions B 2025年 1-21页

作者： Wang, Liang Yang, Jian Zhang, Yinhui Zhang, Yuqi Chen, Yanli Dai, Zhipeng Li, Tingting State Key Laboratory of Advanced Special Steel School of Materials Science and Engineering Shanghai University Shanghai P. R. China

The effect of Ca addition on phase transformation and impact toughness of coarse-grained heat-affected zone (CGHAZ) during high heat input welding (HHIW) in Mg deoxidized shipbuilding steel plates is investigated. The Ca addition exacerbates TiN particles dissolution and coarsening by altering the equilibrium Ti concentration in austenite during HHIW, resulting in increasing the average size and decreasing the number density from 2.47 to 1.37 μm-2 for TiN particles. The pinning effect of residual TiN particles on austenite grain boundaries is weakened after HHIW, which is consistent with the in-situ observation results that the growth rate of austenite grain in Mg-Ca steel is faster than that in Mg steel. This leads to the increase in average size of prior austenite grain (PAG) from 367 to 444 μm. In-situ observation shows that the Widmanstätten ferrites (WFs) will more preferentially form than the intragranular acicular ferrites (IAFs) due to a relatively smaller driving force required. The length of WFs in Mg-Ca steel is longer because of the sufficient growth space in larger PAGs in Mg-Ca steel. Meanwhile, the length of IAFs in Mg-Ca steel is also becomes longer due to the fewer effective inclusions inducing the formation of IAFs with chaotic orientations in Mg-Ca steel. These factors lead to a decrease in high-angle grain boundaries (HAGBs) fraction and an increase in the effective grain size (EGS). Therefore, the Ca addition results in the decreases in the number density of TiN particles and HAGBs fraction, the increases in PAG size, WFs content and EGS, which ultimately leads to the deterioration of mechanical properties of CGHAZ, especially with a decrease in the impact toughness at − 20° C from 175 J of Mg steel to 23 J of Mg-Ca steel.

关键词： Fracture toughness

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Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400℃

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Journal of materials science & Technology 2024年第5期172卷 71-82页

作者： Xiang Su Yuan Lei Yang Chen Hongjie Qu Zhixiang Qi Gong Zheng Xu Liu Henggao Xiang Guang Chen National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China School of Aviation and Mechanical Engineering Changzhou Institute of TechnologyChangzhou 213032China

Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy ***,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening ***,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3Ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum *** enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one *** significant segregation of Ni,Ce,and Zr elements at the interfaces helps improve the thermal stability of the T *** thermostable T phase effectively strengthens the matrix by in-hibiting dislocation ***,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high *** finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications.

关键词： Aluminum alloys Precipitation Thermally reinforcement phase Re-aging treatment High-temperature strength

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Prediction of the thermal conductivity of Mg–Al–La alloys by CALPHAD method

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International Journal of Minerals,Metallurgy and materials 2024年第1期31卷 129-137页

作者： Hongxia Li Wenjun Xu Yufei Zhang Shenglan Yang Lijun Zhang Bin Liu Qun Luo Qian Li State Key Laboratory of Advanced Special Steels&Shanghai Key Laboratory of Advanced Ferrometallurgy&School of Materials Science and Engineering Shanghai UniversityShanghai 200444China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

Mg-Al alloys have excellent strength and ductility but relatively low thermal conductivity due to Al *** accurate prediction of thermal conductivity is a prerequisite for designing Mg-Al alloys with high thermal ***,databases for predicting temperature-and composition-dependent thermal conductivities must be *** this study,Mg-Al-La alloys with different contents of Al2La,Al3La,and Al11La3phases and solid solubility of Al in the α-Mg phase were *** influence of the second phase(s) and Al solid solubility on thermal conductivity was *** results revealed a second phase transformation from Al_(2)La to Al_(3)La and further to Al_(11)La_(3)with the increasing Al content at a constant La *** degree of the negative effect of the second phase(s) on thermal diffusivity followed the sequence of Al2La>Al3La>Al_(11)La_(3).Compared with the second phase,an increase in the solid solubility of Al in α-Mg remarkably reduced the thermal *** the basis of the experimental data,a database of the reciprocal thermal diffusivity of the Mg-Al-La system was established by calculation of the phase diagram (CALPHAD)*** a standard error of±1.2 W/(m·K),the predicted results were in good agreement with the experimental *** established database can be used to design Mg-Al alloys with high thermal conductivity and provide valuable guidance for expanding their application prospects.

关键词： magnesium alloy thermal conductivity thermodynamic calculations materials computation

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High-strength,electrically insulated industrial meta-aramid paper reinforced with polyethylene terephthalate microfibre pulp in a sandwich structure

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High Voltage 2024年第6期9卷 1402-1413页

作者： Meijun Chen Songjun Yao Guobin Zhu Mengyun Wu Zhiying Li Siwei Xiong Shiwen Yang Hua Wang Liangbo Zhu Luoxin Wang State Key Laboratory of New Textile Materials&Advanced Processing Technology College of Materials Science and EngineeringWuhan Textile UniversityWuhanChina High-Tech Organic Fibers Key Laboratory of Sichuan Province ChengduSichuanChina

The weak interfacial strength and porous structure of the meso-aramid paper cause mechanical and insulating *** density,regulating pore structure,and improving interfacial interactions of meso-aramid are crucial for promoting the perfor-mance of meso-aramid papers.A PMIA/polyethylene terephthalate(PET)composite paper was prepared using the wet method with meso-aramid short cut fibres(PMIA)and PET pulp as raw *** sandwich-structured PMIA/PET paper was achieved by covering PET microfiber non-wovens served as the surface layer while the PMIA/PET composite paper acted as the core *** the high-temperature hot pressing process,the PET pulp transformed into a viscous melt that coated on aramid fibres in between layers,forming a typical‘reinforced concrete’interface structure within the core layer of the PMIA/PET composite *** PET non-wovens on top and bottom surfaces were converted into a dense PET film that filled and covered the holes and defects in the PMIA/PET composite *** unique structure enabled the sandwich-structured PMIA/PET composite paper to exhibit excellent tensile strength(80.41 N/cm)and breakdown strength(56.35 kV/mm),surpassing most reported performances of meso-aramid papers in *** work not only provides novel insights for pre-paring high-performance meso-aramid papers,but also shows potential applications for other materials and structures.

关键词： strength structure sandwich

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Multicolor emission from lanthanide ions doped lead-free Cs_(3)Sb_(2)Cl_(9) perovskite nanocrystals

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Journal of Rare Earths 2024年第5期42卷 940-946,I0005页

作者： He Shao Lifang Li Xiufeng Wu Lin Xu Biao Dong Donglei Zhou Xue Bai Hongwei Song State Key Laboratory of Organic Electronics and Information Displays&Institute of Advanced Materials College of Materials Science and EngineeringNanjing University of Posts&TelecommunicationsNanjing210023China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and Engineering Jilin UniversityChangchun130012China

The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence quantum yield(PLQY)of these materials is still ***,because the halogen ions can be easily exchanged,the controllable multicolor emission in perovskite NCs is difficult to realize in current *** this work,we introduced lanthanide ions into lead-free Cs_(3)Sb_(2)Cl_(9) perovskite *** from the energy transfer between Cs_(3)Sb_(2)Cl_(9) perovskite NC host and lanthanide ions,the multicolor emission was *** on controlling the doping concentration of Tb^(3+)and Eu^(3+)ions,the white light emission under UV excitation would be turned easily in the Tb^(3+)/Eu^(3+)codoped *** addition,efficient energy transfer from perovskite NCs to Tb^(3+)or Eu^(3+)ions is beneficial to improving the optical properties of lead-free perovskite NCs,resulting in maximum PLQYs of red,green and white light emission of 22.6%,19.7%and 28.5%,***,a white light emitting device(WLED)was fabricated with a power efficiency of 18.5 lm/W,which presents the Commission Internationale de l'Eclairage(CIE)of(0.33,0.35).

关键词： Perovskite nanocrystals Lead free Lanthanide ions Energy transfer White light emitting device Rare earths

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Identification of the highly active Zn-N_(4) sites with pyrrole/pyridine-N synergistic coordination by dz^(2)+s-band center for electrocatalytic H_(2)O_(2) production

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Journal of Energy Chemistry 2024年第11期98卷 105-113页

作者： Rui Chen Wei Liu Zhiyuan Sang Jingjing Jia Zhenxin Li Jiahuan Nie Qiao Jiang Zixian Mao Baitong Guo Qiuying Wang Feng Hou Lichang Yin De'an Yang Ji Liang Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016LiaoningChina

Single metal atoms anchored on nitrogen-doped carbon materials(M-N_(4))have been identified as effective active sites for catalyzing the two-electron oxygen reduction reaction(2e-ORR).However,the relationship between the local atomic/electronic environments of the M-N_(4) sites(metal atoms coordinated with different types of N species)and their catalytic activity for 2e-ORR has rarely been elaborated clearly,which imposes significant ambiguity for the rational design of ***,guided by the comprehensive density-functional theory calculations and predictions,a series of Zn-N_(4) single-atom catalysts(SACs)are designed with pyrrole/pyridine-N(N_(Po)/N_(Pd))synergistic coordination and prepared by controlling the pyrolysis temperature(600,700,and 800℃),Among them,the dominated Zn-N_(4) configurations with rationally combined N_(Po)/N_(Pd)coordination show~*OOH adsorption strength close to the optimal value,much superior to those with mono N ***,the as-prepared catalyst exhibits a high H_(2)O_(2) selectivity of over 90%both in neutral and alkaline environments,with a superb H_(2)O_(2) yield of up to 33.63 mol g^(-1)h^(-1)in an alkaline with flow *** importantly,a new descriptor,dz^(2)+s band center,has been proposed,which is especially feasible for predicting the activity for metal types with fully occupied s and d *** work thus presents clear guidance for the rational design of highly active SACs toward ORR and provides a complement to the d-band theory for more accurately predicting the catalytic activity of the materials.

关键词： Zinc single-atom catalysts Hydrogen peroxide Local coordination environments d+s-Band modulation

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Spray pyrolysis-derived W-doped MoSe_(2)/rGO paper-like microspheres:optimization of microstructure and mesostructure for enhanced lithium storage

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Rare Metals 2024年第7期43卷 3019-3031页

作者： Wei Wang Jun-Yu Chen Jie Ouyang Hong Yin Ao-Jie Li Liang Chen Jun-Lin Huang Yu-Can Zhu Gang-Yong Li Zhao-Hui Hou Key Laboratory of Hunan Province for Advanced Carbon-based Functional Materials Hunan Institute of Science and TechnologyYueyang 414006China School of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang414006China Hunan Province Key Laboratory of Materials Surface&Interface Science and Technology Material Science and Engineering SchoolCentral South University of Forestry and TechnologyChangsha 410004China International Iberian Nanotechnology Laboratory(INL) AvMestre Jose Veiga4715-330 BragaPortuga

Two-dimensional MoSe_(2) is a promising candidate for lithium-ion battery ***,its conductivity and lithium storage volumetric effect still need to be *** this work,W-doped MoSe_(2)/rGO paper-like microspheres are successfully prepared through ultrasonic spray pyrolysis,achieving optimization at both the microstructure and mesostructure to enhance the lithium storage performance of the ***,by utilizing the similar two-dimensional structure between MoSe_(2) and rGO,self-assembly is achieved through spray pyrolysis,resulting in a well-defined van der Waals heterostructure at the interface on the microscale,enhancing the electron and ion transfer capability of the ***,the mesoscale paper-like microsphere morphology provides additional volume expansion buffering ***,W-doping not only increases the interlayer spacing of MoSe_(2)(0.73 nm),thereby reducing the diffusion resistance of Li+,but also allow for the modulation of the energy band structure of the *** functional theory(DFT)calculations confirm that W-doped MoSe_(2)/rGO exhibits the narrowest bandgap(0.892 eV).Therefore,the composite demonstrates excellent lithium storage performance,maintaining a specific capacity of 732.9 mAh·g^(-1)after 300 cycles at a current density of 1 A·g^(-1).

关键词： Molybdenum selenide Heterostructure Microspheres Li-ion batteries Kinetics

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Much enhanced electromagnetic wave absorbing properties from the synergistic effect of graphene/γ-graphyne heterostructure in both gigahertz and terahertz band ranges

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Nano Research 2023年第1期16卷 88-100页

作者： Zhiwei Zhang Zhuo Li Lun Xia Ruofeng Wang Yishu Cao Zheng Cheng Yi Huang National Institute for Advanced Materials Tianjin Key Laboratory of Metal and Molecule Based Material ChemistryKey Laboratory of Functional Polymer MaterialsCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)School of Materials Science and EngineeringNankai UniversityTianjin 300350China

Exploring advanced electromagnetic wave(EMW)absorbers is one of the most feasible ways to solve the increasing electromagnetic pollution in both military and civil *** this work,γ-graphyne(γ-GY)is synthesized by a mechanochemical route using CaC2 and hexabromobenzene(PhBr6).Then three-dimensional(3D)reduced graphene oxide/γ-GY(RGO/GY)heterostructures are prepared through facile solvothermal self-assembly and subsequent thermal *** influences of calcination temperature and the content ofγ-GY of the composite on EMW absorption performance are fully *** minimum reflection loss(RL)value of the RGO/GY composite foam is−71.73 dB at 10.48 GHz with the matching thickness of 3.54 mm,and the effective absorption bandwidth(EAB)less than−10 dB is 7.36 ***,excellent terahertz(THz)absorption property is also obtained at 0.2–1.6 *** RL of 84.08 dB is acquired,and the EAB covers 100%of the entire measured *** addition,the composite is also a promising anticorrosive EMW *** work provides encouraging findings,which are also instructive for the potential advantages of graphyne-based materials as highly efficient EMW absorbers in both gigahertz and terahertz band ranges.

关键词： γ-Graphyne mechanochemical graphene oxide electromagnetic wave(EMW)absorption anticorrosive

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A machine learning method approach for designing novel high strength and plasticity metastable β titanium alloys

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Progress in Natural science:materials International 2025年第1期35卷 156-165页

作者： Zhiduo Liu Haoyu Zhang Shuai Zhang Jun Cheng Yixuan He Ge Zhou Jiawei Liu Suping Song Lijia Chen School of Materials Science and Engineering Shenyang University of Technology Shenyang Key Laboratory of Advanced Structural Materials and Applications Shenyang University of Technology Northwest Institute for Nonferrous Metal Research Shaanxi Key Laboratory of Biomedical Metal Materials State Key Laboratory of Solidification Processing Northwestern Polytechnical University Ansteel Group Automation Co. Ltd

In order to improve efficiency and reduce costs, four machine learning models were established for the design of metastable β titanium alloys, including the Adaboost model, the LightGBM model, the Voting model, and the Stacking model. The accuracy of these models was evaluated, and all models exhibited excellent accuracy for tensile strength, yield strength, and elongation. The values of R-squared coefficients（R2） all greater than *** them, the LightGBM model showed the highest accuracy, with relatively smallest values of mean absolute error（MAE） and root mean square error（RMSE） and relatively largest value of R2. To further verify the accuracy of the model, a metastable β titanium alloy Ti-5.5Cr-5Al-4Mo-3Nb-2Zr was designed by the LightGBM model. The predicted values of the alloy's tensile strength, yield strength, and elongation under three heat treatment processes were in high agreement with the experimental values. The alloy exhibited optimal strength-plasticity matching after undergoing a solution treatment at 850°C for 0.5 h, followed by aging at 650°C for 8 h, with a tensile strength of 1317 MPa, an elongation of 11.17 %, and a strength-plasticity product of 14.711 GPa·%.

关键词： Machine learning Metastable β titanium alloy Microstructure Plasticity Strength

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