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Abnormal dielectric behavior of glaserite-type Ba_(3−x)Sr_(x)MgSi_(2)O_(8)solid solution

Journal of advanced Ceramics 2025年第2期14卷 77-86页

作者： Jiaqing Yang Peng Lei Xiaoqiang Song Changzhi Yin Meng Zhang Weicheng Lei Yiyang Cai Mingfei Cheng Yaodong Liu Zihang Chen Yaqing Hu Wenzhong Lu Wen Lei School of Optical and Electronic Information Key Lab of Functional Materials for Electronic Information(B)of MOEHuazhong University of Science and TechnologyWuhan 430074China Wenzhou Key Laboratory of Microwave Communication Materials and Devices Wenzhou Advanced Manufacturing Institute of HUSTWenzhou 325035China

The temperature coefficient of the resonant frequency(τ_(f))of low-permittivity(ε_(r))microwave dielectric ceramics is required to be near 0 ppm/℃for practical ***,owing to the polarization mechanism,τ_(f)of low-ε_(r)microwave dielectric ceramics is generally ***,a novel microwave dielectric ceramic,Ba_(3−x)Sr_(x)MgSi_(2)O_(8),with an abnormal positiveτ_(f)at the applied temperature is *** this study,Sr^(2+)with a relatively small ionic radius was introduced to replace Ba^(2+),and a single-phase solid solution was formed(x>0.5).Ba_(3−x)Sr_(x)MgSi_(2)O_(8)ceramics were discussed in glaserite-type topology with space groups of P_(3)^(-)for x≤0.5,relatively high symmetry P_(3)^(-)m1 for 0.5functional theory simulation calculations revealed that the preferential occupation of Sr^(2+)ions could decrease the intrinsic formation energy and improve the microwave dielectric properties by mitigating the ionic size mismatch within the crystal *** present research offers a strategy for discovering novel microwave dielectric ceramics with abnormalτ_(f)values,which could serve as τ_(f)regulators in practical applications because of their low cost and excellent microwave dielectric properties.

关键词： microwave dielectric ceramics abnormal dielectric behavior ion size mismatch [SiO4]tetrahedra tilting phase transition density functional theory(DFT)

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The practically renewable and highly efficient electrocatalysts derived from a newly-designed Mo_(8)Pt polyoxometalate compound

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science China Chemistry 2023年第2期66卷 492-499页

作者： Di Yin Yun-Dong Cao Yi Feng Guang-Gang Gao Hong Liu Lin-Lin Fan Zhen-Hui Kang School of Materials Science and Engineering University of JinanJinan250022China Institute of Functional Nano and Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-based Functional Materials and DevicesSoochow UniversitySuzhou215123China Macao Institute of Materials Science and Engineering(MIMSE) MUST-SUDA Joint Research Center for Advanced Functional MaterialsMacao University of Science and TechnologyTaipaMacao999078China

Platinum(Pt)catalysts are the most practical electrocatalysts;however,their low abundance and high cost severely limit their large-scale *** recovery is a key issue to be resolved before the use of Pt-based electrocatalysts can be broadly ***,the newly designed polyoxometalate[Pt^(II)(NH_(3))_(4)]_(2)[Mo_(8)O26](Mo_(8)Pt)acts as an ideal recycling medium for renewable and highly effective Pt *** from Mo_(8)Pt,by a facile reduction reaction,the formed Pt/Mo_(2)C/Mo_(2)N@C-N electrocatalyst shows superior electrocatalytic activity as compared to commercial Pt/C(20%)under both acidic and alkaline ***,the reaction of Pt/Mo_(2)C/Mo_(2)N@C-N in H_(2)O_(2)solution can regenerate Mo_(8)Pt for Pt *** is also demonstrated that the Pt electrocatalyst can be used for at least five rounds of recycling and regeneration,showing its efficiency and stability as well as its *** work highlights a recycling medium strategy to the new generation of renewable Pt-based catalysts.

关键词： platinum polyoxometalate electrocatalyst recycling-medium renewability

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Chiral carbon dots from glucose by room temperature alkaliassisted synthesis for electrocatalytic oxidation of tryptophan enantiomers

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Nano Research 2023年第7期16卷 8929-8936页

作者： Mengling Zhang Xing Fan Xin Du Yurong Ma Xiting Wang Hui Huang Yang Liu Youyong Li Zhenhui Kang Macao Institute of Materials Science and Engineering(MIMSE) MUST-SUDA Joint Research Center for Advanced Functional MaterialsMacao University of Science and TechnologyTaipaMacao 999078China Institute of Functional Nano and Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-based Functional Materials and DevicesJoint International Research Laboratory of Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhou 215123China Research Center for Carbon-based Electronics and Key Laboratory for the Physics and Chemistry of Nanodevices School of ElectronicsPeking UniversityBeijing 100871China

Chiral catalysis is one of the most direct and effective approach to obtain pure optical *** carbon dots(CDs)as carbon-based chiral catalysts show great potential in chiral ***,we report a facile one step base-catalyzed aldol condensation to fabricate the chiral CDs from glucose at ambient temperature and *** formation of chiral CDs involves the processes of isomerization and aldol *** chiral CDs have been demonstrated that they have selective capacity for electrocatalytic oxidization of tryptophan enantiomers.L type of CDs(LCDs)is more likely to catalyze L-tryptophan(Trp)than D-Trp with the selective factor(I_(L)/I_(D))of 1.60,whereas the D type of CDs(DCDs)tends to catalyze D-Trp(I_(L)/I_(D):0.63).Theoretical calculations combined with various contrast experiments(temperature and pH)demonstrate that the selectively electrocatalytic capacity of chiral CDs toward Trp isomers is due to the different hydrogen-bond interactions between chiral CDs and Trp.

关键词： chiral carbon dots synthesis mechanism electrocatalysis chiral catalysis

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Prediction of sintered density of binary W(Mo)alloys using machine learning

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Rare Metals 2023年第8期42卷 2713-2724页

作者： He-Xiong Liu Yun-Fei Yang Yong-Feng Cai Chang-Hao Wang Chen Lai Yao-Wu Hao Jin-Shu Wang Key Laboratory of Advanced Functional Materials Ministry of EducationFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Department of Materials Science and Engineering University of Texas at ArlingtonArlingtonTX 76019USA

Powder metallurgy is the optimal method for the consolidation and preparation of W(Mo)alloys,which exhibit excellent application prospects at high *** properties of W(Mo)alloys are closely related to the sintered ***,controlling the sintered density and porosity of these alloys is still *** the past,the regulation methods mainly focused on timeconsuming and costly trial-and-error *** this study,the sintering data for more than a dozen W(Mo)alloys constituted a small-scale dataset,including both solid and liquid phases ***,simple descriptors were used to predict the sintered density of W(Mo)alloys based on the descriptor selection strategy and machine learning method(ML),where ML algorithm included the least absolute shrinkage and selection operator(Lasso)regression,k-nearest neighbor(k-NN),random forest(RF),and multi-layer perceptron(MLP).The results showed that the interpretable descriptors extracted by our proposed selection strategy and the MLP neural network achieved a high prediction accuracy(R>0.950).By further predicting the sintered density of W(Mo)alloys using different sintering processes,the error between the predicted and experimental values was less than 0.063,confirming the application potential of the model.

关键词： Sintered density W(Mo)alloy Machine learning(ML) Interpretable descriptors Multi-layer perceptron(MLP)

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In-situ study of the hydrogen peroxide photoproduction in seawater on carbon dot-based metal-free catalyst under operation condition

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Nano Research 2024年第7期17卷 5956-5964页

作者： Jiaxuan Wang Jiacheng Li Zenan Li Jie Wu Honglin Si Yangbo Wu Zhiyong Guo Xuepeng Wang Fan Liao Hui Huang Mingwang Shao Yang Liu Zhenhui Kang Institute of Functional Nano and Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products School of Material Science and Chemical EngineeringNingbo UniversityNingbo 315211China Macao Institute of Materials Science and Engineering(MIMSE) MUST-SUDA Joint Research Center for Advanced Functional MaterialsMacao University of Science and TechnologyTaipa 999078MacaoChina

Hydrogen peroxide(H_(2)O_(2))photoproduction in seawater with metal-free photocatalysts derived from biomass materials is a green,sustainable,and ultra environmentally friendly ***,most photocatalysts are always corroded or poisoned in seawater,resulting in a significantly reduced catalytic ***,we report the metal-free photocatalysts(RUT-1 to RUT-5)with in-situ generated carbon dots(CDs)from biomass materials(Rutin)by a simple microwave-assisted pyrolysis *** visible light(λ≥420 nm,81.6 mW/cm^(2)),the optimized catalyst of RUT-4 is stable and can achieve a high H_(2)O_(2)yield of 330.36μmol/L in seawater,1.78 times higher than that in normal *** transient potential scanning(TPS)tests are developed and operated to in-situ study the H_(2)O_(2)photoproduction of RUT-4 under operation ***-4 has strong oxygen(O_(2))absorption capacity,and the O_(2)reduction rate in seawater is higher than that in *** cations in seawater further promote the photo-charge separation and facilitate the photo-reduction *** RUT-4,the conduction band level under operating conditions only satisfies the requirement of O_(2)reduction but not for hydrogen(H2)*** work provides new insights for the in-situ study of photocatalyst under operation condition,and gives a green and sustainable path for the H_(2)O_(2)photoproduction with metal-free catalysts in seawater.

关键词： carbon dots hydrogen peroxide photocatalysis transient potential scanning in-situ study operation condition

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Tracking Regulatory Mechanism of Trace Fe on Graphene Electromagnetic Wave Absorption

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Nano-Micro Letters 2024年第4期16卷 79-96页

作者： Kaili Zhang Yuhao Liu Yanan Liu Yuefeng Yan Guansheng Ma Bo Zhong Renchao Che Xiaoxiao Huang School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China MIIT Key Laboratory of Advanced Structural‑Functional Integration Materials&Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of Materials Science and Engineering Harbin Institute of Technology at WeihaiWeihai 264209People’s Republic of China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438People’s Republic of China

Polarization and conductance losses are the fundamental dielectric attenuation mechanisms for graphene-based absorbers, but it is not fully understood in revealing the loss mechanism of affect graphene itself. For the first time, the reduced graphene oxide(RGO) based absorbers are developed with regulatory absorption properties and the absorption mechanism of RGO is mainly originated from the carrier injection behavior of trace metal Fe nanosheets on graphene. Accordingly, the minimum reflection loss(RLmin) of Fe/RGO-2composite reaches-53.38 dB(2.45 mm), and the effective absorption bandwidth achieves 7.52 GHz(2.62 mm) with lower filling loading of 2 wt%. Using off-axis electron hologram testing combined with simulation calculation and carrier transport property experiments, we demonstrate here the carrier injection behavior from Fe to graphene at the interface and the induced charge accumulation and rearrangement, resulting in the increased interfacial and dipole polarization and the conductance loss. This work has confirmed that regulating the dielectric property of graphene itself by adding trace metals can not only ensure good impedance matching, but also fully exploit the dielectric loss ability of graphene at low filler content,which opens up an efficient way for designing lightweight absorbers and may be extended to other types materials.

关键词： Reduced graphene oxide Fe nanosheets Dielectric loss Electromagnetic wave absorption

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Highly efficient electrocatalytic nitrogen fixation enabled by the bridging effect of Ru in plasmonic nanoparticles

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Nano Research 2023年第1期16卷 360-370页

作者： Hang Yin Jinwu Hu Caihong Fang Yuyang Wang Lixia Ma Nan Zhang Shouren Zhang Ruibin Jiang Jianfang Wang Shaanxi Key Laboratory for Advanced Energy Devices Shaanxi Engineering Lab for Advanced Energy TechnologySchool of Materials Science and EngineeringShaanxi Normal UniversityXi’an 710119China College of Chemistry and Materials Science The Key Laboratory of Functional Molecular SolidsMinistry of EducationAnhui Laboratory of Molecular-Based MaterialsCenter for Nano Science and TechnologyKey Laboratory of Electrochemical Clean Energy of Anhui Higher Education InstitutesAnhui Normal UniversityWuhu 241000China Henan Provincial Key Laboratory of Nanocomposites and Applications Institute of Nanostructured Functional MaterialsHuanghe Science and Technology CollegeZhengzhou 450006China Department of Physics The Chinese University of Hong KongHong Kong 999077China

Plasmon-generated hot electrons show great potential for driving chemical *** utilization efficiency of hot electrons is highly dependent on the interaction of the electronic states at the interfaces between plasmonic nanoparticles and other materials/*** interaction can produce new hybridized electron states,which permit direct hot-electron transfer,a more efficient transfer ***,Au usually has very weak interaction with most molecules because of its inertness,which makes direct hot-electron transfer ***,the improvement of the hot-electron transfer efficiency from Au to N_(2)is demonstrated by introducing a Ru bridging *** the N_(2)fixation rate and Faradic efficiency(FE)are enhanced by the excitation of *** enhancement of the N_(2)fixation rate is found to arise from plasmon-generated hot *** calculations show that the strong interaction of the Ru electronic states with the N_(2)molecular orbitals produces new hybridized electronic states,and the Ru d electrons also strongly couple with the Au sp *** a bridging role of Ru makes direct hot-electron transfer from Au to N_(2)possible,improving the FE of nitrogen *** findings demonstrate a new approach to increasing the utilization efficiency of plasmonic hot electrons for chemical reactions and will be helpful to the design of plasmonic catalysts in the future.

关键词： electrocatalytic nitrogen fixation Au/Ru electrocatalysts localized surface plasmon resonance electronic state hybridization hot electron

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A novel hybrid design method of lattice structure based on failure mode

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science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 79-91页

作者： Chuanlei Li Junfeng Qi Panding Wang Zeang Zhao Zhe Wang Hongshuai Lei Shengyu Duan Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and Structures Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Beijing Spacecrafts Beijing 100094China

Adjusting the mechanical properties of lattice structures is important for many modern application fields. In this paper, a new design method for hybrid multi-layer lattice structures was developed to improve the mechanical properties and energy absorption, by altering and suppressing the formation of the shear band. In these hybrids, all unit cells were divided into two parts:(i) diagonal unit cells and(ii) matrix unit cells. Four categories of unit cells were selected to construct the hybrid multi-layer structures. The compressive moduli, ultimate strengths, and energy absorption properties of the laser powder bed fusion(L-PBF)fabricated structures were assessed by experiments and finite element analysis(FEA). The results revealed the great impact of diagonal unit cells on the mechanical properties of the structures. Stronger diagonal unit cells than matrix unit cells led to hybrid structures with enhanced mechanical properties. Compared with a uniform body-centered cubic(BCC) lattice structure, the relative density of the lattice structure consisting of the weakest BCC matrix unit cells and strongest BFVC diagonal unit cells(coupling of BCC, FCC, and VC) exhibited an increase of 20%. The compressive modulus and ultimate strength of this structure rose by more than 200% and 90%, respectively. Two types of structures with specific properties were generated by hybrid *** first displayed higher modulus, superior strength, and elevated specific energy absorption(SEA) but lower crash load efficiency(CLE). The second illustrated simultaneously higher SEA and elevated CLE. The present results provide a new insight for improving the load-bearing and energy absorption capacities of lattice structures.

关键词： additive manufacturing lattice structure shear deformation hybrid mechanical properties

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Dimensionality-driven metal to Mott insulator transition in two-dimensional 1T-TaSe2

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National science Review 2024年第3期11卷 108-118页

作者： Ning Tian Zhe Huang Bo Gyu Jang Shuaifei Guo Ya-Jun Yan Jingjing Gao Yijun Yu Jinwoong Hwang Cenyao Tang Meixiao Wang Xuan Luo Yu Ping Sun Zhongkai Liu Dong-Lai Feng Xianhui Chen Sung-Kwan Mo Minjae Kim Young-Woo Son Dawei Shen Wei Ruan Yuanbo Zhang State Key Laboratory of Surface Physics New Cornerstone Science Laboratory and Department of PhysicsFudan University Shanghai Qi Zhi Institute Shanghai Research Center for Quantum Sciences Institute for Nanoelectronic Devices and Quantum Computing Fudan University Zhangjiang Fudan International Innovation Center Fudan University State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology(SIMIT)Chinese Academy of Sciences School of Physical Science and Technology ShanghaiTech University Korea Institute for Advanced Study School of Emerging Technology and Department of Physics University of Science and Technology of China Advanced Light Source Lawrence Berkeley National Laboratory ShanghaiTech Laboratory for Topological Physics Key Laboratory of Materials Physics Institute of Solid State Physics Hefei Institutes of Physical ScienceChinese Academy of Sciences High Magnetic Field Laboratory Hefei Institutes of Physical Science Chinese Academy of Sciences Collaborative Innovation Centre of Advanced Microstructures Nanjing University Department of Physics University of Science and Technology of China and Key Laboratory of Strongly Coupled Quantum Matter Physics Chinese Academy of Sciences National Synchrotron Radiation Laboratory University of Science and Technology of China

Two-dimensional materials represent a major frontier for research into exotic many-body quantum phenomena. In the extreme two-dimensional limit, electron-electron interaction often dominates over other electronic energy scales, leading to strongly correlated effects such as quantum spin liquid and unconventional *** dominance is conventionally attributed to the lack of electron screening in the third dimension. Here, we discover an intriguing metal to Mott insulator transition in 1T-TaSe2that defies conventional wisdom. Specifically, we find that dimensionality crossover, instead of reduced screening, drives the transition in atomically thin 1T-TaSe2. A dispersive band crossing the Fermi level is found to be responsible for the bulk metallicity in the material. Reducing the dimensionality,however, effectively quenches the kinetic energy of these initially itinerant electrons, and drives the material into a Mott insulating *** dimensionality-driven metal to Mott insulator transition resolves the long-standing dichotomy between metallic bulk and insulating surface of 1T-TaSe2. Our work further reveals a new pathway for modulating two-dimensional materials that enables exploring strongly correlated systems across uncharted parameter space.

关键词： two-dimensional materials 1T-TaSe2 dimensionality crossover metal to Mott insulator transition

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Constructing the coherent transition interface structure for enhancing strength and ductility of hexagonal boron nitride nanosheets/Al composites

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Journal of Materials science & technology 2023年第14期145卷 235-248页

作者： Lishi Ma Xiang Zhang Yonghua Duan Siyuan Guo Dongdong Zhao Chunnian He Naiqin Zhao School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional MaterialsTianjin UniversityTianjin 300072China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou 350207China School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China Key Laboratory of Advanced Ceramics and Machining Technology Ministry of EducationTianjin UniversityTianjin 300072China

The deformation incompatibility of components is a bottleneck restricting the exaltation of the strength and ductility of ***,the coherent transition interface was designed and produced in hexagonal boron nitride nanosheets(BNNSs)/Al composites by reaction sintering route,expecting to re-lieve the deformation incompatibility between BNNSs and *** is demonstrated that with the sintering temperature for composites raising from 600℃ to 650℃,700℃ and 750℃,different interface bonding characteristics,which involve nucleation and growth of AlN continuous nanolayer,were ***-thermore,first-principles calculations show that the generation of the coherent transition interface im-proved the interfacial bonding strength of BNNSs/Al composites through covalent *** composites with coherent transition interface exhibit excellent strength-toughness combination in tensile and impact *** finite element simulation and in-situ approach under tensile tests were applied to investigate the influence of transition interface structure on deformation behavior of BNNSs/Al *** is found that the generation of the transition interface can not only weaken the stress partitioning behavior in the elastic stage,but also constrain the crack initiation and propagation behavior in the elastic-plastic stage and plastic stage,thereby improving the deformation compatibility between BNNSs and *** present work provides a novel view into the breakthrough for the trade-offrelationship of strength and ductility by coherent transition interface design in nanocomposites.

关键词： Nanocomposites Al-BNNSs system In-situ interface reaction Coherent transition interface Strength and ductility

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