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Gradient structured nanocrystalline-amorphous Fe-based composite coatings with superior strength and wear resistance 认领 引用
1
作者 Guoliang Ma Hongzhi Cui +4 位作者 Qing Du Xiaojie Song Hao Zhang Hongwei Zhang Hao Chen 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2026年第1期144-155,共12页
Gradient nanocrystalline–amorphous nanostructures are considered to be an effective approach to achieve exceptional strength–plasticity synergy,with significantly improved wear performance.Here,gradient nanostructur... Gradient nanocrystalline–amorphous nanostructures are considered to be an effective approach to achieve exceptional strength–plasticity synergy,with significantly improved wear performance.Here,gradient nanostructured Fe-based coatings were successfully fabricated by extremely high-speed-rate laser deposition and remelting.The microstructure evolution along the depth direction varies in a nanocrystalline,equiaxial dendrites,columnar dendrites gradient,respectively.Noticeably,amorphous grain boundaries and carbide nanoprecipitates could be identified within the topmost surface nanocrystalline layer owing to the extremely high cooling rate during remelting,which exhibits the highest hardness and wear resisance(microhardness of ~1136 HV,and wear rate of 4.36×10−6mm3/(m N)).The superior wear resistance is mainly attributed to the synergistic nanocrystalline–amorphous deformation and gradient refinement effects.Meanwhile,multi-scale carbides effectively impede dislocation motion and further improve strength and wear resistance at different depths.This gradient structure provides promising insights into the design of high-performance wear-resistant alloys. 展开更多
关键词 Gradient nanostructure Nanocrystalline-amorphous structure Extremely high-speed-rate laser remelting Wear resistance
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Structure-controlled piping and flow-like erosion in granite residual soil:critical gradients and conceptual model 认领 引用
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作者 CHEN Yicheng ZHOU Xiaowen +1 位作者 WAN Tian ZHANG Guochun 《Journal of Mountain Science》 SCIE CSCD 2026年第4期1581-1593,共13页
Granite residual soil(GRS)is highly disturbance-sensitive and prone to aggressive seepage,often triggering geohazards and engineering failures.However,previous studies have largely relied on simplified permeability te... Granite residual soil(GRS)is highly disturbance-sensitive and prone to aggressive seepage,often triggering geohazards and engineering failures.However,previous studies have largely relied on simplified permeability tests that decouple hydraulic measurements from deformation processes,leaving seepage-induced failure modes,critical hydraulic thresholds,and structure-controlled mechanisms poorly understood.To address these gaps,we conducted laboratory infiltration–deformation tests on undisturbed(UD)and remoulded(RM)GRS using a modified permeameter that couples hydraulic monitoring with real-time surface observation.UD specimens exhibited piping failure,whereas RM specimens underwent flow-like erosion,revealing fundamentally different failure modes governed by soil structure.The lower critical hydraulic gradient(onset of sustained particle mobilisation,iL)and upper critical hydraulic gradient(bulk failure threshold,iU)were determined as iL≈45,iU≈60 for UD,and iL≈95,iU≈105 for RM,indicating that natural structure reduces critical gradients by approximately half.The hydraulic conductivity-hydraulic gradient(k−i)trajectory provides a robust,less subjective basis for identifying these thresholds,revealing a pre-failure dip(transient clogging),a rebound at iL(sustained mobilisation),and a plateau beyond iU(stable conduit formation).Integrating mineral–chemical evolution,particle-size distribution,seepage behaviour,and eroded-particle spectra,we propose a fabric-controlled conceptual model:key support grains(0.075–0.02 mm)pin critical throats,while kaolinite-rich fines(<0.02 mm)and Fe-oxide cements bridge contacts.Under upward seepage,cement dispersion and key-grain mobilisation promote channelisation and piping in UD,whereas the homogenised fabric in RM delays channelisation and favours flow-like erosion.These findings advance the mechanistic understanding of structure-dependent seepage failures and offer practical guidance for GRS-bearing excavations and embankments,including limiting the hydraulic head difference relative to seepage path length(Δh/L)below iLand employing continuous hydraulic conductivity monitoring as an early-warning indicator for imminent piping. 展开更多
关键词 Granite residual soil Piping erosion Critical hydraulic gradient Soil structure Seepageinduced failure Conceptual model
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Reconstruction of bridge‑sensor data and detection of structural damage based on gradient‑coupled autoencoder and fully connected network 认领 引用
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作者 DUAN Yuanfeng DING Pengyao +1 位作者 DUAN Zhengteng CHENG J.J.Roger 《Journal of Southeast University(English Edition)》 EI CAS 2026年第1期1-11,共11页
A dual‑task parallel machine learning framework was developed by integrating a convolutional autoencoder(CAE)and a fully connected neural network(FCNN)via the gradient‑coupled mechanism,enabling simultaneous data comp... A dual‑task parallel machine learning framework was developed by integrating a convolutional autoencoder(CAE)and a fully connected neural network(FCNN)via the gradient‑coupled mechanism,enabling simultaneous data compression‑reconstruction and structural damage identification.Under the condition where 40% of the sensor nodes are missing,the model successfully reconstructs the full sensor network with an R2 of 0.916 and normalized root mean square error(NRMSE)of 0.0288.Even under significant noise contamination with an SNR of 12 dB,the model maintains strong reconstruction performance,achieving a R2 of 0.910 and NRMSE of 0.0253.Forty‑six structural damage scenarios were simulated using the scaled bridge model.The accuracy of spatial localization and quantification of the damage severity using the framework exceeds 99.3%.The proposed framework reduces the training time by 54.4%and iteration counts by 45.5% compared to conventional two‑stage machine learning approaches,demonstrating the efficiency of gradient‑coupled optimization. 展开更多
关键词 structural health monitoring machine learning data compression damage identification convolutional neural network fully connected neural network gradient‑coupled mechanism
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Mechanical Properties of Star-Shaped Gradient Lattice Structures Under Tensile Load 认领 引用
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作者 Hongyan Chen Xiufang Zhu +1 位作者 Shuxiang Ma Haiyang Yang 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2025年第1期65-77,共13页
Star-shaped lattice structures with a negative Poisson’s ratio(NPR)effect exhibit excellent energy absorption capacity,making them highly promising for applications in aerospace,vehicles,and civil protection.While pr... Star-shaped lattice structures with a negative Poisson’s ratio(NPR)effect exhibit excellent energy absorption capacity,making them highly promising for applications in aerospace,vehicles,and civil protection.While previous research has primarily focused on single-walled cells,there is limited investigation into negative Poisson’s ratio structures with nested multi-walled cells.This study designed three star-shaped cell structures and three lattice configurations,analyzing the Poisson’s ratio,stress–strain relationship,and energy absorption capacity through tensile experiments and finite element simulations.Among the single structures,the star-shaped configuration r3 demonstrated the best elastic modulus,NPR effect,and energy absorption effect.In contrast,the uniform lattice structure R3 exhibited the highest tensile strength and energy absorption capacity.Additionally,the stress intensity and energy absorption of gradient structures increased with the number of layers.This study aims to provide a theoretical reference for the application of NPR materials in safety protection across civil and vehicle engineering,as well as other fields. 展开更多
关键词 Negative Poisson's ratio Gradient lattice structure Quasi-static stretching Energy absorption
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Multifunctional CNT/cellulose-BN/PVA Composites Integrating Dual-continuous Network Structure with Gradient Conductivity for Electromagnetic Interference Shielding and Joule Heating 认领 引用
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作者 Xiao-Rui Wang Ting-Ting Liu +2 位作者 Cheng-Hua Cui Xin Xu Liang-Qing Zhang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2026年第3期803-812,I0015,共10页
In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(... In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(CNT/cellulose-BN/PVA)composite.Using cellulose aerogel as a template,CNT were incorporated into the cellulose template by vertically impregnating the CNT suspension.Following the impregnation of BN/PVA and high-pressure compression,three-dimensional dual-continuous network structure was successfully constructed in the CNT/cellulose-BN/PVA composite.The comprehensive performance of the composite,including electromagnetic interference(EMI)shielding and Joule heating performance,was investigated.The results indicate that the total EMI shielding effectiveness(SE)for the CNT/cellulose-BN/PVA composite reveals similar values for electromagnetic waves incident from different directions,but totally different shielding mechanisms.For the CNT/cellulose-BN/PVA composite with three impregnation cycles of CNT,the EMI SE values exceeded 39 dB for electromagnetic waves incident from both the high-and low-CNT-content sides.93%of the microwaves were reflected when electromagnetic waves were incident from the high-CNT-content side,while the reflection coefficient decreased to 0.44 for the transverse direction.In addition,the construction of the dual-continuous network structure enabled the composite to exhibit both excellent electrical conductivity and good thermal conductivity simultaneously,endowing the material with good Joule heating performance.CNT/cellulose-BN/PVA composite films have significant potential for application as EMI shielding materials in extremely cold weather. 展开更多
关键词 Cellulose Dual-continuous network structure Gradient conductivity Electromagnetic interference shielding Joule heating
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Tuning the Structure and Properties of Poly(ethylene terephthalate)/Poly(butylene terephthalate)Blend Monofilaments:Mechanism of Transesterification and Gradient Structure Development 认领 引用
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作者 Zhog-Li Zhang Bo-Hao Li +4 位作者 Jia-Ke Fan Kang Chen Yi-Ning Hao Xin-Yu Liu Xian-Ming Zhang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2026年第8期2775-2786,I0021,共12页
To address the limited toughness of poly(ethylene terephthalate)(PET)monofilaments arising from the inherent molecular chain rigidity,this study prepared PET/poly(butylene terephthalate)(PBT)blend monofilaments via th... To address the limited toughness of poly(ethylene terephthalate)(PET)monofilaments arising from the inherent molecular chain rigidity,this study prepared PET/poly(butylene terephthalate)(PBT)blend monofilaments via the melt-blend spinning method to enhance their toughness.The influence of PBT content on the structural evolution and properties of the blend system was systematically investigated.These results indicate that the PBT content significantly influences the extent of transesterification and compatibility,thereby dictating the mechanical behavior of the monofilaments.At a low PBT content of 2 wt%,transesterification was negligible.The monofilaments exhibited a uniform radial gradient orientation without a distinct skin-core structure,demonstrating optimal overall mechanical performance with markedly improved strength.Specifically,the tensile,loop,and knot strengths were 611,421,and 443 MPa,respectively.When the PBT content exceeded 5 wt%,the flexible chain segments of PBT enhanced the molecular chain mobility in the blend chips,leading to an increase in crystallite size.However,intensified transesterification concurrently reduces the crystallizability and degrades the mechanical properties.At PBT contents above 15 wt%,SEM analysis revealed phase separation and pronounced heterogeneity in the radial gradient structure of the blend monofilaments,resulting in a significant deterioration of the mechanical properties.This study elucidates the pivotal role of blending ratio in governing the“composition-structure-property”relationship of PET/PBT-blended monofilaments,revealing the underlying mechanism of transesterification and gradient structure development.These findings provide a theoretical foundation for the design of high-performance PET monofilaments. 展开更多
关键词 Poly(ethylene terephthalate)monofilament Gradient structure Melt-blend spinning
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Corrosion risk assessment of chloride-contaminated concrete structures using embeddable multi-cell sensor system 认领 引用 被引量：2
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作者 卢爽 巴恒静 《Journal of Central South University》 SCIE EI CAS 2011年第1期230-237,共8页
Monitoring the service condition of concrete structures requires the quantitative assessment of properties and corrosion rate of structural steels surrounded by concrete.A multi-cell sensor system that included a refe... Monitoring the service condition of concrete structures requires the quantitative assessment of properties and corrosion rate of structural steels surrounded by concrete.A multi-cell sensor system that included a reference electrode,a chloride content sensor,a macrocell current unit and an electrical resistance measurement unit was developed.This system provided the following important electrochemical data in the cover-zone concrete on site:open circuit potential,macrocell current from anodes to cathode,chloride profile,concrete resistance and corrosion rate of built-in anodes.The experimental results show that the macrocell current increases when the chloride content in concrete is higher.Thus,monitoring the chloride content is a good method for monitoring the corrosion state.The chloride ion content and cover depth are the key factors that affect the electrical resistance of concrete.Without considering the temperature and time,a simplified model of the instantaneous corrosion rate of steel rebar in a concrete structure based on the measured chloride contents and concrete resistance was proposed.The test results further prove the reliability of this simplified predicting model. 展开更多
关键词 concrete structures corrosion rate resistance chloride content macrocell current multi-cell sensor
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Design and Impact Resistance Analysis of Ex-press Cushioning Materials Based on Biomimetic Gradient Structure 认领 引用
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作者 Zixuan Xia 《Journal of Electronic Research and Application》 2026年第7期1-12,共12页
With the rapid development of the logistics industry, the contradiction between green packaging and cargo safety has become increasingly prominent. Inspired by the lightweight, high-strength, and graded energy-absorbi... With the rapid development of the logistics industry, the contradiction between green packaging and cargo safety has become increasingly prominent. Inspired by the lightweight, high-strength, and graded energy-absorbing microstructure of pomelo peel, this study proposes a novel biomimetic gradient porous cushioning structure. Using the ANSYS Explicit Dynamics module under a constant velocity crushing condition of 4.4 m/s, the impact resistance of three topologies, namely uniform circular holes (U-C), gradient circular holes (G-C), and gradient square holes (G-S), is compared. The simulation results indicate that, compared with the conventional uniform structure, the biomimetic gradient design successfully induces a controllable deformation mode characterized by layer-by-layer collapse, effectively reducing the initial impact peak. Among the three structures, G-C exhibits the best overall performance. Its peak contact reaction force is reduced by 16.2% compared with that of the uniform structure, and it avoids the mechanical instability due to stress concentration that occurs in the square-hole structure. Cross-checking the three simulation reports further indicates that the foam masses of the three models are all about 8.76g with only negligible differences. Therefore, the advantage of G-C should be interpreted as better overall cushioning performance under nearly equal-mass conditions, rather than as a direct proof of significantly reduced mass or the highest specific energy absorption. The study demonstrates that the biomimetic gradient circular hole structure has clear potential for impact protection, structural stability, and engineering feasibility in express packaging design. 展开更多
关键词 Biomimetic design Gradient structure Impact resistance Finite element analysis Lightweight
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Compressive mechanical properties and shape memory effect of NiTi gradient lattice structures fabricated by laser powder bed fusion 认领 引用 被引量：21
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作者 Wei Chen Dongdong Gu +3 位作者 Jiankai Yang Qin Yang Jie Chen Xianfeng Shen 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2022年第4期189-205,共17页
Laser additive manufacturing (AM) of lattice structures with light weight, excellent impact resistance, and energy absorption performance is receiving considerable attention in aerospace, transportation, and mechanica... Laser additive manufacturing (AM) of lattice structures with light weight, excellent impact resistance, and energy absorption performance is receiving considerable attention in aerospace, transportation, and mechanical equipment application fields. In this study, we designed four gradient lattice structures (GLSs) using the topology optimization method, including the unidirectional GLS, the bi-directional increasing GLS, the bi-directional decreasing GLS and the none-GLS. All GLSs were manufactureed by laser powder bed fusion (LPBF). The uniaxial compression tests and finite element analysis were conducted to investigate the influence of gradient distribution features on deformation modes and energy absorption performance of GLSs. The results showed that, compared with the 45° shear fracture characteristic of the none-GLS, the unidirectional GLS, the bi-directional increasing GLS and the bi-directional decreasing GLS had the characteristics of the layer-by-layer fracture, showing considerably improved energy absorption capacity. The bi-directional increasing GLS showed a unique combination of shear fracture and layer-by-layer fracture, having the optimal energy absorption performance with energy absorption and specific energy absorption of 235.6 J and 9.5 J g-1 at 0.5 strain, respectively. Combined with the shape memory effect of NiTi alloy, multiple compression-heat recovery experiments were carried out to verify the shape memory function of LPBF-processed NiTi GLSs. These findings have potential value for the future design of GLSs and the realization of shape memory function of NiTi components through laser AM. 展开更多
关键词 additive manufacturing laser powder bed fusion gradient lattice structures deformation behavior shape memory effect
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Effects of gradient structure on the microstructures and properties of coated cemented carbides 认领 引用 被引量：24
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作者 Li Chen Enxi Wu +1 位作者 Fei Yin Jia Li 《Journal of University of Science and Technology Beijing》 2006年第4期363-367,共5页
The effects of gradient structure on the microstructure and properties of coated cemented carbides were researched with optical microscopy （OM）, scanning electron microscopy （SEM）, strength measurements, and cutti... The effects of gradient structure on the microstructure and properties of coated cemented carbides were researched with optical microscopy （OM）, scanning electron microscopy （SEM）, strength measurements, and cutting tests. It shows that vacuum sintering of WC-Ti（C, N）-TaC-Co cemented carbides results in the formation of a surface ductile zone. The ductile zone prevents crack propagation and leads to the increase of transverse rupture strength of the substrate. The impact resistance of coated gradient inserts was obviously improved on the basis of maintaining resistance to abrasion and the forming mechanism of the gradient structure was also analyzed. 展开更多
关键词 cemented carbide chemical vapor deposition （CVD） coating gradient structure
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Unveiling the Deformation Mechanism of High-Strength Low-Alloy Structural Steel with Gradient Dislocation-Cell Structure 认领 引用
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作者 Jing Han Yumin Zhang +4 位作者 Zheng Zhang Chao Cao Di Huang Jiapeng Sun Jiyun Zhao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2025年第2期183-192,共10页
There is a pressing need for high-performance,high-strength low-alloy structural(HSLA)steels in various engineering fields,such as hydraulic components,engineering machinery,bridges,ships,and pressure vessels.In this ... There is a pressing need for high-performance,high-strength low-alloy structural(HSLA)steels in various engineering fields,such as hydraulic components,engineering machinery,bridges,ships,and pressure vessels.In this study,a gradient dislocation-cell structure is introduced into an HSLA steel through ultrasonic severe surface rolling.The cell size is approximately 614 nm at the topmost surface layer,and increases with increasing the depth.Most of the cell walls have a misorientation ranging from 2°to 15°,indicating they belong to low angle grain boundaries(LAGBs),while some cell walls have a misorientation of less than 2°,corresponding to dense dislocation walls(DDWs).This unique gradient structure offers an exceptional combination of strength and ductility,with a high yield strength of 522.3±1.4 MPa and an accepted elongation of 25.5±1.7%.The morphology and size of the dislocation cells remain remarkably stable after uniaxial tension,demonstrating their efficacy as effective barriers hindering dislocation movement and thus enhancing strength and hardness.This gradient dislocation-cell structure facilitates inhomogeneous plastic deformation during uniaxial tensile loading,resulting in a pronounced accumulation of geometrically necessary dislocations(GNDs).These GNDs play a significant role in conferring favorable mechanical properties by inducing hetero-deformation-induced(HDI)strengthening effects and forest hardening effects.This study presents a promising avenue for achieving the desired mechanical properties in HSLA steel. 展开更多
关键词 Steel Deformation mechanism Dislocation cell Gradient structure Microstructure
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Compressive properties and energy absorption of BCC lattice structures with bio-inspired gradient design 认领 引用 被引量：13
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作者 Fuchao Gao Qinglei Zeng +2 位作者 Jing Wang Zengfei Liu Jun Liang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2022年第1期110-122,共13页
Inspired by the gradient structure of the nature,two gradient lattice structures,i.e.,unidirectional gradient lattice(UGL)and bidirectional gradient lattice(BGL),are proposed based on the body-centered cubic(BCC)latti... Inspired by the gradient structure of the nature,two gradient lattice structures,i.e.,unidirectional gradient lattice(UGL)and bidirectional gradient lattice(BGL),are proposed based on the body-centered cubic(BCC)lattice to obtain specially designed mechanical behaviors,such as load-bearing and energy absorption capacities.First,a theoretical model is proposed to predict the initial stiffness of the gradient lattice structure under compressive loading,and validated against quasi-static compression tests and finite element models(FEMs).The deformation and failure mechanisms of the two structures are further studied based on experiments and simulations.The UGL structure exhibits a layer-by-layer failure mode,which avoids structure-wise shear failure in uniform structures.The BGL structure presents a symmetry deformation pattern,and the failure initiates at the weakest part.Finally,the energy absorption behaviors are also discussed.This study demonstrates the potential application of gradient lattice structures in load-transfer-path modification and energy absorption by topology design. 展开更多
关键词 Gradient lattice structure Quasi-static compression test Mechanical performance Finite element analysis Energy absorption
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Advances of machining techniques for gradient structures in multi-principal-element alloys 认领 引用 被引量：9
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作者 Bo Li Chun-Ming Niu +5 位作者 Tian-Long Zhang Gong-Yu Chen Gang Zhang Dong Wang Xiao-Ye Zhou Jia-Ming Zhu 《Rare Metals》 SCIE EI CAS CSCD 2022年第12期4015-4026,共12页
Multi-principal-element alloys(MPEAs)are attracting increasing attentions because of their high strength and ductility,high fracture toughness,excellent corrosion resistance,outstanding thermal-softening resistance an... Multi-principal-element alloys(MPEAs)are attracting increasing attentions because of their high strength and ductility,high fracture toughness,excellent corrosion resistance,outstanding thermal-softening resistance and high oxidation resistance.Moreover,gradient structures(GSs)have been shown to be effective in alleviating the strength-ductility trade-off although strength and ductility are mutually exclusive properties for metals,which provides an opportunity for developing highperformance MPEAs.Here,we summarized four processing methods for creating GSs in MPEAs,including rotationally accelerated shot peening(RASP),ultra-precision machining technology(UPMT),cyclic dynamic torsion(CDT),and ultrasonic surface rolling processing(USRP).Principles,advantages,disadvantages,and typical applications of these methods are discussed in this work. 展开更多
关键词 Gradient structures(GSs) Multi-principalelement alloys(MPEAs) Strength-ductility trade-off Advanced processing technology
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Achieving ultrahigh strength and ductility in a Co-Cr-Ni multi-principal element alloy through gradient grain and nanoprecipitate structure 认领 引用
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作者 Lu Yang Chengxia Wei +5 位作者 Feilong Jiang Dingshan Liang Qiming Zhuang Jiasi Luo Kangjie Chu Fuzeng Ren 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2025年第33期262-269,共8页
Achieving high yield strength and ductility in alloys remains a significant challenge in structural materials.In this study,combined nanoprecipitation and gradient grain structure were introduced into a Co-Cr-Ni-based... Achieving high yield strength and ductility in alloys remains a significant challenge in structural materials.In this study,combined nanoprecipitation and gradient grain structure were introduced into a Co-Cr-Ni-based multi-principal element alloy(MPEA)using surface mechanical attrition treatment(SMAT).The multi-scale composite structure,featuring grain sizes refined from∼43.6μm to∼24.3 nm at the topmost surface and high-density L12nanoprecipitates within the grains,results in a substantial tensile strength of 1733 MPa and a well-maintained ductility of∼23%.The alloy with low local stacking fault energy provides sufficient flow stress to reach the critical value for twinning,a phenomenon rarely observed in MPEAs with high-density L12nanoprecipitates under quasi-static tensile conditions.The formation of nanotwins further facilitates additional strain hardening,enhancing mechanical performance at ultrahigh strength levels.This work offers significant insights into the deformation behavior of gradient-structured materials with high-density nanoprecipitates. 展开更多
关键词 Multi-principal element alloy L12 nanoprecipitate Gradient grain structure Deformation nanotwinning
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Designing Symmetric Gradient Honeycomb Structures with Carbon‑Coated Iron‑Based Composites for High‑Efficiency Microwave Absorption 认领 引用 被引量：20
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作者 Yu Zhang Shu‑Hao Yang +9 位作者 Yue Xin Bo Cai Peng‑Fei Hu Hai‑Yang Dai Chen‑Ming Liang Yun‑Tong Meng Ji‑Hao Su Xiao‑Juan Zhang Min Lu Guang‑Sheng Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期224-241,共18页
The impedance matching of absorbers is a vital factor affecting their microwave absorption(MA)properties.In this work,we controllably synthesized Material of Institute Lavoisier 88C(MIL-88C)with varying aspect ratios(... The impedance matching of absorbers is a vital factor affecting their microwave absorption(MA)properties.In this work,we controllably synthesized Material of Institute Lavoisier 88C(MIL-88C)with varying aspect ratios(AR)as a precursor by regulating oil bath conditions,followed by one-step thermal decomposition to obtain carbon-coated iron-based composites.Modifying the precursor MIL-88C(Fe)preparation conditions,such as the molar ratio between metal ions and organic ligands(M/O),oil bath temperature,and oil bath time,influenced the phases,graphitization degree,and AR of the derivatives,enabling low filler loading,achieving well-matched impedance,and ensuring outstanding MA properties.The MOF-derivatives 2(MD2)/polyvinylidene Difluoride(PVDF),MD3/PVDF,and MD4/PVDF absorbers all exhibited excellent MA properties with optimal filler loadings below 20 wt%and as low as 5 wt%.The MD2/PVDF(5 wt%)achieved a maximum effective absorption bandwidth(EAB)of 5.52 GHz(1.90 mm).The MD3/PVDF(10 wt%)possessed a minimum reflection loss(RLmin)value of−67.4 at 12.56 GHz(2.13 mm).A symmetric gradient honeycomb structure(SGHS)was constructed utilizing the high-frequency structure simulator(HFSS)to further extend the EAB,achieving an EAB of 14.6 GHz and a RLmin of−59.0 dB.This research offers a viable inspiration to creating structures or materials with high-efficiency MA properties. 展开更多
关键词 MIL-88C(Fe) Fe/Fe3O4/Fe3C@C Controllable preparation Symmetric gradient honeycomb structure Microwave absorbing
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Superior dynamic shear properties by structures with dual gradients in medium entropy alloys 认领 引用 被引量：1
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作者 Shuang Qin Muxin Yang +4 位作者 Ping Jiang Jian Wang Xiaolei Wu Hao Zhou Fuping Yuan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第22期166-180,共15页
Structures with single gradient and dual gradients have been designed and fabricated in an Al0.5Cr0.9FeNi2.5V0.2 medium entropy alloy.Structures with dual gradients(with increasing grain size and a decreas... Structures with single gradient and dual gradients have been designed and fabricated in an Al0.5Cr0.9FeNi2.5V0.2 medium entropy alloy.Structures with dual gradients(with increasing grain size and a decreasing volume fraction of nanoprecipitates from the surface to the center)were observed to show much better dynamic shear properties compared to both structures with single grainsize gradient and coarse-grained structures with homogeneously distributed nanoprecipitates.Thus,the dual gradients have a synergetic strengtheningoughening effect as compared to the sole effect of a single gradient and the sole precipitation effect.Initiation of the adiabatic shear band(ASB)is delayed and propagation of ASB is slowed down in structures with dual gradients compared to structures with single gradients,resulting in better dynamic shear properties.A higher magnitude of strain gradient and higher density of geometrically necessary dislocations are induced in the structures with dual gradients,resulting in extra strain hardening.Higher density dislocations,stacking faults,and Lomer-Cottrell locks can be accumulated by the interactions between these defects and B2/L12 precipitates,due to the higher volume fraction of nanoprecipitates in the surface layer of the structures with dual gradients,which could retard the early strain localization in the surface layer for better dynamic shear properties. 展开更多
关键词 Medium-entropy alloys Gradient structures Precipitates Strain hardening Dynamic properties Adiabatic shear band
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Transient thermal shock induced radial gradient Cu+ -Ov-Ce3+/Ce4+boosted CO2 electroreduction to C2 products 认领 引用
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作者 Mingwang Wang Xiang Fei +2 位作者 Hui Ning Han Hu Mingbo Wu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2026年第3期639-645,共7页
Electrocatalytic CO2 reduction(CO2 RR)toward multi-carbon compounds is a challenging but meaningful route for carbon cycling.Copper-based catalysts are the most promising candidate for C2+generation due to th... Electrocatalytic CO2 reduction(CO2 RR)toward multi-carbon compounds is a challenging but meaningful route for carbon cycling.Copper-based catalysts are the most promising candidate for C2+generation due to their unique C–C coupling activity,yet the in situ reduction from Cu+ to Cu0 under cathodic potentials causes the catalyst deactivation.Herein,we develop a transient thermal shock strategy to embed Cu+ species into CeO2 lattices,constructing a CuOx/CuCeOxcatalyst with a radial gradient Cu+ -Ov-Ce3+/Ce4+structure.Depth-profiling X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT)calculations reveal that mismatched metal/oxygen diffusion kinetics drive continuous electron transfer from surface Cu+ to bulk Ce3+/Ce4+via oxygen vacancies(Ov),forming a dynamic“self-sacrificial”structure to preserve surface Cu+ states.In CO2-saturated 0.1 M KHCO3,the optimized CuOx/CuCeOx-10 achieves a high C2 Faradaic efficiency(FE)of 85.8%at-1.4 V vs.RHE.In situ attenuated total reflection surface-enhanced infrared adsorption spectroscopy(ATR-SEIRAS)identifies the key intermediates of C2 are*OCCO and*OCCOH,while DFT reveals a drastic reduction of C–C coupling barrier from 0.842 to0.274 eV.This work demonstrates kinetically tailored metal-support interactions,enabling oxidationstate control for pathway-selective catalysis. 展开更多
关键词 Carbon dioxide Metal-support interactions Gradient structure
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Evolutionary Characteristics of Linear Free-radical Polymerization Behavior under Gradient Condition 认领 引用
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作者 Hui Li Bing-Bing Pan +4 位作者 Yi-Yi Zhang Wen Li Zi-Jian Xue Zhen-Bin Chen Hong Liu 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2026年第8期2691-2703,I0018,共13页
This study investigates the evolution of free-radical polymerization under spatially graded conditions by constructing a position-dependent reaction probability model.Given the strong temperature dependence of thermal... This study investigates the evolution of free-radical polymerization under spatially graded conditions by constructing a position-dependent reaction probability model.Given the strong temperature dependence of thermal initiators,spatial temperature variations significantly affect both local monomer reactivity and the macroscopic evolution of polymer structures.Understanding this coupling is crucial for designing gradient-controlled synthesis strategies.The dissipative particle dynamics(DPD)method was employed to investigate free radical polymerization under gradient temperature conditions.IncreasingΔT enhances spatial heterogeneity:high-temperature regions form dense networks with lower molecular weights(Mn and Mw)due to rapid initiation and frequent termination.In contrast,low-temperature regions yield higher molecular weights and expanded chain conformations()resulting from longer radical lifetimes.These structural differences further govern pore evolution:porosity decreases rapidly and reaches lower final values in high-temperature zones,while low-temperature regions exhibit delayed evolution but higher final porosity.This study demonstrates that the precise control of polymer growth orientation,molecular weight distribution,and porous morphology can be achieved by incorporating gradient conditions,thereby establishing a new paradigm for the targeted synthesis of gradient functional materials. 展开更多
关键词 Free radical polymerization Gradient structure Dissipative particle dynamics Polymerization kinetics
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An inverse opal structure-based human alveolar lung-on-a-chip for the study of Osimertinib treatment in non-small cell lung cancer 认领 引用
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作者 Weifei Zhang Danfeng Xu +5 位作者 Jinru Tian Ying Kan Xuanlin Feng Jia Liu Hongmei Li Nan Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2026年第4期683-687,共5页
The deficiency of reliable and physiologically relevant distal lung models has been regarded as a crucial issue for drug research on non small cell lung cancer(NSCLC).In this study,an inverse opal structure-based lung... The deficiency of reliable and physiologically relevant distal lung models has been regarded as a crucial issue for drug research on non small cell lung cancer(NSCLC).In this study,an inverse opal structure-based lung-on-a-chip was established to replicate the geometric dimensions and topography of the native lung alveoli,and two lateral microchambers were designed to induce pressure-driven stretching for the simulation of respiratory movement.Further,a concentration gradient generator was applied to connect with lung-on-a-chip for the creation of different enzyme environments to mimic the individual variability of P450s enzymes in lung patients.Based on this microfluidic platform,the Osimertinib implications in NSLC was investigated from the aspect of metabolism and adapted resistance.The results suggested that Osimertinib exhibited discernible difference in metabolism under diverse enzyme condition.Additionally,in contrast with the control group,all groups with Osimertinib treatment triggered the alterations of amino acid metabolisms and energy supply,indicating that targeting energy supply process might be an effective measure to prevent tumor cells from generating drug resistance. 展开更多
关键词 Lung-on-a-chip Inverse opal structure Concentration gradient generator Osimertinib metabolism Adapted resistance Amino acid metabolism
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Tailoring layer-by-layer gradient porous ultra-thick electrodes via solvent-free processing method for high-areal-capacity and high-rate lithium-ion batteries 认领 引用
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作者 Haotian Yang Jinke Shen +9 位作者 Nan Qin Yaoxin Du Yuhan An Chen Hu Yifan Li Wenlong Cai Cunman Zhang Zonghai Chen Jim P.Zheng Liming Jin 《Chinese Chemical Letters》 SCIE CAS CSCD 2026年第7期634-639,共6页
Ultra-thick electrodes(UTEs)hold great promise for high-energy-density lithium-ion batteries(LIBs),yet the practical application is hindered by challenges in precise fabrication and reaction kinetics modification.In t... Ultra-thick electrodes(UTEs)hold great promise for high-energy-density lithium-ion batteries(LIBs),yet the practical application is hindered by challenges in precise fabrication and reaction kinetics modification.In this contribution,a solvent-free processing method is introduced to tailor UTEs through layerby-layer fabrication with positive,uniform,and negative gradient porosity from the separator side to the current collector side,denoted as P-UTEs,U-UTEs,and N-UTEs.In contrast to conventional slurry coating,the proposed solvent-free approach effectively circumvents capillary stress,thereby facilitating the fabrication of crack-free UTEs(>300μm)while simultaneously mitigating environmental toxicity concerns.The three-layer N-UTEs(>220μm)with a gradient porosity of(~34%,~31%,~27%)deliver an exceeding areal capacity over 5 m Ah/cm2 at 0.29 mA/cm2 and a high-capacity retention over 62% at 2.9 m A/cm2,indicating a favorable balance between the areal capacity and the high-rate behavior.Detailed mechanistic simulations reveal that the multi-center reaction pathways enabled by enhanced ionic accessibility in N-UTEs significantly improve reaction kinetics.This work offers new insights into the gradient porosity tailoring for high-areal-capacity and high-rate UTEs for the next generation LIBs. 展开更多
关键词 Gradient porous structure Electrode kinetics Ultra-thick electrodes Solvent-free processing method Lithium-ion battery
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