Owing to their good biocompatibility,polysaccharide hydrogels have broad application prospects in the field of flexible strain sensors.However,there are still significant challenges in the preparation of polysaccharid...Owing to their good biocompatibility,polysaccharide hydrogels have broad application prospects in the field of flexible strain sensors.However,there are still significant challenges in the preparation of polysaccharide hydrogels with good mechanical properties.MCA-Li Cl hydrogels were prepared by introducing methacrylated hyaluronic acid(Me HA)into the polymer network in the presence of acrylic acid(AA),acryloyloxyethyltrimethyl ammonium chloride(CATAC),and metal ions.The polymer network not only has a chemically cross-linked network and a tough network structure,but also benefits from a variety of supramolecular interactions,such as hydrogen bonding and coordination covalent bonding,resulting in excellent mechanical properties,with an elongation at break of 1390%,a tensile strength of up to 1200 k Pa,a toughness of 9.4546 MJ/m^(3),and adhesive properties towards various substrates.At the same time,the hydrogel has a high conductivity(5.33 mS/cm)and high strain-sensing sensitivity(Gauge factor=2.55).The flexible strain sensor assembled from the prepared MCA-Li Cl hydrogel can be used to detect human movements,from micro-expressions(smiles,swallowing)to pulse signals and other physiological activities,as well as large-scale joint movements(wrists,elbows,knees,fingers,etc.),realizing the real-time monitoring of full-scale human movements.The prepared hydrogels have potential applications in wearable devices,electronic skin,and strain-sensor components.展开更多
Single-crystal GaN epilayers were irradiated with heavy inert gas ions(2.3-MeV Ne^(8+),5.3-MeV Kr^(19+))to fluences ranging from 1.0×1.0^(11) to 1.0×1.0^(15)ions∕cm^(2).The strain-related damage accumulatio...Single-crystal GaN epilayers were irradiated with heavy inert gas ions(2.3-MeV Ne^(8+),5.3-MeV Kr^(19+))to fluences ranging from 1.0×1.0^(11) to 1.0×1.0^(15)ions∕cm^(2).The strain-related damage accumulation versus ion fluences was studied using highresolution X-ray diffraction(HRXRD)and ultraviolet–visible(UV–Vis)spectroscopy.The results showed that the damage accumulation was mainly dominated by nuclear energy loss.When the ion fluence was less than∼0.055 displacement per atom(dpa),the lattice expansions and lattice strains markedly increased linearly with increasing ion fluences,accompanied by a slow enhancement in the dislocation densities,distortion parameters,and Urbach energy for both ion irradiations.Above this fluence(∼0.055 dpa),the lattice strains presented a slight increase,whereas a remarkable increase was observed in the dislocation densities,distortion parameters,and Urbach energy with the ion fluences after both ion irradiations.∼0.055 dpa is the threshold ion fluence for defect evolution and lattice damage related to strain.The mechanisms underlying the damage accumulation are discussed in detail.展开更多
Granular materials exhibit complex macroscopic mechanical behaviors closely related to their microscalemicrostructural features.Traditional macroscopic phenomenological elasto-plastic models,however,usually have compl...Granular materials exhibit complex macroscopic mechanical behaviors closely related to their microscalemicrostructural features.Traditional macroscopic phenomenological elasto-plastic models,however,usually have complex formulations and lack explicit relations to these microstructural features.To avoid these limitations,this study proposes a micromechanics-based softening hyperelastic model for granular materials,integrating softening hyperelasticity withmicrostructural insights to capture strain softening,critical state,and strain localization behaviors.The model has two key advantages:(1)a clear conceptualization,straightforward formulation,and ease of numerical implementation(via Abaqus UMAT subroutine in this study);(2)explicit incorporation of micro-scale features(e.g.,contact stiffness,particle size,porosity)to reveal their influences on macroscopic responses.An isotropic directional distribution density of contacts and three specific microstructures are considered,and their softening hyperelastic constitutive modulus tensors are explicitly derived.By introducing a softening factor and critical failure energy density,the model can describe geomaterial behaviors,simulating residual strength,X-shaped shear bands,and strain localization evolution.Numerical validations in comparison with themacro-scale hyperelastic model,Abaqus Drucker-Prager model,and the experiment confirm its accuracy.Parametric studies reveal critical dependencies:a normal to tangential contact stiffness ratio of 2-8(depending on stiffness magnitude),an internal length of 2-4 mm to ensure shear band formation,and a critical failure energy density(≤10 kJ/m^(3))to trigger strain softening and localization.Influences of the specific microstructures on strain localization and softening are investigated.The model also shows mesh independence due to the introduction of an internal length.The model’s applicability is further demonstrated by slope stability analysis,capturing slip surface evolution,and load-displacement characteristics.This study develops a robust microstructure-aware hyperelastic framework to describe the mechanical behaviors of granular materials,providing multiscale insights for geotechnical engineering applications.展开更多
Large magnetic entropy change(△S_(M))can realize a prominent heat transformation under the magnetic field and directly strengthen the efficacy of the magnetocaloric effect,which provides a pioneering environmentally ...Large magnetic entropy change(△S_(M))can realize a prominent heat transformation under the magnetic field and directly strengthen the efficacy of the magnetocaloric effect,which provides a pioneering environmentally friendly solidstate strategy to improve refrigeration capacities and efficiencies.The second-order magnetic transition(SOMT)materials have broader△S_(M) peaks without thermal hysteresis,making them highly attractive in magnetic refrigeration,especially in the room temperature range.Here,we report a significant enhancement of△S_(M) at room temperature in single-crystal Mn_(5)Ge_(3).In this SOMT system,we realize a 60%improvement of-△S_(M)^(max) from 3.5 J/kg·K to 5.6 J/kg·K at T=300 K.This considerable enhancement of△S_(M) is achieved by intentionally introducing strain energy through high-pressure constrained deformation.Both experimental results and Monte Carlo simulations demonstrate that the enhancement of△S_(M) originates from the microscopic strain and lattice deformation induced by strain energy after deformation.This strain energy will reconstruct the energy landscape of this ferromagnetic system and enhance magnetization,resulting in a giant intensity of magnetocaloric responses.Our findings provide an approach to increase magnetic entropy change and may give fresh ideas for exploring advanced magnetocaloric materials.展开更多
High-performance fiber fabrics and composites experienced transverse compression deformation at ultrahigh strain rates near the impact point when subjected to high-velocity impacts,which significantly affected their b...High-performance fiber fabrics and composites experienced transverse compression deformation at ultrahigh strain rates near the impact point when subjected to high-velocity impacts,which significantly affected their ballistic limits.In this paper,a fiber-scale experimental method for characterizing ultrahigh strain-rate transverse compression behavior was proposed.To begin with,in order to measure the extremely low stress and strain in small specimens,the conventional Hopkinson bar was reduced to the hundred-micron scale,thereby achieving wave impedance matching with single fibers.In addition,tangential and normal laser Doppler velocimetry(LDV)methods were employed to realize non-contact,high-precision,and high-speed axial velocity measurements of micron-scale incident and transmission bars,respectively.Meanwhile,a microscopic observation system was used to facilitate the installation of miniature fiber samples.The experimental setup and procedures were introduced,and the system accuracy was verified through sample-free loading tests based on one-dimensional stress wave propagation theory.Dynamic compression experiments on Graphene-UHMWPE fibers were carried out,followed by post-compression microstructural characterization via scanning electron microscopy(SEM).Results demonstrated that successful mechanical characterization was achieved at strain rates exceeding 105,an order of magnitude higher than the previously reported maximum rates.Furthermore,during the loading process,the fibers underwent uniform compression deformation while exhibiting pronounced strain-rate effects.This method offers a novel approach for dynamic mechanical characterization of microscale single fibers,enabling the development of comprehensive strain-ratedependent material models to guide the design of advanced composites and high-performance fibers.展开更多
High-performance intelligent protective materials are vital for nuclear energy systems exposed to extreme irradiation.Among them,tungsten-based alloys demonstrate exceptional potential owing to their superior irradiat...High-performance intelligent protective materials are vital for nuclear energy systems exposed to extreme irradiation.Among them,tungsten-based alloys demonstrate exceptional potential owing to their superior irradiation resistance.Recent experimental studies have demonstrated that W-Ta-Cr-V alloys exhibit excellent irradiation resistance under helium(He)ion irradiation.However,the underlying mechanisms,especially the migration behavior of He atoms,remain unclear.In this work,the influences of uniaxial tensile and compressive strain on He migration in W-Ta-Cr-V complex alloys have been systematically studied through first-principles calculations.Our results demonstrate that He atoms preferentially occupy the tetrahedral interstitial sites,with interstitial formation energies significantly reduced compared to pure W.The introduction of Ta,Cr,and V alloying elements markedly increases the He migration barriers,effectively suppressing He diffusion.Compressive strain increases the migration barriers,inhibiting He bubbles nucleation and growth,while tensile strain decreases the barriers,facilitating bubble formation.Compared to pure W,the W-Ta-Cr-V alloys exhibit both lower He interstitial formation energies and higher migration barriers,with further enhancement under compressive strain.Specifically,compressive strain of 6%increases the He migration barrier of the W-Ta-Cr-V alloy by 0.166 e V,which further widens the difference relative to pure W.These findings provide a theoretical explanation for the superior irradiation resistance of tungsten-based alloys observed experimentally and promote the understanding of irradiation damage in these alloys under strain.展开更多
Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study el...Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.展开更多
Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The t...Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.展开更多
Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment ...Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.展开更多
The deformation characteristics and thermal response of anchor rods are crucial for ensuring the stability and safety of surrounding rock support structures.However,existing research has predominantly concentrated on ...The deformation characteristics and thermal response of anchor rods are crucial for ensuring the stability and safety of surrounding rock support structures.However,existing research has predominantly concentrated on the mechanical performance of anchor rods,with limited attention to the coupled evolution of strain and temperature fields during tensile deformation.This knowledge gap hinders a comprehensive understanding of the synergistic mechanical-thermal response mechanisms in anchor rods under loading conditions.To address this limitation,the present study systematically investigated the evolution of strain and temperature fields,along with their correlation,during the test of micro-negative Poisson's ratio(NPR)and ordinary Poisson's ratio(PR)anchor rods.Digital image correlation(DIC)and infrared thermography(IRT)techniques were employed for this exploration.The uniaxial tensile tests were conducted at two different rates,and the ordinary PR anchor rod(Q235 anchor rod)was established as a control group for comparative analysis.The findings reveal that the micro-NPR anchor rod exhibit strain localization at multiple locations during the tensile process,whereas Q235 anchors show local strain concentration in only one region.The standard deviation evolution curves for both the strain and temperature field exhibit two distinct phases in the two anchor rods.The evolution patterns between these two types of curves are basically consistent.The two standard deviation curves for the micro-NPR anchor rod display a wavy increase in the second phase,while for the Q235 anchor rod,they increase steadily until the specimen is damaged.The correlation analysis reveals that the standard deviations of strain and temperature differences for both types of anchor rods are significantly correlated.These findings demonstrate the synergistic evolution mechanism of deformation and thermal response,providing a potential foundation for utilizing thermal monitoring to assess the stability of rock support structures.展开更多
The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges be...The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.展开更多
The complex wiring,bulky data collection devices,and difficulty in fast and on-site data interpretation significantly limit the practical application of flexible strain sensors as wearable devices.To tackle these chal...The complex wiring,bulky data collection devices,and difficulty in fast and on-site data interpretation significantly limit the practical application of flexible strain sensors as wearable devices.To tackle these challenges,this work develops an artificial intelligenceassisted,wireless,flexible,and wearable mechanoluminescent strain sensor system(AIFWMLS)by integration of deep learning neural network-based color data processing system(CDPS)with a sandwich-structured flexible mechanoluminescent sensor(SFLC)film.The SFLC film shows remarkable and robust mechanoluminescent performance with a simple structure for easy fabrication.The CDPS system can rapidly and accurately extract and interpret the color of the SFLC film to strain values with auto-correction of errors caused by the varying color temperature,which significantly improves the accuracy of the predicted strain.A smart glove mechanoluminescent sensor system demonstrates the great potential of the AIFWMLS system in human gesture recognition.Moreover,the versatile SFLC film can also serve as a encryption device.The integration of deep learning neural network-based artificial intelligence and SFLC film provides a promising strategy to break the“color to strain value”bottleneck that hinders the practical application of flexible colorimetric strain sensors,which could promote the development of wearable and flexible strain sensors from laboratory research to consumer markets.展开更多
This study presents a breakthrough in flexible strain sensor technology with the development of an ultrahigh sensitivity and wide-range sensor,addressing the critical challenge of reconciling sensitivity with measurem...This study presents a breakthrough in flexible strain sensor technology with the development of an ultrahigh sensitivity and wide-range sensor,addressing the critical challenge of reconciling sensitivity with measurement range.Inspired by the structure of bamboo slips,we introduce a novel approach that utilises liquid metal to modulate the electrical pathways within a cracked platinum fabric electrode.The resulting sensor demonstrates a gauge factor greater than 108 and a strain measurement capability exceeding 100%.The integration of patterned liquid metal enables customisable tuning of the sensor’s response,while the porous fabric structure ensures superior comfort and air permeability for the wearer.Our design not only optimises the sensor’s performance but also enhances the electrical stability that is essential for practical applications.Through systematic investigation,we reveal the intrinsic mechanisms governing the sensor’s response,offering valuable insights for the design of wearable strain sensors.The sensor’s exceptional performance across a spectrum of applications,from micro-strain to large-strain detection,highlights its potential for a wide range of real-world uses,demonstrating a significant advancement in the field of flexible electronics.展开更多
High manganese steels(HMS),known for their exceptional strength-ductility balance,are increasingly utilized in dynamic loading applications.This review examines the effects of strain rate on their mechanical propertie...High manganese steels(HMS),known for their exceptional strength-ductility balance,are increasingly utilized in dynamic loading applications.This review examines the effects of strain rate on their mechanical properties and microstructural evolution,focusing on strain rate hardening,adiabatic heating softening,and dynamic strain aging(DSA).The influence of strain rate on yield strength,ultimate tensile strength,strain hardening,and ductility is discussed,highlighting both positive and negative sensitivities across different alloy compositions and strain rate regimes.The strain rate response of various deformation mechanisms,including deformation twinning,dislocation slip,and phase transformation,is examined alongside their influence on microstructural evolution,alloy design,and industrial applications.The intricate role of DSA is also analyzed,emphasizing its contribution to strain rate sensitivity.To optimize HMS for dynamic environments,future research should focus on advanced modeling and processing techniques,in-situ characterization methods,and a deeper understanding of thermally activated processes and stacking fault energy-controlled mechanisms.This review provides insights into strain rate effects,guiding alloy design,and technological advancements of the new HMS.展开更多
Fracture strain becomes critical for the local formability and crash performance of carbody components when the tensile strength exceeds 1000 MPa.Regrettably,high-strength quenching and partitioning(Q&P)steels and...Fracture strain becomes critical for the local formability and crash performance of carbody components when the tensile strength exceeds 1000 MPa.Regrettably,high-strength quenching and partitioning(Q&P)steels and dual-phase(DP)steels always focus on improving the tensile ductility for stretch formability,while ignoring their limited fracture strain.In this work,we explored a novel strategy,i.e.,developing a high fracture strain ferrite-martensite dual-phase steel(HFS-DP)maintaining good strength–ductility balance by suppressing intense strain localization during deformation and enhancing martensite deformability via microstructure design including grain refinement,nano-precipitate hardening in soft ferrite phase,low-carbon and high fraction martensite.HFS-DP demonstrates a remarkable 26%and 47%improvement in tensile ductility and fracture strain,respectively,compared to commercial DP1180 steel with similar ultimate tensile strength.Furthermore,HFS-DP also exhibits a substantial 39%improvement in fracture strain compared to retained austenite-involved commercial QP1180 steel.The detailed processes of strain partitioning,strain localization,and damage formation during deformation were revealed through in-situ scanning electron microscopy(SEM)observation combined with digital image correlation(DIC).The results indicate that the excellent coordinated deformation between ferrite and martensite,coupled with microstructure refinement,effectively suppresses intense strain localization.Moreover,the excellent martensite deformability resulting from the low carbon content also aids in retarding crack formation.This combination effectively suppresses damage initiation and development during deformation,therefore the fracture strain is significantly improved.This study not only contributes to a deeper understanding of the strain localization and damage process during tensile deformation of DP steels,but also provides a new perspective on designing ultrahigh strength steels with high ductility and fracture strain.展开更多
The dominated contradiction in optimizing the performance of magnesium-air battery anode lies in the difficulty of achieving a good balance between activation and passivation during discharge process.To further reconci...The dominated contradiction in optimizing the performance of magnesium-air battery anode lies in the difficulty of achieving a good balance between activation and passivation during discharge process.To further reconcile this contradiction,two Mg-0.1Sc-0.1Y-0.1Ag anodes with different residual strain distribution through extrusion with/without annealing are fabricated.The results indicate that annealing can significantly lessen the“pseudo-anode”regions,thereby changing the dissolution mode of the matrix and achieving an effective dissolution during discharge.Additionally,p-type semiconductor characteristic of discharge productfilm could suppress the self-corrosion reaction without reducing the polarization of anode.The magnesium-air battery utilizing annealed Mg-0.1Sc-0.1Y-0.1Ag as anode achieves a synergistic improvement in specific capacity(1388.89 mA h g^(-1))and energy density(1960.42 mW h g^(-1)).This anode modification method accelerates the advancement of high efficiency and long lifespan magnesium-air batteries,offering renewable and cost-effective energy solutions for electronics and emergency equipment.展开更多
Hot deformation with high strain rate has been paid more attention due to its high efficiency and low cost,however,the strain rate dependent dynamic recrystallization(DRX)and texture evolution in hot deformation proce...Hot deformation with high strain rate has been paid more attention due to its high efficiency and low cost,however,the strain rate dependent dynamic recrystallization(DRX)and texture evolution in hot deformation process,which affect the formability of metals,are lack of study.In this work,the DRX behavior and texture evolution of Mg-8Gd-1Er-0.5Zr alloy hot compressed with strain rates of 0.1 s^(−1),1 s^(−1),10 s^(−1) and 50 s^(−1) are studied,and the corresponding dominant mechanisms for DRX and texture weakening are discussed.Results indicated the DRX fraction was 20%and the whole texture intensity was 16.89 MRD when the strain rate was 0.1 s^(−1),but they were 76%and 6.55 MRD,respectively,when the strain rate increased to 50 s^(−1).The increment of DRX fraction is suggested to result from the reduced DRX critical strain and the increased dislocation density as well as velocity,while the weakened whole texture is attributed to the increased DRX grains.At the low strain rate of 0.1 s^(−1),discontinuous DRX(DDRX)was the dominant,but the whole texture was controlled by the deformed grains with the preferred orientation of{0001}⊥CD,because the number of DDRX grains was limited.At the high strain rate of 50 s^(−1),continuous DRX(CDRX)and twin-induced DRX(TDRX)were promoted,and more DRX grains resulted in orientation randomization.The whole texture was mainly weakened by CDRX and TDRX grains,in which CDRX plays a major role.The results of present work are significant for understanding the hot workability of Mg-RE alloys with a high strain rate.展开更多
By the random distribution of metals in a single phase,entropy engineering is applied to construct dense neighboring active centers with diverse electronic and geometric structures,realizing the continuous optimizatio...By the random distribution of metals in a single phase,entropy engineering is applied to construct dense neighboring active centers with diverse electronic and geometric structures,realizing the continuous optimization of multiple primary reactions for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Many catalysts developed through entropy engineering have been built in nearly equimolar ratios to pursue high entropy,hindering the identification of the active sites and potentially diluting the concentration of real active sites while weakening their electronic interactions with reaction intermediates.Herein,this work proposes an entropy-engineering strategy in metal nanoparticle-embedded nitrogen carbon electrocatalysts,implemented by entropy-engineered Prussian blue analogs(PBA)as precursors to enhance the catalytic activity of primary Cu-Fe active sites.Through the introduction of the micro-strains driven by entropy engineering,density functional theory(DFT)calculations and geometric phase analysis(GPA)using Lorentz electron microscopy further elucidate the optimization of the adsorption/desorption of intermediates.Furthermore,the multi-dimensional morphology and the size diminishment of the nanocrystals serve to expand the electrochemical area,maximizing the catalytic activity for both ORR and OER.Notably,the Zn-air battery assembled with CuFeCoNiZn-NC operated for over 1300 h with negligible decay.This work presents a paradigm for the design of low-cost electrocatalysts with entropy engineering for multi-step reactions.展开更多
Although time-dependent deformation of geomaterials underpins slope-failure prediction models,the influence of strain rate on shearing strength and deformation behavior of loess remains unclear.The consolidated undrai...Although time-dependent deformation of geomaterials underpins slope-failure prediction models,the influence of strain rate on shearing strength and deformation behavior of loess remains unclear.The consolidated undrained(CU)and drained(CD)triaxial testing elucidated the impact of strain rate(0.005–0.3 mm/min)on strength envelopes,deformation moduli,pore pressures,and dilatancy characteristics of unsaturated and quasi-saturated loess.Under drained conditions with a controlled matric suction of 50 kPa,increasing strain rates from 0.005 mm/min to 0.011 mm/min induced decreases in failure deviatoric stress(qf),initial deformation modulus(Ei),and cohesion(c),while friction angles remained unaffected.Specimens displayed initial contractive volumetric strains transitioning to dilation across varying confining pressures.Higher rates diminished contractive volumetric strains and drainage volumes,indicating reduced densification and strength in the shear zone.Under undrained conditions,both unsaturated and quasi-saturated(pore pressure coefficient B=0.75)loess exhibited deteriorating mechanical properties with increasing rates from 0.03 mm/min to 0.3 mm/min.For unsaturated loess,reduced contractive volumetric strains at higher rates manifested relatively looser structures in the pre-peak stress phase.The strength decrement in quasi-saturated loess arose from elevated excess porewater pressures diminishing effective stresses.Negative porewater pressures emerged in quasi-saturated loess at lower confining pressures and strain rates.Compared to previous studies,the qf and Ei exhibited rate sensitivity below threshold values before attaining minima with marginal subsequent influence.The underlying mechanism mirrors the transition from creep to accelerated deformation phase of landslides.展开更多
As the main geomaterials for coral reefs oil or gas extraction and underground infrastructure construction,coral reef limestone demonstrates significantly distinct mechanical responses compared to terrigenous rocks.To...As the main geomaterials for coral reefs oil or gas extraction and underground infrastructure construction,coral reef limestone demonstrates significantly distinct mechanical responses compared to terrigenous rocks.To investigate the mechanical behaviour of coral reef limestone under the coupling impact of size and strain rate,the uniaxial compression tests were conducted on reef limestone samples with length-to-diameter(L/D)ratio ranging from 0.5 to 2.0 at strain rate ranging from 10^(−5)·s^(−1)to 10^(−2)·s^(−1).It is revealed that the uniaxial compressive strength(UCS)and residual compressive strength(RCS)of coral reef limestone exhibits a decreasing trend with L/D ratio increasing.The dynamic increase factor(DIF)of UCS is linearly correlated with the logarithm of strain rate,while increasing the L/D ratio further enhances the DIF.The elastic modulus increases with strain rate or L/D ratio increasing,whereas the Poisson’s ratio approximates to a constant value of 0.24.The failure strain increases with strain rate increasing or L/D ratio decreasing,while the increase in L/D ratio will inhibit the enhancing effect of the strain rate.The high porosity and low mineral strength are the primary factors contributing to a high RCS of 16.7%–64.9%of UCS,a lower brittleness index and multiple irregular fracture planes.The failure pattern of coral reef limestone transits from the shear-dominated to the splitting-dominated failure with strain rate increasing or L/D ratio decreasing,which is mainly governed by the constrained zones induced by end friction and the strain rate-dependent crack propagation.Moreover,a predictive formula incorporating coupling effect of size and strain rate for the UCS of reef limestone was established and verified to effectively capture the trend of UCS.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22271074)Natural Science Foundation of Hebei Province(Nos.B2023208042,B2022208032,B2021208066,E2024208084,and E2024208088)+2 种基金Science Research Project of Hebei Education Department(No.JZX2024013)Special Fund for Local Scientific and Technological Development under the Guidance of the Central Government(No.236Z3704G)Hebei Province High Level Talent Funding(No.A202001010)。
文摘Owing to their good biocompatibility,polysaccharide hydrogels have broad application prospects in the field of flexible strain sensors.However,there are still significant challenges in the preparation of polysaccharide hydrogels with good mechanical properties.MCA-Li Cl hydrogels were prepared by introducing methacrylated hyaluronic acid(Me HA)into the polymer network in the presence of acrylic acid(AA),acryloyloxyethyltrimethyl ammonium chloride(CATAC),and metal ions.The polymer network not only has a chemically cross-linked network and a tough network structure,but also benefits from a variety of supramolecular interactions,such as hydrogen bonding and coordination covalent bonding,resulting in excellent mechanical properties,with an elongation at break of 1390%,a tensile strength of up to 1200 k Pa,a toughness of 9.4546 MJ/m^(3),and adhesive properties towards various substrates.At the same time,the hydrogel has a high conductivity(5.33 mS/cm)and high strain-sensing sensitivity(Gauge factor=2.55).The flexible strain sensor assembled from the prepared MCA-Li Cl hydrogel can be used to detect human movements,from micro-expressions(smiles,swallowing)to pulse signals and other physiological activities,as well as large-scale joint movements(wrists,elbows,knees,fingers,etc.),realizing the real-time monitoring of full-scale human movements.The prepared hydrogels have potential applications in wearable devices,electronic skin,and strain-sensor components.
基金supported by the Program for National Natural Science Foundation of China(No.11675231)the Sichuan Science and Technology Program(Nos.2022YFG0263 and 2024NSFSC1097)the Scientific Research Starting Foundation for talents(Nos.21zx7109 and 22zx7175,24ycx1005).
文摘Single-crystal GaN epilayers were irradiated with heavy inert gas ions(2.3-MeV Ne^(8+),5.3-MeV Kr^(19+))to fluences ranging from 1.0×1.0^(11) to 1.0×1.0^(15)ions∕cm^(2).The strain-related damage accumulation versus ion fluences was studied using highresolution X-ray diffraction(HRXRD)and ultraviolet–visible(UV–Vis)spectroscopy.The results showed that the damage accumulation was mainly dominated by nuclear energy loss.When the ion fluence was less than∼0.055 displacement per atom(dpa),the lattice expansions and lattice strains markedly increased linearly with increasing ion fluences,accompanied by a slow enhancement in the dislocation densities,distortion parameters,and Urbach energy for both ion irradiations.Above this fluence(∼0.055 dpa),the lattice strains presented a slight increase,whereas a remarkable increase was observed in the dislocation densities,distortion parameters,and Urbach energy with the ion fluences after both ion irradiations.∼0.055 dpa is the threshold ion fluence for defect evolution and lattice damage related to strain.The mechanisms underlying the damage accumulation are discussed in detail.
基金supported by the National Natural Science Foundation of China through grant numbers 12002245 and 12172263the Science and Technology Research Program of Chongqing Municipal Education Commission through grant number KJQN202300742+1 种基金the National Natural Science Foundation of ChongqingMunicipality through grant number CSTB2025NSCQ-GPX0841Chongqing Jiaotong University through grant number F1220038.
文摘Granular materials exhibit complex macroscopic mechanical behaviors closely related to their microscalemicrostructural features.Traditional macroscopic phenomenological elasto-plastic models,however,usually have complex formulations and lack explicit relations to these microstructural features.To avoid these limitations,this study proposes a micromechanics-based softening hyperelastic model for granular materials,integrating softening hyperelasticity withmicrostructural insights to capture strain softening,critical state,and strain localization behaviors.The model has two key advantages:(1)a clear conceptualization,straightforward formulation,and ease of numerical implementation(via Abaqus UMAT subroutine in this study);(2)explicit incorporation of micro-scale features(e.g.,contact stiffness,particle size,porosity)to reveal their influences on macroscopic responses.An isotropic directional distribution density of contacts and three specific microstructures are considered,and their softening hyperelastic constitutive modulus tensors are explicitly derived.By introducing a softening factor and critical failure energy density,the model can describe geomaterial behaviors,simulating residual strength,X-shaped shear bands,and strain localization evolution.Numerical validations in comparison with themacro-scale hyperelastic model,Abaqus Drucker-Prager model,and the experiment confirm its accuracy.Parametric studies reveal critical dependencies:a normal to tangential contact stiffness ratio of 2-8(depending on stiffness magnitude),an internal length of 2-4 mm to ensure shear band formation,and a critical failure energy density(≤10 kJ/m^(3))to trigger strain softening and localization.Influences of the specific microstructures on strain localization and softening are investigated.The model also shows mesh independence due to the introduction of an internal length.The model’s applicability is further demonstrated by slope stability analysis,capturing slip surface evolution,and load-displacement characteristics.This study develops a robust microstructure-aware hyperelastic framework to describe the mechanical behaviors of granular materials,providing multiscale insights for geotechnical engineering applications.
基金Project supported by the National Key Research and Decelopment Program of China(Grant No.2021YFB3500302)the National Natural Science Foundation of China(Grant Nos.U22A20116 and 52371200)the Innovation Capability Improvement Project of Hebei Province,China(Grant No.22567605H)。
文摘Large magnetic entropy change(△S_(M))can realize a prominent heat transformation under the magnetic field and directly strengthen the efficacy of the magnetocaloric effect,which provides a pioneering environmentally friendly solidstate strategy to improve refrigeration capacities and efficiencies.The second-order magnetic transition(SOMT)materials have broader△S_(M) peaks without thermal hysteresis,making them highly attractive in magnetic refrigeration,especially in the room temperature range.Here,we report a significant enhancement of△S_(M) at room temperature in single-crystal Mn_(5)Ge_(3).In this SOMT system,we realize a 60%improvement of-△S_(M)^(max) from 3.5 J/kg·K to 5.6 J/kg·K at T=300 K.This considerable enhancement of△S_(M) is achieved by intentionally introducing strain energy through high-pressure constrained deformation.Both experimental results and Monte Carlo simulations demonstrate that the enhancement of△S_(M) originates from the microscopic strain and lattice deformation induced by strain energy after deformation.This strain energy will reconstruct the energy landscape of this ferromagnetic system and enhance magnetization,resulting in a giant intensity of magnetocaloric responses.Our findings provide an approach to increase magnetic entropy change and may give fresh ideas for exploring advanced magnetocaloric materials.
基金financial support provided by the National Natural Science Foundation of China(Grant No.12302472)the Science and Technology Support Program of Jiangsu Province(Grant No.BK20230874)+2 种基金the Aeronautical Science Fund(ASF)(Grant No.2023Z057052005)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and Astronautics)(Grant No.MCAS-I-0124G02)the funding received from Jiangsu Hanvo Safety Product Co.,Ltd。
文摘High-performance fiber fabrics and composites experienced transverse compression deformation at ultrahigh strain rates near the impact point when subjected to high-velocity impacts,which significantly affected their ballistic limits.In this paper,a fiber-scale experimental method for characterizing ultrahigh strain-rate transverse compression behavior was proposed.To begin with,in order to measure the extremely low stress and strain in small specimens,the conventional Hopkinson bar was reduced to the hundred-micron scale,thereby achieving wave impedance matching with single fibers.In addition,tangential and normal laser Doppler velocimetry(LDV)methods were employed to realize non-contact,high-precision,and high-speed axial velocity measurements of micron-scale incident and transmission bars,respectively.Meanwhile,a microscopic observation system was used to facilitate the installation of miniature fiber samples.The experimental setup and procedures were introduced,and the system accuracy was verified through sample-free loading tests based on one-dimensional stress wave propagation theory.Dynamic compression experiments on Graphene-UHMWPE fibers were carried out,followed by post-compression microstructural characterization via scanning electron microscopy(SEM).Results demonstrated that successful mechanical characterization was achieved at strain rates exceeding 105,an order of magnitude higher than the previously reported maximum rates.Furthermore,during the loading process,the fibers underwent uniform compression deformation while exhibiting pronounced strain-rate effects.This method offers a novel approach for dynamic mechanical characterization of microscale single fibers,enabling the development of comprehensive strain-ratedependent material models to guide the design of advanced composites and high-performance fibers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11505003 and 52325103)the Anhui Provincial Natural Science Foundation(Grant No.2108085MA25)。
文摘High-performance intelligent protective materials are vital for nuclear energy systems exposed to extreme irradiation.Among them,tungsten-based alloys demonstrate exceptional potential owing to their superior irradiation resistance.Recent experimental studies have demonstrated that W-Ta-Cr-V alloys exhibit excellent irradiation resistance under helium(He)ion irradiation.However,the underlying mechanisms,especially the migration behavior of He atoms,remain unclear.In this work,the influences of uniaxial tensile and compressive strain on He migration in W-Ta-Cr-V complex alloys have been systematically studied through first-principles calculations.Our results demonstrate that He atoms preferentially occupy the tetrahedral interstitial sites,with interstitial formation energies significantly reduced compared to pure W.The introduction of Ta,Cr,and V alloying elements markedly increases the He migration barriers,effectively suppressing He diffusion.Compressive strain increases the migration barriers,inhibiting He bubbles nucleation and growth,while tensile strain decreases the barriers,facilitating bubble formation.Compared to pure W,the W-Ta-Cr-V alloys exhibit both lower He interstitial formation energies and higher migration barriers,with further enhancement under compressive strain.Specifically,compressive strain of 6%increases the He migration barrier of the W-Ta-Cr-V alloy by 0.166 e V,which further widens the difference relative to pure W.These findings provide a theoretical explanation for the superior irradiation resistance of tungsten-based alloys observed experimentally and promote the understanding of irradiation damage in these alloys under strain.
基金financial support from NSF ExpandQISE program.The synthesis of tellurene was supported by NSF under grant no.CMMI-2046936supports from Purdue Research Foundation.
文摘Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.
基金Supported by the National Natural Science Foundation of China under Grant No.51975138the High-Tech Ship Scientific Research Project from the Ministry of Industry and Information Technology under Grant No.CJ05N20the National Defense Basic Research Project under Grant No.JCKY2023604C006.
文摘Marine thin plates are susceptible to welding deformation owing to their low structural stiffness.Therefore,the efficient and accurate prediction of welding deformation is essential for improving welding quality.The traditional thermal elastic-plastic finite element method(TEP-FEM)can accurately predict welding deformation.However,its efficiency is low because of the complex nonlinear transient computation,making it difficult to meet the needs of rapid engineering evaluation.To address this challenge,this study proposes an efficient prediction method for welding deformation in marine thin plate butt welds.This method is based on the coupled temperature gradient-thermal strain method(TG-TSM)that integrates inherent strain theory with a shell element finite element model.The proposed method first extracts the distribution pattern and characteristic value of welding-induced inherent strain through TEP-FEM analysis.This strain is then converted into the equivalent thermal load applied to the shell element model for rapid computation.The proposed method-particularly,the gradual temperature gradient-thermal strain method(GTG-TSM)-achieved improved computational efficiency and consistent precision.Furthermore,the proposed method required much less computation time than the traditional TEP-FEM.Thus,this study lays the foundation for future prediction of welding deformation in more complex marine thin plates.
基金supported by the National Key Research and Development Program of China(2023YFD2100104)Henan Provincial Major Science and Technology Special Fund(231100110400).
文摘Microorganisms are crucial for the breakdown of proteins and lipids in dry-fermented sausages and are intimately associated with the flavor profile of sausages.In this study,we used a mixed starter culture to ferment sausages and investigated the flavor turnover.During the fermentation of salami,the data from free amino acids(FAAs),free fatty acids(FFAs)and volatile flavor substances were used to assess the quality of salami.At the end of fermentation,the total FAAs increased from 1171.32 to 4582.48 mg/kg in the control group and 5053.25 mg/kg in the experimental group.Additionally,following inoculation with the mixed starter culture,the levels of glutamic acid,lysine,methionine,valine and leucine were significantly higher(P<0.05)than those in the control group.Oleic acid(C_(18:1))and chondritic acid(C_(16:0))were the two most abundant FFAs in both salami samples with 45.86%and 26.07%on the 23^(th)day in mixed culture inoculated salami.The mixed starter inoculated group had significantly lower saturated fatty acids and higher percentage levels of monounsaturated fatty acids than the control group(P<0.05).In the volatile flavor substance analysis,a total of 61 volatile compounds were found.Ester compounds were progressively enriched with drying time,significantly increasing the flavor substances,like ethyl diphosgene,1-octen-3-ol,and 2,3-butanediol at P<0.05.The correlation analysis between the core flora and volatile flavor compounds during fermentation and maturation of salami indicates Lactobacillus sakei and Lactobacillus rhamnosus were significantly higher and positively correlated with the major volatile organic compounds,which are the key core microorganisms affecting the flavor quality of fermented sausages.
基金supported by State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining&Technology,Beijing(Grant No.SKLGDUEK2120)。
文摘The deformation characteristics and thermal response of anchor rods are crucial for ensuring the stability and safety of surrounding rock support structures.However,existing research has predominantly concentrated on the mechanical performance of anchor rods,with limited attention to the coupled evolution of strain and temperature fields during tensile deformation.This knowledge gap hinders a comprehensive understanding of the synergistic mechanical-thermal response mechanisms in anchor rods under loading conditions.To address this limitation,the present study systematically investigated the evolution of strain and temperature fields,along with their correlation,during the test of micro-negative Poisson's ratio(NPR)and ordinary Poisson's ratio(PR)anchor rods.Digital image correlation(DIC)and infrared thermography(IRT)techniques were employed for this exploration.The uniaxial tensile tests were conducted at two different rates,and the ordinary PR anchor rod(Q235 anchor rod)was established as a control group for comparative analysis.The findings reveal that the micro-NPR anchor rod exhibit strain localization at multiple locations during the tensile process,whereas Q235 anchors show local strain concentration in only one region.The standard deviation evolution curves for both the strain and temperature field exhibit two distinct phases in the two anchor rods.The evolution patterns between these two types of curves are basically consistent.The two standard deviation curves for the micro-NPR anchor rod display a wavy increase in the second phase,while for the Q235 anchor rod,they increase steadily until the specimen is damaged.The correlation analysis reveals that the standard deviations of strain and temperature differences for both types of anchor rods are significantly correlated.These findings demonstrate the synergistic evolution mechanism of deformation and thermal response,providing a potential foundation for utilizing thermal monitoring to assess the stability of rock support structures.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos.XDB28000000 and XDB0460000)the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2021ZD0302600)the National Key Research and Development Program of China(Grant No.2024YFA1409002)。
文摘The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
基金funded by the National Natural Science Foundation of China(52475580)the Special Foundation of the Taishan Scholar Project(tsqn202211077,tsqn202311077)+3 种基金Shandong Provincial Excellent Overseas Young Scholar Foundation(2023HWYQ-069)the Shandong Provincial Natural Science Foundation(ZR2023ME118,ZR2023QF080)the Natural Science Foundation of Qingdao City(23-2-1-219-zyyd-jch,23-2-1-111-zyyd-jch)the Fundamental Research Funds for the Central Universities(23CX06032A).
文摘The complex wiring,bulky data collection devices,and difficulty in fast and on-site data interpretation significantly limit the practical application of flexible strain sensors as wearable devices.To tackle these challenges,this work develops an artificial intelligenceassisted,wireless,flexible,and wearable mechanoluminescent strain sensor system(AIFWMLS)by integration of deep learning neural network-based color data processing system(CDPS)with a sandwich-structured flexible mechanoluminescent sensor(SFLC)film.The SFLC film shows remarkable and robust mechanoluminescent performance with a simple structure for easy fabrication.The CDPS system can rapidly and accurately extract and interpret the color of the SFLC film to strain values with auto-correction of errors caused by the varying color temperature,which significantly improves the accuracy of the predicted strain.A smart glove mechanoluminescent sensor system demonstrates the great potential of the AIFWMLS system in human gesture recognition.Moreover,the versatile SFLC film can also serve as a encryption device.The integration of deep learning neural network-based artificial intelligence and SFLC film provides a promising strategy to break the“color to strain value”bottleneck that hinders the practical application of flexible colorimetric strain sensors,which could promote the development of wearable and flexible strain sensors from laboratory research to consumer markets.
基金support from the National Key R&D Program of China(2021YFB3200700)the National Natural Science Foundation of China(Grant No.0214100221,51925503).
文摘This study presents a breakthrough in flexible strain sensor technology with the development of an ultrahigh sensitivity and wide-range sensor,addressing the critical challenge of reconciling sensitivity with measurement range.Inspired by the structure of bamboo slips,we introduce a novel approach that utilises liquid metal to modulate the electrical pathways within a cracked platinum fabric electrode.The resulting sensor demonstrates a gauge factor greater than 108 and a strain measurement capability exceeding 100%.The integration of patterned liquid metal enables customisable tuning of the sensor’s response,while the porous fabric structure ensures superior comfort and air permeability for the wearer.Our design not only optimises the sensor’s performance but also enhances the electrical stability that is essential for practical applications.Through systematic investigation,we reveal the intrinsic mechanisms governing the sensor’s response,offering valuable insights for the design of wearable strain sensors.The sensor’s exceptional performance across a spectrum of applications,from micro-strain to large-strain detection,highlights its potential for a wide range of real-world uses,demonstrating a significant advancement in the field of flexible electronics.
基金supported by the National Natural Science Foundation(No.52101128)the Jiangsu Provincial Key Research and Development Program(No.BE023059)+1 种基金Postdoctoral Science Foundation(No.2022M710021)the Northeastern University Postdoctoral Research Fund(No.20220202)of China。
文摘High manganese steels(HMS),known for their exceptional strength-ductility balance,are increasingly utilized in dynamic loading applications.This review examines the effects of strain rate on their mechanical properties and microstructural evolution,focusing on strain rate hardening,adiabatic heating softening,and dynamic strain aging(DSA).The influence of strain rate on yield strength,ultimate tensile strength,strain hardening,and ductility is discussed,highlighting both positive and negative sensitivities across different alloy compositions and strain rate regimes.The strain rate response of various deformation mechanisms,including deformation twinning,dislocation slip,and phase transformation,is examined alongside their influence on microstructural evolution,alloy design,and industrial applications.The intricate role of DSA is also analyzed,emphasizing its contribution to strain rate sensitivity.To optimize HMS for dynamic environments,future research should focus on advanced modeling and processing techniques,in-situ characterization methods,and a deeper understanding of thermally activated processes and stacking fault energy-controlled mechanisms.This review provides insights into strain rate effects,guiding alloy design,and technological advancements of the new HMS.
基金supported by the National Natural Science Foundation of China(No.52101128)the Jiangsu Provincial Key Research and Development Program(No.BE023059)+1 种基金the Post-doctoral Science Foundation of China(No.2022M710021)the Northeastern University Postdoctoral Research Fund of China(No.20220202).
文摘Fracture strain becomes critical for the local formability and crash performance of carbody components when the tensile strength exceeds 1000 MPa.Regrettably,high-strength quenching and partitioning(Q&P)steels and dual-phase(DP)steels always focus on improving the tensile ductility for stretch formability,while ignoring their limited fracture strain.In this work,we explored a novel strategy,i.e.,developing a high fracture strain ferrite-martensite dual-phase steel(HFS-DP)maintaining good strength–ductility balance by suppressing intense strain localization during deformation and enhancing martensite deformability via microstructure design including grain refinement,nano-precipitate hardening in soft ferrite phase,low-carbon and high fraction martensite.HFS-DP demonstrates a remarkable 26%and 47%improvement in tensile ductility and fracture strain,respectively,compared to commercial DP1180 steel with similar ultimate tensile strength.Furthermore,HFS-DP also exhibits a substantial 39%improvement in fracture strain compared to retained austenite-involved commercial QP1180 steel.The detailed processes of strain partitioning,strain localization,and damage formation during deformation were revealed through in-situ scanning electron microscopy(SEM)observation combined with digital image correlation(DIC).The results indicate that the excellent coordinated deformation between ferrite and martensite,coupled with microstructure refinement,effectively suppresses intense strain localization.Moreover,the excellent martensite deformability resulting from the low carbon content also aids in retarding crack formation.This combination effectively suppresses damage initiation and development during deformation,therefore the fracture strain is significantly improved.This study not only contributes to a deeper understanding of the strain localization and damage process during tensile deformation of DP steels,but also provides a new perspective on designing ultrahigh strength steels with high ductility and fracture strain.
基金the National Natural Science:Foundation of China(52375370)the Open Project of Salt Lake Chemical Engineering Research Complex,Qinghai University(2023-DXSSKF-Z02)+2 种基金the Nat-ural Science Foundation of Shanxi(202103021224049)GDAS Projects of International cooperation platform of Sci-ence and Technology(2022GDASZH-2022010203-003)Guangdong province Science and Technology Plan Projects(2023B1212060045).
文摘The dominated contradiction in optimizing the performance of magnesium-air battery anode lies in the difficulty of achieving a good balance between activation and passivation during discharge process.To further reconcile this contradiction,two Mg-0.1Sc-0.1Y-0.1Ag anodes with different residual strain distribution through extrusion with/without annealing are fabricated.The results indicate that annealing can significantly lessen the“pseudo-anode”regions,thereby changing the dissolution mode of the matrix and achieving an effective dissolution during discharge.Additionally,p-type semiconductor characteristic of discharge productfilm could suppress the self-corrosion reaction without reducing the polarization of anode.The magnesium-air battery utilizing annealed Mg-0.1Sc-0.1Y-0.1Ag as anode achieves a synergistic improvement in specific capacity(1388.89 mA h g^(-1))and energy density(1960.42 mW h g^(-1)).This anode modification method accelerates the advancement of high efficiency and long lifespan magnesium-air batteries,offering renewable and cost-effective energy solutions for electronics and emergency equipment.
基金supported by the Nation Key Research and Development Program of China(No.2021YFB3701100).
文摘Hot deformation with high strain rate has been paid more attention due to its high efficiency and low cost,however,the strain rate dependent dynamic recrystallization(DRX)and texture evolution in hot deformation process,which affect the formability of metals,are lack of study.In this work,the DRX behavior and texture evolution of Mg-8Gd-1Er-0.5Zr alloy hot compressed with strain rates of 0.1 s^(−1),1 s^(−1),10 s^(−1) and 50 s^(−1) are studied,and the corresponding dominant mechanisms for DRX and texture weakening are discussed.Results indicated the DRX fraction was 20%and the whole texture intensity was 16.89 MRD when the strain rate was 0.1 s^(−1),but they were 76%and 6.55 MRD,respectively,when the strain rate increased to 50 s^(−1).The increment of DRX fraction is suggested to result from the reduced DRX critical strain and the increased dislocation density as well as velocity,while the weakened whole texture is attributed to the increased DRX grains.At the low strain rate of 0.1 s^(−1),discontinuous DRX(DDRX)was the dominant,but the whole texture was controlled by the deformed grains with the preferred orientation of{0001}⊥CD,because the number of DDRX grains was limited.At the high strain rate of 50 s^(−1),continuous DRX(CDRX)and twin-induced DRX(TDRX)were promoted,and more DRX grains resulted in orientation randomization.The whole texture was mainly weakened by CDRX and TDRX grains,in which CDRX plays a major role.The results of present work are significant for understanding the hot workability of Mg-RE alloys with a high strain rate.
基金supported by the National Natural Science Foundation of China(52071083,52231007,12327804,52471224)Zhuhai Fudan Innovation Institute,and the Science and Technology Commission of Shanghai Municipality(23ZR1405000).
文摘By the random distribution of metals in a single phase,entropy engineering is applied to construct dense neighboring active centers with diverse electronic and geometric structures,realizing the continuous optimization of multiple primary reactions for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).Many catalysts developed through entropy engineering have been built in nearly equimolar ratios to pursue high entropy,hindering the identification of the active sites and potentially diluting the concentration of real active sites while weakening their electronic interactions with reaction intermediates.Herein,this work proposes an entropy-engineering strategy in metal nanoparticle-embedded nitrogen carbon electrocatalysts,implemented by entropy-engineered Prussian blue analogs(PBA)as precursors to enhance the catalytic activity of primary Cu-Fe active sites.Through the introduction of the micro-strains driven by entropy engineering,density functional theory(DFT)calculations and geometric phase analysis(GPA)using Lorentz electron microscopy further elucidate the optimization of the adsorption/desorption of intermediates.Furthermore,the multi-dimensional morphology and the size diminishment of the nanocrystals serve to expand the electrochemical area,maximizing the catalytic activity for both ORR and OER.Notably,the Zn-air battery assembled with CuFeCoNiZn-NC operated for over 1300 h with negligible decay.This work presents a paradigm for the design of low-cost electrocatalysts with entropy engineering for multi-step reactions.
文摘Although time-dependent deformation of geomaterials underpins slope-failure prediction models,the influence of strain rate on shearing strength and deformation behavior of loess remains unclear.The consolidated undrained(CU)and drained(CD)triaxial testing elucidated the impact of strain rate(0.005–0.3 mm/min)on strength envelopes,deformation moduli,pore pressures,and dilatancy characteristics of unsaturated and quasi-saturated loess.Under drained conditions with a controlled matric suction of 50 kPa,increasing strain rates from 0.005 mm/min to 0.011 mm/min induced decreases in failure deviatoric stress(qf),initial deformation modulus(Ei),and cohesion(c),while friction angles remained unaffected.Specimens displayed initial contractive volumetric strains transitioning to dilation across varying confining pressures.Higher rates diminished contractive volumetric strains and drainage volumes,indicating reduced densification and strength in the shear zone.Under undrained conditions,both unsaturated and quasi-saturated(pore pressure coefficient B=0.75)loess exhibited deteriorating mechanical properties with increasing rates from 0.03 mm/min to 0.3 mm/min.For unsaturated loess,reduced contractive volumetric strains at higher rates manifested relatively looser structures in the pre-peak stress phase.The strength decrement in quasi-saturated loess arose from elevated excess porewater pressures diminishing effective stresses.Negative porewater pressures emerged in quasi-saturated loess at lower confining pressures and strain rates.Compared to previous studies,the qf and Ei exhibited rate sensitivity below threshold values before attaining minima with marginal subsequent influence.The underlying mechanism mirrors the transition from creep to accelerated deformation phase of landslides.
基金supported by the National Natural Science Foundation of China(Nos.52222110,52401354,and 52301353).
文摘As the main geomaterials for coral reefs oil or gas extraction and underground infrastructure construction,coral reef limestone demonstrates significantly distinct mechanical responses compared to terrigenous rocks.To investigate the mechanical behaviour of coral reef limestone under the coupling impact of size and strain rate,the uniaxial compression tests were conducted on reef limestone samples with length-to-diameter(L/D)ratio ranging from 0.5 to 2.0 at strain rate ranging from 10^(−5)·s^(−1)to 10^(−2)·s^(−1).It is revealed that the uniaxial compressive strength(UCS)and residual compressive strength(RCS)of coral reef limestone exhibits a decreasing trend with L/D ratio increasing.The dynamic increase factor(DIF)of UCS is linearly correlated with the logarithm of strain rate,while increasing the L/D ratio further enhances the DIF.The elastic modulus increases with strain rate or L/D ratio increasing,whereas the Poisson’s ratio approximates to a constant value of 0.24.The failure strain increases with strain rate increasing or L/D ratio decreasing,while the increase in L/D ratio will inhibit the enhancing effect of the strain rate.The high porosity and low mineral strength are the primary factors contributing to a high RCS of 16.7%–64.9%of UCS,a lower brittleness index and multiple irregular fracture planes.The failure pattern of coral reef limestone transits from the shear-dominated to the splitting-dominated failure with strain rate increasing or L/D ratio decreasing,which is mainly governed by the constrained zones induced by end friction and the strain rate-dependent crack propagation.Moreover,a predictive formula incorporating coupling effect of size and strain rate for the UCS of reef limestone was established and verified to effectively capture the trend of UCS.
