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
This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and...This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries.展开更多
To investigate the impact of temporary structures on the mechanical behavior of shaped bridge towers during the construction process,the Dianbu River Special Bridge was selected as the engineering background.A finite ...To investigate the impact of temporary structures on the mechanical behavior of shaped bridge towers during the construction process,the Dianbu River Special Bridge was selected as the engineering background.A finite element model of the middle tower column during the construction stage was established using ABAQUS to analyze the effects of key parameters,including the angle and pretension of temporary cables,as well as the wall thickness and diameter of temporary diagonal braces.The study examines how these parameters influence the stresses at the towergirder consolidation.The results indicate that the angle of temporary cables significantly affects the tensile stresses at the tower-girder consolidation,while its impact on compressive stresses is minimal.Among all parameters,the pretension of temporary cables has the most pronounced effect on the stresses at the tower-girder consolidation.In contrast,the wall thickness of temporary diagonal braces has only a minor influence,whereas the diameter of temporary diagonal braces has an almost negligible impact.These findings provide valuable insights for optimizing the design and arrangement of temporary support structures in similar bridge construction projects.展开更多
The roughness of the fracture surface directly affects the strength,deformation,and permeability of the surrounding rock in deep underground engineering.Understanding the effect of high temperature and thermal cycle o...The roughness of the fracture surface directly affects the strength,deformation,and permeability of the surrounding rock in deep underground engineering.Understanding the effect of high temperature and thermal cycle on the fracture surface roughness plays an important role in estimating the damage degree and stability of deep rock mass.In this paper,the variations of fracture surface roughness of granite after different heating and thermal cycles were investigated using the joint roughness coefficient method(JRC),three-dimensional(3D)roughness parameters,and fractal dimension(D),and the mechanism of damage and deterioration of granite were revealed.The experimental results show an increase in the roughness of the granite fracture surface as temperature and cycle number were incremented.The variations of JRC,height parameter,inclination parameter and area parameter with the temperature conformed to the Boltzmann's functional distribution,while the D decreased linearly as the temperature increased.Besides,the anisotropy index(Ip)of the granite fracture surface increased as the temperature increased,and the larger parameter values of roughness characterization at different temperatures were attained mainly in directions of 20°–40°,60°–100°and 140°–160°.The fracture aperture of granite after fracture followed the Gauss distribution and the average aperture increased with increasing temperature,which increased from 0.665 mm at 25℃to 1.058 mm at 800℃.High temperature caused an uneven thermal expansion,water evaporation,and oxidation of minerals within the granite,which promoted the growth and expansion of microfractures,and reduced interparticle bonding strength.In particular,the damage was exacerbated by the expansion and cracking of the quartz phase transition after T>500℃.Thermal cycles contributed to the accumulation of this damage and further weakened the interparticle bonding forces,resulting in a significant increase in the roughness,anisotropy,and aperture of the fracture surface after five cycles.展开更多
Carbon dioxide(CO_(2))geological sequestration represents a critical technology in mitigating climate change.Shale reservoirs demonstrate a pronounced affinity for CO_(2),resulting in adsorption-induced swelling that ...Carbon dioxide(CO_(2))geological sequestration represents a critical technology in mitigating climate change.Shale reservoirs demonstrate a pronounced affinity for CO_(2),resulting in adsorption-induced swelling that significantly impacts permeability,mechanical strength,injection efficiency,and sequestration safety.For this,we tried to explore the key factors driving the swelling of shale upon CO_(2)injection and its subsequent impact on reservoir properties.Utilizing a self-developed high-temperature-pressure gas adsorption apparatus,we measured strain in Jurassic shale at 308 K under constant hydrostatic pressure with helium(He)at 1300 psi(1 psi=6.895 kPa)and CO_(2)at 850 psi.Next,we investigated the influence of CO_(2)concentration on swelling protentional while maintaining constant pressure,uncovering the anisotropic deformation in relation to pressure.It shows that CO_(2)adsorption induces significant swelling in shale,following a Langmuir-type pressure relationship.Deformation is more pronounced perpendicular than that parallel to the bedding plane.At low pressure,vertical swelling is 2.28 times greater than the horizontal;while at high pressure,the vertical compression is 31.26 times greater than the horizontal.It seems that the anisotropic swelling enhances permeability predictions during CO_(2)injection.Mixed gases under constant compression can prompt gas desorption,stress redistribution,and alterations in pore structure,amplifying He compression effect.The strain induced after replacing CO_(2)with He exceeds that from pure He injection.The asynchronous response of CO_(2)-induced swelling and mechanical compression can precipitate crack propagation and fracturing.Overall,anisotropic swelling from CO_(2)adsorption changes pore structure and permeability,affecting fluid flow and storage.Considering CO_(2)concentration and anisotropic characteristics in reservoir modeling is essential for optimizing injection strategies and enhancing reservoir efficiency.展开更多
The stimulation of shale reservoirs frequently involves significant shear failure,which is crucial for creating fracture networks and enhancing permeability to boost production.As the depth of extraction increases,the...The stimulation of shale reservoirs frequently involves significant shear failure,which is crucial for creating fracture networks and enhancing permeability to boost production.As the depth of extraction increases,the impact of elevated temperatures on the anisotropic shear strength and failure mechanisms of shale becomes pronounced,yet there is a notable lack of relevant research.This study conducts,for the first time,direct shear experiment on shales at four different temperatures and seven bedding angles.By employing acoustic emission(AE)and digital image correlation(DIC)techniques,the evolution of damage and the mechanism of crack propagation under anisotropic direct shearing at varying temperatures is revealed.The results indicate that both shear displacement and strength of shale increase with temperature across different bedding angles.Additionally,shale demonstrates distinct brittle failure characteristics under various conditions during direct shearing tests.The types of anisotropic shear failure observed under the influence of temperature include central shearing fracture,central shearing with secondary fracture,and deflected slip along the bedding.Moreover,the temperature effect enhances shear-induced crack propagation along bedding planes.Shear failure in shale predominantly occurs during higher loading stages,which coincide with a substantial amount of AE signals.Finally,the introduction of the anisotropy index and temperature sensitivity coefficient further elucidates the interaction mechanism between thermal effects and anisotropy.This study offers a novel methodology to explore the anisotropic shear failure behavior of shale under elevated temperatures,and also provides crucial theoretical and experimental insights into shear failure behavior relevant to practical shale reservoir stimulation.展开更多
Percussion drilling technology can be used to increase the rate of penetration in deep shale reservoirs,but the interaction mechanism among impact loads,drilling teeth and rock has not been sufficiently investigated.F...Percussion drilling technology can be used to increase the rate of penetration in deep shale reservoirs,but the interaction mechanism among impact loads,drilling teeth and rock has not been sufficiently investigated.For this reason,shales with different bedding angles are used to carry out impact compression and tensile experiments as well as the rock-breaking experiments by single axe-shaped tooth,the variation of dynamic strengths,rock failure characteristics,fractal dimensions,and tensile/compression ratios under different load-bedding angles(α)are investigated.Then,the three-dimensional scanning device is used to measure the penetration depth and rock-breaking volume under different load-bedding angles.The results show that with the increase of load-bedding angle(0°-90°),the compressive strength decreases and then increases,with the lowest strength atα=45°and the highest strength atα=0°;the tensile strength decreases and then increases,with the lowest strength nearα=30°and the highest strength atα=90°.With the growing impact rate,the effect of load-bedding angle on dynamic compressive strength decreases,and the effect on dynamic tensile strength becomes more significant.When the impact velocity is high(≥8.0 m/s),the tensile-compressive ratio first decreases and then increases,and both reach a minimum at a load-bedding angle of 30°and a maximum at 60°.With the increasing of the load-bedding angle,the depth of tooth penetration increases and then decreases,and the highest depth of tooth penetration and the highest energy absorption efficiency are achieved atα=45°;the width of the impact pit increases and then decreases,and the maximum width value is achieved atα=30°,with the smallest value of the specific work value of the rock-breaking.The results have significant reference value for improving the rock-breaking efficiency of percussion drilling in deep anisotropic formations.展开更多
Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge....Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge.Herein,inspired by the human muscle,an anisotropic fire safety aerogel(ACMCA)with precise self-actuated temperature monitoring performance is developed by combining aramid nanofibers with eicosane/MXene to form an anisotropically oriented conductive network.By combining the two synergies of the negative temperaturedependent thermal conductive eicosane,which induces a high-temperature differential,and directionally ordered MXene that establishes a conductive network along the directional freezing direction.The resultant ACMCA exhibited remarkable thermoelectric properties,with S values reaching 46.78μV K^(−1)andκvalues as low as 0.048 W m^(−1)K^(−1)at room temperature.Moreover,the prepared anisotropic aerogel ACMCA exhibited electrical responsiveness to temperature variations,facilitating its application in intelligent temperature monitoring systems.The designed anisotropic aerogel ACMCA could be incorporated into the firefighting clothing as a thermal barrier layer,demonstrating a wide temperature sensing range(50-400℃)and a rapid response time for early high-temperature alerts(~1.43 s).This work provides novel insights into the design and application of temperature-sensitive anisotropic aramid nanofibers aerogel in firefighting clothing.展开更多
In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and...In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.展开更多
Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing systems.However,the piezoelectric sensor strugg...Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing systems.However,the piezoelectric sensor struggles to satisfy the requirements for directional recognition due to the limited piezoelectric coefficient matrix,and achieving sensitivity for detecting micrometer-scale deformations is also challenging.Herein,we develop a vector sensor composed of lead zirconate titanate-electronic grade glass fiber composite filaments with oriented arrangement,capable of detecting minute anisotropic deformations.The as-prepared vector sensor can identify the deformation directions even when subjected to an unprecedented nominal strain of 0.06%,thereby enabling its utility in accurately discerning the 5μm-height wrinkles in thin films and in monitoring human pulse waves.The ultra-high sensitivity is attributed to the formation of porous ferroelectret and the efficient load transfer efficiency of continuous lead zirconate titanate phase.Additionally,when integrated with machine learning techniques,the sensor’s capability to recognize multi-signals enables it to differentiate between 10 types of fine textures with 100%accuracy.The structural design in piezoelectric devices enables a more comprehensive perception of mechanical stimuli,offering a novel perspective for enhancing recognition accuracy.展开更多
The bending springback of magnesium alloys is difficult to predict accurately by numerical simulations because of their anisotropic characteristics.The springback of magnesium alloy V-shaped roll-bending was analyzed ...The bending springback of magnesium alloys is difficult to predict accurately by numerical simulations because of their anisotropic characteristics.The springback of magnesium alloy V-shaped roll-bending was analyzed using the error optimization function in Matlab to optimize the anisotropic potential values required for the Hill’48 yield criterion in ABAQUS.The optimized Hill’48 yield criterion model was used to numerically simulate the springback of magnesium alloy V-shaped roll-bending.The simulation results were compared with the experimental results.Results show that the error between the springback change ratio obtained using the optimized Hill’48 yield criterion and experimentally formed parts is within 2%.Overall,the optimized Hill’48 yield criterion improves the prediction accuracy of springback in magnesium alloy V-shaped roll-bending.展开更多
The existence and uniqueness of stationary solutions to anisotropic Navier-Stokes equations is investigated by a Galerkin technique in this work.Based on this conclusion,we further explore the exponential stability of...The existence and uniqueness of stationary solutions to anisotropic Navier-Stokes equations is investigated by a Galerkin technique in this work.Based on this conclusion,we further explore the exponential stability of weak solutions to stochastic anisotropic NavierStokes equations.We present a relationship among different growth exponents,which is sufficient to guarantee the existence,uniqueness and exponential stability of stationary solutions.展开更多
Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a...Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment,without complex geometry or a control module.In this work,we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated,continuous rolling motions under constant light irradiation.The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient.The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion.The hydrogel robots can reach a rolling speed of 1.27 mm·s^(-1)on a horizonal surface and even climb a ramp of 18°at a speed of 0.57 mm·s^(-1)in an aqueous environment.Furthermore,the hydrogel robots can overcome an obstacle,with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions.This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.展开更多
In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadra...In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadratic and quadratic behaviors simultaneously in different variable components.展开更多
The vectorial evolution of light polarization can reveal the microstructure and anisotropy of a medium beyond what can be obtained from measuring light intensity alone.However,polarization imaging in reflection geomet...The vectorial evolution of light polarization can reveal the microstructure and anisotropy of a medium beyond what can be obtained from measuring light intensity alone.However,polarization imaging in reflection geometry,which is ubiquitous and often preferred in diverse applications,has often suffered from poor and even incorrect characterization of anisotropic media.We present reciprocal polarization imaging of complex media in reflection geometry with the reciprocal polar decomposition of backscattering Mueller matrices enforcing reciprocity.We demonstrate that reciprocal polarization imaging of complex chiral and anisotropic media ac-curately quantifies their anisotropic properties in reflection geometry,whereas traditional approaches encounter difficulties and produce inferior and often erroneous results from the violation of reciprocity.In particular,reciprocal polarization imaging provides a consistent characterization of complex media of different thicknesses,accurately measures the optical activity and glucose concentration of turbid media in reflection,and discriminates between cancerous and normal tissue with even stronger contrast than forward measurement.Reciprocal polarization imaging promises broad applications of polarization optics ranging from remote sensing to bio-medicine in reflection geometries,especially in in vivo biomedical imaging,where reflection is the only feasible geometry.展开更多
Oxysulfide semiconductors are promising photocatalysts for visible light-driven water splitting.For a widely studied narrow-bandgap Sm_(2)Ti_(2)O_(5)S_(2)(STOS),limited bulk charge separation and slow surface reaction...Oxysulfide semiconductors are promising photocatalysts for visible light-driven water splitting.For a widely studied narrow-bandgap Sm_(2)Ti_(2)O_(5)S_(2)(STOS),limited bulk charge separation and slow surface reaction heavily restrict its photocatalytic performance.Here,well-crystallized STOS oxysulfide nanosheets,synthesized by a flux-assisted solid-state reaction,were proved to show prominent facet-oriented charge transport property,in which photogenerated electrons migrated to{101}planes and holes to{001}planes of each particle.Hydrogen evolution cocatalysts were therefore precisely positioned on the electron-rich facets to boost the water reduction reaction.In particular,in-situ formation of a Ptshell@Ircore core-shell structure on the electron-rich{101}facets and an IrO_(2) on the hole-accumulated{001}facets greatly assisted the sacrificial photocatalytic H_(2) production over STOS,resulting in an apparent quantum yield as high as 35.9%at 420 nm.By using the highly-active STOS as H_(2) evolution photocatalyst,a Mo:BiVO_(4) as oxygen evolution photocatalyst,and a[Co(bpy)_(3)]^(2+/3+)as redox shuttle,a Z-Scheme overall water splitting system was constructed to achieve a solar-to-hydrogen conversion efficiency of 0.175%.This work not only elucidates the facet-dependent charge transfer mechanism on STOS but also proposes an ideal strategy for enhancing its photocatalytic performance.展开更多
Predictions of fluid distribution,stress field,and natural fracture are essential for exploiting unconventional shale gas reservoirs.Given the high likelihood of tilted fractures in subsurface formations,this study fo...Predictions of fluid distribution,stress field,and natural fracture are essential for exploiting unconventional shale gas reservoirs.Given the high likelihood of tilted fractures in subsurface formations,this study focuses on simultaneous seismic inversion to estimate fluid bulk modulus,effective stress parameter,and fracture density in the tilted transversely isotropic(TTI)medium.In this article,a novel PP-wave reflection coefficient approximation equation is first derived based on the constructed TTI stiffness matrix incorporating fracture density,effective stress parameter,and fluid bulk modulus.The high accuracy of the proposed equation has been demonstrated using an anisotropic two-layer model.Furthermore,a stepwise seismic inversion strategy with the L_(P) quasi-norm sparsity constraint is implemented to obtain the anisotropic and isotropic parameters.Three synthetic model tests with varying signal-to-noise ratios(SNRs)confirm the method's feasibility and noise robustness.Ultimately,the proposed method is applied to a 3D fractured shale gas reservoir in the Sichuan Basin,China.The results have effectively characterized shale gas distribution,stress fields,and tilted natural fractures,with validation from geological structures,well logs,and microseismic events.These findings can provide valuable guidance for hydraulic fracturing development,enabling more reliable predictions of reservoir heterogeneity and completion quality.展开更多
This study evaluates the accuracy of large-eddy simulation(LES)analyses using a commonly used subgrid-scale(SGS)model based on the eddy viscosity hypothesis.The evaluation is performed by examining the Reynolds number...This study evaluates the accuracy of large-eddy simulation(LES)analyses using a commonly used subgrid-scale(SGS)model based on the eddy viscosity hypothesis.The evaluation is performed by examining the Reynolds number dependence of turbulence maintained by anisotropic and isotropic forcing techniques derived from Tay-lor analytical solutions.The Smagorinsky model,the Vreman model,and the coherent structure model are used as SGS models.LES outcomes were evaluated against those produced by direct numerical simulation(DNS).In contrast to the results with isotropic forcing,the turbulent kinetic energy of anisotropic forcing-induced tur-bulence,as calculated by DNS,exhibits a minimum in the intermediate Reynolds number range.However,all three LES analyses fail to reproduce this minimum and instead show overestimated values.This discrepancy is attributed to reduced spatial inhomogeneity of the turbulent diffusion,pressure diffusion,and pressure-strain correlation terms in the transport equations of the velocity fluctuation intensities in this Reynolds number range.Visualization results for the LES and DNS analyses further show that within this range,LES analyses reproduce two-dimensional tubular flow structures that are not observed in DNS results.展开更多
We discovered two distinctive features in the mechanical properties of extruded Mg alloys containing a long-period stacking ordered(LPSO)phase,which are highly desirable for a new class of high-strength,lightweight ma...We discovered two distinctive features in the mechanical properties of extruded Mg alloys containing a long-period stacking ordered(LPSO)phase,which are highly desirable for a new class of high-strength,lightweight materials.First,the Mg/LPSO-extruded alloy shows greater elongation compared to other Mg solid-solution-extruded alloys when a certain high strength is required.Second,the simultaneous achievement of high strength and large elongation in the Mg/LPSO-extruded alloy enhances with a reduction in extrusion speed.In this study,the physical origins of these features were examined,focusing on how changes in the microstructure affect the mechanical properties of the extruded alloys.Our findings clarify that the LPSO phase contributes not only to increased strength but also to enhanced elongation through an increase in the work-hardening rate,a mechanism we termed aanisotropic mechanical property-induced ductilizationo(AMID).Until now,most efforts to improve the ductility of Mg materials have focused on achieving aisotropic mechanical propertieso via grain refinement.Based on our results,we propose an entirely opposite approach:increasing the elongation of Mg alloy by locally enhancing theiraanisotropic mechanical propertieso through the AMID mechanism.Computational analysis further suggests that reducing the diameter of Mg-worked grains should effectively improving elongation in Mg/LPSO alloys with a high volume fraction of Mg-worked grains.展开更多
Understanding the mechanical behavior and failure characteristics of anisotropic sedimentary rocks under true-triaxial in-situ stress conditions is critical in understanding and mitigating damaging formation slippage ...Understanding the mechanical behavior and failure characteristics of anisotropic sedimentary rocks under true-triaxial in-situ stress conditions is critical in understanding and mitigating damaging formation slippage in subsurface reservoirs and containment structures.In particular,threshold conditions where structure dominates over intact failure remain undefined.By conducting systematic true-triaxial compression tests,we followed the evolution of deformation and failure in sedimentary rocks across a documented spectrum of lithological and structural characteristics in order to quantify and then classify this cross-impact.The failure features were characterized using acoustic emission(AE)monitoring,optical imaging,X-ray CT scans,and thin-section analysis.We characterized structural and deformational anisotropies in order to define the risk of structurally controlled slip failure.We identified three deformational and failure modes dominated by(Ⅰ)purely stress-controlled failure,(Ⅱ)mixed stress--structure-controlled failure,and(Ⅲ)purely structurally controlled failure.As structural overprinting increased,failure mechanisms were found to shift progressively from Type Ⅰ to Ⅲ,thereby progressively capturing inherent rock anisotropy and complex fabric as well as ductile failure.This transition was characterized in terms of two parameters that alternately characterize structural(α)and deformational anisotropies(β)of rocks with these related to key visual,mechanical,and acoustic(AE)indicators.The greater the α(α>2),the higher the β(β>0),the more likely the transition from brittle failure to structurally controlled ductile shear reactivation along the bedding.展开更多
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(Nos.52471156,U20A20274,and 52071158)the China Postdoctoral Science Foundation(Nos.2024M751173 and 2024M752703)+1 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talent,China(No.2024ZB229)the Natural Science Foundation of Jiangsu Higher Education Institutions,China(No.24KJB430012).
文摘This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries.
文摘To investigate the impact of temporary structures on the mechanical behavior of shaped bridge towers during the construction process,the Dianbu River Special Bridge was selected as the engineering background.A finite element model of the middle tower column during the construction stage was established using ABAQUS to analyze the effects of key parameters,including the angle and pretension of temporary cables,as well as the wall thickness and diameter of temporary diagonal braces.The study examines how these parameters influence the stresses at the towergirder consolidation.The results indicate that the angle of temporary cables significantly affects the tensile stresses at the tower-girder consolidation,while its impact on compressive stresses is minimal.Among all parameters,the pretension of temporary cables has the most pronounced effect on the stresses at the tower-girder consolidation.In contrast,the wall thickness of temporary diagonal braces has only a minor influence,whereas the diameter of temporary diagonal braces has an almost negligible impact.These findings provide valuable insights for optimizing the design and arrangement of temporary support structures in similar bridge construction projects.
基金funding support from the National Natural Science Foundation of China(Grant No.52274082)the Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology(Grant No.JXUSTQJBJ2020003)the Innovation Fund Designated for Graduate Students of Jiangxi Province(Grant No.YC2023-B215).
文摘The roughness of the fracture surface directly affects the strength,deformation,and permeability of the surrounding rock in deep underground engineering.Understanding the effect of high temperature and thermal cycle on the fracture surface roughness plays an important role in estimating the damage degree and stability of deep rock mass.In this paper,the variations of fracture surface roughness of granite after different heating and thermal cycles were investigated using the joint roughness coefficient method(JRC),three-dimensional(3D)roughness parameters,and fractal dimension(D),and the mechanism of damage and deterioration of granite were revealed.The experimental results show an increase in the roughness of the granite fracture surface as temperature and cycle number were incremented.The variations of JRC,height parameter,inclination parameter and area parameter with the temperature conformed to the Boltzmann's functional distribution,while the D decreased linearly as the temperature increased.Besides,the anisotropy index(Ip)of the granite fracture surface increased as the temperature increased,and the larger parameter values of roughness characterization at different temperatures were attained mainly in directions of 20°–40°,60°–100°and 140°–160°.The fracture aperture of granite after fracture followed the Gauss distribution and the average aperture increased with increasing temperature,which increased from 0.665 mm at 25℃to 1.058 mm at 800℃.High temperature caused an uneven thermal expansion,water evaporation,and oxidation of minerals within the granite,which promoted the growth and expansion of microfractures,and reduced interparticle bonding strength.In particular,the damage was exacerbated by the expansion and cracking of the quartz phase transition after T>500℃.Thermal cycles contributed to the accumulation of this damage and further weakened the interparticle bonding forces,resulting in a significant increase in the roughness,anisotropy,and aperture of the fracture surface after five cycles.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(Grant No.52121003)the National Natural Science Foundation of China(Grant No.52104046).
文摘Carbon dioxide(CO_(2))geological sequestration represents a critical technology in mitigating climate change.Shale reservoirs demonstrate a pronounced affinity for CO_(2),resulting in adsorption-induced swelling that significantly impacts permeability,mechanical strength,injection efficiency,and sequestration safety.For this,we tried to explore the key factors driving the swelling of shale upon CO_(2)injection and its subsequent impact on reservoir properties.Utilizing a self-developed high-temperature-pressure gas adsorption apparatus,we measured strain in Jurassic shale at 308 K under constant hydrostatic pressure with helium(He)at 1300 psi(1 psi=6.895 kPa)and CO_(2)at 850 psi.Next,we investigated the influence of CO_(2)concentration on swelling protentional while maintaining constant pressure,uncovering the anisotropic deformation in relation to pressure.It shows that CO_(2)adsorption induces significant swelling in shale,following a Langmuir-type pressure relationship.Deformation is more pronounced perpendicular than that parallel to the bedding plane.At low pressure,vertical swelling is 2.28 times greater than the horizontal;while at high pressure,the vertical compression is 31.26 times greater than the horizontal.It seems that the anisotropic swelling enhances permeability predictions during CO_(2)injection.Mixed gases under constant compression can prompt gas desorption,stress redistribution,and alterations in pore structure,amplifying He compression effect.The strain induced after replacing CO_(2)with He exceeds that from pure He injection.The asynchronous response of CO_(2)-induced swelling and mechanical compression can precipitate crack propagation and fracturing.Overall,anisotropic swelling from CO_(2)adsorption changes pore structure and permeability,affecting fluid flow and storage.Considering CO_(2)concentration and anisotropic characteristics in reservoir modeling is essential for optimizing injection strategies and enhancing reservoir efficiency.
基金supported by the National Natural Science Fund of China (Grant Nos.U22A20166 and 52374131)the Shenzhen Science and Technology Program (Grant No.JCYJ20220531102012028)the Young Elite Scientists Sponsorship Program by CAST.
文摘The stimulation of shale reservoirs frequently involves significant shear failure,which is crucial for creating fracture networks and enhancing permeability to boost production.As the depth of extraction increases,the impact of elevated temperatures on the anisotropic shear strength and failure mechanisms of shale becomes pronounced,yet there is a notable lack of relevant research.This study conducts,for the first time,direct shear experiment on shales at four different temperatures and seven bedding angles.By employing acoustic emission(AE)and digital image correlation(DIC)techniques,the evolution of damage and the mechanism of crack propagation under anisotropic direct shearing at varying temperatures is revealed.The results indicate that both shear displacement and strength of shale increase with temperature across different bedding angles.Additionally,shale demonstrates distinct brittle failure characteristics under various conditions during direct shearing tests.The types of anisotropic shear failure observed under the influence of temperature include central shearing fracture,central shearing with secondary fracture,and deflected slip along the bedding.Moreover,the temperature effect enhances shear-induced crack propagation along bedding planes.Shear failure in shale predominantly occurs during higher loading stages,which coincide with a substantial amount of AE signals.Finally,the introduction of the anisotropy index and temperature sensitivity coefficient further elucidates the interaction mechanism between thermal effects and anisotropy.This study offers a novel methodology to explore the anisotropic shear failure behavior of shale under elevated temperatures,and also provides crucial theoretical and experimental insights into shear failure behavior relevant to practical shale reservoir stimulation.
基金supported by the National Natural Science Foundation of China(52374001,52104001).
文摘Percussion drilling technology can be used to increase the rate of penetration in deep shale reservoirs,but the interaction mechanism among impact loads,drilling teeth and rock has not been sufficiently investigated.For this reason,shales with different bedding angles are used to carry out impact compression and tensile experiments as well as the rock-breaking experiments by single axe-shaped tooth,the variation of dynamic strengths,rock failure characteristics,fractal dimensions,and tensile/compression ratios under different load-bedding angles(α)are investigated.Then,the three-dimensional scanning device is used to measure the penetration depth and rock-breaking volume under different load-bedding angles.The results show that with the increase of load-bedding angle(0°-90°),the compressive strength decreases and then increases,with the lowest strength atα=45°and the highest strength atα=0°;the tensile strength decreases and then increases,with the lowest strength nearα=30°and the highest strength atα=90°.With the growing impact rate,the effect of load-bedding angle on dynamic compressive strength decreases,and the effect on dynamic tensile strength becomes more significant.When the impact velocity is high(≥8.0 m/s),the tensile-compressive ratio first decreases and then increases,and both reach a minimum at a load-bedding angle of 30°and a maximum at 60°.With the increasing of the load-bedding angle,the depth of tooth penetration increases and then decreases,and the highest depth of tooth penetration and the highest energy absorption efficiency are achieved atα=45°;the width of the impact pit increases and then decreases,and the maximum width value is achieved atα=30°,with the smallest value of the specific work value of the rock-breaking.The results have significant reference value for improving the rock-breaking efficiency of percussion drilling in deep anisotropic formations.
基金funding support from Guiding Project of Scientific Research Plan of Education Department of Hubei Province and Wuhan Textile University School Fund(B)(k24016).
文摘Enhancing the firefighting protective clothing with exceptional thermal barrier and temperature sensing functions to ensure high fire safety for firefighters has long been anticipated,but it remains a major challenge.Herein,inspired by the human muscle,an anisotropic fire safety aerogel(ACMCA)with precise self-actuated temperature monitoring performance is developed by combining aramid nanofibers with eicosane/MXene to form an anisotropically oriented conductive network.By combining the two synergies of the negative temperaturedependent thermal conductive eicosane,which induces a high-temperature differential,and directionally ordered MXene that establishes a conductive network along the directional freezing direction.The resultant ACMCA exhibited remarkable thermoelectric properties,with S values reaching 46.78μV K^(−1)andκvalues as low as 0.048 W m^(−1)K^(−1)at room temperature.Moreover,the prepared anisotropic aerogel ACMCA exhibited electrical responsiveness to temperature variations,facilitating its application in intelligent temperature monitoring systems.The designed anisotropic aerogel ACMCA could be incorporated into the firefighting clothing as a thermal barrier layer,demonstrating a wide temperature sensing range(50-400℃)and a rapid response time for early high-temperature alerts(~1.43 s).This work provides novel insights into the design and application of temperature-sensitive anisotropic aramid nanofibers aerogel in firefighting clothing.
基金funded by National Natural Science Foundation of China(Grant Nos.52130504,52305577,and 52175509)the Key Research and Development Plan of Hubei Province(Grant No.2022BAA013)+4 种基金the Major Program(JD)of Hubei Province(Grant No.2023BAA008-2)the Interdisciplinary Research Program of Huazhong University of Science and Technology(2023JCYJ047)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2023PY003)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GZB20230244)the fellowship from the China Postdoctoral Science Foundation(2024M750995)。
文摘In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.
基金financially supported by the National Key Research and Development Program of China(No.2022YFA1205300 and No.2022YFA1205304)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2022ZD103).
文摘Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing systems.However,the piezoelectric sensor struggles to satisfy the requirements for directional recognition due to the limited piezoelectric coefficient matrix,and achieving sensitivity for detecting micrometer-scale deformations is also challenging.Herein,we develop a vector sensor composed of lead zirconate titanate-electronic grade glass fiber composite filaments with oriented arrangement,capable of detecting minute anisotropic deformations.The as-prepared vector sensor can identify the deformation directions even when subjected to an unprecedented nominal strain of 0.06%,thereby enabling its utility in accurately discerning the 5μm-height wrinkles in thin films and in monitoring human pulse waves.The ultra-high sensitivity is attributed to the formation of porous ferroelectret and the efficient load transfer efficiency of continuous lead zirconate titanate phase.Additionally,when integrated with machine learning techniques,the sensor’s capability to recognize multi-signals enables it to differentiate between 10 types of fine textures with 100%accuracy.The structural design in piezoelectric devices enables a more comprehensive perception of mechanical stimuli,offering a novel perspective for enhancing recognition accuracy.
基金National Natural Science Foundation of China(52274389)Key Research and Development Plan of Shanxi Province(202102010101010,202202150401010)+3 种基金Science and Technology Activities for Overseas Students Selected Funding Project of Shanxi Province(20220028)Raise Funds to Help Returnees of Shanxi Province(2022-160)National Natural Science Foundation of China(Youth Science Foundation Project)(52004169)Returnee Research Support Project of Shanxi Province(2021-132)。
文摘The bending springback of magnesium alloys is difficult to predict accurately by numerical simulations because of their anisotropic characteristics.The springback of magnesium alloy V-shaped roll-bending was analyzed using the error optimization function in Matlab to optimize the anisotropic potential values required for the Hill’48 yield criterion in ABAQUS.The optimized Hill’48 yield criterion model was used to numerically simulate the springback of magnesium alloy V-shaped roll-bending.The simulation results were compared with the experimental results.Results show that the error between the springback change ratio obtained using the optimized Hill’48 yield criterion and experimentally formed parts is within 2%.Overall,the optimized Hill’48 yield criterion improves the prediction accuracy of springback in magnesium alloy V-shaped roll-bending.
基金supported by the Natural Science Foundation of Hunan Province of China(2024JJ5123)supported by the Shandong Provincial Natural Science Foundation(ZR2023MA072,ZR2020MA036)。
文摘The existence and uniqueness of stationary solutions to anisotropic Navier-Stokes equations is investigated by a Galerkin technique in this work.Based on this conclusion,we further explore the exponential stability of weak solutions to stochastic anisotropic NavierStokes equations.We present a relationship among different growth exponents,which is sufficient to guarantee the existence,uniqueness and exponential stability of stationary solutions.
基金supported by the National Natural Science Foundation of China(Nos.52325302 and 52173012)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SZ-FR005)。
文摘Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment,without complex geometry or a control module.In this work,we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated,continuous rolling motions under constant light irradiation.The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient.The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion.The hydrogel robots can reach a rolling speed of 1.27 mm·s^(-1)on a horizonal surface and even climb a ramp of 18°at a speed of 0.57 mm·s^(-1)in an aqueous environment.Furthermore,the hydrogel robots can overcome an obstacle,with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions.This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.
基金supported by the NSFC(12301138)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2021L377)+1 种基金the Doctoral Scientific Research Foundation of Shanxi Datong University(2018-B-15)The second author’s work was supported by the NSFC(12171108).
文摘In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadratic and quadratic behaviors simultaneously in different variable components.
基金upported by the Natural Science Foundation of Zhejiang Province(Grant No.LZ16H180002)the National Natural Science Foundation of China(Grant No.61905181)+1 种基金the Wenzhou Municipal Science and Technology Bureau(Grant No.ZS2017022)the National Science Foundation of the U.S.(Grant No.1607664).
文摘The vectorial evolution of light polarization can reveal the microstructure and anisotropy of a medium beyond what can be obtained from measuring light intensity alone.However,polarization imaging in reflection geometry,which is ubiquitous and often preferred in diverse applications,has often suffered from poor and even incorrect characterization of anisotropic media.We present reciprocal polarization imaging of complex media in reflection geometry with the reciprocal polar decomposition of backscattering Mueller matrices enforcing reciprocity.We demonstrate that reciprocal polarization imaging of complex chiral and anisotropic media ac-curately quantifies their anisotropic properties in reflection geometry,whereas traditional approaches encounter difficulties and produce inferior and often erroneous results from the violation of reciprocity.In particular,reciprocal polarization imaging provides a consistent characterization of complex media of different thicknesses,accurately measures the optical activity and glucose concentration of turbid media in reflection,and discriminates between cancerous and normal tissue with even stronger contrast than forward measurement.Reciprocal polarization imaging promises broad applications of polarization optics ranging from remote sensing to bio-medicine in reflection geometries,especially in in vivo biomedical imaging,where reflection is the only feasible geometry.
文摘Oxysulfide semiconductors are promising photocatalysts for visible light-driven water splitting.For a widely studied narrow-bandgap Sm_(2)Ti_(2)O_(5)S_(2)(STOS),limited bulk charge separation and slow surface reaction heavily restrict its photocatalytic performance.Here,well-crystallized STOS oxysulfide nanosheets,synthesized by a flux-assisted solid-state reaction,were proved to show prominent facet-oriented charge transport property,in which photogenerated electrons migrated to{101}planes and holes to{001}planes of each particle.Hydrogen evolution cocatalysts were therefore precisely positioned on the electron-rich facets to boost the water reduction reaction.In particular,in-situ formation of a Ptshell@Ircore core-shell structure on the electron-rich{101}facets and an IrO_(2) on the hole-accumulated{001}facets greatly assisted the sacrificial photocatalytic H_(2) production over STOS,resulting in an apparent quantum yield as high as 35.9%at 420 nm.By using the highly-active STOS as H_(2) evolution photocatalyst,a Mo:BiVO_(4) as oxygen evolution photocatalyst,and a[Co(bpy)_(3)]^(2+/3+)as redox shuttle,a Z-Scheme overall water splitting system was constructed to achieve a solar-to-hydrogen conversion efficiency of 0.175%.This work not only elucidates the facet-dependent charge transfer mechanism on STOS but also proposes an ideal strategy for enhancing its photocatalytic performance.
基金financially supported by the Natural Science Foundation of Sichuan Province(Grant Nos.2023NSFSC0767 and2024NSFSC0809)the China Postdoctoral Science Foundation(Grant No.2024MF750281)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20230326)。
文摘Predictions of fluid distribution,stress field,and natural fracture are essential for exploiting unconventional shale gas reservoirs.Given the high likelihood of tilted fractures in subsurface formations,this study focuses on simultaneous seismic inversion to estimate fluid bulk modulus,effective stress parameter,and fracture density in the tilted transversely isotropic(TTI)medium.In this article,a novel PP-wave reflection coefficient approximation equation is first derived based on the constructed TTI stiffness matrix incorporating fracture density,effective stress parameter,and fluid bulk modulus.The high accuracy of the proposed equation has been demonstrated using an anisotropic two-layer model.Furthermore,a stepwise seismic inversion strategy with the L_(P) quasi-norm sparsity constraint is implemented to obtain the anisotropic and isotropic parameters.Three synthetic model tests with varying signal-to-noise ratios(SNRs)confirm the method's feasibility and noise robustness.Ultimately,the proposed method is applied to a 3D fractured shale gas reservoir in the Sichuan Basin,China.The results have effectively characterized shale gas distribution,stress fields,and tilted natural fractures,with validation from geological structures,well logs,and microseismic events.These findings can provide valuable guidance for hydraulic fracturing development,enabling more reliable predictions of reservoir heterogeneity and completion quality.
基金supported by the Japanese Ministry of Education,Culture,Sports,Science and Technol-ogy through Grants-in-Aid(Grant Nos.21K03859 and 22H01684)the Kurita Water and Environment Foundation(Grant No.25B042)the Okayama Foundation for Science and Technology(2025).
文摘This study evaluates the accuracy of large-eddy simulation(LES)analyses using a commonly used subgrid-scale(SGS)model based on the eddy viscosity hypothesis.The evaluation is performed by examining the Reynolds number dependence of turbulence maintained by anisotropic and isotropic forcing techniques derived from Tay-lor analytical solutions.The Smagorinsky model,the Vreman model,and the coherent structure model are used as SGS models.LES outcomes were evaluated against those produced by direct numerical simulation(DNS).In contrast to the results with isotropic forcing,the turbulent kinetic energy of anisotropic forcing-induced tur-bulence,as calculated by DNS,exhibits a minimum in the intermediate Reynolds number range.However,all three LES analyses fail to reproduce this minimum and instead show overestimated values.This discrepancy is attributed to reduced spatial inhomogeneity of the turbulent diffusion,pressure diffusion,and pressure-strain correlation terms in the transport equations of the velocity fluctuation intensities in this Reynolds number range.Visualization results for the LES and DNS analyses further show that within this range,LES analyses reproduce two-dimensional tubular flow structures that are not observed in DNS results.
基金supported by the Japan Science and Technology Agency(JST),CREST(grant number JPMJCR2094)。
文摘We discovered two distinctive features in the mechanical properties of extruded Mg alloys containing a long-period stacking ordered(LPSO)phase,which are highly desirable for a new class of high-strength,lightweight materials.First,the Mg/LPSO-extruded alloy shows greater elongation compared to other Mg solid-solution-extruded alloys when a certain high strength is required.Second,the simultaneous achievement of high strength and large elongation in the Mg/LPSO-extruded alloy enhances with a reduction in extrusion speed.In this study,the physical origins of these features were examined,focusing on how changes in the microstructure affect the mechanical properties of the extruded alloys.Our findings clarify that the LPSO phase contributes not only to increased strength but also to enhanced elongation through an increase in the work-hardening rate,a mechanism we termed aanisotropic mechanical property-induced ductilizationo(AMID).Until now,most efforts to improve the ductility of Mg materials have focused on achieving aisotropic mechanical propertieso via grain refinement.Based on our results,we propose an entirely opposite approach:increasing the elongation of Mg alloy by locally enhancing theiraanisotropic mechanical propertieso through the AMID mechanism.Computational analysis further suggests that reducing the diameter of Mg-worked grains should effectively improving elongation in Mg/LPSO alloys with a high volume fraction of Mg-worked grains.
基金funded by the joint fund of the National Key Research and Development Program of China(No.2021YF C2902101)National Natural Science Foundation of China(Grant No.52374084)+2 种基金Open Foundation of National Energy Shale Gas R&D(Experiment)Center(2022-KFKT-12)the 111 Project(B17009)support from the G.Albert Shoemaker endowment。
文摘Understanding the mechanical behavior and failure characteristics of anisotropic sedimentary rocks under true-triaxial in-situ stress conditions is critical in understanding and mitigating damaging formation slippage in subsurface reservoirs and containment structures.In particular,threshold conditions where structure dominates over intact failure remain undefined.By conducting systematic true-triaxial compression tests,we followed the evolution of deformation and failure in sedimentary rocks across a documented spectrum of lithological and structural characteristics in order to quantify and then classify this cross-impact.The failure features were characterized using acoustic emission(AE)monitoring,optical imaging,X-ray CT scans,and thin-section analysis.We characterized structural and deformational anisotropies in order to define the risk of structurally controlled slip failure.We identified three deformational and failure modes dominated by(Ⅰ)purely stress-controlled failure,(Ⅱ)mixed stress--structure-controlled failure,and(Ⅲ)purely structurally controlled failure.As structural overprinting increased,failure mechanisms were found to shift progressively from Type Ⅰ to Ⅲ,thereby progressively capturing inherent rock anisotropy and complex fabric as well as ductile failure.This transition was characterized in terms of two parameters that alternately characterize structural(α)and deformational anisotropies(β)of rocks with these related to key visual,mechanical,and acoustic(AE)indicators.The greater the α(α>2),the higher the β(β>0),the more likely the transition from brittle failure to structurally controlled ductile shear reactivation along the bedding.
