The magnetic structure of the spin-chain antiferromagnet SrCo2 V208 is determined by single-crystal neutron diffraction experiment. The system undergoes a long-range magnetic order below the critical temperature TN=4....The magnetic structure of the spin-chain antiferromagnet SrCo2 V208 is determined by single-crystal neutron diffraction experiment. The system undergoes a long-range magnetic order below the critical temperature TN=4.96 K. The moment of 2.16#B per Co at 1.6K in the screw chain running along the c axis Mternates in the c axis. The moments of neighboring screw chains are arranged antiferromagnetically along one in-plane axis and ferromagnetieally Monk the other in-plane axis. This magnetic configuration breaks the four-fold symmetry of the tetragonM crystal structure and leads to two equally populated magnetic twins with the antiferromagnetic vector in the a or b axis. The very similar magnetic state to the isostructural BaCo2 V~ 08 warrants SrCo2 V2 08 as another interesting half-integer spin-chain antiferromagnet for investigation on quantum antiferromagnetism.展开更多
The magnetic structure of CsCo_2 Se_2 was investigated using single-crystal neutron diffraction technique. An antiferromagnetic transition with the propagation vector（0,0,1） was observed at TN= 78 K. The Co magnetic...The magnetic structure of CsCo_2 Se_2 was investigated using single-crystal neutron diffraction technique. An antiferromagnetic transition with the propagation vector（0,0,1） was observed at TN= 78 K. The Co magnetic moment 0.772（6） μB at 10 K pointing in the basal plane couples ferromagnetically in the plane, which stacks antiferromagnetically along the c direction. Tuning and suppressing the interplane antiferromagnetic interaction may be crucial to induce a superconducting state in the material.展开更多
A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of t...A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.展开更多
We present a theoretical scheme to realize two-dimensional(2D)asymmetric diffraction grating in a five-level inverted Y-type asymmetric double semiconductor quantum wells(SQWs)structure with resonant tunneling.The SQW...We present a theoretical scheme to realize two-dimensional(2D)asymmetric diffraction grating in a five-level inverted Y-type asymmetric double semiconductor quantum wells(SQWs)structure with resonant tunneling.The SQW structure interacts with a weak probe laser field,a spatially independent 2D standing-wave(SW)field,and a Laguerre–Gaussian(LG)vortex field,respectively.The results indicate that the diffraction patterns are highly sensitive to amplitude modulation and phase modulation.Because of the existence of vortex light,it is possible to realize asymmetric high-order diffraction in the SQW structure,and then a 2D asymmetric grating is established.By adjusting the detunings of the probe field,vortex field,and SW field,as well as the interaction length,diffraction intensity,and direction of the 2D asymmetric electromagnetically induced grating(EIG)can be controlled effectively.In addition,the number of orbital angular momenta(OAM)and beam waist parameter can be used to modulate the diffraction intensity and energy transfer of the probe light in different regions.High-order diffraction intensity is enhanced and high-efficiency 2D asymmetric diffraction grating with different diffraction patterns is obtained in the scheme.Such 2D asymmetric diffraction grating may be beneficial to the research of optical communication and innovative semiconductor quantum devices.展开更多
In oil and gas exploration,small-scale karst cavities and faults are important targets.The former often serve as reservoir space for carbonate reservoirs,while the latter often provide migration pathways for oil and g...In oil and gas exploration,small-scale karst cavities and faults are important targets.The former often serve as reservoir space for carbonate reservoirs,while the latter often provide migration pathways for oil and gas.Due to these differences,the classification and identification of karst cavities and faults are of great significance for reservoir development.Traditional seismic attributes and diffraction imaging techniques can effectively identify discontinuities in seismic images,but these techniques do not distinguish whether these discontinuities are karst cavities,faults,or other structures.It poses a challenge for seismic interpretation to accurately locate and classify karst cavities or faults within the seismic attribute maps and diffraction imaging profiles.In seismic data,the scattering waves are associated with small-scale scatters like karst cavities,while diffracted waves are seismic responses from discontinuous structures such as faults,reflector edges and fractures.In order to achieve classification and identification of small-scale karst cavities and faults in seismic images,we propose a diffraction classification imaging method which classifies diffracted and scattered waves in the azimuth-dip angle image matrix using a modified DenseNet.We introduce a coordinate attention module into DenseNet,enabling more precise extraction of dynamic and azimuthal features of diffracted and scattered waves in the azimuth-dip angle image matrix.Leveraging these extracted features,the modified DenseNet can produce reliable probabilities for diffracted/scattered waves,achieving high-accuracy automatic classification of cavities and faults based on diffraction imaging.The proposed method achieves 96%classification accuracy on the synthetic dataset.The field data experiment demonstrates that the proposed method can accurately classify small-scale faults and scatterers,further enhancing the resolution of diffraction imaging in complex geologic structures,and contributing to the localization of karstic fracture-cavern reservoirs.展开更多
Nickel-based single-crystal(SX)superalloys are the key metallic materials of aeroengines.However,thermomechanical deformation always occurs during the directional solidification of SX superalloys,negatively influencin...Nickel-based single-crystal(SX)superalloys are the key metallic materials of aeroengines.However,thermomechanical deformation always occurs during the directional solidification of SX superalloys,negatively influencing the SX structure.Casting deformation is simulated in most of the previous studies,whereas the direct simulation of dendritic thermomechanical deformation has been largely ignored,resulting in a lack of comprehensive understanding of this process.In this study,we systematically investigate dendritic thermomechanical deformation with a model coupled with dendrite growth,fluid flow,and thermomechanical deformation behavior.Results reveal that the dendritic thermomechanical deformation-induced dendrite bending is not randomly distributed but is mainly concentrated on the casting surface.The dendritic thermal stress increases as dendrite grows and accumulates after dendrite bridging.Transverse thermal contraction mainly occurs at the edge of casting in the corner,and axial thermal contraction is larger than transverse contraction.The high-stress region of the primary dendrite trunk is mainly distributed below the dendrite bridging near the solidified part,and the stress along the transverse direction reaches its maximum value on the casting surface.Stress concentrated on the casting surface is mainly attributed to variations in transverse temperature gradients caused by heat dissipation on the lateral mold wall,and inconsistent constraints in the lateral mold walls.展开更多
Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)...Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)(H_(2)O)_(21){Ca(H_(2)O)_(2)@Sb_(12)O_(18)[Ni_(2)(OH)(A-α-Si W_(10)O_(37))]_(3)}_(2)·40H_(2)O(1),was constructed using Keggintype polyoxotungstate A-α-Si W_(10)O_(37),along with Ni and Sb elements.The structure features a Tdsymmetric Sb_(12)O_(18)({Sb_(12)})cage that encapsulates an 8-coordinate Ca^(2+)ion at its face.Additionally,the{Sb_(12)}cage forms an 18-nuclear 3d-5p heterometallic cluster by connecting with three di-nuclear nickel clusters through shared oxygen atoms.Electrochemical impedance spectra studies reveal that the single crystal of 1 achieves a proton conductivity of 1.11×10^(-1)S/cm along the[110]direction and 1.04×10^(-1)S/cm along the[100]direction at 85℃ and 98%relative humidity(RH).Furthermore,the powder form of 1 exhibits a proton conductivity of 3.00×10^(-2)S/cm.These findings suggest that compound 1 holds promise as a practical proton conducting material.展开更多
When a laser beam is incident on a nonlinear grating with a laterally modulated second-order nonlinear coefficient,nonlinear diffraction of the noncollinear second-harmonic generation(SHG)signal occurs,with Raman–Nat...When a laser beam is incident on a nonlinear grating with a laterally modulated second-order nonlinear coefficient,nonlinear diffraction of the noncollinear second-harmonic generation(SHG)signal occurs,with Raman–Nath nonlinear diffraction(NRND)being a prominent example.As these SHG NRND processes involve coupling between the fundamental-wave pump laser vectorial field and the SHG laser vectorial field through the second-order nonlinearity secondrank tensor of the nonlinear crystal,the nonlinear interaction between light and the nonlinear grating can be manipulated by adjusting the polarization state of the pump laser.In this paper,we derive the relationship between the polarization state of the incident light and the generated nonlinear diffraction signal based on the nonlinear coupled wave equation and experimentally validate the predicted diffraction characteristics.The results show that the optical properties of each order of NRND are highly sensitive to the polarization angle of the incident pump laser beam.展开更多
The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded micros...The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded microstructure on the HCF behavior remains unclear.In this work,a PtAl-coated third-generation SX superalloy with sheet specimen was thermal-exposed at 1100℃ with different durations and then subjected to HCF tests at 900℃.The influence of microstructural degradation on the HCF life and crack initiation were clarified by analyzing the development of microcracks and coating-substrate microstructure.Notably,the HCF life of the thermal-exposed coated alloy increased abnormally,which was attributed to the transformation of the fatigue crack initiation site from surface mi-crocracks to internal micropores compared to the as-deposited coated alloy.Although the nucleation and growth of surface microcracks occurred along the grain boundaries in the coating and the interdiffusion zone(IDZ)for both the as-deposited and the thermal-exposed coated alloys,remarkable differences of the microcrack growth into the substrate adjacent to the IDZ were observed,changing the crack initiation site.Specifically,the surface microcracks grew into the substrate through the cracking of the non-protective oxide layers in the as-deposited coated alloy.In comparison,the hinderance of the surface microcracks growth was found in the thermal-exposed coated al-loy,due to the formation of a protective Al_(2)O_(3) layer within the microcrack and theγ′rafting in the substrate close to the IDZ.This study will aid in improving the HCF life prediction model for the coated SX superalloys.展开更多
Conventional polycrystalline LiMn_(2)O_(4)(PC-LMO)suffers from poor Li^(+)diffusion rates and structural instability,negatively affecting its electrochemical performance.Here,we design a single-crystal LMO cathode mat...Conventional polycrystalline LiMn_(2)O_(4)(PC-LMO)suffers from poor Li^(+)diffusion rates and structural instability,negatively affecting its electrochemical performance.Here,we design a single-crystal LMO cathode material using BaO flux(SC-LMOB)to address these issues.The BaO flux enables the fabrication of brick-like single-crystal particles,enhancing Li^(+)diffusion by shortening the diffusion path and increasing the unit cell volume.This process also reduces the specific surface area and stabilizes the crystal structure,effectively mitigating Mn dissolution and polarization.As a result,SC-LMOB exhibits ultra-high rate performance and superior structural stability,retaining 88.8%of its capacity at a 20 C discharge rate and achieving capacity retentions of 85.3%and 86.0%after 500 and 300 cycles at 1 C at room and elevated temperatures,respectively.This structural design offers a low-cost,scalable approach for fabricating single-crystal cathode materials with excellent performance.展开更多
Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morpho...Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.展开更多
Optical monitoring of object position and alignment with nanoscale precision is critical for ultra-precision measurement applications,such as micro/nano-fabrication,weak force sensing,and micro-scopic imaging.Traditio...Optical monitoring of object position and alignment with nanoscale precision is critical for ultra-precision measurement applications,such as micro/nano-fabrication,weak force sensing,and micro-scopic imaging.Traditional optical nanometry methods often rely on precision nanostructure fabrication,multi-beam interferometry,or complex post-processing algorithms,which can limit their practical use.In this study,we introduced a simplified and robust quantum measurement technique with an achievable resolution of 2.2 pm and an experimental demonstration of 1 nm resolution,distinguishing it from conventional interferometry,which depended on multiple reference beams.We designed a metasurface substrate with a mode-conversion function,in which an incident Gaussian beam is converted into higher-order transverse electromagnetic mode(TEM)modes.A theoretical analysis,including calculations of the Fisher information,demonstrated that the accuracy was maintained for nanoscale displacements.In conclusion,the study findings provide a new approach for precise alignment and metrology of nanofabrication and other advanced applications.展开更多
Magnesium(Mg)alloys typically exhibit anisotropic mechanical behaviors due to their hexagonal close-packed(hcp)crystal structures,often leading to tension-compression asymmetries.Understanding of the asymmetrical and ...Magnesium(Mg)alloys typically exhibit anisotropic mechanical behaviors due to their hexagonal close-packed(hcp)crystal structures,often leading to tension-compression asymmetries.Understanding of the asymmetrical and related deformation mechanisms is crucial for their structural applications,particularly in the lightweight transportation industries.Nevertheless,the underlying deformation mechanisms(e.g.,slip versus twinning)at each deformation stage during tension and compression have not been fully understood.In this study,we employed tensile and compressive tests on extruded Al and Mn containing Mg alloy,i.e.,an AM alloy Mg-0.6Mn-0.5Al-0.5Zn-0.4Ca,during the synchrotron X-ray diffraction.Our results show that distinct deformation behaviors and mechanisms in tension and compression are associated with the strong texture in the extruded samples:(i)The tensile deformation is dominated by dislocation slips,with activation of non-basaland<c+a>slip,but deformation twinning is suppressed.(ii)The compressive deformation shows early-stage tensile twinning,followed by dislocation slips.Twinning induces grain reorientation,leading to significant lattice strain evolution aligned with the texture.The pronounced tension-compression asymmetry is attributed to the favorable shear stress direction formed in the twinning system during compression,which facilitates the activation of tensile twins.During tension,the strain hardening rate(SHR)drops significantly after yielding due to limited activated slip systems.In contrast,the samples under compression exhibit significant increases in SHR after yielding.During compression,dislocation multiplication dominates the initial strain hardening,while twinning progressively contributes more significantly than dislocation slip at higher strains.This study improves our understanding of the tension-compression and strain hardening asymmetries in extruded AM Mg alloys.展开更多
Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the de...Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the degradation mechanisms associated with the complex multi-layer damage and inter-layer diffusion behavior for TBC/SX systems have not yet been fully elucidated.In this study,using integrated experimental efforts and multiscale characterization techniques,the creep degradation mechanisms of TBC/SX systems at 900℃/500 MPa,980℃/300 MPa,and 1050℃/160 MPa are systematically investigated.Results demonstrate that the creep degradation from TBC intensifies with increasing temperature(T)and stress(σ)ratio(T/σ),exhibiting significant dependency on these two factors,and primarily reduces lifespan of the steady-state stage,with minimal effects on the accelerating stage.During creep deformation,the cracking behavior caused by thermally grown oxide(TGO)beneath the top coat(TC)layer,voids resulting from internal oxidation and interdiffusion in the bond coat(BC)layer,and the recrystallization growth driven by the sandblasting process in the secondary reaction zone(SRZ)are temperature-sensitive damages.In contrast,the initiation and propagation of cracks associated with the topologically close-packed(TCP)phases in the SRZ exhibit pronounced stress sensitivity.Furthermore,the formation of the substrate diffusion zone(SDZ)and the decomposition ofγ/γ′interfacial dislocation networks driven by the Cr-Ru diffusion,as well as the increased stacking fault energy in theγ′phase due to Co loss,are responsible for the acceleration of steady-state creep rate at 1050℃/160 MPa.This work provides a comprehensive and in-depth understanding of the degradation mechanisms under thermal-mechanical coupling in TBC/SX systems,offering new insights into targeted design optimization for multilayered coatings.展开更多
When a pump laser beam strikes the surface of a nonlinear crystal with modulated second-order nonlinearity,various nonlinear diffraction phenomena occur,with nonlinear Raman–Nath diffraction(NRND)being a prominent ex...When a pump laser beam strikes the surface of a nonlinear crystal with modulated second-order nonlinearity,various nonlinear diffraction phenomena occur,with nonlinear Raman–Nath diffraction(NRND)being a prominent example.In this study,we use an 800-nm Ti:sapphire femtosecond laser beam to pump the surface of a periodically poled lithium niobate(PPLN)crystal thin-plate nonlinear grating.By rotating the crystal,we change the incidence angle and observe and measure the exit angle,polarization,and power of NRND spots on the other side of the crystal.The experiment shows that NRND characteristics are highly sensitive to the incidence angle of the pump laser beam,which are consistent with the theoretical prediction.We expect that this research will advance the understanding of nonlinear diffraction and provide valuable insights for nonlinear optical interaction in complicated geometric and physical configurations.展开更多
Feature extraction in the optical domain offers a promising low-latency,high-throughput solution.Optical diffraction-based feature extraction operating under a coherent light source can further achieve parallel output...Feature extraction in the optical domain offers a promising low-latency,high-throughput solution.Optical diffraction-based feature extraction operating under a coherent light source can further achieve parallel outputs with low energy consumption.However,it presents significant challenges for maintaining the coherent input,scaling the operation rates beyond 10 GHz,and ensuring the effective extraction of functional configuration simultaneously.We propose an optical feature extraction engine(OFE^(2)),which is composed of a diffraction operator and a data preparation module,powering high-speed feature extraction for both image and temporal series tasks.This OFE^(2)can achieve a core latency of less than 250.5 ps;in addition,it can reach a throughput of 250 GOPS and an efficiency of 2.06 TOPS/W.Supported by the OFE^(2),a novel feature extraction paradigm is emerging,enabling high-speed,low-latency service access for applications in scene recognition,medical assistance,and digital finance.展开更多
Face-centered cubic(FCC)equi-atomic multi-principal element alloys(MPEAs)exhibit excellent mechan-ical properties over a broad temperature range from cryogenic temperatures(CTs)to room temperature(RT).Specifically,whi...Face-centered cubic(FCC)equi-atomic multi-principal element alloys(MPEAs)exhibit excellent mechan-ical properties over a broad temperature range from cryogenic temperatures(CTs)to room temperature(RT).Specifically,while the deformation mechanism is dominated solely by dislocation slip at RT,the re-duction in stacking fault energy(SFE)at CTs leads to enhanced strain hardening with deformation twin-ning.This study employs in-situ neutron diffraction to reveal the temperature-dependent deformation be-havior of the FCC/body-centered cubic(BCC)dual-phase(DP)Al7(CoNiV)93 medium-entropy alloy(MEA),which possesses a matrix exhibiting deformation behavior analogous to that of representative equi-atomic MPEAs.Alongside the increased lattice friction stress associated with reduced temperature as a thermal component,deformation twinning at liquid nitrogen temperature(LNT)facilitates dislocation activity in the FCC matrix,leading to additional strain hardening induced by the dynamic Hall-Petch effect.This would give the appearance that the improved strengthening/hardening behaviors at LNT,compared to RT,are primarily attributable to the FCC phase.In contrast,the BCC precipitates are governed solely by dislocation slip for plastic deformation at both 77 K and 298 K,exhibiting a similar trend in dislocation density evolution.Nevertheless,empirical and quantitative findings indicate that the intrinsically high Peierls-Nabarro barriers in the BCC precipitates exhibit pronounced temperature-dependent lattice fric-tion stress,suggesting that the BCC precipitates play a more significant role in the temperature-dependent strengthening/hardening behaviors for the DP-MEA.This study provides a comprehensive understanding of deformation behavior by thoroughly analyzing temperature-dependent strengthening/hardening mech-anisms across various DP-MPEA systems,offering valuable guidelines for future alloy design.展开更多
The effects of solid solution on the deformation behavior of binary Mg-xZn(x=0,1,2 wt%)alloys featuring a designated texture that enables extension twinning under tension parallel to the basal pole in most grains,were...The effects of solid solution on the deformation behavior of binary Mg-xZn(x=0,1,2 wt%)alloys featuring a designated texture that enables extension twinning under tension parallel to the basal pole in most grains,were investigated using in-situ neutron diffraction and the EVPSC-TDT model.Neutron diffraction was used to quantitatively track grain-level lattice strains and diffraction intensity changes(related to mechanical twinning)in differently oriented grains of each alloy during cyclic tensile/compressive loadings.These measurements were accurately captured by the model.The stress-strain curves of Mg-1 wt%Zn and Mg-2 wt%Zn alloys show as-expected solid solution strengthening from the addition of Zn compared to pure Mg.The macroscopic yielding and hardening behaviors are explained by alternating slip and twinning modes as calculated by the model.The solid solution's influence on individual deformation modes,including basal〈a〉slip,prismatic〈a〉slip,and extension twinning,was then quantitatively assessed in terms of activity,yielding behavior,and hardening response by combining neutron diffraction results with crystal plasticity predictions.The Mg-1 wt%Zn alloy displays distinct yielding and hardening behavior due to solid solution softening of prismatic〈a〉slip.Additionally,the dependence of extension twinning,in terms of the twinning volume fraction,on Zn content exhibits opposite trends under tensile and compressive loadings.展开更多
The detrimental phase transformations of sodium layered transition metal oxides(Na_(x)TMO_(2))during desodiation/sodiation seriously suppress their practical applications for sodium ion batteries(SIBs).Undoubtedly,com...The detrimental phase transformations of sodium layered transition metal oxides(Na_(x)TMO_(2))during desodiation/sodiation seriously suppress their practical applications for sodium ion batteries(SIBs).Undoubtedly,comprehensively investigating of the dynamic crystal structure evolutions of Na_(x)TMO_(2)associating with Na ions extraction/intercalation and then deeply understanding of the relationships between electrochemical performances and phase structures drawing support from advanced characterization techniques are indispensable.In-situ high-energy X-ray diffraction(HEXRD),a powerful technology to distinguish the crystal structure of electrode materials,has been widely used to identify the phase evolutions of Na_(x)TMO_(2)and then profoundly revealed the electrochemical reaction processes.In this review,we begin with the descriptions of synchrotron characterization techniques and then present the advantages of synchrotron X-ray diffraction(XRD)over conventional XRD in detail.The optimizations of structural stability and electrochemical properties for P2-,O3-,and P2/O3-type Na_(x)TMO_(2)cathodes through single/dual-site substitution,high-entropy design,phase composition regulation,and surface engineering are summarized.The dynamic crystal structure evolutions of Na_(x)TMO_(2)polytypes during Na ion extraction/intercalation as well as corresponding structural enhancement mechanisms characterizing by means of HEXRD are concluded.The interior relationships between structure/component of Na_(x)TMO_(2)polytypes and their electrochemical properties are discussed.Finally,we look forward the research directions and issues in the route to improve the electrochemical properties of Na_(x)TMO_(2)cathodes for SIBs in the future and the combined utilizations of multiple characterization techniques.This review will provide significant guidelines for rational designs of high-performance Na_(x)TMO_(2)cathodes.展开更多
Lithography is a Key enabling technique in modern micro/nano scale technology.Achieving the optimal trade-off between resolution,throughput,and cost remains a central focus in the ongoing development.However,current l...Lithography is a Key enabling technique in modern micro/nano scale technology.Achieving the optimal trade-off between resolution,throughput,and cost remains a central focus in the ongoing development.However,current lithographic techniques such as direct-write,projection,and extreme ultraviolet lithography achieve higher resolution at the expense of increased complexity in optical systems or the use of shorter-wavelength light sources,thus raising the overall cost of production.Here,we present a cost-effective and wafer-level perfect conformal contact lithography at the diffraction limit.By leveraging a transferable photoresist,the technique ensures optimal contact between the mask and photoresist with zero-gap,facilitating the transfer of patterns at the diffraction limit while maintaining high fidelity and uniformity across large wafers.This technique applies to a wide range of complex surfaces,including non-conductive glass surfaces,flexible substrates,and curved surfaces.The proposed technique expands the potential of contact photolithography for novel device architectures and practic al manufacturing processes.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB921700 and 2011CBA00112the National Natural Science Foundation of China under Grant Nos 11034012 and 11190024
文摘The magnetic structure of the spin-chain antiferromagnet SrCo2 V208 is determined by single-crystal neutron diffraction experiment. The system undergoes a long-range magnetic order below the critical temperature TN=4.96 K. The moment of 2.16#B per Co at 1.6K in the screw chain running along the c axis Mternates in the c axis. The moments of neighboring screw chains are arranged antiferromagnetically along one in-plane axis and ferromagnetieally Monk the other in-plane axis. This magnetic configuration breaks the four-fold symmetry of the tetragonM crystal structure and leads to two equally populated magnetic twins with the antiferromagnetic vector in the a or b axis. The very similar magnetic state to the isostructural BaCo2 V~ 08 warrants SrCo2 V2 08 as another interesting half-integer spin-chain antiferromagnet for investigation on quantum antiferromagnetism.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB921700)the National Natural Science Foundation of China(Grant No.11190024)+2 种基金the Fundamental Research Funds for the Central Universities,Chinathe Research Funds of Renmin University of China(Grant Nos.17XNLF04 and 17XNLF06)support from China Scholarship Council
文摘The magnetic structure of CsCo_2 Se_2 was investigated using single-crystal neutron diffraction technique. An antiferromagnetic transition with the propagation vector（0,0,1） was observed at TN= 78 K. The Co magnetic moment 0.772（6） μB at 10 K pointing in the basal plane couples ferromagnetically in the plane, which stacks antiferromagnetically along the c direction. Tuning and suppressing the interplane antiferromagnetic interaction may be crucial to induce a superconducting state in the material.
基金China Postdoctoral Science Foundation General Project(2024M760034)Postdoctoral Research Programs of Anhui Province(2024A774)。
文摘A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.
基金supported by the National Natural Science Foundation of China(Grant No.12105210)the Knowledge Innovation Program of Wuhan-Basi Research(Grant No.2023010201010149)。
文摘We present a theoretical scheme to realize two-dimensional(2D)asymmetric diffraction grating in a five-level inverted Y-type asymmetric double semiconductor quantum wells(SQWs)structure with resonant tunneling.The SQW structure interacts with a weak probe laser field,a spatially independent 2D standing-wave(SW)field,and a Laguerre–Gaussian(LG)vortex field,respectively.The results indicate that the diffraction patterns are highly sensitive to amplitude modulation and phase modulation.Because of the existence of vortex light,it is possible to realize asymmetric high-order diffraction in the SQW structure,and then a 2D asymmetric grating is established.By adjusting the detunings of the probe field,vortex field,and SW field,as well as the interaction length,diffraction intensity,and direction of the 2D asymmetric electromagnetically induced grating(EIG)can be controlled effectively.In addition,the number of orbital angular momenta(OAM)and beam waist parameter can be used to modulate the diffraction intensity and energy transfer of the probe light in different regions.High-order diffraction intensity is enhanced and high-efficiency 2D asymmetric diffraction grating with different diffraction patterns is obtained in the scheme.Such 2D asymmetric diffraction grating may be beneficial to the research of optical communication and innovative semiconductor quantum devices.
基金supported by Science Fund for Creative Research Groups of the National Natural Science Foundation of China,No.42321002。
文摘In oil and gas exploration,small-scale karst cavities and faults are important targets.The former often serve as reservoir space for carbonate reservoirs,while the latter often provide migration pathways for oil and gas.Due to these differences,the classification and identification of karst cavities and faults are of great significance for reservoir development.Traditional seismic attributes and diffraction imaging techniques can effectively identify discontinuities in seismic images,but these techniques do not distinguish whether these discontinuities are karst cavities,faults,or other structures.It poses a challenge for seismic interpretation to accurately locate and classify karst cavities or faults within the seismic attribute maps and diffraction imaging profiles.In seismic data,the scattering waves are associated with small-scale scatters like karst cavities,while diffracted waves are seismic responses from discontinuous structures such as faults,reflector edges and fractures.In order to achieve classification and identification of small-scale karst cavities and faults in seismic images,we propose a diffraction classification imaging method which classifies diffracted and scattered waves in the azimuth-dip angle image matrix using a modified DenseNet.We introduce a coordinate attention module into DenseNet,enabling more precise extraction of dynamic and azimuthal features of diffracted and scattered waves in the azimuth-dip angle image matrix.Leveraging these extracted features,the modified DenseNet can produce reliable probabilities for diffracted/scattered waves,achieving high-accuracy automatic classification of cavities and faults based on diffraction imaging.The proposed method achieves 96%classification accuracy on the synthetic dataset.The field data experiment demonstrates that the proposed method can accurately classify small-scale faults and scatterers,further enhancing the resolution of diffraction imaging in complex geologic structures,and contributing to the localization of karstic fracture-cavern reservoirs.
基金financially sponsored by the National Natural Science Foundation of China(Nos.U2441268 and 52304406)the Natural Science Foundation of Shanghai,China(No.23TS1401900)+2 种基金the Science Foundation of Aeronautics(PSSFA),China(No.2024Z053057002)the Science and Technology Cooperation Program of Shanghai Jiao Tong University in Inner Mongolia Autonomous Region-Action Plan of Shanghai Jiao Tong University for“Revitalizing Inner Mongolia through Science and Technology”,ChinaLuwei Yang would like to thank the financial support from the Chinese Scholarship Council(No.202306230337).
文摘Nickel-based single-crystal(SX)superalloys are the key metallic materials of aeroengines.However,thermomechanical deformation always occurs during the directional solidification of SX superalloys,negatively influencing the SX structure.Casting deformation is simulated in most of the previous studies,whereas the direct simulation of dendritic thermomechanical deformation has been largely ignored,resulting in a lack of comprehensive understanding of this process.In this study,we systematically investigate dendritic thermomechanical deformation with a model coupled with dendrite growth,fluid flow,and thermomechanical deformation behavior.Results reveal that the dendritic thermomechanical deformation-induced dendrite bending is not randomly distributed but is mainly concentrated on the casting surface.The dendritic thermal stress increases as dendrite grows and accumulates after dendrite bridging.Transverse thermal contraction mainly occurs at the edge of casting in the corner,and axial thermal contraction is larger than transverse contraction.The high-stress region of the primary dendrite trunk is mainly distributed below the dendrite bridging near the solidified part,and the stress along the transverse direction reaches its maximum value on the casting surface.Stress concentrated on the casting surface is mainly attributed to variations in transverse temperature gradients caused by heat dissipation on the lateral mold wall,and inconsistent constraints in the lateral mold walls.
基金the financial support from the National Natural Science Foundation of China(Nos.22109164 and 22371046)the Key Program of the Natural Science Foundation of Fujian Province(No.2021J02007)。
文摘Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)(H_(2)O)_(21){Ca(H_(2)O)_(2)@Sb_(12)O_(18)[Ni_(2)(OH)(A-α-Si W_(10)O_(37))]_(3)}_(2)·40H_(2)O(1),was constructed using Keggintype polyoxotungstate A-α-Si W_(10)O_(37),along with Ni and Sb elements.The structure features a Tdsymmetric Sb_(12)O_(18)({Sb_(12)})cage that encapsulates an 8-coordinate Ca^(2+)ion at its face.Additionally,the{Sb_(12)}cage forms an 18-nuclear 3d-5p heterometallic cluster by connecting with three di-nuclear nickel clusters through shared oxygen atoms.Electrochemical impedance spectra studies reveal that the single crystal of 1 achieves a proton conductivity of 1.11×10^(-1)S/cm along the[110]direction and 1.04×10^(-1)S/cm along the[100]direction at 85℃ and 98%relative humidity(RH).Furthermore,the powder form of 1 exhibits a proton conductivity of 3.00×10^(-2)S/cm.These findings suggest that compound 1 holds promise as a practical proton conducting material.
基金Project supported by Science and Technology Project of Guangdong(Grant No.2020B010190001)the National Natural Science Foundation of China(Grant No.12434016)National Funded Postdoctoral Researcher Program(Grant No.GZB20240785)。
文摘When a laser beam is incident on a nonlinear grating with a laterally modulated second-order nonlinear coefficient,nonlinear diffraction of the noncollinear second-harmonic generation(SHG)signal occurs,with Raman–Nath nonlinear diffraction(NRND)being a prominent example.As these SHG NRND processes involve coupling between the fundamental-wave pump laser vectorial field and the SHG laser vectorial field through the second-order nonlinearity secondrank tensor of the nonlinear crystal,the nonlinear interaction between light and the nonlinear grating can be manipulated by adjusting the polarization state of the pump laser.In this paper,we derive the relationship between the polarization state of the incident light and the generated nonlinear diffraction signal based on the nonlinear coupled wave equation and experimentally validate the predicted diffraction characteristics.The results show that the optical properties of each order of NRND are highly sensitive to the polarization angle of the incident pump laser beam.
基金financially supported by National Key Research and Development Program of China(No.2022YFB 3708100)the Science Center for Gas Turbine Project,China(No.P2021-A-IV-002-001)+1 种基金the National Natural Science Foundation of China(Nos.52331005 and 52201100)the State Key Laboratory for Advanced Metals and Materials,China(No.2024-Z02).
文摘The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded microstructure on the HCF behavior remains unclear.In this work,a PtAl-coated third-generation SX superalloy with sheet specimen was thermal-exposed at 1100℃ with different durations and then subjected to HCF tests at 900℃.The influence of microstructural degradation on the HCF life and crack initiation were clarified by analyzing the development of microcracks and coating-substrate microstructure.Notably,the HCF life of the thermal-exposed coated alloy increased abnormally,which was attributed to the transformation of the fatigue crack initiation site from surface mi-crocracks to internal micropores compared to the as-deposited coated alloy.Although the nucleation and growth of surface microcracks occurred along the grain boundaries in the coating and the interdiffusion zone(IDZ)for both the as-deposited and the thermal-exposed coated alloys,remarkable differences of the microcrack growth into the substrate adjacent to the IDZ were observed,changing the crack initiation site.Specifically,the surface microcracks grew into the substrate through the cracking of the non-protective oxide layers in the as-deposited coated alloy.In comparison,the hinderance of the surface microcracks growth was found in the thermal-exposed coated al-loy,due to the formation of a protective Al_(2)O_(3) layer within the microcrack and theγ′rafting in the substrate close to the IDZ.This study will aid in improving the HCF life prediction model for the coated SX superalloys.
基金supported by National Key Research and Development Program of China(No.2021YFB3502000)the National Natural Science Foundation of China(Nos.22309207,52325405,U21A20284,52261135632,51874358 and 51772333)。
文摘Conventional polycrystalline LiMn_(2)O_(4)(PC-LMO)suffers from poor Li^(+)diffusion rates and structural instability,negatively affecting its electrochemical performance.Here,we design a single-crystal LMO cathode material using BaO flux(SC-LMOB)to address these issues.The BaO flux enables the fabrication of brick-like single-crystal particles,enhancing Li^(+)diffusion by shortening the diffusion path and increasing the unit cell volume.This process also reduces the specific surface area and stabilizes the crystal structure,effectively mitigating Mn dissolution and polarization.As a result,SC-LMOB exhibits ultra-high rate performance and superior structural stability,retaining 88.8%of its capacity at a 20 C discharge rate and achieving capacity retentions of 85.3%and 86.0%after 500 and 300 cycles at 1 C at room and elevated temperatures,respectively.This structural design offers a low-cost,scalable approach for fabricating single-crystal cathode materials with excellent performance.
基金the National Natural Science Foundation of China(No.22274021)Natural Science Foundation of Fujian Province(No.2022J01535)for financial support。
文摘Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.
基金supported by the West Light Project,CAS(xbzg-zdsys-202206)the National Key Research and Development Program of China(2021YFA1401003)+1 种基金the National Natural Science Foundation of China(NSFC)(62222513,U24A6010,and U24A20317)the Sichuan Engineering Research Center of Digital Materials.
文摘Optical monitoring of object position and alignment with nanoscale precision is critical for ultra-precision measurement applications,such as micro/nano-fabrication,weak force sensing,and micro-scopic imaging.Traditional optical nanometry methods often rely on precision nanostructure fabrication,multi-beam interferometry,or complex post-processing algorithms,which can limit their practical use.In this study,we introduced a simplified and robust quantum measurement technique with an achievable resolution of 2.2 pm and an experimental demonstration of 1 nm resolution,distinguishing it from conventional interferometry,which depended on multiple reference beams.We designed a metasurface substrate with a mode-conversion function,in which an incident Gaussian beam is converted into higher-order transverse electromagnetic mode(TEM)modes.A theoretical analysis,including calculations of the Fisher information,demonstrated that the accuracy was maintained for nanoscale displacements.In conclusion,the study findings provide a new approach for precise alignment and metrology of nanofabrication and other advanced applications.
文摘Magnesium(Mg)alloys typically exhibit anisotropic mechanical behaviors due to their hexagonal close-packed(hcp)crystal structures,often leading to tension-compression asymmetries.Understanding of the asymmetrical and related deformation mechanisms is crucial for their structural applications,particularly in the lightweight transportation industries.Nevertheless,the underlying deformation mechanisms(e.g.,slip versus twinning)at each deformation stage during tension and compression have not been fully understood.In this study,we employed tensile and compressive tests on extruded Al and Mn containing Mg alloy,i.e.,an AM alloy Mg-0.6Mn-0.5Al-0.5Zn-0.4Ca,during the synchrotron X-ray diffraction.Our results show that distinct deformation behaviors and mechanisms in tension and compression are associated with the strong texture in the extruded samples:(i)The tensile deformation is dominated by dislocation slips,with activation of non-basaland<c+a>slip,but deformation twinning is suppressed.(ii)The compressive deformation shows early-stage tensile twinning,followed by dislocation slips.Twinning induces grain reorientation,leading to significant lattice strain evolution aligned with the texture.The pronounced tension-compression asymmetry is attributed to the favorable shear stress direction formed in the twinning system during compression,which facilitates the activation of tensile twins.During tension,the strain hardening rate(SHR)drops significantly after yielding due to limited activated slip systems.In contrast,the samples under compression exhibit significant increases in SHR after yielding.During compression,dislocation multiplication dominates the initial strain hardening,while twinning progressively contributes more significantly than dislocation slip at higher strains.This study improves our understanding of the tension-compression and strain hardening asymmetries in extruded AM Mg alloys.
基金supported by the National Science and Technology Major Project of China(No.J2019-Ⅲ-0008-0051)the National Natural Science Foundation of China(Nos.52201140,52375225,and 92360307)the Natural Science Foundation for Youths of Shaanxi Province(No.2023-JC-QN-0521).
文摘Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the degradation mechanisms associated with the complex multi-layer damage and inter-layer diffusion behavior for TBC/SX systems have not yet been fully elucidated.In this study,using integrated experimental efforts and multiscale characterization techniques,the creep degradation mechanisms of TBC/SX systems at 900℃/500 MPa,980℃/300 MPa,and 1050℃/160 MPa are systematically investigated.Results demonstrate that the creep degradation from TBC intensifies with increasing temperature(T)and stress(σ)ratio(T/σ),exhibiting significant dependency on these two factors,and primarily reduces lifespan of the steady-state stage,with minimal effects on the accelerating stage.During creep deformation,the cracking behavior caused by thermally grown oxide(TGO)beneath the top coat(TC)layer,voids resulting from internal oxidation and interdiffusion in the bond coat(BC)layer,and the recrystallization growth driven by the sandblasting process in the secondary reaction zone(SRZ)are temperature-sensitive damages.In contrast,the initiation and propagation of cracks associated with the topologically close-packed(TCP)phases in the SRZ exhibit pronounced stress sensitivity.Furthermore,the formation of the substrate diffusion zone(SDZ)and the decomposition ofγ/γ′interfacial dislocation networks driven by the Cr-Ru diffusion,as well as the increased stacking fault energy in theγ′phase due to Co loss,are responsible for the acceleration of steady-state creep rate at 1050℃/160 MPa.This work provides a comprehensive and in-depth understanding of the degradation mechanisms under thermal-mechanical coupling in TBC/SX systems,offering new insights into targeted design optimization for multilayered coatings.
基金supported by the Science and Technology Project of Guangdong Province,China(Grant No.2020B010190001)the National Natural Science Foundation of China(Grant No.12434016)the National Funded Postdoctoral Researcher Program(Grant No.GZB20240785).
文摘When a pump laser beam strikes the surface of a nonlinear crystal with modulated second-order nonlinearity,various nonlinear diffraction phenomena occur,with nonlinear Raman–Nath diffraction(NRND)being a prominent example.In this study,we use an 800-nm Ti:sapphire femtosecond laser beam to pump the surface of a periodically poled lithium niobate(PPLN)crystal thin-plate nonlinear grating.By rotating the crystal,we change the incidence angle and observe and measure the exit angle,polarization,and power of NRND spots on the other side of the crystal.The experiment shows that NRND characteristics are highly sensitive to the incidence angle of the pump laser beam,which are consistent with the theoretical prediction.We expect that this research will advance the understanding of nonlinear diffraction and provide valuable insights for nonlinear optical interaction in complicated geometric and physical configurations.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFE0203600)the National Natural Science Foundation of China(Grant No.62135009).
文摘Feature extraction in the optical domain offers a promising low-latency,high-throughput solution.Optical diffraction-based feature extraction operating under a coherent light source can further achieve parallel outputs with low energy consumption.However,it presents significant challenges for maintaining the coherent input,scaling the operation rates beyond 10 GHz,and ensuring the effective extraction of functional configuration simultaneously.We propose an optical feature extraction engine(OFE^(2)),which is composed of a diffraction operator and a data preparation module,powering high-speed feature extraction for both image and temporal series tasks.This OFE^(2)can achieve a core latency of less than 250.5 ps;in addition,it can reach a throughput of 250 GOPS and an efficiency of 2.06 TOPS/W.Supported by the OFE^(2),a novel feature extraction paradigm is emerging,enabling high-speed,low-latency service access for applications in scene recognition,medical assistance,and digital finance.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(Nos.NRF-2021R1A2C3006662,NRF-2022R1A5A1030054,and RS-2023-00281246)supported by the Basic Science Research Program‘Fostering the Next Generation of Researchers(Ph.D.Candidate)’through the NRF funded by the Ministry of Edu-cation(No.RS-2023-00275651).
文摘Face-centered cubic(FCC)equi-atomic multi-principal element alloys(MPEAs)exhibit excellent mechan-ical properties over a broad temperature range from cryogenic temperatures(CTs)to room temperature(RT).Specifically,while the deformation mechanism is dominated solely by dislocation slip at RT,the re-duction in stacking fault energy(SFE)at CTs leads to enhanced strain hardening with deformation twin-ning.This study employs in-situ neutron diffraction to reveal the temperature-dependent deformation be-havior of the FCC/body-centered cubic(BCC)dual-phase(DP)Al7(CoNiV)93 medium-entropy alloy(MEA),which possesses a matrix exhibiting deformation behavior analogous to that of representative equi-atomic MPEAs.Alongside the increased lattice friction stress associated with reduced temperature as a thermal component,deformation twinning at liquid nitrogen temperature(LNT)facilitates dislocation activity in the FCC matrix,leading to additional strain hardening induced by the dynamic Hall-Petch effect.This would give the appearance that the improved strengthening/hardening behaviors at LNT,compared to RT,are primarily attributable to the FCC phase.In contrast,the BCC precipitates are governed solely by dislocation slip for plastic deformation at both 77 K and 298 K,exhibiting a similar trend in dislocation density evolution.Nevertheless,empirical and quantitative findings indicate that the intrinsically high Peierls-Nabarro barriers in the BCC precipitates exhibit pronounced temperature-dependent lattice fric-tion stress,suggesting that the BCC precipitates play a more significant role in the temperature-dependent strengthening/hardening behaviors for the DP-MEA.This study provides a comprehensive understanding of deformation behavior by thoroughly analyzing temperature-dependent strengthening/hardening mech-anisms across various DP-MPEA systems,offering valuable guidelines for future alloy design.
基金supported by the National Research Foundation grant funded by the Korean government(No,2023R1A2C2007190,RS-2024-00398068)partially funded by the Natural Science Foundation of Shandong Province,China(No.ZR2022QE206).
文摘The effects of solid solution on the deformation behavior of binary Mg-xZn(x=0,1,2 wt%)alloys featuring a designated texture that enables extension twinning under tension parallel to the basal pole in most grains,were investigated using in-situ neutron diffraction and the EVPSC-TDT model.Neutron diffraction was used to quantitatively track grain-level lattice strains and diffraction intensity changes(related to mechanical twinning)in differently oriented grains of each alloy during cyclic tensile/compressive loadings.These measurements were accurately captured by the model.The stress-strain curves of Mg-1 wt%Zn and Mg-2 wt%Zn alloys show as-expected solid solution strengthening from the addition of Zn compared to pure Mg.The macroscopic yielding and hardening behaviors are explained by alternating slip and twinning modes as calculated by the model.The solid solution's influence on individual deformation modes,including basal〈a〉slip,prismatic〈a〉slip,and extension twinning,was then quantitatively assessed in terms of activity,yielding behavior,and hardening response by combining neutron diffraction results with crystal plasticity predictions.The Mg-1 wt%Zn alloy displays distinct yielding and hardening behavior due to solid solution softening of prismatic〈a〉slip.Additionally,the dependence of extension twinning,in terms of the twinning volume fraction,on Zn content exhibits opposite trends under tensile and compressive loadings.
基金supported by the State Grid Corporation Science and Technology Project(No.5419-202158503A-0-5-ZN)。
文摘The detrimental phase transformations of sodium layered transition metal oxides(Na_(x)TMO_(2))during desodiation/sodiation seriously suppress their practical applications for sodium ion batteries(SIBs).Undoubtedly,comprehensively investigating of the dynamic crystal structure evolutions of Na_(x)TMO_(2)associating with Na ions extraction/intercalation and then deeply understanding of the relationships between electrochemical performances and phase structures drawing support from advanced characterization techniques are indispensable.In-situ high-energy X-ray diffraction(HEXRD),a powerful technology to distinguish the crystal structure of electrode materials,has been widely used to identify the phase evolutions of Na_(x)TMO_(2)and then profoundly revealed the electrochemical reaction processes.In this review,we begin with the descriptions of synchrotron characterization techniques and then present the advantages of synchrotron X-ray diffraction(XRD)over conventional XRD in detail.The optimizations of structural stability and electrochemical properties for P2-,O3-,and P2/O3-type Na_(x)TMO_(2)cathodes through single/dual-site substitution,high-entropy design,phase composition regulation,and surface engineering are summarized.The dynamic crystal structure evolutions of Na_(x)TMO_(2)polytypes during Na ion extraction/intercalation as well as corresponding structural enhancement mechanisms characterizing by means of HEXRD are concluded.The interior relationships between structure/component of Na_(x)TMO_(2)polytypes and their electrochemical properties are discussed.Finally,we look forward the research directions and issues in the route to improve the electrochemical properties of Na_(x)TMO_(2)cathodes for SIBs in the future and the combined utilizations of multiple characterization techniques.This review will provide significant guidelines for rational designs of high-performance Na_(x)TMO_(2)cathodes.
基金supported by the National Key Research and Development Program of China (2022YFB4602600)National Natural Science Foundation of China (Grant Nos. 52425508 & 52221001)the Hunan Provincial Natural Science Foundation of China (2025JJ60286)。
文摘Lithography is a Key enabling technique in modern micro/nano scale technology.Achieving the optimal trade-off between resolution,throughput,and cost remains a central focus in the ongoing development.However,current lithographic techniques such as direct-write,projection,and extreme ultraviolet lithography achieve higher resolution at the expense of increased complexity in optical systems or the use of shorter-wavelength light sources,thus raising the overall cost of production.Here,we present a cost-effective and wafer-level perfect conformal contact lithography at the diffraction limit.By leveraging a transferable photoresist,the technique ensures optimal contact between the mask and photoresist with zero-gap,facilitating the transfer of patterns at the diffraction limit while maintaining high fidelity and uniformity across large wafers.This technique applies to a wide range of complex surfaces,including non-conductive glass surfaces,flexible substrates,and curved surfaces.The proposed technique expands the potential of contact photolithography for novel device architectures and practic al manufacturing processes.
