Sheet-metal products are integral parts of engineering industries and academia research. Various testing techniques have revealed the deformation behaviors of sheet metals under complex stress states. Information obta...Sheet-metal products are integral parts of engineering industries and academia research. Various testing techniques have revealed the deformation behaviors of sheet metals under complex stress states. Information obtained from tensile and compression tests, however, are insufficient for the identification of material parameters relevant to modern constitutive laws, which require experimental setups capable of generating various loading conditions and applying great amounts of strain to sheet metals. In-plane shear testing has emerged as an important method to overcome the challenges associated with tension and compression tests and can provide additional information about deformation behaviors under large plastic strains. Materials such as Mg alloys with poor levels of both ductility and formability cannot accommodate large plastic strains. Therefore, tension and compression tests have limitations in explaining the material behaviors that occur during sheet metal forming where large plastic strains are introduced. Many studies have been conducted to explain the deformation behaviors of Mg alloys under shear deformation techniques. These include severe plastic deformation(SPD), especially the equal channel angular pressing(ECAP)and equal channel angular extrusion, rolling combined with shear deformation i.e. differential speed rolling(DSR), and also in-plane shear for sheet metals, particularly under large levels of plastic strain. These in-plane shear technique involves the Miyauchi shear test, ASTM shear test, and twin bridge shear tests. Moreover, many experimental results have revealed that the evolution of microstructure and texture during in-plane shear is closely related to the failure behavior of materials. Therefore, this review is focused on techniques for in-plane shear testing that have been reported thus far, on the effect of in-plane shear on the microstructure development of Mg alloy sheets, and on the usefulness of in-plane shear testing to evaluate the formability of Mg alloy sheets.展开更多
The popularization of portable,implantable and wearable microelectronics has greatly stimulated the rapid development of high-power planar micro-supercapacitors(PMSCs).Particularly,the introduction of new functionalit...The popularization of portable,implantable and wearable microelectronics has greatly stimulated the rapid development of high-power planar micro-supercapacitors(PMSCs).Particularly,the introduction of new functionalities(e.g.,high voltage,flexibility,stretchability,self-healing,electrochromism and photo/thermal response)to PMSCs is essential for building multifunctional PMSCs and their smart selfpowered integrated microsystems.In this review,we summarized the latest advances in PMSCs from various functional microdevices to their smart integrated microsystems.Primarily,the functionalities of PMSCs are characterized by three major factors to emphasize their electrochemical behavior and unique scope of application.These include but are not limited to high-voltage outputs(realized through asymmetric configuration,novel electrolyte and modular integration),mechanical resilience that includes various feats of flexibility or stretchability,and response to stimuli(self-healing,electrochromic,photo-responsive,or thermal-responsive properties).Furthermore,three representative integrated microsystems including energy harvester-PMSC,PMSC-energy consumption,and all-in-one selfpowered microsystems are elaborately overviewed to understand the emerging intelligent interaction models.Finally,the key perspectives,challenges and opportunities of PMSCs for powering smart microelectronics are proposed in brief.展开更多
Broad-spectrum absorption and highly effective charge-carrier separation are two essential requirements to improve the photocatalytic performance of semiconductor-based photocatalysts.In this work,a fascinating one-ph...Broad-spectrum absorption and highly effective charge-carrier separation are two essential requirements to improve the photocatalytic performance of semiconductor-based photocatalysts.In this work,a fascinating one-photon system is reported by rationally fabricating 2D in-plane Bi_(2)O_(3)/BiOCl(i-Cl)heterostructures for efficient photocatalytic degradation of RhB and TC.Systematic investigations revealed that the matched band structure generated an internal electric field and a chemical bond connection between the Bi_(2)O_(3)and BiOCl in the Bi_(2)O_(3)/BiOCl composite that could effectively improve the utilization ratio of visible light and the separation effectivity of photo-generated carriers in space.The formed interactions at the 2D in-plane heterojunction interface induced the one-photon excitation pathway which has been confirmed by the experiment and DFT calculations.As a result,the i-Cl samples showed significantly enhanced photocatalytic efficiency towards the degradation of RhB and TC(RhB:0.106 min^(-1);TC:0.048 min^(-1))under visible light.The degradation activities of RhB and TC for i-Cl were 265.08 and 4.08times that of pure BiOCl,as well as 9.27 and 2.14 times that of mechanistically mixed Bi_(2)O_(3)/BiOCl samples,respectively.This work provides a logical strategy to construct other 2D in-plane heterojunctions with a one-photon excitation pathway with enhanced performance.展开更多
The analysis method of lattice dynamics in classical physics is extended to study the propertiesof in-plane wave motion in the hybrid-mass finite element model in this paper. The dispersion equations of Pand SV waves ...The analysis method of lattice dynamics in classical physics is extended to study the propertiesof in-plane wave motion in the hybrid-mass finite element model in this paper. The dispersion equations of Pand SV waves in the discrete model are first obtained by means of separating the characteristic equation of themotion equation, and then used to analyse the properties of P-and SV-homogeneous, inhomogeneous wavesand other types of motion in the model. The dispersion characters, cut-off frequencies of P and SV waves,the polarization drift and appendent anisotropic property of wave motion caused by the discretization are finallydiscussed.展开更多
Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of t...Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of the stable Ntriple bondN triple bonds. Herein, we design a new MoS_(2) with in-plane defect cluster through a bottom-up approach for the first time, where the defect cluster is composed of three adjacent S vacancies. The well-defined in-plane defect clusters could contribute to the strong chemical adsorption and activation towards inert nitrogen, achieving an excellent eNRR performance with an ammonia yield rate of 43.4 ± 3 μg h^(−1) mgcat.^(−1) and a Faradaic efficiency of 16.8 ± 2% at −0.3 V (vs. RHE). The performance is much higher than that of MoS_(2) with the edge defect. Isotopic labeling confirms that N atoms of produced NH4+ originate from N2. Furthermore, the in-plane defect clusters realized the alternate hydrogenation of nitrogen in a side-on way to synthesize ammonia. This work provides a prospecting strategy for fine-tuning in-plane defects in a catalyst, and also promotes the progress of eNRR.展开更多
Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored ...Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.展开更多
Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect ...Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect of cavity interval and spectrum of incident waves on the amplification are studied by numerical examples. It is shown that there may be large interaction between cavities, and group cavities with certain intervals may have significant amplification to seismic ground motion. The amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 45.2% and 84.4%, for an example site in Tianjin, under the excitation of Taft wave and El Centro wave; and group cavities may also affect the spectra of the seismic ground motion. It is suggested that the effect of underground group cavities on design seismic ground motion should be considered.展开更多
Due to the unique deformation characteristics of auxetic materials(Poisson’s ratioμ<0),they have better shock resistance and energy absorption properties than traditional materials.Inspired by the concept of vari...Due to the unique deformation characteristics of auxetic materials(Poisson’s ratioμ<0),they have better shock resistance and energy absorption properties than traditional materials.Inspired by the concept of variable crosssection design,a new auxetic re-entrant honeycomb structure is designed in this study.The detailed design method of re-entrant honeycomb with variable cross-section(VCRH)is provided,and five VCRH structures with the same relative density and different cross-section change rates are proposed.The in-plane impact resistance and energy absorption abilities of VCRH under constant velocity are investigated by ABAQUS/EXPLICIT.The results show that the introduction of variable cross-section design can effectively improve the impact resistance and energy absorption abilities of auxetic re-entrant honeycombs.The VCRH structure has better Young’s modulus,plateau stress,and specific energy absorption(SEA)than traditional re-entrant honeycomb(RH).The influence of microstructure parameters(such as cross-section change rateα)on the dynamic impact performance of VCRH is also studied.Results show that,with the increase in impact velocity andα,the plateau stress and SEA of VCRH increase.A positive correlation is also found between the energy absorption efficiency,impact load uniformity andαunder both medium and high impact speeds.These results can provide a reference for designing improved auxetic re-entrant honeycomb structures.展开更多
The in-plane tensile behaviors of bi-axial warp-knitted(BWK) composites under quasi-static and high strain rates loading were experimentally analyzed in this article. The tensile tests were conducted along warp direct...The in-plane tensile behaviors of bi-axial warp-knitted(BWK) composites under quasi-static and high strain rates loading were experimentally analyzed in this article. The tensile tests were conducted along warp direction( 0°) and weft direction( 90°) at quasi-static rate of 0. 001 s^(-1) and high strain rates ranging from 1 450 to 2 540 s^(-1),respectively. It is found that the significant strain rate sensitivity can be observed in the stress-strain curves of BWK composites. The fracture morphologies of BWK composites demonstrate that the tensile failure modes are shear failure and fiber breakage under the quasi-static testing condition while interface failure and fibers pullout are at high strain rates.展开更多
VARTM (Vacuum Assisted Resin Transfer Molding) is a popular method for manufacturing large-scaled, single-sided mold composite structures, such as wind turbine blades and yachts. Simulation to find the proper infusion...VARTM (Vacuum Assisted Resin Transfer Molding) is a popular method for manufacturing large-scaled, single-sided mold composite structures, such as wind turbine blades and yachts. Simulation to find the proper infusion scenario before manufacturing is essential to avoid dry spots as well as incomplete saturation and various fiber weaves with different permeability affect numerical simulation tremendously. This study focused on deriving the in-plane permeability prediction method for FRP (Fiber Reinforced Plastics) laminates in the VARTM process by experimental measurements and numerical analysis. The method provided an efficient way to determine the permeability of laminates without conducting lots of experiments in the future. In-plane permeability imported into the software, RTM-Worx, to simulate resin flowing pattern before the infusion experiments of a 3D ship hull with two different infusion scenarios. The close agreement between experiments and simulations proved the correctness and applicability of the prediction method for the in-plane permeability.展开更多
We theoretically study the influence of the spin-orbit coupling （SOC） on the in-plane optical anisotropy （IPOA） induced by in-plane uniaxial strain and interface asymmetry in （001） GaAs/A1GaAs quantum wells （QW...We theoretically study the influence of the spin-orbit coupling （SOC） on the in-plane optical anisotropy （IPOA） induced by in-plane uniaxial strain and interface asymmetry in （001） GaAs/A1GaAs quantum wells （QWs） with different well width. It is found that the SOC has more significant impact on the IPOA for the transition of the first valence subhand of heavy hole to the first conduction band （1HIE） than that of ILIE. The reason has been discussed. The IPOA of （001） InGaAs/InP QWs has been measured by reflectance difference spectroscopy, whose amplitude is about one order larger than that of GaAs/AIGaAs QWs. The anisotropic interface potential parameters of InGaAs/InP QWs are also determined. The influence of the SOC effect on the IPOA of InGaAs/lnP QWs when the QWs are under tensile, compressive or zero biaxial strain are also investigated in theory. Our results demonstrate that the SOC has significant effect on the IPOA especially for semiconductor QWs with small well width, and therefore cannot be ignored.展开更多
The in-plane compressive characteristics of the ultra-high molecular weight polyethylene(UHMWPE)fibre(Dyneema█)reinforced composites,both in 0/90°and±45°fibre orientations with respect to the loading d...The in-plane compressive characteristics of the ultra-high molecular weight polyethylene(UHMWPE)fibre(Dyneema█)reinforced composites,both in 0/90°and±45°fibre orientations with respect to the loading direction,have been investigated.The composite made from unidirectional high modulus fibres(volume fraction 83%)and low strength polyurethane matrix(volume fraction 17%)is layered in an orthogonally alternating manner.The different failure mechanisms for the composites with 0/90°and±45°fibre orientations have been detected with the methods of experimental measurement,SEM observation and theoretical analysis.The composites specimens of 0/90°fibre orientation failed with macro-buckling of the high-modulus UHMWEP fibre layers with the matrix damage,whereas the specimens of±45°fibre orientation failed with the shearing of the soft matrix.Hence,the composite specimens in 0/90°fibre orientation had higher stiffness as well as compressive strength than those in±45°fibre orientation.The failure criteria of the composites under in-plane compression was employed to characterize the failure mechanism.Compared with the traditional thermoset matrix,the soft thermoplastic matrix leads to lower strength and higher failure strain of fibre reinforced composites under in-plane compression.In addition,the composite specimens cut by waterjet machine exhibited higher stress levels than those cut by bandsaw that introduced more initial imperfections with the temperature rising and tensile shocking.The comparison between the methodologies for cutting the tough composites can provide a valuable suggestion to obtain required composite structures without reducing the mechanical properties.展开更多
Amorphous Sm-Co films with uniaxial in-plane anisotropy have great potential for application in information-storage media and spintronic materials.The most effective method to produce uniaxial inplane anisotropy is to...Amorphous Sm-Co films with uniaxial in-plane anisotropy have great potential for application in information-storage media and spintronic materials.The most effective method to produce uniaxial inplane anisotropy is to apply an in-plane magnetic field during deposition.However,this method inevitably requires more complex equipment.Here,we report a new way to produce uniaxial in-plane anisotropy by growing amorphous Sm-Co films onto(011)-cut single-crystal substrates in the absence of an external magnetic field.The tunable anisotropy constant,kA,is demonstrated with variation in the lattice parameter of the substrates.A kA value as high as about 3.3×10^4J·m^-3 was obtained in the amorphous Sm-Co film grown on a LaAlO3(011)substrate.Detailed analysis indicated that the preferential seeding and growth of ferromagnetic(FM)domains caused by the anisotropic strain of the substrates,along with the formed Sm-Co,Co-Co directional pair ordering,exert a substantial effect.This work provides a new way to obtain in-plane anisotropy in amorphous Sm-Co films.展开更多
The Cu/Ni multilayers were deposited using ion beam sputtering at room temperature and250℃ respectively. The microstructures of the multilayers including intedecial roughness, grainsize and growth direction have been...The Cu/Ni multilayers were deposited using ion beam sputtering at room temperature and250℃ respectively. The microstructures of the multilayers including intedecial roughness, grainsize and growth direction have been investigated by transmission electron microscopy and X-raydiffraction. The microstructure depends strongly on the substrate temperature and modulationwavelength, bigger grain size and larger intedecial roughness were obtained when the multilayerswere deposited at 250℃, and the multilayers ceased to grow epitaxially due to the increasingdefects in the multilayers. The resistivity of the multilayers is very sensitive to the microstructuredue to the size-effect. In order to study the influence of the microstructure to the resistivity，the in-plane resistivity of Cu/Ni multilayers was measured using fourpoint probe. The resistivityincreases with higher substrate temperature, and it decreases when the modulation wavelengthbecomes short. The interfacial roughness and grain size have co-contribution to the resistivity.The interface scattering is the main factor that has effect on the resistivity of Cu/Ni multilayers.展开更多
The nonlinear in-plane instability of functionally graded carbon nanotube reinforced composite(FG-CNTRC)shallow circular arches with rotational constraints subject to a uniform radial load in a thermal environment is ...The nonlinear in-plane instability of functionally graded carbon nanotube reinforced composite(FG-CNTRC)shallow circular arches with rotational constraints subject to a uniform radial load in a thermal environment is investigated.Assuming arches with thickness-graded material properties,four different distribution patterns of carbon nanotubes(CNTs)are considered.The classical arch theory and Donnell’s shallow shell theory assumptions are used to evaluate the arch displacement field,and the analytical solutions of buckling equilibrium equations and buckling loads are obtained by using the principle of virtual work.The critical geometric parameters are introduced to determine the criteria for buckling mode switching.Parametric studies are carried out to demonstrate the effects of temperature variations,material parameters,geometric parameters,and elastic constraints on the stability of the arch.It is found that increasing the volume fraction of CNTs and distributing CNTs away from the neutral axis significantly enhance the bending stiffness of the arch.In addition,the pretension and initial displacement caused by the temperature field have significant effects on the buckling behavior.展开更多
Effective probing current-induced magnetization switching is highly required in the study of emerging spin-orbit torque(SOT)effect.However,the measurement of in-plane magnetization switching typically relies on the gi...Effective probing current-induced magnetization switching is highly required in the study of emerging spin-orbit torque(SOT)effect.However,the measurement of in-plane magnetization switching typically relies on the giant/tunneling magnetoresistance measurement in a spin valve structure calling for complicated fabrication process,or the non-electric approach of Kerr imaging technique.Here,we present a reliable and convenient method to electrically probe the SOT-induced in-plane magnetization switching in a simple Hall bar device through analyzing the MR signal modified by a magnetic field.In this case,the symmetry of MR is broken,resulting in a resistance difference for opposite magnetization orientations.Moreover,the feasibility of our method is widely evidenced in heavy metal/ferromagnet(Pt/Ni_(20)Fe_(80) and W/Co_(20)Fe_(60)B_(20))and the topological insulator/ferromagnet(Bi_(2)Se_(3)/Ni_(20)Fe_(80)).Our work simplifies the characterization process of the in-plane magnetization switching,which can promote the development of SOT-based devices.展开更多
Transition-metal oxyhalides MOX(M=Fe,Cr,V;O=oxygen,X=F,Cl,Br,I),an emerging type of two-dimensional(2D)van der Waals materials,have been both theoretically and experimentally demonstrated to possess unique electronic ...Transition-metal oxyhalides MOX(M=Fe,Cr,V;O=oxygen,X=F,Cl,Br,I),an emerging type of two-dimensional(2D)van der Waals materials,have been both theoretically and experimentally demonstrated to possess unique electronic and magnetic properties.However,the intrinsic in-plane anisotropic properties of 2D VOCl still lacks in-depth re-search,especially optical anisotropy.Herein,a systematic Raman spectroscopic study is performed on VOCl single-crystal with different incident laser polarization at various temperatures.The polarized-dependent Raman scattering spectra reveal that the Ag mode of VOCl show a 2-lobed shape in parallel polarization configuration while a 4-lobed shape in vertical configuration.In addition,the temperature-dependent and thickness-dependent Raman scattering spectra confirm a rela-tively weak van der Waals interaction between each layers among VOCl single crystal.These findings might provide better understanding on the in-plane anisotropic phenomenon in VOCl layers,thus will accelate further application of 2D single crystals for nanoscale angle-dependent optoelectronics.展开更多
This paper is concerned with the in-plane elastic stability of arches subjected to a radial concentrated load. The equilibrium equation for pin-ended circular arches is established by using energy method, and it is pr...This paper is concerned with the in-plane elastic stability of arches subjected to a radial concentrated load. The equilibrium equation for pin-ended circular arches is established by using energy method, and it is proved that the axial force is nearly a constant along the circumference of the circular arches. Based on force method, the equation for the primary eigen function is derived and solved, and the approximate analytical solution of critical instability load is obtained. Numerical examples are given and discussed.展开更多
In the present work, inverse thermal analysis of heat conduction is carried out to estimate the in-plane thermal conductivity of composites. Numerical simulations were performed to determine the optimal configuration ...In the present work, inverse thermal analysis of heat conduction is carried out to estimate the in-plane thermal conductivity of composites. Numerical simulations were performed to determine the optimal configuration of the heating system to ensure a unidirectional heat transfer in the composite sample. Composite plates made of unsaturated polyester resin and unidirectional glass fibers were fabricated by injection to validate the methodology. A heating and cooling cycle is applied at the bottom and top surfaces of the sample. The thermal conductivity can be deduced from transient temperature measurements given by thermocouples positioned at three chosen locations along the fibers direction. The inverse analysis algorithm is initiated by solving the direct problem defined by the one-dimensional transient heat conduction equation using a first estimate of thermal conductivity. The integral in time of the square distance between the measured and predicted values is the criterion minimized in the inverse analysis algorithm. Finally, the evolution of the in-plane composite thermal conductivity can be deduced from the experimental results by the rule of mixture.展开更多
A representative volume element method and a novel mesomechanical-based polyline model are proposed to describe the misalignment of in-plane fibers induced by the insertion of stitch thread.A multi-scale mathematical ...A representative volume element method and a novel mesomechanical-based polyline model are proposed to describe the misalignment of in-plane fibers induced by the insertion of stitch thread.A multi-scale mathematical model of in-plane elastic parameters for stitched composite laminate is established with ply-angle and stitch parameters as well as material parameters taken into account.Based on the fabrication of specimens and the verification of experimental platform,the superposition influences of stitch on structural anisotropy are revealed by the developed theoretical model.Results indicate that the stitch orientation can increase the structural anisotropy.The decreases of stitch pitch and spacing as well as the increase of thread diameter obviously reduce the elastic and shear moduli of laminates.Furthermore,the elastic and shear moduli as well as Poisson’s ratios show sinusoidal changes with a period of 90°as the ply-angle increases.The theoretical model not only analyzes the in-plane mechanical properties of stitched laminate with ply-angle,but also lays a foundation for the dynamic studies of stitched sandwich structures with ribs in the future.展开更多
基金financially supported by the Science and Engineering Research Board (SERB)a statutory body of the Department of Science&Technology (DST)+1 种基金Government of India through the Start-up Research Grant (SRG) scheme (File No. SRG/2020/000341)National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT)(NRF-2020R1A2C1010134)。
文摘Sheet-metal products are integral parts of engineering industries and academia research. Various testing techniques have revealed the deformation behaviors of sheet metals under complex stress states. Information obtained from tensile and compression tests, however, are insufficient for the identification of material parameters relevant to modern constitutive laws, which require experimental setups capable of generating various loading conditions and applying great amounts of strain to sheet metals. In-plane shear testing has emerged as an important method to overcome the challenges associated with tension and compression tests and can provide additional information about deformation behaviors under large plastic strains. Materials such as Mg alloys with poor levels of both ductility and formability cannot accommodate large plastic strains. Therefore, tension and compression tests have limitations in explaining the material behaviors that occur during sheet metal forming where large plastic strains are introduced. Many studies have been conducted to explain the deformation behaviors of Mg alloys under shear deformation techniques. These include severe plastic deformation(SPD), especially the equal channel angular pressing(ECAP)and equal channel angular extrusion, rolling combined with shear deformation i.e. differential speed rolling(DSR), and also in-plane shear for sheet metals, particularly under large levels of plastic strain. These in-plane shear technique involves the Miyauchi shear test, ASTM shear test, and twin bridge shear tests. Moreover, many experimental results have revealed that the evolution of microstructure and texture during in-plane shear is closely related to the failure behavior of materials. Therefore, this review is focused on techniques for in-plane shear testing that have been reported thus far, on the effect of in-plane shear on the microstructure development of Mg alloy sheets, and on the usefulness of in-plane shear testing to evaluate the formability of Mg alloy sheets.
基金the National Natural Science Foundation of China,China (Grant Nos.22125903,51872283,22109040)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA21000000)+4 种基金the Dalian Innovation Support Plan for High Level Talents,China (2019RT09)DICP,China (DICP I202032)the Dalian National Laboratory For Clean Energy (DNL),CAS,DNL Cooperation Fund,CAS,China (DNL202016,DNL202019)the Top-Notch Talent Program of Henan Agricultural University,China (30500947)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy,China (YLU-DNL Fund 2021002,YLU-DNL Fund 2021009)。
文摘The popularization of portable,implantable and wearable microelectronics has greatly stimulated the rapid development of high-power planar micro-supercapacitors(PMSCs).Particularly,the introduction of new functionalities(e.g.,high voltage,flexibility,stretchability,self-healing,electrochromism and photo/thermal response)to PMSCs is essential for building multifunctional PMSCs and their smart selfpowered integrated microsystems.In this review,we summarized the latest advances in PMSCs from various functional microdevices to their smart integrated microsystems.Primarily,the functionalities of PMSCs are characterized by three major factors to emphasize their electrochemical behavior and unique scope of application.These include but are not limited to high-voltage outputs(realized through asymmetric configuration,novel electrolyte and modular integration),mechanical resilience that includes various feats of flexibility or stretchability,and response to stimuli(self-healing,electrochromic,photo-responsive,or thermal-responsive properties).Furthermore,three representative integrated microsystems including energy harvester-PMSC,PMSC-energy consumption,and all-in-one selfpowered microsystems are elaborately overviewed to understand the emerging intelligent interaction models.Finally,the key perspectives,challenges and opportunities of PMSCs for powering smart microelectronics are proposed in brief.
基金supported by the National Natural Science Foundation of China(11874314,12174157,and 12074150)the Natural Science Foundation of Jiangsu Province(BK20201424)+1 种基金the Modern Agricultural Equipment and Technology Collaborative Innovation Project(XTCX2025)the Graduate Research and Innovation Projects of Jiangsu Province(KYCX22_3602)。
文摘Broad-spectrum absorption and highly effective charge-carrier separation are two essential requirements to improve the photocatalytic performance of semiconductor-based photocatalysts.In this work,a fascinating one-photon system is reported by rationally fabricating 2D in-plane Bi_(2)O_(3)/BiOCl(i-Cl)heterostructures for efficient photocatalytic degradation of RhB and TC.Systematic investigations revealed that the matched band structure generated an internal electric field and a chemical bond connection between the Bi_(2)O_(3)and BiOCl in the Bi_(2)O_(3)/BiOCl composite that could effectively improve the utilization ratio of visible light and the separation effectivity of photo-generated carriers in space.The formed interactions at the 2D in-plane heterojunction interface induced the one-photon excitation pathway which has been confirmed by the experiment and DFT calculations.As a result,the i-Cl samples showed significantly enhanced photocatalytic efficiency towards the degradation of RhB and TC(RhB:0.106 min^(-1);TC:0.048 min^(-1))under visible light.The degradation activities of RhB and TC for i-Cl were 265.08 and 4.08times that of pure BiOCl,as well as 9.27 and 2.14 times that of mechanistically mixed Bi_(2)O_(3)/BiOCl samples,respectively.This work provides a logical strategy to construct other 2D in-plane heterojunctions with a one-photon excitation pathway with enhanced performance.
基金The project sponsored by the Earthquake Science Foundation under Contract No. 90141
文摘The analysis method of lattice dynamics in classical physics is extended to study the propertiesof in-plane wave motion in the hybrid-mass finite element model in this paper. The dispersion equations of Pand SV waves in the discrete model are first obtained by means of separating the characteristic equation of themotion equation, and then used to analyse the properties of P-and SV-homogeneous, inhomogeneous wavesand other types of motion in the model. The dispersion characters, cut-off frequencies of P and SV waves,the polarization drift and appendent anisotropic property of wave motion caused by the discretization are finallydiscussed.
基金This work was supported by the National Natural Science Foundation of China(22078063,21825801).
文摘Electrochemical nitrogen reduction reaction (eNRR) is an alternative promising manner for sustainable N2 fixation with low-emission. The major challenge for developing an efficient electrocatalyst is the cleaving of the stable Ntriple bondN triple bonds. Herein, we design a new MoS_(2) with in-plane defect cluster through a bottom-up approach for the first time, where the defect cluster is composed of three adjacent S vacancies. The well-defined in-plane defect clusters could contribute to the strong chemical adsorption and activation towards inert nitrogen, achieving an excellent eNRR performance with an ammonia yield rate of 43.4 ± 3 μg h^(−1) mgcat.^(−1) and a Faradaic efficiency of 16.8 ± 2% at −0.3 V (vs. RHE). The performance is much higher than that of MoS_(2) with the edge defect. Isotopic labeling confirms that N atoms of produced NH4+ originate from N2. Furthermore, the in-plane defect clusters realized the alternate hydrogenation of nitrogen in a side-on way to synthesize ammonia. This work provides a prospecting strategy for fine-tuning in-plane defects in a catalyst, and also promotes the progress of eNRR.
基金Project supported by the National Natural Science Foundation of China(Grant No.61705066)the Open Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications),China(Grant No.IPOC2018B004)the National Key Research and Development Program,China(Grant No.2016YFA0202401)
文摘Bi2O2Se thin film could be one of the promising material candidates for the next-generation electronic and optoelectronic applications. However, the performance of Bi2O2Se thin film-based device is not fully explored in the photodetecting area. Considering the fact that the electrical properties such as carrier mobility, work function, and energy band structure of Bi2O2Se are thickness-dependent, the in-plane Bi2O2Se homojunctions consisting of layers with different thicknesses are successfully synthesized by the chemical vapor deposition(CVD) method across the terraces on the mica substrates,where terraces are created in the mica surface layer peeling off process. In this way, effective internal electrical fields are built up along the Bi2O2Se homojunctions, exhibiting diode-like rectification behavior with an on/off ratio of 102, what is more, thus obtained photodetectors possess highly sensitive and ultrafast features, with a maximum photoresponsivity of 2.5 A/W and a lifetime of 4.8 μs. Comparing with the Bi2O2Se uniform thin films, the photo-electric conversion efficiency is greatly improved for the in-plane homojunctions.
基金supported by National Natural Science Foundation of China under grant No. 50978183Tianjin Key Project for Applied Basic Research under grant No. 12JCZDJC29000
文摘Amplification of in-plane seismic ground motion by underground group cavities in layered half-space is studied both in frequency domain and time domain by using indirect boundary element method (IBEM), and the effect of cavity interval and spectrum of incident waves on the amplification are studied by numerical examples. It is shown that there may be large interaction between cavities, and group cavities with certain intervals may have significant amplification to seismic ground motion. The amplification of PGA (peak ground acceleration) and its PRS (peak response spectrum) can be increased up to 45.2% and 84.4%, for an example site in Tianjin, under the excitation of Taft wave and El Centro wave; and group cavities may also affect the spectra of the seismic ground motion. It is suggested that the effect of underground group cavities on design seismic ground motion should be considered.
基金This research is supported by the National Natural Science Foundation of China(No.11902232).
文摘Due to the unique deformation characteristics of auxetic materials(Poisson’s ratioμ<0),they have better shock resistance and energy absorption properties than traditional materials.Inspired by the concept of variable crosssection design,a new auxetic re-entrant honeycomb structure is designed in this study.The detailed design method of re-entrant honeycomb with variable cross-section(VCRH)is provided,and five VCRH structures with the same relative density and different cross-section change rates are proposed.The in-plane impact resistance and energy absorption abilities of VCRH under constant velocity are investigated by ABAQUS/EXPLICIT.The results show that the introduction of variable cross-section design can effectively improve the impact resistance and energy absorption abilities of auxetic re-entrant honeycombs.The VCRH structure has better Young’s modulus,plateau stress,and specific energy absorption(SEA)than traditional re-entrant honeycomb(RH).The influence of microstructure parameters(such as cross-section change rateα)on the dynamic impact performance of VCRH is also studied.Results show that,with the increase in impact velocity andα,the plateau stress and SEA of VCRH increase.A positive correlation is also found between the energy absorption efficiency,impact load uniformity andαunder both medium and high impact speeds.These results can provide a reference for designing improved auxetic re-entrant honeycomb structures.
基金National Natural Science Foundations of China(Nos.11272087,11572085)Financial Supports from Foundation for the Fok Ying-Tong Education Foundation of China(No.141070)the Fundamental Research Funds for the Central Universities of China(No.170310103)
文摘The in-plane tensile behaviors of bi-axial warp-knitted(BWK) composites under quasi-static and high strain rates loading were experimentally analyzed in this article. The tensile tests were conducted along warp direction( 0°) and weft direction( 90°) at quasi-static rate of 0. 001 s^(-1) and high strain rates ranging from 1 450 to 2 540 s^(-1),respectively. It is found that the significant strain rate sensitivity can be observed in the stress-strain curves of BWK composites. The fracture morphologies of BWK composites demonstrate that the tensile failure modes are shear failure and fiber breakage under the quasi-static testing condition while interface failure and fibers pullout are at high strain rates.
文摘VARTM (Vacuum Assisted Resin Transfer Molding) is a popular method for manufacturing large-scaled, single-sided mold composite structures, such as wind turbine blades and yachts. Simulation to find the proper infusion scenario before manufacturing is essential to avoid dry spots as well as incomplete saturation and various fiber weaves with different permeability affect numerical simulation tremendously. This study focused on deriving the in-plane permeability prediction method for FRP (Fiber Reinforced Plastics) laminates in the VARTM process by experimental measurements and numerical analysis. The method provided an efficient way to determine the permeability of laminates without conducting lots of experiments in the future. In-plane permeability imported into the software, RTM-Worx, to simulate resin flowing pattern before the infusion experiments of a 3D ship hull with two different infusion scenarios. The close agreement between experiments and simulations proved the correctness and applicability of the prediction method for the in-plane permeability.
基金Pro iect supported by the National Basic Research Program of China （Grant Nos. 2012CB921304 and 2013CB632805）, the National Natural Science Foundation of China （Grant Nos. 60990313, 61306120, and 6106003）, and the Foundation of Fuzhou University of China （Grant No. 022498）.
文摘We theoretically study the influence of the spin-orbit coupling （SOC） on the in-plane optical anisotropy （IPOA） induced by in-plane uniaxial strain and interface asymmetry in （001） GaAs/A1GaAs quantum wells （QWs） with different well width. It is found that the SOC has more significant impact on the IPOA for the transition of the first valence subhand of heavy hole to the first conduction band （1HIE） than that of ILIE. The reason has been discussed. The IPOA of （001） InGaAs/InP QWs has been measured by reflectance difference spectroscopy, whose amplitude is about one order larger than that of GaAs/AIGaAs QWs. The anisotropic interface potential parameters of InGaAs/InP QWs are also determined. The influence of the SOC effect on the IPOA of InGaAs/lnP QWs when the QWs are under tensile, compressive or zero biaxial strain are also investigated in theory. Our results demonstrate that the SOC has significant effect on the IPOA especially for semiconductor QWs with small well width, and therefore cannot be ignored.
基金Funded by the National Natural Science Foundation of China(No.11305138)the Jiangsu Science and Technology Department Support Program(No.BY2019188)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(No.14KJD540004).
文摘The in-plane compressive characteristics of the ultra-high molecular weight polyethylene(UHMWPE)fibre(Dyneema█)reinforced composites,both in 0/90°and±45°fibre orientations with respect to the loading direction,have been investigated.The composite made from unidirectional high modulus fibres(volume fraction 83%)and low strength polyurethane matrix(volume fraction 17%)is layered in an orthogonally alternating manner.The different failure mechanisms for the composites with 0/90°and±45°fibre orientations have been detected with the methods of experimental measurement,SEM observation and theoretical analysis.The composites specimens of 0/90°fibre orientation failed with macro-buckling of the high-modulus UHMWEP fibre layers with the matrix damage,whereas the specimens of±45°fibre orientation failed with the shearing of the soft matrix.Hence,the composite specimens in 0/90°fibre orientation had higher stiffness as well as compressive strength than those in±45°fibre orientation.The failure criteria of the composites under in-plane compression was employed to characterize the failure mechanism.Compared with the traditional thermoset matrix,the soft thermoplastic matrix leads to lower strength and higher failure strain of fibre reinforced composites under in-plane compression.In addition,the composite specimens cut by waterjet machine exhibited higher stress levels than those cut by bandsaw that introduced more initial imperfections with the temperature rising and tensile shocking.The comparison between the methodologies for cutting the tough composites can provide a valuable suggestion to obtain required composite structures without reducing the mechanical properties.
基金supported by the National Key Research and Development Program of China(2017YFB0702702,2018YFA0305704,2016YFB700903,2017YFA0303601,and 2017YFA0206300)the National Natural Sciences Foundation of China(51531008,51771223,51590880,11674378,51971240,U1832219,and 11934016)+2 种基金the Inner Mongolia Science and Technology Major Project of China 2016the Strategic Priority Research Program(B)Key Programof the Chinese Academy of Sciences(CAS).
文摘Amorphous Sm-Co films with uniaxial in-plane anisotropy have great potential for application in information-storage media and spintronic materials.The most effective method to produce uniaxial inplane anisotropy is to apply an in-plane magnetic field during deposition.However,this method inevitably requires more complex equipment.Here,we report a new way to produce uniaxial in-plane anisotropy by growing amorphous Sm-Co films onto(011)-cut single-crystal substrates in the absence of an external magnetic field.The tunable anisotropy constant,kA,is demonstrated with variation in the lattice parameter of the substrates.A kA value as high as about 3.3×10^4J·m^-3 was obtained in the amorphous Sm-Co film grown on a LaAlO3(011)substrate.Detailed analysis indicated that the preferential seeding and growth of ferromagnetic(FM)domains caused by the anisotropic strain of the substrates,along with the formed Sm-Co,Co-Co directional pair ordering,exert a substantial effect.This work provides a new way to obtain in-plane anisotropy in amorphous Sm-Co films.
文摘The Cu/Ni multilayers were deposited using ion beam sputtering at room temperature and250℃ respectively. The microstructures of the multilayers including intedecial roughness, grainsize and growth direction have been investigated by transmission electron microscopy and X-raydiffraction. The microstructure depends strongly on the substrate temperature and modulationwavelength, bigger grain size and larger intedecial roughness were obtained when the multilayerswere deposited at 250℃, and the multilayers ceased to grow epitaxially due to the increasingdefects in the multilayers. The resistivity of the multilayers is very sensitive to the microstructuredue to the size-effect. In order to study the influence of the microstructure to the resistivity，the in-plane resistivity of Cu/Ni multilayers was measured using fourpoint probe. The resistivityincreases with higher substrate temperature, and it decreases when the modulation wavelengthbecomes short. The interfacial roughness and grain size have co-contribution to the resistivity.The interface scattering is the main factor that has effect on the resistivity of Cu/Ni multilayers.
基金Project supported by the National Natural Science Foundation of China (Nos.11972240 and 51875374)。
文摘The nonlinear in-plane instability of functionally graded carbon nanotube reinforced composite(FG-CNTRC)shallow circular arches with rotational constraints subject to a uniform radial load in a thermal environment is investigated.Assuming arches with thickness-graded material properties,four different distribution patterns of carbon nanotubes(CNTs)are considered.The classical arch theory and Donnell’s shallow shell theory assumptions are used to evaluate the arch displacement field,and the analytical solutions of buckling equilibrium equations and buckling loads are obtained by using the principle of virtual work.The critical geometric parameters are introduced to determine the criteria for buckling mode switching.Parametric studies are carried out to demonstrate the effects of temperature variations,material parameters,geometric parameters,and elastic constraints on the stability of the arch.It is found that increasing the volume fraction of CNTs and distributing CNTs away from the neutral axis significantly enhance the bending stiffness of the arch.In addition,the pretension and initial displacement caused by the temperature field have significant effects on the buckling behavior.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11904017, 11974145, 51901008, and 12004024)Shandong Provincial Natural Science Foundation, China (Grant No. ZR2020ZD28)+1 种基金platform from Qingdao Science and Technology Commissionthe Fundamental Research Funds for the Central Universities of China
文摘Effective probing current-induced magnetization switching is highly required in the study of emerging spin-orbit torque(SOT)effect.However,the measurement of in-plane magnetization switching typically relies on the giant/tunneling magnetoresistance measurement in a spin valve structure calling for complicated fabrication process,or the non-electric approach of Kerr imaging technique.Here,we present a reliable and convenient method to electrically probe the SOT-induced in-plane magnetization switching in a simple Hall bar device through analyzing the MR signal modified by a magnetic field.In this case,the symmetry of MR is broken,resulting in a resistance difference for opposite magnetization orientations.Moreover,the feasibility of our method is widely evidenced in heavy metal/ferromagnet(Pt/Ni_(20)Fe_(80) and W/Co_(20)Fe_(60)B_(20))and the topological insulator/ferromagnet(Bi_(2)Se_(3)/Ni_(20)Fe_(80)).Our work simplifies the characterization process of the in-plane magnetization switching,which can promote the development of SOT-based devices.
基金Project financially supported by National Natural Science Foundation of China (Grant No. U1932201)the International Partnership Program (Grant No. 211134KYSB20190063)+3 种基金the CAS (Chinese Academy of Sciences) Collaborative Innovation Program of Hefei Science Center (Grant No. 2020HSCCIP002)the University Synergy Innovation Program of Anhui Province, China (Grant No. GXXT-2020-002)the Youth Innovation Promotion Association of CAS (Grant No. 2022457)the USTC Research Funds of the Double First-Class Initiative (YD2310002004)
文摘Transition-metal oxyhalides MOX(M=Fe,Cr,V;O=oxygen,X=F,Cl,Br,I),an emerging type of two-dimensional(2D)van der Waals materials,have been both theoretically and experimentally demonstrated to possess unique electronic and magnetic properties.However,the intrinsic in-plane anisotropic properties of 2D VOCl still lacks in-depth re-search,especially optical anisotropy.Herein,a systematic Raman spectroscopic study is performed on VOCl single-crystal with different incident laser polarization at various temperatures.The polarized-dependent Raman scattering spectra reveal that the Ag mode of VOCl show a 2-lobed shape in parallel polarization configuration while a 4-lobed shape in vertical configuration.In addition,the temperature-dependent and thickness-dependent Raman scattering spectra confirm a rela-tively weak van der Waals interaction between each layers among VOCl single crystal.These findings might provide better understanding on the in-plane anisotropic phenomenon in VOCl layers,thus will accelate further application of 2D single crystals for nanoscale angle-dependent optoelectronics.
文摘This paper is concerned with the in-plane elastic stability of arches subjected to a radial concentrated load. The equilibrium equation for pin-ended circular arches is established by using energy method, and it is proved that the axial force is nearly a constant along the circumference of the circular arches. Based on force method, the equation for the primary eigen function is derived and solved, and the approximate analytical solution of critical instability load is obtained. Numerical examples are given and discussed.
基金the National Science and Engineering Research Council of Canada(NSERC)Fonds Quebecois de Recherche sur la Nature et la Technologie(FQRNT)
文摘In the present work, inverse thermal analysis of heat conduction is carried out to estimate the in-plane thermal conductivity of composites. Numerical simulations were performed to determine the optimal configuration of the heating system to ensure a unidirectional heat transfer in the composite sample. Composite plates made of unsaturated polyester resin and unidirectional glass fibers were fabricated by injection to validate the methodology. A heating and cooling cycle is applied at the bottom and top surfaces of the sample. The thermal conductivity can be deduced from transient temperature measurements given by thermocouples positioned at three chosen locations along the fibers direction. The inverse analysis algorithm is initiated by solving the direct problem defined by the one-dimensional transient heat conduction equation using a first estimate of thermal conductivity. The integral in time of the square distance between the measured and predicted values is the criterion minimized in the inverse analysis algorithm. Finally, the evolution of the in-plane composite thermal conductivity can be deduced from the experimental results by the rule of mixture.
基金National Natural Science Foundation of China(No.52075280)Natural Science Foundation of Shandong province(No.ZR2019MEE088)。
文摘A representative volume element method and a novel mesomechanical-based polyline model are proposed to describe the misalignment of in-plane fibers induced by the insertion of stitch thread.A multi-scale mathematical model of in-plane elastic parameters for stitched composite laminate is established with ply-angle and stitch parameters as well as material parameters taken into account.Based on the fabrication of specimens and the verification of experimental platform,the superposition influences of stitch on structural anisotropy are revealed by the developed theoretical model.Results indicate that the stitch orientation can increase the structural anisotropy.The decreases of stitch pitch and spacing as well as the increase of thread diameter obviously reduce the elastic and shear moduli of laminates.Furthermore,the elastic and shear moduli as well as Poisson’s ratios show sinusoidal changes with a period of 90°as the ply-angle increases.The theoretical model not only analyzes the in-plane mechanical properties of stitched laminate with ply-angle,but also lays a foundation for the dynamic studies of stitched sandwich structures with ribs in the future.
