Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separ...Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(E_(vac))from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(H_(v)/E_(v))forα-Fe_(2)O_(3)and an 83.33%reduction for Fe_(3)O_(4).Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(M_(s))of Fe_(3)O_(4)reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability.展开更多
To investigate the influence of coarse aggregate parent rock properties on the elastic modulus of concrete,the mineralogical properties and stress-strain curves of granite and dolomite parent rocks,as well as the stre...To investigate the influence of coarse aggregate parent rock properties on the elastic modulus of concrete,the mineralogical properties and stress-strain curves of granite and dolomite parent rocks,as well as the strength and elastic modulus of mortar and concrete prepared with mechanism aggregates of the corresponding lithology,and the stress-strain curves of concrete were investigated.In this paper,a coarse aggregate and mortar matrix bonding assumption is proposed,and a prediction model for the elastic modulus of mortar is established by considering the lithology of the mechanism sand and the slurry components.An equivalent coarse aggregate elastic modulus model was established by considering factors such as coarse aggregate particle size,volume fraction,and mortar thickness between coarse aggregates.Based on the elastic modulus of the equivalent coarse aggregate and the remaining mortar,a prediction model for the elastic modulus of the two and three components of concrete in series and then in parallel was established,and the predicted values differed from the measured values within 10%.It is proposed that the coarse aggregate elastic modulus in highstrength concrete is the most critical factor affecting the elastic modulus of concrete,and as the coarse aggregate elastic modulus increases by 27.7%,the concrete elastic modulus increases by 19.5%.展开更多
The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometr...The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings.展开更多
Background Computed tomography(CT) and cone-beam computed tomography(CBCT) image registration play pivotal roles in computer-assisted navigation for orthopedic surgery. Traditional methods often apply uniform deformat...Background Computed tomography(CT) and cone-beam computed tomography(CBCT) image registration play pivotal roles in computer-assisted navigation for orthopedic surgery. Traditional methods often apply uniform deformation models, neglecting the biomechanical differences between rigid structures and soft tissues, which compromises registration accuracy, especially during significant bone displacements. Method To address this issue, we introduce RE-Reg, a rigid-elastic CT-CBCT image registration framework that jointly learns rigid bone motion and soft tissue deformation. RE-Reg incorporates a rigid alignment(RA) module to estimate global bone motion and an elastic deformation(ED) module to model soft tissue deformation, preserving bony structures through bone shape preservation(BSP) loss. Result Our comprehensive evaluation on publicly available datasets demonstrates that RE-Reg significantly outperforms existing methods in terms of registration accuracy and rigid bone structure preservation, achieving a 1.3% improvement in Dice similarity coefficient(DSC) and a 23% reduction in rigid bone deformation(%Δvol) compared with the best baseline. Conclusion This framework not only enhances anatomical fidelity but also ensures biomechanical plausibility and provides a valuable tool for image-guided orthopedic surgery. This code is available athttps://github.com/Zq-Huang/RE-Reg.展开更多
Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes...Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes with SiO_(2)and Al_(2)O_(3)ratios were investigated using various techniques.It is found that when SiO_(2)is replaced by Al_(2)O_(3),the Q^(4) to Q^(3) transition of silicon-oxygen network decreases while the aluminum-oxygen network increases,which result in the transformation of Si-O-Si bonds to Si-O-Al bonds and an increase in glass network connectivity even though the intermolecular bond strength decreases.The glass transition temperature(T_(g))increases continuously,while the thermal expansion coefficient increases and high-temperature viscosity first decreases and then increases.Meanwhile,the elastic modulus values increase from 93 to 102 GPa.This indicates that the elastic modulus is mainly affected by packing factor and dissociation energy,and elements with higher packing factors and dissociation energies supplant those with lower values,resulting in increased rigidity within the glass.展开更多
Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation fo...Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation for the elastically supported fluid-conveying pipe is transformed into ordinary differential equations using the Galerkin truncation method.The Chebyshev interval approach,integrated with the assumed mode method is then used to investigate the effects of uncertainties of support stiffness,fluid speed,and pipe length on the natural frequencies and mode shapes of the pipe.Additionally,both symmetrical and asymmetrical support stiffnesses are discussed.The accuracy and effectiveness of the Chebyshev interval approach are verified through comparison with the Monte Carlo method.The results reveal that,for the same deviation coefficient,uncertainties in symmetrical support stiffness have a greater impact on the first four natural frequencies than those of the asymmetrical one.There may be significant differences in the sensitivity of natural frequencies and mode shapes of the same order to uncertain parameters.Notably,mode shapes susceptible to uncertain parameters exhibit wider fluctuation intervals near the elastic supports,requiring more attention.展开更多
BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different tre...BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different treatment options.AIM To analyze the clinical effect and prognosis of mixed hemorrhoids treated with polidocanol injection combined with automatic elastic thread ligation operation(RPH).METHODS A total of 100 patients with mixed hemorrhoids who visited our hospital from October 2022 to September 2023 were selected and randomly divided into the control group(n=50)and the treatment group(n=50)by rolling the dice.The procedure for prolapse and hemorrhoids(PPH)was adopted in the control group,while polidocanol foam injection+RPH was adopted in the treatment group.The therapeutic effects,operation time,wound healing time,hospital stay,pain situation(24 hours post-operative pain score,first defecation pain score),quality of life(QOL),incidence of complications(post-operative hemorrhage,edema,infection),incidence of anal stenosis 3 months post-operatively and recurrence rate 1 year post-operatively of the two groups were compared.RESULTS Compared with the control group,the total effective rate of treatment group was higher,and the difference was significant(P<0.05).The operation time/wound healing time/hospital stay in the treatment group were shorter than those in the control group(P<0.05).The pain scores at 24 hours after operation/first defecation pain score of the treatment group was significantly lower than those in the control group(P<0.05).After surgery,the QOL scores of the two groups decreased,with the treatment group having higher scores than that of the control group(P<0.05).Compared with the control group,the incidence of postoperative complications in the treatment group was lower,and the difference was significant(P<0.05);However,there was no significant difference in the incidence of postoperative bleeding between the two groups(P>0.05);There was no significant difference in the incidence of anal stenosis 3 months after operation and the recurrence rate 1 year after operation between the two groups(P>0.05).CONCLUSION For patients with mixed hemorrhoids,the therapeutic effect achieved by using polidocanol injection combined with RPH was better.The wounds of the patients healed faster,the postoperative pain was milder,QOL improved,and the incidence of complications was lower,and the short-term and long-term prognosis was good.展开更多
Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we...Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids.展开更多
Based on waveform fitting,full waveform inversion(FWI)is an important inversion method with the ability to reconstruct multi-parameter models in high precision.However,the strong nonlinear equation used in FWI present...Based on waveform fitting,full waveform inversion(FWI)is an important inversion method with the ability to reconstruct multi-parameter models in high precision.However,the strong nonlinear equation used in FWI presents the following challenges,such as low convergence efficiency,high dependence on the initial model,and the energy imbalance in deep region of the inverted model.To solve these inherent problems,we develop a timedomain elastic FWI method based on gradient preconditioning with the following details:(1)the limited memory Broyden Fletcher Goldfarb Shanno method with faster convergence is adopted to im-prove the inversion stability;(2)a multi-scaled inversion strategy is used to alleviate the nonlinear inversion instead of falling into the local minimum;(3)in addition,the pseudo-Hessian preconditioned illumination operator is involved for preconditioning the parameter gradients to improve the illumination equilibrium degree of deep structures.Based on the programming implementation of the new method,a deep depression model with five diffractors is used for testing.Compared with the conventional elastic FWI method,the technique proposed by this study has better effectiveness and accuracy on the inversion effect and con-vergence,respectively.展开更多
The incomplete understanding of nanoscale surface interactions arising from underlying atomistic long-range forces limits our ability to simulate and design their performance. In this paper, the surface elasticity is ...The incomplete understanding of nanoscale surface interactions arising from underlying atomistic long-range forces limits our ability to simulate and design their performance. In this paper, the surface elasticity is constructed from underlying atomistic nonlocal interactions in spherical nanoparticles. By introducing an intrinsic length scale,we quantify the surface region thickness, and demonstrate the progressive elastic modulus transition caused by asymmetric atomistic nonlocal interactions. The universal surface scaling law, relating the intrinsic length scale to the particle dimensions, is established, and a surface-dominated criterion is developed for quantifying the transition to the surfacedominated behaviors. The model is thoroughly validated through the molecular static simulations and experimental data with the material-specific intrinsic length constants.展开更多
The reduced elastic modulus Er and indentation hardness HIT of various brittle solids including ceramics,semiconductors,glasses,single crystals,and laser material were evaluated using nanoindentation.Various analysis ...The reduced elastic modulus Er and indentation hardness HIT of various brittle solids including ceramics,semiconductors,glasses,single crystals,and laser material were evaluated using nanoindentation.Various analysis procedures were compared such as Oliver&Pharr and nominal hardness-based methods,which require area function of the indenter,and other methods based on energy,displacement,contact depth,and contact stiffness,which do not require calibration of the indenter.Elastic recovery of the imprint by the Knoop indenter was also utilized to evaluate elastic moduli of brittle solids.Expressions relating HIT/Er and dimensionless nanoindentation variables(e.g.,the ratio of elastic work over total work and the ratio of permanent displacement over maximum displacement)are found to be nonlinear rather than linear for brittle solids.The plastic hardness Hp of brittle solids(except traditional glasses)extracted based on Er is found to be proportional to E_(r)√H_(IT).展开更多
This paper proposes an efficient strategy for resource utilization in Elastic Optical Networks (EONs) to minimize spectrum fragmentation and reduce connection blocking probability during Routing and Spectrum Allocatio...This paper proposes an efficient strategy for resource utilization in Elastic Optical Networks (EONs) to minimize spectrum fragmentation and reduce connection blocking probability during Routing and Spectrum Allocation (RSA). The proposed method, Dynamic Threshold-Based Routing and Spectrum Allocation with Fragmentation Awareness (DT-RSAF), integrates rerouting and spectrum defragmentation as needed. By leveraging Yen’s shortest path algorithm, DT-RSAF enhances resource utilization while ensuring improved service continuity. A dynamic threshold mechanism enables the algorithm to adapt to varying network conditions, while its fragmentation awareness effectively mitigates spectrum fragmentation. Simulation results on NSFNET and COST 239 topologies demonstrate that DT-RSAF significantly outperforms methods such as K-Shortest Path Routing and Spectrum Allocation (KSP-RSA), Load Balanced and Fragmentation-Aware (LBFA), and the Invasive Weed Optimization-based RSA (IWO-RSA). Under heavy traffic, DT-RSAF reduces the blocking probability by up to 15% and achieves lower Bandwidth Fragmentation Ratios (BFR), ranging from 74% to 75%, compared to 77% - 80% for KSP-RSA, 75% - 77% for LBFA, and approximately 76% for IWO-RSA. DT-RSAF also demonstrated reasonable computation times compared to KSP-RSA, LBFA, and IWO-RSA. On a small-sized network, its computation time was 8710 times faster than that of Integer Linear Programming (ILP) on the same network topology. Additionally, it achieved a similar execution time to LBFA and outperformed IWO-RSA in terms of efficiency. These results highlight DT-RSAF’s capability to maintain large contiguous frequency blocks, making it highly effective for accommodating high-bandwidth requests in EONs while maintaining reasonable execution times.展开更多
Elastic electronics are increasingly prevalent in information storage,smart sensing and health monitoring due to their softness,stretchability and portability.Wearable electronic devices should possess elasticity and ...Elastic electronics are increasingly prevalent in information storage,smart sensing and health monitoring due to their softness,stretchability and portability.Wearable electronic devices should possess elasticity and stretchability that align with biological tissues.Specifically,their materials should be capable of elastic strain up to 50–80%,while the devices themselves must maintain electric stability under strains that accommodate body movements[1].展开更多
The study of collision between metastable positronium(Ps)and antihydrogen(H)is crucial for precision experiments involving H.In this paper,we investigate the elastic scattering between H and Ps(2s)by combining the con...The study of collision between metastable positronium(Ps)and antihydrogen(H)is crucial for precision experiments involving H.In this paper,we investigate the elastic scattering between H and Ps(2s)by combining the confined variational method with the projection method,for scattering energies from 0.0245 eV to 0.068 eV.Our calculations provide accurate phase shifts and cross sections for the 1,3S and 1,3P symmetries.Near the binding threshold,the rapid increase in the total cross section may be attributed to the P-wave resonance effect.Additionally,we determined the S-wave scattering lengths to be 9.34 a_(0)and 5.81 a_(0)for singlet and triplet elastic scattering,respectively.展开更多
Elastic strain constitutes a decisive factor in determining the recoverable deformability of thermoelectric materials.Plastic deformation for microstructure engineering has been demonstrated as a viable approach to en...Elastic strain constitutes a decisive factor in determining the recoverable deformability of thermoelectric materials.Plastic deformation for microstructure engineering has been demonstrated as a viable approach to enhance the elastic strain.However,this approach is highly dependent on the material's plasticity,which is rather limited by the rigidity for the majority of inorganic semiconducting thermoelectric materials.Thermocouple materials,as metallic thermoelectric materials,possess a favorable plasticity,motivating this work to focus on the elastic bendability of a metallic thermoelectric generator that is composed of K-type thermocouple components,namely p-type Ni_(90)Cr_(10) and n-type Ni_(95)Al_(2)Mn_(2)Si.The cold-rolling process enables a large elastic modulus and a high yield strength,thanks to the texturized direction along<111>,and dense dislocations and refined grains,respectively,eventually resulting in a 400%increase in the elastic strain.Such superior elasticity ensures the preservation of the initial transport properties for the rolled films even after being bent 100000 times within a radius of~8 mm.A power output of~414μW is achieved in a ten-leg flexible thermoelectric device,suggesting its substantial potential for powering wearable electronics.展开更多
This work investigates the indentation response of an elastic plate resting upon a thin,transversely isotropic elastic layer supported by a rigid substrate.Such a scenario is encountered across a range of length scale...This work investigates the indentation response of an elastic plate resting upon a thin,transversely isotropic elastic layer supported by a rigid substrate.Such a scenario is encountered across a range of length scales from piezoresistive tests on graphite nanoflakes to the bending of floating ice shelves atop seabed,where the elastic layer commonly exhibits certain anisotropy.We first develop an approximate model to describe the elastic response of a transversely isotropic layer by exploiting the slenderness of the layer.We show that this approximate model can be reduced to the classic compressible Winkler foundation model as the elastic constants of the layer are set isotropic.We then investigate the combined response of an elastic plate on the transversely isotropic elastic layer.Facilitated by the simplicity of our proposed approximate model,we can derive simple analytical solutions for the cases of small and large indenter radi.The analytical results agree well with numerical calculations obtained via finite element methods,as long as the system is sufficiently slender in a mechanical sense.These results offer quantitative insights into the mechanical behavior of numerous semiconductor materials characterized by transverse isotropy and employed with slender geometries in various practical applications where the thin layer works as conductive and functional layers.展开更多
Rubberized concrete is one of the most studied applications of discarded tires and offers a promising approach to developing materials with enhanced properties.The rubberized concrete mixture results in a reduced modu...Rubberized concrete is one of the most studied applications of discarded tires and offers a promising approach to developing materials with enhanced properties.The rubberized concrete mixture results in a reduced modulus of elasticity and a reduced compressive and tensile strength compared to traditional concrete.This study employs finite element simulations to investigate the elastic properties of rubberized mortar(RuM),considering the influence of inclusion stiffness and interfacial debonding.Different homogenization schemes,including Voigt,Reuss,and mean-field approaches,are implemented using DIGIMAT and ANSYS.Furthermore,the influence of the interfacial transition zone(ITZ)between mortar and rubber is analyzed by periodic homogenization.Subsequently,the influence of the ITZ is examined through a linear fracture analysis with the stress intensity factor as a key parameter,using the ANSYS SMART crack growth tool.Finally,a non-linear study in FEniCS is carried out to predict the strength of the composite material through a compression test.Comparisons with high density polyethylene(HDPE)and gravel inclusions show that increasing inclusion stiffness enhances compressive strength far more effectively than simply improving the mortar/rubber bond.Indeed,when the inclusions are much softer than the surrounding matrix,any benefit gained on the elastic modulus or strength from stronger interfacial adhesion becomes almost negligible.This study provide numerical evidence that tailoring the rubber’s intrinsic stiffness—not merely strengthening the rubber/mortar interface—is a decisive factor for improving the mechanical performance of RuM.展开更多
The successful development of shale oil and gas reservoirs is the biggest technological revolution in the oil and gas industry.Its key technologies are horizontal well drilling and fracturing,which are based on unders...The successful development of shale oil and gas reservoirs is the biggest technological revolution in the oil and gas industry.Its key technologies are horizontal well drilling and fracturing,which are based on understanding the mechanical properties of reservoir rocks.Therefore,it is critical to obtain the reservoir mechanical parameters quickly,efficiently,and inexpensively.In this study,shale samples were collected from three basins in Southwest China,and the elastic modulus of shale in the indentation depth range of 0-5000 nm was obtained by nanoindentation experiments.Experimental results showed that different indentation depths had different physical characteristics.The shallower depths had the mechanical properties of single minerals,while the deeper depths had the mechanical properties of a multi-mineral composite.The difference between the two represented the cementation strength between the mineral particles.The error between the calculation results of the existing equivalent medium theoretical model and experimental data reached 324%.In this study,a weak cementation model was adopted,and three parameters obtained by nanoindentation experiments were considered:the soft component volume content,intergranular cementation strength,and mineral particle size.This solved the problem of assuming rather than calculating the values of some parameters in the existing model and realized the prediction of the macroscopic mechanical parameters of shale.The calculation error was reduced to less than 20%,and the test method and calculation model can be popularized and applied in engineering.展开更多
基金Supported by National Natural Science Foundation of China(50976032,51776070)。
文摘Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(E_(vac))from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(H_(v)/E_(v))forα-Fe_(2)O_(3)and an 83.33%reduction for Fe_(3)O_(4).Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(M_(s))of Fe_(3)O_(4)reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability.
基金Funded by State Railway Administration Research Project(No.2023JS007)National Natural Science Foundation of China(No.52438002)+1 种基金Research and Development Programs for Science and Technology of China Railways Corporation(No.J2023G003)New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘To investigate the influence of coarse aggregate parent rock properties on the elastic modulus of concrete,the mineralogical properties and stress-strain curves of granite and dolomite parent rocks,as well as the strength and elastic modulus of mortar and concrete prepared with mechanism aggregates of the corresponding lithology,and the stress-strain curves of concrete were investigated.In this paper,a coarse aggregate and mortar matrix bonding assumption is proposed,and a prediction model for the elastic modulus of mortar is established by considering the lithology of the mechanism sand and the slurry components.An equivalent coarse aggregate elastic modulus model was established by considering factors such as coarse aggregate particle size,volume fraction,and mortar thickness between coarse aggregates.Based on the elastic modulus of the equivalent coarse aggregate and the remaining mortar,a prediction model for the elastic modulus of the two and three components of concrete in series and then in parallel was established,and the predicted values differed from the measured values within 10%.It is proposed that the coarse aggregate elastic modulus in highstrength concrete is the most critical factor affecting the elastic modulus of concrete,and as the coarse aggregate elastic modulus increases by 27.7%,the concrete elastic modulus increases by 19.5%.
基金Project supported by the National Natural Science Foundation of China(Nos.52405095,12272089,and 92360305)the Guangdong Basic and Applied Basic Research Foundation of China(No.2023A1515110557)+4 种基金the Natural Science Foundation of Liaoning Province of China(No.2023-BSBA-102)the Open Fund of National Key Laboratory of Particle Transport and Separation Technology of China(No.WZKF-2024-6)the Open Project of Guangxi Key Laboratory of Automobile Components and Vehicle Technology of China(Nos.2024GKLACVTKF07 and 2024GKLACVTKF06)the Basic Research Projects of Liaoning Provincial Department of Education of China(No.JYTQN2023162)the Fundamental Research Funds for the Central Universities of China(No.N2403022)。
文摘The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings.
基金Supported by the National Natural Science Foundation of China(Grant Nos.62025104,62331005,and U22A2052)the Beijing Natural Science Foundation(Grant No.L242100).
文摘Background Computed tomography(CT) and cone-beam computed tomography(CBCT) image registration play pivotal roles in computer-assisted navigation for orthopedic surgery. Traditional methods often apply uniform deformation models, neglecting the biomechanical differences between rigid structures and soft tissues, which compromises registration accuracy, especially during significant bone displacements. Method To address this issue, we introduce RE-Reg, a rigid-elastic CT-CBCT image registration framework that jointly learns rigid bone motion and soft tissue deformation. RE-Reg incorporates a rigid alignment(RA) module to estimate global bone motion and an elastic deformation(ED) module to model soft tissue deformation, preserving bony structures through bone shape preservation(BSP) loss. Result Our comprehensive evaluation on publicly available datasets demonstrates that RE-Reg significantly outperforms existing methods in terms of registration accuracy and rigid bone structure preservation, achieving a 1.3% improvement in Dice similarity coefficient(DSC) and a 23% reduction in rigid bone deformation(%Δvol) compared with the best baseline. Conclusion This framework not only enhances anatomical fidelity but also ensures biomechanical plausibility and provides a valuable tool for image-guided orthopedic surgery. This code is available athttps://github.com/Zq-Huang/RE-Reg.
基金Supported by the National Key Research Program(No.2024-1129-954-112)National Natural Science Foundation of China(No.52372033)Guangxi Science and Technology Major Program(No.AA24263054)。
文摘Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes with SiO_(2)and Al_(2)O_(3)ratios were investigated using various techniques.It is found that when SiO_(2)is replaced by Al_(2)O_(3),the Q^(4) to Q^(3) transition of silicon-oxygen network decreases while the aluminum-oxygen network increases,which result in the transformation of Si-O-Si bonds to Si-O-Al bonds and an increase in glass network connectivity even though the intermolecular bond strength decreases.The glass transition temperature(T_(g))increases continuously,while the thermal expansion coefficient increases and high-temperature viscosity first decreases and then increases.Meanwhile,the elastic modulus values increase from 93 to 102 GPa.This indicates that the elastic modulus is mainly affected by packing factor and dissociation energy,and elements with higher packing factors and dissociation energies supplant those with lower values,resulting in increased rigidity within the glass.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272211,12072181,and 12121002).
文摘Uncertain parameters are widespread in engineering systems.This study investigates the modal analysis of a fluid-conveying pipe subjected to elastic supports with unknown-but-bound parameters.The governing equation for the elastically supported fluid-conveying pipe is transformed into ordinary differential equations using the Galerkin truncation method.The Chebyshev interval approach,integrated with the assumed mode method is then used to investigate the effects of uncertainties of support stiffness,fluid speed,and pipe length on the natural frequencies and mode shapes of the pipe.Additionally,both symmetrical and asymmetrical support stiffnesses are discussed.The accuracy and effectiveness of the Chebyshev interval approach are verified through comparison with the Monte Carlo method.The results reveal that,for the same deviation coefficient,uncertainties in symmetrical support stiffness have a greater impact on the first four natural frequencies than those of the asymmetrical one.There may be significant differences in the sensitivity of natural frequencies and mode shapes of the same order to uncertain parameters.Notably,mode shapes susceptible to uncertain parameters exhibit wider fluctuation intervals near the elastic supports,requiring more attention.
文摘BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different treatment options.AIM To analyze the clinical effect and prognosis of mixed hemorrhoids treated with polidocanol injection combined with automatic elastic thread ligation operation(RPH).METHODS A total of 100 patients with mixed hemorrhoids who visited our hospital from October 2022 to September 2023 were selected and randomly divided into the control group(n=50)and the treatment group(n=50)by rolling the dice.The procedure for prolapse and hemorrhoids(PPH)was adopted in the control group,while polidocanol foam injection+RPH was adopted in the treatment group.The therapeutic effects,operation time,wound healing time,hospital stay,pain situation(24 hours post-operative pain score,first defecation pain score),quality of life(QOL),incidence of complications(post-operative hemorrhage,edema,infection),incidence of anal stenosis 3 months post-operatively and recurrence rate 1 year post-operatively of the two groups were compared.RESULTS Compared with the control group,the total effective rate of treatment group was higher,and the difference was significant(P<0.05).The operation time/wound healing time/hospital stay in the treatment group were shorter than those in the control group(P<0.05).The pain scores at 24 hours after operation/first defecation pain score of the treatment group was significantly lower than those in the control group(P<0.05).After surgery,the QOL scores of the two groups decreased,with the treatment group having higher scores than that of the control group(P<0.05).Compared with the control group,the incidence of postoperative complications in the treatment group was lower,and the difference was significant(P<0.05);However,there was no significant difference in the incidence of postoperative bleeding between the two groups(P>0.05);There was no significant difference in the incidence of anal stenosis 3 months after operation and the recurrence rate 1 year after operation between the two groups(P>0.05).CONCLUSION For patients with mixed hemorrhoids,the therapeutic effect achieved by using polidocanol injection combined with RPH was better.The wounds of the patients healed faster,the postoperative pain was milder,QOL improved,and the incidence of complications was lower,and the short-term and long-term prognosis was good.
基金Project supported by the National Key R&D Program of China (Grant Nos. 2022YFA1602602 and 2023YFA1609600)the National Natural Science Foundation of China (Grant No. U23A20580)+3 种基金the open research fund of Songshan Lake Materials Laboratory (Grant No. 2022SLABFN27)Beijing National Laboratory for Condensed Matter Physics (Grant No. 2024BNLCMPKF004)Guangdong Basic and Applied Basic Research Foundation (Grant No. 2022B1515120020)the interdisciplinary program of Wuhan National High Magnetic Field Center at Huazhong University of Science and Technology (Grant No. WHMFC202132)。
文摘Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(Grant No.2021QNLM020001)the National Key R&D Program of China(Grant No.2019YFC0605503C)+2 种基金the Major Scientific and Technological Projects of China National Petroleum Corporation(CNPC)(Grant No.ZD2019-183-003)the National Outstanding Youth Science Foundation(Grant No.41922028)the National Innovation Group Project(Grant No.41821002).
文摘Based on waveform fitting,full waveform inversion(FWI)is an important inversion method with the ability to reconstruct multi-parameter models in high precision.However,the strong nonlinear equation used in FWI presents the following challenges,such as low convergence efficiency,high dependence on the initial model,and the energy imbalance in deep region of the inverted model.To solve these inherent problems,we develop a timedomain elastic FWI method based on gradient preconditioning with the following details:(1)the limited memory Broyden Fletcher Goldfarb Shanno method with faster convergence is adopted to im-prove the inversion stability;(2)a multi-scaled inversion strategy is used to alleviate the nonlinear inversion instead of falling into the local minimum;(3)in addition,the pseudo-Hessian preconditioned illumination operator is involved for preconditioning the parameter gradients to improve the illumination equilibrium degree of deep structures.Based on the programming implementation of the new method,a deep depression model with five diffractors is used for testing.Compared with the conventional elastic FWI method,the technique proposed by this study has better effectiveness and accuracy on the inversion effect and con-vergence,respectively.
基金Project supported by the National Natural Science Foundation of China (No.52175095)。
文摘The incomplete understanding of nanoscale surface interactions arising from underlying atomistic long-range forces limits our ability to simulate and design their performance. In this paper, the surface elasticity is constructed from underlying atomistic nonlocal interactions in spherical nanoparticles. By introducing an intrinsic length scale,we quantify the surface region thickness, and demonstrate the progressive elastic modulus transition caused by asymmetric atomistic nonlocal interactions. The universal surface scaling law, relating the intrinsic length scale to the particle dimensions, is established, and a surface-dominated criterion is developed for quantifying the transition to the surfacedominated behaviors. The model is thoroughly validated through the molecular static simulations and experimental data with the material-specific intrinsic length constants.
基金supported by the National Natural Science Foundation of China (Grant No.51705082)Fujian Provincial Minjiang Scholar Program (Grant No.0020-510759)+1 种基金Qishan Sholar program in Fuzhou University (Grant No.0020-650289)Fuzhou University Testing Fund of precious apparatus (Grant No.2023T018).
文摘The reduced elastic modulus Er and indentation hardness HIT of various brittle solids including ceramics,semiconductors,glasses,single crystals,and laser material were evaluated using nanoindentation.Various analysis procedures were compared such as Oliver&Pharr and nominal hardness-based methods,which require area function of the indenter,and other methods based on energy,displacement,contact depth,and contact stiffness,which do not require calibration of the indenter.Elastic recovery of the imprint by the Knoop indenter was also utilized to evaluate elastic moduli of brittle solids.Expressions relating HIT/Er and dimensionless nanoindentation variables(e.g.,the ratio of elastic work over total work and the ratio of permanent displacement over maximum displacement)are found to be nonlinear rather than linear for brittle solids.The plastic hardness Hp of brittle solids(except traditional glasses)extracted based on Er is found to be proportional to E_(r)√H_(IT).
文摘This paper proposes an efficient strategy for resource utilization in Elastic Optical Networks (EONs) to minimize spectrum fragmentation and reduce connection blocking probability during Routing and Spectrum Allocation (RSA). The proposed method, Dynamic Threshold-Based Routing and Spectrum Allocation with Fragmentation Awareness (DT-RSAF), integrates rerouting and spectrum defragmentation as needed. By leveraging Yen’s shortest path algorithm, DT-RSAF enhances resource utilization while ensuring improved service continuity. A dynamic threshold mechanism enables the algorithm to adapt to varying network conditions, while its fragmentation awareness effectively mitigates spectrum fragmentation. Simulation results on NSFNET and COST 239 topologies demonstrate that DT-RSAF significantly outperforms methods such as K-Shortest Path Routing and Spectrum Allocation (KSP-RSA), Load Balanced and Fragmentation-Aware (LBFA), and the Invasive Weed Optimization-based RSA (IWO-RSA). Under heavy traffic, DT-RSAF reduces the blocking probability by up to 15% and achieves lower Bandwidth Fragmentation Ratios (BFR), ranging from 74% to 75%, compared to 77% - 80% for KSP-RSA, 75% - 77% for LBFA, and approximately 76% for IWO-RSA. DT-RSAF also demonstrated reasonable computation times compared to KSP-RSA, LBFA, and IWO-RSA. On a small-sized network, its computation time was 8710 times faster than that of Integer Linear Programming (ILP) on the same network topology. Additionally, it achieved a similar execution time to LBFA and outperformed IWO-RSA in terms of efficiency. These results highlight DT-RSAF’s capability to maintain large contiguous frequency blocks, making it highly effective for accommodating high-bandwidth requests in EONs while maintaining reasonable execution times.
基金supported by generous grants from the Natural Science Foundation of Zhejiang Province(LR24E030003)Zhejiang Province Qianjiang Talent Program(ZJ-QJRC-2020-32).
文摘Elastic electronics are increasingly prevalent in information storage,smart sensing and health monitoring due to their softness,stretchability and portability.Wearable electronic devices should possess elasticity and stretchability that align with biological tissues.Specifically,their materials should be capable of elastic strain up to 50–80%,while the devices themselves must maintain electric stability under strains that accommodate body movements[1].
基金supported by the National Natural Science Foundation of China under Grant Nos.12174399,12147146 and 11934014by the Natural Science Foundation of Hainan Province under Grant No.122QN219+1 种基金through the Innovational Fund for Scientific and Technological Personnel of Hainan Provinceby the Natural Science Foundation of Shandong Provincial under Grant No.ZR2021QA046。
文摘The study of collision between metastable positronium(Ps)and antihydrogen(H)is crucial for precision experiments involving H.In this paper,we investigate the elastic scattering between H and Ps(2s)by combining the confined variational method with the projection method,for scattering energies from 0.0245 eV to 0.068 eV.Our calculations provide accurate phase shifts and cross sections for the 1,3S and 1,3P symmetries.Near the binding threshold,the rapid increase in the total cross section may be attributed to the P-wave resonance effect.Additionally,we determined the S-wave scattering lengths to be 9.34 a_(0)and 5.81 a_(0)for singlet and triplet elastic scattering,respectively.
基金supported by the National Key Research and Development Program of China(2023YFB3809400)the National Natural Science Foundation of China(Grant nos.T2125008,92163203,and 52371234)+1 种基金the Hong Kong,Macao,and Taiwan Science and Technology Cooperation Project for Science and Technology Innovation Plan of Shanghai(23520760600)the Fundamental Research Funds for the Central Universities.
文摘Elastic strain constitutes a decisive factor in determining the recoverable deformability of thermoelectric materials.Plastic deformation for microstructure engineering has been demonstrated as a viable approach to enhance the elastic strain.However,this approach is highly dependent on the material's plasticity,which is rather limited by the rigidity for the majority of inorganic semiconducting thermoelectric materials.Thermocouple materials,as metallic thermoelectric materials,possess a favorable plasticity,motivating this work to focus on the elastic bendability of a metallic thermoelectric generator that is composed of K-type thermocouple components,namely p-type Ni_(90)Cr_(10) and n-type Ni_(95)Al_(2)Mn_(2)Si.The cold-rolling process enables a large elastic modulus and a high yield strength,thanks to the texturized direction along<111>,and dense dislocations and refined grains,respectively,eventually resulting in a 400%increase in the elastic strain.Such superior elasticity ensures the preservation of the initial transport properties for the rolled films even after being bent 100000 times within a radius of~8 mm.A power output of~414μW is achieved in a ten-leg flexible thermoelectric device,suggesting its substantial potential for powering wearable electronics.
基金supported by the National Natural Science Foundation of China(12372103)the Opening Fund of State Key Laboratory of Nonlinear Mechanics(Institute of Mechanics,CAS)the Fundamental Research Funds for Central Universities(Peking University).
文摘This work investigates the indentation response of an elastic plate resting upon a thin,transversely isotropic elastic layer supported by a rigid substrate.Such a scenario is encountered across a range of length scales from piezoresistive tests on graphite nanoflakes to the bending of floating ice shelves atop seabed,where the elastic layer commonly exhibits certain anisotropy.We first develop an approximate model to describe the elastic response of a transversely isotropic layer by exploiting the slenderness of the layer.We show that this approximate model can be reduced to the classic compressible Winkler foundation model as the elastic constants of the layer are set isotropic.We then investigate the combined response of an elastic plate on the transversely isotropic elastic layer.Facilitated by the simplicity of our proposed approximate model,we can derive simple analytical solutions for the cases of small and large indenter radi.The analytical results agree well with numerical calculations obtained via finite element methods,as long as the system is sufficiently slender in a mechanical sense.These results offer quantitative insights into the mechanical behavior of numerous semiconductor materials characterized by transverse isotropy and employed with slender geometries in various practical applications where the thin layer works as conductive and functional layers.
基金financial support from the Chilean National Agency for Research and Development(ANID),National Doctorate No.21212028financial support from ANID,FONDECYT Regular Research Project No.1221793.
文摘Rubberized concrete is one of the most studied applications of discarded tires and offers a promising approach to developing materials with enhanced properties.The rubberized concrete mixture results in a reduced modulus of elasticity and a reduced compressive and tensile strength compared to traditional concrete.This study employs finite element simulations to investigate the elastic properties of rubberized mortar(RuM),considering the influence of inclusion stiffness and interfacial debonding.Different homogenization schemes,including Voigt,Reuss,and mean-field approaches,are implemented using DIGIMAT and ANSYS.Furthermore,the influence of the interfacial transition zone(ITZ)between mortar and rubber is analyzed by periodic homogenization.Subsequently,the influence of the ITZ is examined through a linear fracture analysis with the stress intensity factor as a key parameter,using the ANSYS SMART crack growth tool.Finally,a non-linear study in FEniCS is carried out to predict the strength of the composite material through a compression test.Comparisons with high density polyethylene(HDPE)and gravel inclusions show that increasing inclusion stiffness enhances compressive strength far more effectively than simply improving the mortar/rubber bond.Indeed,when the inclusions are much softer than the surrounding matrix,any benefit gained on the elastic modulus or strength from stronger interfacial adhesion becomes almost negligible.This study provide numerical evidence that tailoring the rubber’s intrinsic stiffness—not merely strengthening the rubber/mortar interface—is a decisive factor for improving the mechanical performance of RuM.
基金supported by the Key R&D Program Project of Xinjiang Province(2024B01013)the National Key Research and Development Program of China(2022YFE0129800).
文摘The successful development of shale oil and gas reservoirs is the biggest technological revolution in the oil and gas industry.Its key technologies are horizontal well drilling and fracturing,which are based on understanding the mechanical properties of reservoir rocks.Therefore,it is critical to obtain the reservoir mechanical parameters quickly,efficiently,and inexpensively.In this study,shale samples were collected from three basins in Southwest China,and the elastic modulus of shale in the indentation depth range of 0-5000 nm was obtained by nanoindentation experiments.Experimental results showed that different indentation depths had different physical characteristics.The shallower depths had the mechanical properties of single minerals,while the deeper depths had the mechanical properties of a multi-mineral composite.The difference between the two represented the cementation strength between the mineral particles.The error between the calculation results of the existing equivalent medium theoretical model and experimental data reached 324%.In this study,a weak cementation model was adopted,and three parameters obtained by nanoindentation experiments were considered:the soft component volume content,intergranular cementation strength,and mineral particle size.This solved the problem of assuming rather than calculating the values of some parameters in the existing model and realized the prediction of the macroscopic mechanical parameters of shale.The calculation error was reduced to less than 20%,and the test method and calculation model can be popularized and applied in engineering.
