An orthogoual experimental scheme was designed for optimizing a water-cooled structure of the divertor plate. There were three influencing factors： the radius R of the water- cooled pipe, and the pipe spacing L1 and ...An orthogoual experimental scheme was designed for optimizing a water-cooled structure of the divertor plate. There were three influencing factors： the radius R of the water- cooled pipe, and the pipe spacing L1 and L3. The influence rule of different factors on the cooling effect and thermal stress of the plate were studied, for which the influence rank was respectively R 〉 L1 〉 L3 and L3 〉 R 〉 L1. The highest temperature value decreased when R and L1 increased~ and the maximum thermal stress value dropped when R, L1 and L3 increased. The final optimized results can be summarized as： R equals 6 mm or 7 mm, L1 equals 19 mm, and L3 equals 20 mm. Compared with the initial design, the highest temperature value had a small decline~ and the maximum thermal stress value dropped by 19~ to 24~. So it was not ideal to improve the cooling effect by optimizing the geometry sizes of the water-cooled structure, even worse than increasing the flow speed, but it was very effective for dropping the maximum thermal stress value. The orthogoaal experimental method reduces the number of experiments by 80%, and thus it is feasible and effective to optimize the water-cooled structure of the divertor plate with the orthogonal theory.展开更多
For the first time,the linear and nonlinear vibrations of composite rectangular sandwich plates with various geometric patterns of lattice core have been analytically examined in this work.The plate comprises a lattic...For the first time,the linear and nonlinear vibrations of composite rectangular sandwich plates with various geometric patterns of lattice core have been analytically examined in this work.The plate comprises a lattice core located in the middle and several homogeneous orthotropic layers that are symmetrical relative to it.For this purpose,the partial differential equations of motion have been derived based on the first-order shear deformation theory,employing Hamilton’s principle and Von Kármán’s nonlinear displacement-strain relations.Then,the nonlinear partial differential equations of the plate are converted into a time-dependent nonlinear ordinary differential equation(Duffing equation)by applying the Galerkin method.From the solution of this equation,the natural frequencies are extracted.Then,to calculate the non-linear frequencies of the plate,the non-linear equation of the plate has been solved analytically using the method of multiple scales.Finally,the effect of some critical parameters of the system,such as the thickness,height,and different angles of the stiffeners on the linear and nonlinear frequencies,has been analyzed in detail.To confirmthe solution method,the results of this research have been compared with the reported results in the literature and finite elements in ABAQUS,and a perfect match is observed.The results reveal that the geometry and configuration of core ribs strongly affect the natural frequencies of the plate.展开更多
Zirconium-titanium-steel composite plate with the size of 2500 mm×7800 mm×(3+0.7+22)mm was prepared by explosive welding+rolling method,and its properties were analyzed by ultrasonic nondestructive testing,p...Zirconium-titanium-steel composite plate with the size of 2500 mm×7800 mm×(3+0.7+22)mm was prepared by explosive welding+rolling method,and its properties were analyzed by ultrasonic nondestructive testing,phased array waveform shape,interface structure shape,electronic scanning,and mechanical property testing.Results show that the rolling temperature of zirconiumtitanium complex should be controlled at 760°C,and the rolling reduction of each pass should be controlled at 10%–25%.The explosive velocity to prepare zirconium-titanium-steel composite plates should be controlled at 2450–2500 m/s,the density should be 0.78 g/cm3,the stand-off height should be 12 mm,and the explosive height of Zone A and Zone B should be 45–50 mm.Explosive welding combined with rolling method reduces the impact of explosive welding and multiple heat treatment on material properties.Meanwhile,the problems of surface wrinkling and cracking,which occur during the preparation process of large-sized zirconiumtitanium-steel composite plate,can be solved.展开更多
Background and Objectives: The distal radius fracture (DRF) is a major public health problem in northern countries. Its frequency is constantly increasing. The locked anterior plate with its well-established biomechan...Background and Objectives: The distal radius fracture (DRF) is a major public health problem in northern countries. Its frequency is constantly increasing. The locked anterior plate with its well-established biomechanical properties, offers a reliable alternative. The aim of this study was to evaluate the radiological, the functional results and to determine the factors of poor postoperative prognosis of DRF treated with Newclip radial plates®. Methodology: This prospective cohort study evaluates the radiological and functional outcames of displaced radius fractures (DRFs) in patients ≥50 years old treated with Newclip® (locked anterior plates) at the Basse-Terre Hospital in Guadeloupe from 2022 to 2024. The patients were categorized into those with epiphyseal involvement (E1 - E4) and without epiphyseal involvement (E0) based on Laulan’s MEU classification. Radiological parameters (distal radio-ulnar index (DRUI), radial inclination frant view (IRF), radial inclination sagittal view (IRS) were assessed pre and post-operatively. Functional recovery was evaluated at 12 months using the QuickDash questionnaire. Results: Falls were the most common cause of fracture. Post-operatively, SRI was the least restored parameter. Poor prognostic factor for SRI improvement included posterior commimution and unstable fractures. Factors associated with higher QuickDash scores included unstable factures, unrestored DRUI, low plate position, metaphyseal features, and ulnar features. Conclusion: The anterior locking plate osteosynthesis is reliable treatment option with excellent functional outcomes.展开更多
The influences of different factors,including whether the transverse frames are actually built,longitudinal and transverse welding residual stresses,and unloaded edge boundaries,on the ultimate strength and failure mo...The influences of different factors,including whether the transverse frames are actually built,longitudinal and transverse welding residual stresses,and unloaded edge boundaries,on the ultimate strength and failure mode of a real hull bottom full-scale stiffened plate under axial compression and lateral pressure are investigated via numerical analysis.Result shows that the failure mode of the stiffened plate under axial compression is the tripping of the stiffeners.Whether transverse frames are built has little effect on the ultimate strength of the stiffened plate under axial compression,which can be replaced by the degree of freedom constraint.However,when lateral pressure is present,the transverse frame cannot be simply replaced by a free-degree constraint.The longitudinal residual stress has a greater effect on the ultimate strength,whereas the effect of the transverse residual stress is smaller.Stronger unloaded edge boundary conditions can slightly enhance the stiffness and ultimate strength of the stiffened plate.Under combined axial compression and lateral pressure,the failure mode of stiffened plates changes from the tripping of stiffeners to beam-column failure,as the lateral pressure increases.The ability of stiffened plates in which transverse frames are actually built out to resist beam-column shape deformation becomes weaker with lower ultimate strength.Stronger unloaded edge boundary conditions can improve the ability of stiffened plates to resist beam-column deformation and increase the ultimate strength.展开更多
Throughout the 20th century, several large megathrust earthquakes were observed in the Colombia–Ecuador subduction zone which widely ruptured plate interfaces, causing considerable damage and loss of life. The occurr...Throughout the 20th century, several large megathrust earthquakes were observed in the Colombia–Ecuador subduction zone which widely ruptured plate interfaces, causing considerable damage and loss of life. The occurrence of earthquakes in subduction zones is thought to be closely related to the thermal structure of the incoming plate. However, in the case of the subducting Nazca Plate beneath the Colombia–Ecuador zone, the thermal structure remains unclear, especially its hydraulic distribution. On the basis of 3D thermal models, we present new insights into the plate interface conditions of Colombia–Ecuador interplate and megathrust earthquakes. We show that the plate geometry strongly affects the along-strike thermal structure of the slab beneath Colombia and Ecuador, with the subduction of the Carnegie Ridge playing an important role. Our results further reveal that the unique geometry of the Nazca Plate is the primary reason for the relatively high temperatures of the slab beneath Colombia. We suggest that the positions of the100–200 ℃ and 350–450 ℃ isotherms on the plate interface determine the updip and downdip limits of the seismogenic zone. For Colombia–Ecuador interplate earthquakes, the released fluids control the distribution of shallow-depth earthquakes, whereas the age and geometry of the slab control the distribution of intermediate-depth earthquakes. The average temperature of the plate interface at the upper limit of large megathrust earthquakes is hotter than previously thought, which is more consistent with our understanding of the Colombia–Ecuador subduction zone. We predict that the potential location of future large seismic events could be in the rupture zone of past seismic events or offshore of northern Colombia.展开更多
In clinical settings,tantalum(Ta)is extensively implemented as a bone implant material.Ta is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone tissue.However,...In clinical settings,tantalum(Ta)is extensively implemented as a bone implant material.Ta is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone tissue.However,since Ta is a refractory metal,its application as bone implant material is limited.Most recently,additive manufacturing technology has introduced a novel approach to producing Ta implants.The present study compared the microstructure,surface and mechanical characteristics,and in vitro and in vivo biological characteristics of selective laser melted Ta(SLM Ta),selective laser melted titanium alloy Ti6Al4V with Ta coating(SLM Ti6Al4V with Ta coating),and selective laser melted Ti6Al4V(SLM Ti6Al4V).Results indicate that SLM Ta possesses superior mechanical characteristics contrasted with SLM Ti6Al4V and SLM Ti6Al4V with Ta coating.Furthermore,SLM Ta has anti-inflammatory activity,excellent osseointegration performance,and osteogenic bioactivity.We fabricated an SLM porous Ta bone plate and employed it for internal fixation of ulnar and radius fractures,which has been known to promote fracture healing.Further,the SLM porous Ta bone plate could form an integrated bone plate structure with the bone tissue at the implant site.Afterward,the porous structure of the plate minimizes its elastic modulus and eliminates stress shielding,leaving no need for further surgical removal.In conclusion,the SLM porous Ta bone plate meets the performance requirements(stimulating bone regeneration,non-stress shelter,and no need for second surgery)of an ideal bone plate and may revolutionize the field of internal fixation bone plates for fractures.展开更多
Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade compone...Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade components.In this paper,a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established.Based on Kirchhoff's plate assumptions,the displacement variables of the plate are expressed.By incorporating the braiding directions into the constitutive equation of the braided composites,the dynamic model of the plate considering braiding directions is obtained.The effects of the speeds,braiding directions,and braided angles on the responses of the plate with fixed-axis rotation and translational motion,respectively,are investigated.This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions.It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.展开更多
This paper presents,for the first time,an effective numerical approach based on the isogeometric analysis(IGA)and the six-variable quasi-three dimensional(3D)higher-order shear deformation theory(HSDT)to study the fre...This paper presents,for the first time,an effective numerical approach based on the isogeometric analysis(IGA)and the six-variable quasi-three dimensional(3D)higher-order shear deformation theory(HSDT)to study the free vibration characteristics of functionally-graded(FG)graphene origami(GOri)-enabled auxetic metamaterial(GOEAM)plates submerged in a fluid medium.The plate theory incorporates the thickness stretching and the effects of transverse shear deformation without using any shear correction factors.The velocity potential function and Bernoulli's equation are used to derive the hydrodynamic pressure acting on the plate surface.Both horizontally and vertically immersed plate configurations are considered here in the form of inertia effects.The plates are composed of multilayer GOEAMs,with the GOri content varying through the plate's thickness in a layer-wise manner.This design results in graded auxetic growth.The material properties are evaluated by mixing rules and a genetic programming(GP)-assisted micromechanical model.The governing equations of motion for the FG-GOEAM plates immersed in a fluid medium are derived by Hamilton's principle.After validating the convergence and accuracy of the present model,a comprehensive parametric study is carried out to examine the effects of the GOri content,GOri distribution pattern,GOri folding degree,fluid level,immersed depth,and geometric parameter on the natural frequencies of the FG-GOEAM plates.The results show that the natural frequencies for the four GOri distribution patterns increase with the increase in the layer number when the lay number is fewer than 10,and then stabilize after the layer number reaches 10.Besides,in general,the natural frequency of the FG-GOEAM plate in a vacuum or fluid increases when the GOri content increases,while decreases when the GOri folding degree increases.Some additional findings related to the numerical results are presented in the conclusions.It is believed that the present results are useful for the precise design and optimization of FG-GOEAM plates immersed in a fluid medium.展开更多
A new process of welding aluminum water-cooled busbars is proposed, It can not only reduce the weight and cost, but also improve the dynamic and thermal stability. Furthermore~ both finite element method analysis and ...A new process of welding aluminum water-cooled busbars is proposed, It can not only reduce the weight and cost, but also improve the dynamic and thermal stability. Furthermore~ both finite element method analysis and a prototype test testify the advantages of the design which is not limited by load current and provides a new approach for water-cooled reactors.展开更多
A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The ...A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The model is proved logical and credible by comparing calculated results and measured data. Then, the relationship between water flow velocity, inlet water temperature, furnace temperature and roller cross section temperature, outlet water temperature, water temperature rise, cooling water heat absorption was studied. The conclusions and recommendations are mainly as follows： l） Cooling water temperature rise decreases with the increase of water flow velocity, but it has small relationship with inlet water temperature; 2） In order to get little water scale, inlet water temperature should be controlled below 30 ℃. 3） The cooling water flow velocity should be greater than critical velocity. The critical velocity is 0.07 m/s and water flow velocity should be controlled within 0.4-0.8 m/s. Within this velocity range, water cooling efficiency is high and water temperature rise is little. If cooling water velocity increases again, heat loss will increase, leading to energy wasting.展开更多
In order to realize safe and stable operation of a water-cooled W/Cu divertor under high heating condition,the exact knowledge of its subcooled boiling heat transfer characteristics under different design parameters i...In order to realize safe and stable operation of a water-cooled W/Cu divertor under high heating condition,the exact knowledge of its subcooled boiling heat transfer characteristics under different design parameters is crucial.In this paper,subcooled boiling heat transfer in a water-cooled W/Cu divertor was numerically investigated based on computational fluid dynamic（CFD）.The boiling heat transfer was simulated based on the Euler homogeneous phase model,and local differences of liquid physical properties were considered under one-sided high heating conditions.The calculated wall temperature was in good agreement with experimental results,with the maximum error of 5%only.On this basis,the void fraction distribution,flow field and heat transfer coefficient（HTC）distribution were obtained.The effects of heat flux,inlet velocity and inlet temperature on temperature distribution and pressure drop of a water-cooled W/Cu divertor were also investigated.These results provide a valuable reference for the thermal-hydraulic design of a water-cooled W/Cu divertor.展开更多
The water-cooling heat dissipation technology can solve the heat dissipation and noise problems of the calculation plate.Therefore,the structural design of the water-cooling plate directly affects its flow and heat tr...The water-cooling heat dissipation technology can solve the heat dissipation and noise problems of the calculation plate.Therefore,the structural design of the water-cooling plate directly affects its flow and heat transfer characteristics,which restricts the promotion and application of the technology.To this end,the water-cooling plate of a heat dissipation system was taken as the research object,and its flow and heat transfer characteristics were numerical simulated and experimental studied.Through comparative analysis,the rationality of the numerical simulation method was verified.Based on this,three improved schemes of water-cooling plate structure were proposed and numerical simulation was carried out,and the optimal model was verified by experiments.The results of the study show that compared with the original water-cooling plate,the optimized water-cooling plate has increased internal flow velocity and distributes uniformly,increased heat transfer amount by 4.2%,and the average temperature of the calculation plate decreased by 5.3%.展开更多
The semisolid slurry of Al-Zn-Mg-Cu alloy was prepared through a self-designed water-cooled copper serpentine pouring channel(WSPC) machine. Influences of pouring temperature, the number of turns and the cooling water...The semisolid slurry of Al-Zn-Mg-Cu alloy was prepared through a self-designed water-cooled copper serpentine pouring channel(WSPC) machine. Influences of pouring temperature, the number of turns and the cooling water flow rate on the microstructure of the semisolid Al-Zn-Mg-Cu alloy slurry were investigated. The results show that the semisolid Al-Zn-Mg-Cu alloy slurry with satisfactory quality can be generated by the WSPC when the pouring temperature is in the range between 680 ℃ and 700 ℃. At a given pouring temperature, the average grain size of primary α-Al decreases and the shape factor increases with the increase of the number of turns. When the cooling water flow rate is 450 L·h^(-1), the obtained semisolid slurry is optimal. During the preparation of the semisolid Al-Zn-Mg-Cu alloy slurry with low superheat pouring, the alloy melt has mixed inhibition and convection flow characteristics by "self-stirring". When the alloy melt flows through the serpentine channel, the chilling effect of the inner wall of the channel, the convection and mixed inhibition of the alloy melt greatly promote the heterogeneous nucleation and grain segregation. This effect destroys the dendrite growth mode under traditional solidification conditions, and the primary nuclei gradually evolve into spherical or nearspherical grains.展开更多
In the direct fired furnace of a continuous annealing line, seal rolls are susceptible to deformation that leads to surface defects of steel strips. According to failure analysis, the reasons include improper structur...In the direct fired furnace of a continuous annealing line, seal rolls are susceptible to deformation that leads to surface defects of steel strips. According to failure analysis, the reasons include improper structural design and heat imbalance. An improved design has been proposed to reduce stress concentration and thermal radiation. A heat transfer model has been employed to determine the proper water flow rate for roll cooling. Industrial application proves that seal rolls with the new design has less deformation and longer service life.展开更多
Through combined applications of the transfer-matrix method and asymptotic expansion technique,we formulate a theory to predict the three-dimensional response of micropolar plates.No ad hoc assumptions regarding throu...Through combined applications of the transfer-matrix method and asymptotic expansion technique,we formulate a theory to predict the three-dimensional response of micropolar plates.No ad hoc assumptions regarding through-thickness assumptions of the field variables are made,and the governing equations are two-dimensional,with the displacements and microrotations of the mid-plane as the unknowns.Once the deformation of the mid-plane is solved,a three-dimensional micropolar elastic field within the plate is generated,which is exact up to the second order except in the boundary region close to the plate edge.As an illustrative example,the bending of a clamped infinitely long plate caused by a uniformly distributed transverse force is analyzed and discussed in detail.展开更多
A novel scheme of fully immersing water cooling is proposed for a Nd：glass radial slab laser. The slab medium is entirely immersed in the circulating water Ailing the pumping cavity, which enables much lower temperat...A novel scheme of fully immersing water cooling is proposed for a Nd：glass radial slab laser. The slab medium is entirely immersed in the circulating water Ailing the pumping cavity, which enables much lower temperature and reasonably smaller thermal gradient in the slab medium. The radial slab is symmetrically and synchronously pumped by eight flash lamps, and produces multi-output beams with a total energy of 469md. Incoherent beam combination property of the multi-output beams is also investigated. The approach suggested here provides a way of scaling the slab lasers to much higher output levels and also a convenience for beam combinations.展开更多
In this paper,the effects of recrystallization,grain growth and texture evolution on the formability and anisotropy of Mg/Al composite plates were studied by different annealing processes.The results show that the rol...In this paper,the effects of recrystallization,grain growth and texture evolution on the formability and anisotropy of Mg/Al composite plates were studied by different annealing processes.The results show that the rolled Mg/Al composite plate exhibits obvious anisotropy and poor formability in the rolling directions(RD)and transverse directions(TD),which is the result of the synergistic effect of matrix texture and grain characteristics.Annealing-activated recrystallization can eliminate local shear bands,hardening and other defects formed by rolling,thereby softening the structure and improving the formability of the sheet.The occurrence of recrystallization behavior also makes the bimodal texture parallel to the TD distribution in the Mg matrix transform into the RD-TD surface dispersion distribution,which weakens the strong deformation texture.The Schmidt factor(SF)of each slip system is calculated to evaluate the slip system start-up probability(deformation difficulty)of the material in a certain direction.The results show that the average SF values of matrix slip in RD and TD directions increase after annealing treatment,which makes the slip system easier to start.The tensile test results show that the formability of the composite plate is the best when the annealing temperature is 300℃.At this time,the ultimate tensile strength(UTS)and yield strength(YS)are small,the elongation(EL)is large and the anisotropy of mechanical properties is the weakest.In addition,the annealing of the composite plate leads to the transformation of the fracture mechanism from brittle fracture to ductile-brittle mixed fracture.In summary,annealing treatment can effectively improve the formability and weaken the anisotropy of Mg/Al composite plates.展开更多
Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic accidents.To effectively monitor compliance,the utilization of target detection algorithms through traffic cam...Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic accidents.To effectively monitor compliance,the utilization of target detection algorithms through traffic cameras plays a vital role in identifying helmet usage by electric bicycle riders and recognizing license plates on electric bicycles.However,manual enforcement by traffic police is time-consuming and labor-intensive.Traditional methods face challenges in accurately identifying small targets such as helmets and license plates using deep learning techniques.This paper proposes an enhanced model for detecting helmets and license plates on electric bicycles,addressing these challenges.The proposedmodel improves uponYOLOv8n by deepening the network structure,incorporating weighted connections,and introducing lightweight convolutional modules.These modifications aim to enhance the precision of small target recognition while reducing the model’s parameters,making it suitable for deployment on low-performance devices in real traffic scenarios.Experimental results demonstrate that the model achieves an mAP@0.5 of 91.8%,showing an 11.5%improvement over the baselinemodel,with a 16.2%reduction in parameters.Additionally,themodel achieves a frames per second(FPS)rate of 58,meeting the accuracy and speed requirements for detection in actual traffic scenarios.展开更多
基金supported by National Basic Research Program of China(973 Program)(No.2013GB102000)
文摘An orthogoual experimental scheme was designed for optimizing a water-cooled structure of the divertor plate. There were three influencing factors： the radius R of the water- cooled pipe, and the pipe spacing L1 and L3. The influence rule of different factors on the cooling effect and thermal stress of the plate were studied, for which the influence rank was respectively R 〉 L1 〉 L3 and L3 〉 R 〉 L1. The highest temperature value decreased when R and L1 increased~ and the maximum thermal stress value dropped when R, L1 and L3 increased. The final optimized results can be summarized as： R equals 6 mm or 7 mm, L1 equals 19 mm, and L3 equals 20 mm. Compared with the initial design, the highest temperature value had a small decline~ and the maximum thermal stress value dropped by 19~ to 24~. So it was not ideal to improve the cooling effect by optimizing the geometry sizes of the water-cooled structure, even worse than increasing the flow speed, but it was very effective for dropping the maximum thermal stress value. The orthogoaal experimental method reduces the number of experiments by 80%, and thus it is feasible and effective to optimize the water-cooled structure of the divertor plate with the orthogonal theory.
文摘For the first time,the linear and nonlinear vibrations of composite rectangular sandwich plates with various geometric patterns of lattice core have been analytically examined in this work.The plate comprises a lattice core located in the middle and several homogeneous orthotropic layers that are symmetrical relative to it.For this purpose,the partial differential equations of motion have been derived based on the first-order shear deformation theory,employing Hamilton’s principle and Von Kármán’s nonlinear displacement-strain relations.Then,the nonlinear partial differential equations of the plate are converted into a time-dependent nonlinear ordinary differential equation(Duffing equation)by applying the Galerkin method.From the solution of this equation,the natural frequencies are extracted.Then,to calculate the non-linear frequencies of the plate,the non-linear equation of the plate has been solved analytically using the method of multiple scales.Finally,the effect of some critical parameters of the system,such as the thickness,height,and different angles of the stiffeners on the linear and nonlinear frequencies,has been analyzed in detail.To confirmthe solution method,the results of this research have been compared with the reported results in the literature and finite elements in ABAQUS,and a perfect match is observed.The results reveal that the geometry and configuration of core ribs strongly affect the natural frequencies of the plate.
基金Key R&D Plan of Shaanxi Province(2021LLRH-05-09)Shaanxi Province Youth Talent Support Program Project(CLGC202234)Sponsored by Innovative Pilot Platform for Layered Metal Composite Materials(2024CX-GXPT-20)。
文摘Zirconium-titanium-steel composite plate with the size of 2500 mm×7800 mm×(3+0.7+22)mm was prepared by explosive welding+rolling method,and its properties were analyzed by ultrasonic nondestructive testing,phased array waveform shape,interface structure shape,electronic scanning,and mechanical property testing.Results show that the rolling temperature of zirconiumtitanium complex should be controlled at 760°C,and the rolling reduction of each pass should be controlled at 10%–25%.The explosive velocity to prepare zirconium-titanium-steel composite plates should be controlled at 2450–2500 m/s,the density should be 0.78 g/cm3,the stand-off height should be 12 mm,and the explosive height of Zone A and Zone B should be 45–50 mm.Explosive welding combined with rolling method reduces the impact of explosive welding and multiple heat treatment on material properties.Meanwhile,the problems of surface wrinkling and cracking,which occur during the preparation process of large-sized zirconiumtitanium-steel composite plate,can be solved.
文摘Background and Objectives: The distal radius fracture (DRF) is a major public health problem in northern countries. Its frequency is constantly increasing. The locked anterior plate with its well-established biomechanical properties, offers a reliable alternative. The aim of this study was to evaluate the radiological, the functional results and to determine the factors of poor postoperative prognosis of DRF treated with Newclip radial plates®. Methodology: This prospective cohort study evaluates the radiological and functional outcames of displaced radius fractures (DRFs) in patients ≥50 years old treated with Newclip® (locked anterior plates) at the Basse-Terre Hospital in Guadeloupe from 2022 to 2024. The patients were categorized into those with epiphyseal involvement (E1 - E4) and without epiphyseal involvement (E0) based on Laulan’s MEU classification. Radiological parameters (distal radio-ulnar index (DRUI), radial inclination frant view (IRF), radial inclination sagittal view (IRS) were assessed pre and post-operatively. Functional recovery was evaluated at 12 months using the QuickDash questionnaire. Results: Falls were the most common cause of fracture. Post-operatively, SRI was the least restored parameter. Poor prognostic factor for SRI improvement included posterior commimution and unstable fractures. Factors associated with higher QuickDash scores included unstable factures, unrestored DRUI, low plate position, metaphyseal features, and ulnar features. Conclusion: The anterior locking plate osteosynthesis is reliable treatment option with excellent functional outcomes.
基金financially supported by the National Natural Science Foundation of China(Grant No.52001040),the Natural Science Foundation Project of Chongqing,Chongqing Science and Technology Commission(Grant No.cstc2021jcyj-msxmX0944)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202300710).
文摘The influences of different factors,including whether the transverse frames are actually built,longitudinal and transverse welding residual stresses,and unloaded edge boundaries,on the ultimate strength and failure mode of a real hull bottom full-scale stiffened plate under axial compression and lateral pressure are investigated via numerical analysis.Result shows that the failure mode of the stiffened plate under axial compression is the tripping of the stiffeners.Whether transverse frames are built has little effect on the ultimate strength of the stiffened plate under axial compression,which can be replaced by the degree of freedom constraint.However,when lateral pressure is present,the transverse frame cannot be simply replaced by a free-degree constraint.The longitudinal residual stress has a greater effect on the ultimate strength,whereas the effect of the transverse residual stress is smaller.Stronger unloaded edge boundary conditions can slightly enhance the stiffness and ultimate strength of the stiffened plate.Under combined axial compression and lateral pressure,the failure mode of stiffened plates changes from the tripping of stiffeners to beam-column failure,as the lateral pressure increases.The ability of stiffened plates in which transverse frames are actually built out to resist beam-column shape deformation becomes weaker with lower ultimate strength.Stronger unloaded edge boundary conditions can improve the ability of stiffened plates to resist beam-column deformation and increase the ultimate strength.
基金benefited from the financial support of the CAS Pioneer Hundred Talents Program and the Second Tibetan Plateau Scientific Expedition and Research Program (2019QZKK0708)。
文摘Throughout the 20th century, several large megathrust earthquakes were observed in the Colombia–Ecuador subduction zone which widely ruptured plate interfaces, causing considerable damage and loss of life. The occurrence of earthquakes in subduction zones is thought to be closely related to the thermal structure of the incoming plate. However, in the case of the subducting Nazca Plate beneath the Colombia–Ecuador zone, the thermal structure remains unclear, especially its hydraulic distribution. On the basis of 3D thermal models, we present new insights into the plate interface conditions of Colombia–Ecuador interplate and megathrust earthquakes. We show that the plate geometry strongly affects the along-strike thermal structure of the slab beneath Colombia and Ecuador, with the subduction of the Carnegie Ridge playing an important role. Our results further reveal that the unique geometry of the Nazca Plate is the primary reason for the relatively high temperatures of the slab beneath Colombia. We suggest that the positions of the100–200 ℃ and 350–450 ℃ isotherms on the plate interface determine the updip and downdip limits of the seismogenic zone. For Colombia–Ecuador interplate earthquakes, the released fluids control the distribution of shallow-depth earthquakes, whereas the age and geometry of the slab control the distribution of intermediate-depth earthquakes. The average temperature of the plate interface at the upper limit of large megathrust earthquakes is hotter than previously thought, which is more consistent with our understanding of the Colombia–Ecuador subduction zone. We predict that the potential location of future large seismic events could be in the rupture zone of past seismic events or offshore of northern Colombia.
基金supported by the National Natural Science Foundation of China(No.82172398)Liaoning Revitalization Talents Program(No.XLYC2203102).
文摘In clinical settings,tantalum(Ta)is extensively implemented as a bone implant material.Ta is highly stable and biocompatible in vivo,being one of the metallic biomaterials having high affinity for bone tissue.However,since Ta is a refractory metal,its application as bone implant material is limited.Most recently,additive manufacturing technology has introduced a novel approach to producing Ta implants.The present study compared the microstructure,surface and mechanical characteristics,and in vitro and in vivo biological characteristics of selective laser melted Ta(SLM Ta),selective laser melted titanium alloy Ti6Al4V with Ta coating(SLM Ti6Al4V with Ta coating),and selective laser melted Ti6Al4V(SLM Ti6Al4V).Results indicate that SLM Ta possesses superior mechanical characteristics contrasted with SLM Ti6Al4V and SLM Ti6Al4V with Ta coating.Furthermore,SLM Ta has anti-inflammatory activity,excellent osseointegration performance,and osteogenic bioactivity.We fabricated an SLM porous Ta bone plate and employed it for internal fixation of ulnar and radius fractures,which has been known to promote fracture healing.Further,the SLM porous Ta bone plate could form an integrated bone plate structure with the bone tissue at the implant site.Afterward,the porous structure of the plate minimizes its elastic modulus and eliminates stress shielding,leaving no need for further surgical removal.In conclusion,the SLM porous Ta bone plate meets the performance requirements(stimulating bone regeneration,non-stress shelter,and no need for second surgery)of an ideal bone plate and may revolutionize the field of internal fixation bone plates for fractures.
基金Project supported by the National Natural Science Foundation of China(Nos.12372071 and 12372070)the Aeronautical Science Fund of China(No.2022Z055052001)the Foundation of China Scholarship Council(No.202306830079)。
文摘Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade components.In this paper,a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established.Based on Kirchhoff's plate assumptions,the displacement variables of the plate are expressed.By incorporating the braiding directions into the constitutive equation of the braided composites,the dynamic model of the plate considering braiding directions is obtained.The effects of the speeds,braiding directions,and braided angles on the responses of the plate with fixed-axis rotation and translational motion,respectively,are investigated.This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions.It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.
基金Project supported by the National Natural Science Foundation of China(Nos.12162004 and 11562001)the Doctoral Research Start-up Fund Project at University of South China(No.Y00043-13)。
文摘This paper presents,for the first time,an effective numerical approach based on the isogeometric analysis(IGA)and the six-variable quasi-three dimensional(3D)higher-order shear deformation theory(HSDT)to study the free vibration characteristics of functionally-graded(FG)graphene origami(GOri)-enabled auxetic metamaterial(GOEAM)plates submerged in a fluid medium.The plate theory incorporates the thickness stretching and the effects of transverse shear deformation without using any shear correction factors.The velocity potential function and Bernoulli's equation are used to derive the hydrodynamic pressure acting on the plate surface.Both horizontally and vertically immersed plate configurations are considered here in the form of inertia effects.The plates are composed of multilayer GOEAMs,with the GOri content varying through the plate's thickness in a layer-wise manner.This design results in graded auxetic growth.The material properties are evaluated by mixing rules and a genetic programming(GP)-assisted micromechanical model.The governing equations of motion for the FG-GOEAM plates immersed in a fluid medium are derived by Hamilton's principle.After validating the convergence and accuracy of the present model,a comprehensive parametric study is carried out to examine the effects of the GOri content,GOri distribution pattern,GOri folding degree,fluid level,immersed depth,and geometric parameter on the natural frequencies of the FG-GOEAM plates.The results show that the natural frequencies for the four GOri distribution patterns increase with the increase in the layer number when the lay number is fewer than 10,and then stabilize after the layer number reaches 10.Besides,in general,the natural frequency of the FG-GOEAM plate in a vacuum or fluid increases when the GOri content increases,while decreases when the GOri folding degree increases.Some additional findings related to the numerical results are presented in the conclusions.It is believed that the present results are useful for the precise design and optimization of FG-GOEAM plates immersed in a fluid medium.
文摘A new process of welding aluminum water-cooled busbars is proposed, It can not only reduce the weight and cost, but also improve the dynamic and thermal stability. Furthermore~ both finite element method analysis and a prototype test testify the advantages of the design which is not limited by load current and provides a new approach for water-cooled reactors.
基金Project(2010CB630800) supported by the National Basic Research Program of China
文摘A heat transfer model of furnace roller cooling process was established based on analysis of furnace roller＇s structure. The complicated model was solved with iteration planning algorithm based on Newton search. The model is proved logical and credible by comparing calculated results and measured data. Then, the relationship between water flow velocity, inlet water temperature, furnace temperature and roller cross section temperature, outlet water temperature, water temperature rise, cooling water heat absorption was studied. The conclusions and recommendations are mainly as follows： l） Cooling water temperature rise decreases with the increase of water flow velocity, but it has small relationship with inlet water temperature; 2） In order to get little water scale, inlet water temperature should be controlled below 30 ℃. 3） The cooling water flow velocity should be greater than critical velocity. The critical velocity is 0.07 m/s and water flow velocity should be controlled within 0.4-0.8 m/s. Within this velocity range, water cooling efficiency is high and water temperature rise is little. If cooling water velocity increases again, heat loss will increase, leading to energy wasting.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2010GB104005)Funding of Jiangsu Innovation Program for Graduate Education(CXLX12.0170)the Fundamental Research Funds for the Central Universities of China
文摘In order to realize safe and stable operation of a water-cooled W/Cu divertor under high heating condition,the exact knowledge of its subcooled boiling heat transfer characteristics under different design parameters is crucial.In this paper,subcooled boiling heat transfer in a water-cooled W/Cu divertor was numerically investigated based on computational fluid dynamic（CFD）.The boiling heat transfer was simulated based on the Euler homogeneous phase model,and local differences of liquid physical properties were considered under one-sided high heating conditions.The calculated wall temperature was in good agreement with experimental results,with the maximum error of 5%only.On this basis,the void fraction distribution,flow field and heat transfer coefficient（HTC）distribution were obtained.The effects of heat flux,inlet velocity and inlet temperature on temperature distribution and pressure drop of a water-cooled W/Cu divertor were also investigated.These results provide a valuable reference for the thermal-hydraulic design of a water-cooled W/Cu divertor.
文摘The water-cooling heat dissipation technology can solve the heat dissipation and noise problems of the calculation plate.Therefore,the structural design of the water-cooling plate directly affects its flow and heat transfer characteristics,which restricts the promotion and application of the technology.To this end,the water-cooling plate of a heat dissipation system was taken as the research object,and its flow and heat transfer characteristics were numerical simulated and experimental studied.Through comparative analysis,the rationality of the numerical simulation method was verified.Based on this,three improved schemes of water-cooling plate structure were proposed and numerical simulation was carried out,and the optimal model was verified by experiments.The results of the study show that compared with the original water-cooling plate,the optimized water-cooling plate has increased internal flow velocity and distributes uniformly,increased heat transfer amount by 4.2%,and the average temperature of the calculation plate decreased by 5.3%.
基金financially supported by the National Natural Science Foundation of China(Grant No.51701078)China Postdoctoral Science Foundation(Grant Nos.2018M632846 and 2018T110756)the Scientific Research Program of Hubei Provincial Education Department(Grant No.B2016053)
文摘The semisolid slurry of Al-Zn-Mg-Cu alloy was prepared through a self-designed water-cooled copper serpentine pouring channel(WSPC) machine. Influences of pouring temperature, the number of turns and the cooling water flow rate on the microstructure of the semisolid Al-Zn-Mg-Cu alloy slurry were investigated. The results show that the semisolid Al-Zn-Mg-Cu alloy slurry with satisfactory quality can be generated by the WSPC when the pouring temperature is in the range between 680 ℃ and 700 ℃. At a given pouring temperature, the average grain size of primary α-Al decreases and the shape factor increases with the increase of the number of turns. When the cooling water flow rate is 450 L·h^(-1), the obtained semisolid slurry is optimal. During the preparation of the semisolid Al-Zn-Mg-Cu alloy slurry with low superheat pouring, the alloy melt has mixed inhibition and convection flow characteristics by "self-stirring". When the alloy melt flows through the serpentine channel, the chilling effect of the inner wall of the channel, the convection and mixed inhibition of the alloy melt greatly promote the heterogeneous nucleation and grain segregation. This effect destroys the dendrite growth mode under traditional solidification conditions, and the primary nuclei gradually evolve into spherical or nearspherical grains.
文摘In the direct fired furnace of a continuous annealing line, seal rolls are susceptible to deformation that leads to surface defects of steel strips. According to failure analysis, the reasons include improper structural design and heat imbalance. An improved design has been proposed to reduce stress concentration and thermal radiation. A heat transfer model has been employed to determine the proper water flow rate for roll cooling. Industrial application proves that seal rolls with the new design has less deformation and longer service life.
基金Project supported by the National Natural Science Foundation of China (No. 12072337)。
文摘Through combined applications of the transfer-matrix method and asymptotic expansion technique,we formulate a theory to predict the three-dimensional response of micropolar plates.No ad hoc assumptions regarding through-thickness assumptions of the field variables are made,and the governing equations are two-dimensional,with the displacements and microrotations of the mid-plane as the unknowns.Once the deformation of the mid-plane is solved,a three-dimensional micropolar elastic field within the plate is generated,which is exact up to the second order except in the boundary region close to the plate edge.As an illustrative example,the bending of a clamped infinitely long plate caused by a uniformly distributed transverse force is analyzed and discussed in detail.
基金Supported by the Major Innovation Program of Shandong Province under Grant No 2013CXA10006the National Natural Science Foundation of China under Grant No 61108008
文摘A novel scheme of fully immersing water cooling is proposed for a Nd：glass radial slab laser. The slab medium is entirely immersed in the circulating water Ailing the pumping cavity, which enables much lower temperature and reasonably smaller thermal gradient in the slab medium. The radial slab is symmetrically and synchronously pumped by eight flash lamps, and produces multi-output beams with a total energy of 469md. Incoherent beam combination property of the multi-output beams is also investigated. The approach suggested here provides a way of scaling the slab lasers to much higher output levels and also a convenience for beam combinations.
基金supported by the National Natural Science Foundation of China(U1910213)the Graduate Education Innovation Project of Shanxi Province(2022Y670)+1 种基金Fundamental Research Program of Shanxi Province(20210302124446)Technological Innovation Talent Team Special Plan of Shanxi Province(no.202204051002002)。
文摘In this paper,the effects of recrystallization,grain growth and texture evolution on the formability and anisotropy of Mg/Al composite plates were studied by different annealing processes.The results show that the rolled Mg/Al composite plate exhibits obvious anisotropy and poor formability in the rolling directions(RD)and transverse directions(TD),which is the result of the synergistic effect of matrix texture and grain characteristics.Annealing-activated recrystallization can eliminate local shear bands,hardening and other defects formed by rolling,thereby softening the structure and improving the formability of the sheet.The occurrence of recrystallization behavior also makes the bimodal texture parallel to the TD distribution in the Mg matrix transform into the RD-TD surface dispersion distribution,which weakens the strong deformation texture.The Schmidt factor(SF)of each slip system is calculated to evaluate the slip system start-up probability(deformation difficulty)of the material in a certain direction.The results show that the average SF values of matrix slip in RD and TD directions increase after annealing treatment,which makes the slip system easier to start.The tensile test results show that the formability of the composite plate is the best when the annealing temperature is 300℃.At this time,the ultimate tensile strength(UTS)and yield strength(YS)are small,the elongation(EL)is large and the anisotropy of mechanical properties is the weakest.In addition,the annealing of the composite plate leads to the transformation of the fracture mechanism from brittle fracture to ductile-brittle mixed fracture.In summary,annealing treatment can effectively improve the formability and weaken the anisotropy of Mg/Al composite plates.
基金supported by the Ningxia Key Research and Development Program(Talent Introduction Special Project)Project(2022YCZX0013)North Minzu University 2022 School-Level Scientific Research Platform“Digital Agriculture Enabling Ningxia Rural Revitalization Innovation Team”(2022PT_S10)+1 种基金Yinchuan City University-Enterprise Joint Innovation Project(2022XQZD009)Ningxia Key Research and Development Program(Key Project)Project(2023BDE02001).
文摘Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic accidents.To effectively monitor compliance,the utilization of target detection algorithms through traffic cameras plays a vital role in identifying helmet usage by electric bicycle riders and recognizing license plates on electric bicycles.However,manual enforcement by traffic police is time-consuming and labor-intensive.Traditional methods face challenges in accurately identifying small targets such as helmets and license plates using deep learning techniques.This paper proposes an enhanced model for detecting helmets and license plates on electric bicycles,addressing these challenges.The proposedmodel improves uponYOLOv8n by deepening the network structure,incorporating weighted connections,and introducing lightweight convolutional modules.These modifications aim to enhance the precision of small target recognition while reducing the model’s parameters,making it suitable for deployment on low-performance devices in real traffic scenarios.Experimental results demonstrate that the model achieves an mAP@0.5 of 91.8%,showing an 11.5%improvement over the baselinemodel,with a 16.2%reduction in parameters.Additionally,themodel achieves a frames per second(FPS)rate of 58,meeting the accuracy and speed requirements for detection in actual traffic scenarios.
