With the deep integration of cloud computing,edge computing and the Internet of Things(IoT)technologies,smart manufacturing systems are undergoing profound changes.Over the past ten years,an extensive body of research...With the deep integration of cloud computing,edge computing and the Internet of Things(IoT)technologies,smart manufacturing systems are undergoing profound changes.Over the past ten years,an extensive body of research on cloud-edge-end systems has been generated.However,challenges such as heterogeneous data fusion,real-time processing and system optimization still exist,and there is a lack of systematic review studies.In this paper,we review a cloud-edge-end collaborative sensing-communication-computing-control(SC3)system.This system integrates four layers of sensing,communication,computing and control to address the complex challenges of real-time decision making,resource scheduling and system optimization.The paper combs through the key implementation methods of intelligent sensing,data preprocessing,task offloading and resource allocation in this system,and analyzes their advantages and disadvantages.Onthis basis,feasible methods for overall systemoptimization are further explored.Finally,the paper summarizes the main challenges facing the deep integration of cloud-edgeend and proposes prospective research directions,providing a structured knowledge base and development framework for subsequent research.The paper aims to stimulate further exploration of multilevel collaborative mechanisms for smart manufacturing systems to enhance the real-time decision-making and overall performance of the smart manufacturing system.展开更多
The rapid development of magnetic materials provides the possibility for the application of permanent magnet stirring(PMS).Numerical and experimental investigations were employed with respect to the solidification pro...The rapid development of magnetic materials provides the possibility for the application of permanent magnet stirring(PMS).Numerical and experimental investigations were employed with respect to the solidification process of the Al—2Sc alloy controlled by a novel PMS using NdFeB permanent magnets under various rotation speeds(0,50,100 and 150 r/min).The simulated results reveal that the maximum electromagnetic force increases proportionally from 4.14 to 12.39 kN/m3and the maximum tangential velocity increases from 0.13 to 0.36 m/s when the rotation speed of PMS enhances from 50 to 150 r/min in the ingot melt.Besides,the experimental results demonstrate that PMS can achieve a uniform distribution of blocky Al3Sc precipitated phase in the longitudinal direction under the impact of a forced fluid flow.Moreover,increasing rotation speed of PMS is beneficial to refining aluminum grain size significantly and decreasing the texture intensity in the alloy.In addition,the Brinell hardness of Al-2Sc alloy is increased by 33%to 27.8 HB and the tensile strength is enhanced by 34%-128.2 MPa,due to the improved distribution of the strengthening Al3SC phase and the grain refinement of Al matrix under the impact of PMS.This work provides an effective application of NdFeB permanent magnets in the metal cast field.展开更多
This work mainly deals with the segregating behaviors of Sc and the growth of unique primary Al3Sc in AlSc alloys prepared by molten salt electrolysis. The alloys contain 0.23–1.38 wt%Sc where Sc segregation is obser...This work mainly deals with the segregating behaviors of Sc and the growth of unique primary Al3Sc in AlSc alloys prepared by molten salt electrolysis. The alloys contain 0.23–1.38 wt%Sc where Sc segregation is observed. It is found that a high current density and long electrolysis time are in favor of high Sc content, and so do the high temperature and the addition level of Sc2O3. Sc content at the edge of Al based alloy(average Sc content: 0.75 wt%) can be as high as 1.09 wt%, while it is merely 0.24 wt% at the central area. The cooling rates have a strong impact on the morphology and particle size of primary Al3Sc,but a weak influence on Sc segregation. The cusped cubic and dendritic primary Al3Sc can precipitate in the prepared Al-Sc alloys. In a slightly hypereutectic Al-0.67 wt%Sc alloy, a large and cusped dendrite grows from the edge into the center. The primary and secondary dendritic arms can be as long as 600 and 250 μm, respectively. The Sc segregating behaviors in Al-Sc alloys is due to the mechanism controlled by the limited diffusion rate of Sc in liquid Al. This can involve the establishment of a near spherical discharge interface between liquid Al and the electrolyte. The Sc rich layer near Al-molten salt interface may provide the potential primary nuclei and sufficient Sc atoms for the growth of large dendritic primary Al3Sc.展开更多
A significant size effect is found in the Al3 Sc dispersoid-mediated precipitation in an Al-Mg-Si-Sc alloy.When the Al3 Sc dispersoid size smaller than about 40 nm,β " precipitates nucleate directly on the coher...A significant size effect is found in the Al3 Sc dispersoid-mediated precipitation in an Al-Mg-Si-Sc alloy.When the Al3 Sc dispersoid size smaller than about 40 nm,β " precipitates nucleate directly on the coherent dispersoids and grow by sacrificing the latter.While the dispersoid size greater than^40 nm,Q' and U2 phases are additionally produced that nucleate on the dislocations induced by the semi-/incoherent dispersoids.Mechanical and electrical properties are highly sensitive to the Al3 Sc dispersoid-tuned precipitation.The co-precipitation of β",Q' and U2 phases leads to an obvious improvement in hardness and simultaneously in electrical conductivity.展开更多
A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg-Marquardt, New...A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg-Marquardt, Newton method, and so on, can be used to solve crystal field parameters by fitting to experimental energy levels. With the numerical eigenvalue derivative, a detailed iteration algorithm to compute crystal field parameters by fitting experimental energy levels has also been described. This method is used to compute the crystal parameters of Yb^3+ in Sc2O3 crystal, which is prepared by a co-precipitation method and whose structure was refined by Rietveld method. By fitting on the parameters of a simple overlap model of crystal field, the results show that the new method can fit the crystal field energy splitting with fast convergence and good stability.展开更多
Effects of intermediate annealing temperature and time after hot working on recrystallization temperature(Tr)of Al-Mg-Sc-Zr alloy subjected to further cold working were investigated.It was found that Tr of cold worked...Effects of intermediate annealing temperature and time after hot working on recrystallization temperature(Tr)of Al-Mg-Sc-Zr alloy subjected to further cold working were investigated.It was found that Tr of cold worked alloy dropped with the rise of intermediate annealing temperature or extension of annealing time,clue to coarsening of Al3(Sc,Zr)particles during intermediate annealing.After annealed at 550℃for 1 h or 475℃for 50 h,Tr is nearly same as that in a Sc,Zr free 5A06 alloy.Coarsening mechanism was also discussed.After hot rolling,residual dislocations promoted diffusion of Sc and Zr atoms at the elevated temperature of the intermediate annealing.Easier diffusion sped the growth of the AI3(Sc,Zr)particles,resulting in a coherency loss and quantity reduction of the particles.展开更多
基金supported by the National Natural Science Foundation of China under Grants 62172033 and 62572042.
摘要With the deep integration of cloud computing,edge computing and the Internet of Things(IoT)technologies,smart manufacturing systems are undergoing profound changes.Over the past ten years,an extensive body of research on cloud-edge-end systems has been generated.However,challenges such as heterogeneous data fusion,real-time processing and system optimization still exist,and there is a lack of systematic review studies.In this paper,we review a cloud-edge-end collaborative sensing-communication-computing-control(SC3)system.This system integrates four layers of sensing,communication,computing and control to address the complex challenges of real-time decision making,resource scheduling and system optimization.The paper combs through the key implementation methods of intelligent sensing,data preprocessing,task offloading and resource allocation in this system,and analyzes their advantages and disadvantages.Onthis basis,feasible methods for overall systemoptimization are further explored.Finally,the paper summarizes the main challenges facing the deep integration of cloud-edgeend and proposes prospective research directions,providing a structured knowledge base and development framework for subsequent research.The paper aims to stimulate further exploration of multilevel collaborative mechanisms for smart manufacturing systems to enhance the real-time decision-making and overall performance of the smart manufacturing system.
基金Project supported by the Natural Science Foundation of Hunan Province(2024JJ4056)the Key Project of Guangxi Zhuang Autonomous Region(AB22080089)the Government of Chongzuo,Guangxi Zhuang Autonomous Region(FA20210716)。
摘要The rapid development of magnetic materials provides the possibility for the application of permanent magnet stirring(PMS).Numerical and experimental investigations were employed with respect to the solidification process of the Al—2Sc alloy controlled by a novel PMS using NdFeB permanent magnets under various rotation speeds(0,50,100 and 150 r/min).The simulated results reveal that the maximum electromagnetic force increases proportionally from 4.14 to 12.39 kN/m3and the maximum tangential velocity increases from 0.13 to 0.36 m/s when the rotation speed of PMS enhances from 50 to 150 r/min in the ingot melt.Besides,the experimental results demonstrate that PMS can achieve a uniform distribution of blocky Al3Sc precipitated phase in the longitudinal direction under the impact of a forced fluid flow.Moreover,increasing rotation speed of PMS is beneficial to refining aluminum grain size significantly and decreasing the texture intensity in the alloy.In addition,the Brinell hardness of Al-2Sc alloy is increased by 33%to 27.8 HB and the tensile strength is enhanced by 34%-128.2 MPa,due to the improved distribution of the strengthening Al3SC phase and the grain refinement of Al matrix under the impact of PMS.This work provides an effective application of NdFeB permanent magnets in the metal cast field.
基金financial support of the project from the Beijing Natural Science Foundation (2184110)the National Natural Science Foundation of China (Nos. 51434005, 51704020 and 51874035)the Fundamental Research Funds for Central Universities of China (No. FRF-TP-17-035A1)
摘要This work mainly deals with the segregating behaviors of Sc and the growth of unique primary Al3Sc in AlSc alloys prepared by molten salt electrolysis. The alloys contain 0.23–1.38 wt%Sc where Sc segregation is observed. It is found that a high current density and long electrolysis time are in favor of high Sc content, and so do the high temperature and the addition level of Sc2O3. Sc content at the edge of Al based alloy(average Sc content: 0.75 wt%) can be as high as 1.09 wt%, while it is merely 0.24 wt% at the central area. The cooling rates have a strong impact on the morphology and particle size of primary Al3Sc,but a weak influence on Sc segregation. The cusped cubic and dendritic primary Al3Sc can precipitate in the prepared Al-Sc alloys. In a slightly hypereutectic Al-0.67 wt%Sc alloy, a large and cusped dendrite grows from the edge into the center. The primary and secondary dendritic arms can be as long as 600 and 250 μm, respectively. The Sc segregating behaviors in Al-Sc alloys is due to the mechanism controlled by the limited diffusion rate of Sc in liquid Al. This can involve the establishment of a near spherical discharge interface between liquid Al and the electrolyte. The Sc rich layer near Al-molten salt interface may provide the potential primary nuclei and sufficient Sc atoms for the growth of large dendritic primary Al3Sc.
基金the financial support of the project from the National Natural Science Foundation of China (No. 51771147)。
摘要A significant size effect is found in the Al3 Sc dispersoid-mediated precipitation in an Al-Mg-Si-Sc alloy.When the Al3 Sc dispersoid size smaller than about 40 nm,β " precipitates nucleate directly on the coherent dispersoids and grow by sacrificing the latter.While the dispersoid size greater than^40 nm,Q' and U2 phases are additionally produced that nucleate on the dislocations induced by the semi-/incoherent dispersoids.Mechanical and electrical properties are highly sensitive to the Al3 Sc dispersoid-tuned precipitation.The co-precipitation of β",Q' and U2 phases leads to an obvious improvement in hardness and simultaneously in electrical conductivity.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50772112 and 50872135)the Natural Science Foundation of Anhui Province of China(Grant No.08040106820)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.YYYJ-1002)
摘要A method to compute the numerical derivative of eigenvalues of parameterized crystal field Hamiltonian matrix is given, based on the numerical derivatives the general iteration methods such as Levenberg-Marquardt, Newton method, and so on, can be used to solve crystal field parameters by fitting to experimental energy levels. With the numerical eigenvalue derivative, a detailed iteration algorithm to compute crystal field parameters by fitting experimental energy levels has also been described. This method is used to compute the crystal parameters of Yb^3+ in Sc2O3 crystal, which is prepared by a co-precipitation method and whose structure was refined by Rietveld method. By fitting on the parameters of a simple overlap model of crystal field, the results show that the new method can fit the crystal field energy splitting with fast convergence and good stability.
基金support by the Innovation Foundationof Chinese Academy of Sciences(Grant No CXJJ-205)
摘要Effects of intermediate annealing temperature and time after hot working on recrystallization temperature(Tr)of Al-Mg-Sc-Zr alloy subjected to further cold working were investigated.It was found that Tr of cold worked alloy dropped with the rise of intermediate annealing temperature or extension of annealing time,clue to coarsening of Al3(Sc,Zr)particles during intermediate annealing.After annealed at 550℃for 1 h or 475℃for 50 h,Tr is nearly same as that in a Sc,Zr free 5A06 alloy.Coarsening mechanism was also discussed.After hot rolling,residual dislocations promoted diffusion of Sc and Zr atoms at the elevated temperature of the intermediate annealing.Easier diffusion sped the growth of the AI3(Sc,Zr)particles,resulting in a coherency loss and quantity reduction of the particles.