1.Introduction.Twinning is a fundamental mechanism for plastic deformation in many face-centered cubic(FCC)metals having low stacking fault energies(SFEs)[1,2].In particular,twinning-induced plasticity(TWIP)alloys hav...1.Introduction.Twinning is a fundamental mechanism for plastic deformation in many face-centered cubic(FCC)metals having low stacking fault energies(SFEs)[1,2].In particular,twinning-induced plasticity(TWIP)alloys have excellent tensile properties as a result of the intensive twinning activity[3-5].The twin boundaries also have been proven to contribute to an improved strengthening-toughening effect,mechanical stability and even fatigue performance,relative to high-angle grain boundaries and low-angle grain boundaries[6-11].Therefore,it is of major interest to clarify the twinning mechanism and thereby improve the mechanical properties of metallic materials.展开更多
Twinning is a deformation mechanism that creates three-dimensional(3D)twin domains through the migration of twin facets.This occurs via the nucleation and glide of twinning disconnections(TDs),which can pile up to cre...Twinning is a deformation mechanism that creates three-dimensional(3D)twin domains through the migration of twin facets.This occurs via the nucleation and glide of twinning disconnections(TDs),which can pile up to create twin facets.A comprehensive under-standing of twin facets associated with 3D twins,including their atomic structures and energies,is crucial for understanding deformation twinning.In this study,we propose a molecular statics/dynamics(MS/MD)approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium{1011}twin domains,which has been much less studied than the counterpart{1012}twin domains.The stability of different TD pile-up arrangement with varying line senses informs the morphology of 3D non-equilibrium twins,which are bounded by{1010}_(T)||{1013}_(M),{1011}_(T)||{0002}_(M)and{1013}_(T)||{1013}_(M)coherent facets associated with pile-up of edge TDs,and discrete non-edge TDs aligned along CTBs with their line senses parallel to<4513>,<1101>,<5416><2113>or<1012>axes.Formation of semi-coherent facets of equilibrium twins is accompanied by rearrangement of TDs around misfit dislocations.3D equilibrium{1011}twins may comprise{1011}_(T)||{0002}_(M),{1457}_(T)||{3419}_(M),{1657}_(T)||{5617}_(M),{1433}_(T)||{3413}_(M),{0110}_(T)||{0111}_(M)and{0221}_(T)||{0221}_(M)semi-coherent facets in<1210>,<4513>,<1101>,<5416>,<2113>and<1012>axes,respectively.展开更多
A statistical analysis of the twinning behavior in a basal-textured Mg sheet under hard orientation loading was performed at strain rates of 1×10^(-5) and 1×10^(-1) s^(-1) with grain sizes of 70 and 20µ...A statistical analysis of the twinning behavior in a basal-textured Mg sheet under hard orientation loading was performed at strain rates of 1×10^(-5) and 1×10^(-1) s^(-1) with grain sizes of 70 and 20µm.There were 1609 tension twins identified including adequate(51%)anomalous twins(Schmid factor m<0).Twin variant selection exhibited almost no grain size or strain rate effects.Most twin variants(74%)correlated well with the proposed normalized Schmid factor(mnor).The Luster-Morris parameter(m′)values failed to correlate with the twin transmission,while 96%of transmitted pairs exhibited large mnor or normalized m′(m′nor)values.Twin transmission occurred more frequently at lower grain boundary misorientation angles(10°-30°).The active anomalous twins correlated well with m of the prismatic slip.The present work provided a statistical perspective that,the mnor and m′nor can correlate the anomalous twinning rather than m and m′.The local condition also played a critical role in anomalous twinning behavior.展开更多
BACKGROUND The incidence of multiple pregnancies has increased worldwide recently and women with a twin pregnancy are at higher risk of adverse outcomes compared with women with a singleton pregnancy.It is important t...BACKGROUND The incidence of multiple pregnancies has increased worldwide recently and women with a twin pregnancy are at higher risk of adverse outcomes compared with women with a singleton pregnancy.It is important to understand the risk factors for adverse fetal outcomes in twin pregnancy in order to guide clinical management.AIM To identify the independent risk factors,including maternal personal and family medical histories and first trimester ultrasound screening findings,for adverse fetal outcomes of twin pregnancy before 28 weeks of gestation.METHODS The data of 126 twin pregnancies in our hospital,including pregnancy outcomes,first trimester ultrasound screening findings and maternal medical history,were retrospectively collected.Twenty-nine women with adverse outcomes were included in the abnormal group and the remaining 97 women were included in the control group.RESULTS Patients in the abnormal group were more likely to be monochorionic diamniotic(13/29 vs 20/97,P=0.009),with a higher mean pulsatility index(PI,1.57±0.55 vs 1.28±0.42,P=0.003;cutoff value:1.393)or a higher mean resistance index(0.71±0.11 vs 0.65±0.11,P=0.008;cutoff value:0.683)or early diastolic notch of bilateral uterine arteries(UtAs,10/29 vs 15/97,P=0.024)or with abnormal ultrasound findings(13/29 vs 2/97,P<0.001),compared with the control group.Monochorionic diamnioticity,higher mean PI of bilateral UtAs and abnormal ultrasound findings during first trimester screening were independent risk factors for adverse fetal outcomes(P<0.05).CONCLUSION First trimester ultrasound screening for twin pregnancy identifies independent risk factors and is useful for the prediction of fetal outcomes.展开更多
This study proposes an automatic control system for Autonomous Underwater Vehicle(AUV)docking,utilizing a digital twin(DT)environment based on the HoloOcean platform,which integrates six-degree-of-freedom(6-DOF)motion...This study proposes an automatic control system for Autonomous Underwater Vehicle(AUV)docking,utilizing a digital twin(DT)environment based on the HoloOcean platform,which integrates six-degree-of-freedom(6-DOF)motion equations and hydrodynamic coefficients to create a realistic simulation.Although conventional model-based and visual servoing approaches often struggle in dynamic underwater environments due to limited adaptability and extensive parameter tuning requirements,deep reinforcement learning(DRL)offers a promising alternative.In the positioning stage,the Twin Delayed Deep Deterministic Policy Gradient(TD3)algorithm is employed for synchronized depth and heading control,which offers stable training,reduced overestimation bias,and superior handling of continuous control compared to other DRL methods.During the searching stage,zig-zag heading motion combined with a state-of-the-art object detection algorithm facilitates docking station localization.For the docking stage,this study proposes an innovative Image-based DDPG(I-DDPG),enhanced and trained in a Unity-MATLAB simulation environment,to achieve visual target tracking.Furthermore,integrating a DT environment enables efficient and safe policy training,reduces dependence on costly real-world tests,and improves sim-to-real transfer performance.Both simulation and real-world experiments were conducted,demonstrating the effectiveness of the system in improving AUV control strategies and supporting the transition from simulation to real-world operations in underwater environments.The results highlight the scalability and robustness of the proposed system,as evidenced by the TD3 controller achieving 25%less oscillation than the adaptive fuzzy controller when reaching the target depth,thereby demonstrating superior stability,accuracy,and potential for broader and more complex autonomous underwater tasks.展开更多
Twins play an important role in the texture transition during annealing.In a cold rolled high rare earth content magnesium(Mg)alloys with{10–12}extension twins,{11–21}extension twins,{10–11}compression twins and{10...Twins play an important role in the texture transition during annealing.In a cold rolled high rare earth content magnesium(Mg)alloys with{10–12}extension twins,{11–21}extension twins,{10–11}compression twins and{10–11}-{10–12}double twins and frequent twin-twin interactions,quasi-in-situ electron backscatter diffraction method was used to observe the twin induced static recrystallization(SRX)and related effect on texture during annealing.The results show that basal component was consumed owing to the SRX occurred in basal oriented{10–12}twins and SRXed grains with several specific orientations show preferential grain growth.SRX widely operated in the{10–12}extension and{11–21}extension twins,but absent in most{10–11}compression and{10–11}-{10–12}double twins,which is different to traditional twin induced SRX.Most compression/double twins detwinned while only partial tension twins detwinned.Operation of{11–21}twins and resultant twin-twin interaction facilitate the formation of serrated twin boundaries,which can serve as nucleation sites.Activation of<c+a>dislocation and related dislocation interaction in high dislocation density areas promote the formation of new grain boundaries and related SRX.Profuse<c+a>dislocations in basal oriented twins release the strain accumulation in compression/double twins and thus result in the absence of SRX.The twin size difference,storage energy and dislocation-twin interaction commonly functioned to the detwinning during annealing.The near-coincide site lattice boundaries that show high mobility were considered to be the important contributor to the preferential grain growth of SRXed grains.展开更多
In this work,the{10–12}tensile twins are introduced to improve the drawability of the AZ31 Mg alloy sheet.Concretely,the drawing depth is increased by 32%compared with the as-received sheet at 200℃.This is because{1...In this work,the{10–12}tensile twins are introduced to improve the drawability of the AZ31 Mg alloy sheet.Concretely,the drawing depth is increased by 32%compared with the as-received sheet at 200℃.This is because{10–12}tensile twins promote the occurrences of many deformation mechanisms during warm deep drawing,such as slips,detwinning,dynamic recrystallization(DRX)behaviors,etc.Further,based on the different stress states during deep drawing,these mechanisms and their competition relationships,as well as texture evolutions,are systematically studied.Combined with critical resolved shear stress(CRSS)and microstructure evolution,the global Schmid factor(GSF)obtained by quantizing stress states by stress tensor(σ)can accurately predict the activation trend of deformation mechanisms.It is found that the stress states have a reverse influence on the activation trend of the{10–12}twinning and detwinning.The change of stress states affects the competitive relationships between detwinning and DRX,and then affects the process and degree of DRX.The{10–12}tensile twins and large plane strain promote the activation of prismatic slips,and the larger plane strain also deflected the{10–12}twinning lattice.The{10–12}tensile twins and their induced deformation mechanisms can prominently weaken the basal texture and improve the drawability.展开更多
Accurately estimating the State of Health(SOH)and Remaining Useful Life(RUL)of lithium-ion batteries(LIBs)is crucial for the continuous and stable operation of battery management systems.However,due to the complex int...Accurately estimating the State of Health(SOH)and Remaining Useful Life(RUL)of lithium-ion batteries(LIBs)is crucial for the continuous and stable operation of battery management systems.However,due to the complex internal chemical systems of LIBs and the nonlinear degradation of their performance,direct measurement of SOH and RUL is challenging.To address these issues,the Twin Support Vector Machine(TWSVM)method is proposed to predict SOH and RUL.Initially,the constant current charging time of the lithium battery is extracted as a health indicator(HI),decomposed using Variational Modal Decomposition(VMD),and feature correlations are computed using Importance of Random Forest Features(RF)to maximize the extraction of critical factors influencing battery performance degradation.Furthermore,to enhance the global search capability of the Convolution Optimization Algorithm(COA),improvements are made using Good Point Set theory and the Differential Evolution method.The Improved Convolution Optimization Algorithm(ICOA)is employed to optimize TWSVM parameters for constructing SOH and RUL prediction models.Finally,the proposed models are validated using NASA and CALCE lithium-ion battery datasets.Experimental results demonstrate that the proposed models achieve an RMSE not exceeding 0.007 and an MAPE not exceeding 0.0082 for SOH and RUL prediction,with a relative error in RUL prediction within the range of[-1.8%,2%].Compared to other models,the proposed model not only exhibits superior fitting capability but also demonstrates robust performance.展开更多
With the continuous advancement and maturation of technologies such as big data,artificial intelligence,virtual reality,robotics,human-machine collaboration,and augmented reality,many enterprises are finding new avenu...With the continuous advancement and maturation of technologies such as big data,artificial intelligence,virtual reality,robotics,human-machine collaboration,and augmented reality,many enterprises are finding new avenues for digital transformation and intelligent upgrading.Industry 5.0,a further extension and development of Industry 4.0,has become an important development trend in industry with more emphasis on human-centered sustainability and flexibility.Accordingly,both the industrial metaverse and digital twins have attracted much attention in this new era.However,the relationship between them is not clear enough.In this paper,a comparison between digital twins and the metaverse in industry is made firstly.Then,we propose the concept and framework of Digital Twin Systems Engineering(DTSE)to demonstrate how digital twins support the industrial metaverse in the era of Industry 5.0 by integrating systems engineering principles.Furthermore,we discuss the key technologies and challenges of DTSE,in particular how artificial intelligence enhances the application of DTSE.Finally,a specific application scenario in the aviation field is presented to illustrate the application prospects of DTSE.展开更多
Asymmetric tilt boundaries on conventional twin boundaries(TBs)are significant for understanding the role of twins on coordinating plastic deformation in many metallic alloys.However,the formation modes of many asymme...Asymmetric tilt boundaries on conventional twin boundaries(TBs)are significant for understanding the role of twins on coordinating plastic deformation in many metallic alloys.However,the formation modes of many asymmetric tilt boundaries are hard to be accounted for based on traditional theoretical models,and the corresponding solute segregation is complex.Herein,atomic structures of a specific asymmetric boundary on{1012}TBs were reveled using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM),molecular dynamics(MD)and density functional theory(DFT)simulations.Reaction between<a60>M dislocations and the{1012}TB can generate a~61°/25°asymmetric tilt boundary.The segregation of Gd and Zn atoms is closely related to the aggregateddislocations and the interfacial interstices of the asymmetric tilt boundary,which is energetically favorable in reducing the total system energy.展开更多
It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the h...It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the heterogeneous nucleation of twinned Al grains on twin-structured TiC nucleants and the preferred growth of twinned dendrites by laser surface remelting of bulk metals. The solidification structure at the surface shows a mixture of lamellar twinned dendrites with ultra-fine twin boundary spacing (∼2 µm), isolated twinned dendrites, and regular dendrites. EBSD analysis and finite element method (FEM) simulations have been used to understand the competitive growth between twinned and regular dendrites, and the solidification conditions for the preferred growth of twinned dendrites during laser remelting and subsequent rapid solidification are established. It is shown that the reduction in the ratio of temperature gradient G to solidification rate V promotes the formation of lamellar twinned dendrites. The primary trunk spacing of lamellar twinned dendrites is refined by the high thermal gradient and solidification rate. The present work paves a new way to generate high-density growth twins in additive-manufactured Al alloys.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52001153,52322105,52271121,52130002 and 52321001)the Youth Innovation Promotion Association CAS(No.202119)+2 种基金the IMR Innovation Fund(No.2023-ZD01)the KC Wong Education Foundation(No.GJTD-2020-09)One of the authors was supported by the European Research Council under grant agreement No.267464-SPDMETALS(TGL).
文摘1.Introduction.Twinning is a fundamental mechanism for plastic deformation in many face-centered cubic(FCC)metals having low stacking fault energies(SFEs)[1,2].In particular,twinning-induced plasticity(TWIP)alloys have excellent tensile properties as a result of the intensive twinning activity[3-5].The twin boundaries also have been proven to contribute to an improved strengthening-toughening effect,mechanical stability and even fatigue performance,relative to high-angle grain boundaries and low-angle grain boundaries[6-11].Therefore,it is of major interest to clarify the twinning mechanism and thereby improve the mechanical properties of metallic materials.
基金supports by the National Key R&D Program of China(No.2022YFB3708900).
文摘Twinning is a deformation mechanism that creates three-dimensional(3D)twin domains through the migration of twin facets.This occurs via the nucleation and glide of twinning disconnections(TDs),which can pile up to create twin facets.A comprehensive under-standing of twin facets associated with 3D twins,including their atomic structures and energies,is crucial for understanding deformation twinning.In this study,we propose a molecular statics/dynamics(MS/MD)approach to determine characteristic twin facets enclosing 3D non-equilibrium/equilibrium{1011}twin domains,which has been much less studied than the counterpart{1012}twin domains.The stability of different TD pile-up arrangement with varying line senses informs the morphology of 3D non-equilibrium twins,which are bounded by{1010}_(T)||{1013}_(M),{1011}_(T)||{0002}_(M)and{1013}_(T)||{1013}_(M)coherent facets associated with pile-up of edge TDs,and discrete non-edge TDs aligned along CTBs with their line senses parallel to<4513>,<1101>,<5416><2113>or<1012>axes.Formation of semi-coherent facets of equilibrium twins is accompanied by rearrangement of TDs around misfit dislocations.3D equilibrium{1011}twins may comprise{1011}_(T)||{0002}_(M),{1457}_(T)||{3419}_(M),{1657}_(T)||{5617}_(M),{1433}_(T)||{3413}_(M),{0110}_(T)||{0111}_(M)and{0221}_(T)||{0221}_(M)semi-coherent facets in<1210>,<4513>,<1101>,<5416>,<2113>and<1012>axes,respectively.
基金supported by the National Natural Science Foundation of China(Nos.52171125,52071178)。
文摘A statistical analysis of the twinning behavior in a basal-textured Mg sheet under hard orientation loading was performed at strain rates of 1×10^(-5) and 1×10^(-1) s^(-1) with grain sizes of 70 and 20µm.There were 1609 tension twins identified including adequate(51%)anomalous twins(Schmid factor m<0).Twin variant selection exhibited almost no grain size or strain rate effects.Most twin variants(74%)correlated well with the proposed normalized Schmid factor(mnor).The Luster-Morris parameter(m′)values failed to correlate with the twin transmission,while 96%of transmitted pairs exhibited large mnor or normalized m′(m′nor)values.Twin transmission occurred more frequently at lower grain boundary misorientation angles(10°-30°).The active anomalous twins correlated well with m of the prismatic slip.The present work provided a statistical perspective that,the mnor and m′nor can correlate the anomalous twinning rather than m and m′.The local condition also played a critical role in anomalous twinning behavior.
基金Supported by Natural Science Foundation of Shanghai,China,No.22ZR1458200Medical Ph.D Innovative Talent Base Project of Changning District,Shanghai,China,No.RCJD2021B09Key Specialty of Changning District,Shanghai,China,No.20231004.
文摘BACKGROUND The incidence of multiple pregnancies has increased worldwide recently and women with a twin pregnancy are at higher risk of adverse outcomes compared with women with a singleton pregnancy.It is important to understand the risk factors for adverse fetal outcomes in twin pregnancy in order to guide clinical management.AIM To identify the independent risk factors,including maternal personal and family medical histories and first trimester ultrasound screening findings,for adverse fetal outcomes of twin pregnancy before 28 weeks of gestation.METHODS The data of 126 twin pregnancies in our hospital,including pregnancy outcomes,first trimester ultrasound screening findings and maternal medical history,were retrospectively collected.Twenty-nine women with adverse outcomes were included in the abnormal group and the remaining 97 women were included in the control group.RESULTS Patients in the abnormal group were more likely to be monochorionic diamniotic(13/29 vs 20/97,P=0.009),with a higher mean pulsatility index(PI,1.57±0.55 vs 1.28±0.42,P=0.003;cutoff value:1.393)or a higher mean resistance index(0.71±0.11 vs 0.65±0.11,P=0.008;cutoff value:0.683)or early diastolic notch of bilateral uterine arteries(UtAs,10/29 vs 15/97,P=0.024)or with abnormal ultrasound findings(13/29 vs 2/97,P<0.001),compared with the control group.Monochorionic diamnioticity,higher mean PI of bilateral UtAs and abnormal ultrasound findings during first trimester screening were independent risk factors for adverse fetal outcomes(P<0.05).CONCLUSION First trimester ultrasound screening for twin pregnancy identifies independent risk factors and is useful for the prediction of fetal outcomes.
基金supported by the National Science and Technology Council,Taiwan[Grant NSTC 111-2628-E-006-005-MY3]supported by the Ocean Affairs Council,Taiwansponsored in part by Higher Education Sprout Project,Ministry of Education to the Headquarters of University Advancement at National Cheng Kung University(NCKU).
文摘This study proposes an automatic control system for Autonomous Underwater Vehicle(AUV)docking,utilizing a digital twin(DT)environment based on the HoloOcean platform,which integrates six-degree-of-freedom(6-DOF)motion equations and hydrodynamic coefficients to create a realistic simulation.Although conventional model-based and visual servoing approaches often struggle in dynamic underwater environments due to limited adaptability and extensive parameter tuning requirements,deep reinforcement learning(DRL)offers a promising alternative.In the positioning stage,the Twin Delayed Deep Deterministic Policy Gradient(TD3)algorithm is employed for synchronized depth and heading control,which offers stable training,reduced overestimation bias,and superior handling of continuous control compared to other DRL methods.During the searching stage,zig-zag heading motion combined with a state-of-the-art object detection algorithm facilitates docking station localization.For the docking stage,this study proposes an innovative Image-based DDPG(I-DDPG),enhanced and trained in a Unity-MATLAB simulation environment,to achieve visual target tracking.Furthermore,integrating a DT environment enables efficient and safe policy training,reduces dependence on costly real-world tests,and improves sim-to-real transfer performance.Both simulation and real-world experiments were conducted,demonstrating the effectiveness of the system in improving AUV control strategies and supporting the transition from simulation to real-world operations in underwater environments.The results highlight the scalability and robustness of the proposed system,as evidenced by the TD3 controller achieving 25%less oscillation than the adaptive fuzzy controller when reaching the target depth,thereby demonstrating superior stability,accuracy,and potential for broader and more complex autonomous underwater tasks.
基金supported by the National Natural Science Foundation of China(Nos.52301164,52371121 and 52271107).
文摘Twins play an important role in the texture transition during annealing.In a cold rolled high rare earth content magnesium(Mg)alloys with{10–12}extension twins,{11–21}extension twins,{10–11}compression twins and{10–11}-{10–12}double twins and frequent twin-twin interactions,quasi-in-situ electron backscatter diffraction method was used to observe the twin induced static recrystallization(SRX)and related effect on texture during annealing.The results show that basal component was consumed owing to the SRX occurred in basal oriented{10–12}twins and SRXed grains with several specific orientations show preferential grain growth.SRX widely operated in the{10–12}extension and{11–21}extension twins,but absent in most{10–11}compression and{10–11}-{10–12}double twins,which is different to traditional twin induced SRX.Most compression/double twins detwinned while only partial tension twins detwinned.Operation of{11–21}twins and resultant twin-twin interaction facilitate the formation of serrated twin boundaries,which can serve as nucleation sites.Activation of<c+a>dislocation and related dislocation interaction in high dislocation density areas promote the formation of new grain boundaries and related SRX.Profuse<c+a>dislocations in basal oriented twins release the strain accumulation in compression/double twins and thus result in the absence of SRX.The twin size difference,storage energy and dislocation-twin interaction commonly functioned to the detwinning during annealing.The near-coincide site lattice boundaries that show high mobility were considered to be the important contributor to the preferential grain growth of SRXed grains.
基金supported by the National Natural Science Foundations of China[No.52374395,52474419]Natural Science Foundation of Chongqing[CSTB2024NSCQMSX0267]+6 种基金the Natural Science Foundation of Shanxi province[No.20210302123135,20210302123163]the China Postdoctoral Science Foundation[No.2022M710541]the Research Project Supported by Shanxi Scholarship Council of China[No.2022-038]Scientific and Technological Achievements Transformation Guidance Special Project of Shanxi Province[202104021301022,202204021301009]the Ministry of Science and Higher Education of the Russian Federation for financial support under the Megagrant[no.075-15-2022-1133]he National Research Foundation(NRF)grant funded by the Ministry of Science and ICT[2015R1A2A1A01006795]Korea through the Research Institute of Advanced Materials.
文摘In this work,the{10–12}tensile twins are introduced to improve the drawability of the AZ31 Mg alloy sheet.Concretely,the drawing depth is increased by 32%compared with the as-received sheet at 200℃.This is because{10–12}tensile twins promote the occurrences of many deformation mechanisms during warm deep drawing,such as slips,detwinning,dynamic recrystallization(DRX)behaviors,etc.Further,based on the different stress states during deep drawing,these mechanisms and their competition relationships,as well as texture evolutions,are systematically studied.Combined with critical resolved shear stress(CRSS)and microstructure evolution,the global Schmid factor(GSF)obtained by quantizing stress states by stress tensor(σ)can accurately predict the activation trend of deformation mechanisms.It is found that the stress states have a reverse influence on the activation trend of the{10–12}twinning and detwinning.The change of stress states affects the competitive relationships between detwinning and DRX,and then affects the process and degree of DRX.The{10–12}tensile twins and large plane strain promote the activation of prismatic slips,and the larger plane strain also deflected the{10–12}twinning lattice.The{10–12}tensile twins and their induced deformation mechanisms can prominently weaken the basal texture and improve the drawability.
基金funded by the Pyramid Talent Training Project of Beijing University of Civil Engineering and Architecture under Grant GJZJ20220802。
文摘Accurately estimating the State of Health(SOH)and Remaining Useful Life(RUL)of lithium-ion batteries(LIBs)is crucial for the continuous and stable operation of battery management systems.However,due to the complex internal chemical systems of LIBs and the nonlinear degradation of their performance,direct measurement of SOH and RUL is challenging.To address these issues,the Twin Support Vector Machine(TWSVM)method is proposed to predict SOH and RUL.Initially,the constant current charging time of the lithium battery is extracted as a health indicator(HI),decomposed using Variational Modal Decomposition(VMD),and feature correlations are computed using Importance of Random Forest Features(RF)to maximize the extraction of critical factors influencing battery performance degradation.Furthermore,to enhance the global search capability of the Convolution Optimization Algorithm(COA),improvements are made using Good Point Set theory and the Differential Evolution method.The Improved Convolution Optimization Algorithm(ICOA)is employed to optimize TWSVM parameters for constructing SOH and RUL prediction models.Finally,the proposed models are validated using NASA and CALCE lithium-ion battery datasets.Experimental results demonstrate that the proposed models achieve an RMSE not exceeding 0.007 and an MAPE not exceeding 0.0082 for SOH and RUL prediction,with a relative error in RUL prediction within the range of[-1.8%,2%].Compared to other models,the proposed model not only exhibits superior fitting capability but also demonstrates robust performance.
基金Supported by Beijing Municipal Natural Science Foundation of China(Grant No.24JL002)China Postdoctoral Science Foundation(Grant No.2024M754054)+2 种基金National Natural Science Foundation of China(Grant No.52120105008)Beijing Municipal Outstanding Young Scientis Program of Chinathe New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘With the continuous advancement and maturation of technologies such as big data,artificial intelligence,virtual reality,robotics,human-machine collaboration,and augmented reality,many enterprises are finding new avenues for digital transformation and intelligent upgrading.Industry 5.0,a further extension and development of Industry 4.0,has become an important development trend in industry with more emphasis on human-centered sustainability and flexibility.Accordingly,both the industrial metaverse and digital twins have attracted much attention in this new era.However,the relationship between them is not clear enough.In this paper,a comparison between digital twins and the metaverse in industry is made firstly.Then,we propose the concept and framework of Digital Twin Systems Engineering(DTSE)to demonstrate how digital twins support the industrial metaverse in the era of Industry 5.0 by integrating systems engineering principles.Furthermore,we discuss the key technologies and challenges of DTSE,in particular how artificial intelligence enhances the application of DTSE.Finally,a specific application scenario in the aviation field is presented to illustrate the application prospects of DTSE.
基金supported by the Scientific and Technological Developing Scheme of Jilin Province under grants no.YDZJ202301ZYTS538the Chinese Academy of Sciences Youth Innovation Promotion Association under grants number 2023234+3 种基金the National Natural Science Foundation of China under grants number U21A20323the Scientific and Technological Developing Scheme of Jilin Province under grants no.SKL202302038the Major Scientific and Technological Projects of Hebei Province under grants No.23291001Zthe Scientific and Technology Project of Hanjiang District.
文摘Asymmetric tilt boundaries on conventional twin boundaries(TBs)are significant for understanding the role of twins on coordinating plastic deformation in many metallic alloys.However,the formation modes of many asymmetric tilt boundaries are hard to be accounted for based on traditional theoretical models,and the corresponding solute segregation is complex.Herein,atomic structures of a specific asymmetric boundary on{1012}TBs were reveled using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM),molecular dynamics(MD)and density functional theory(DFT)simulations.Reaction between<a60>M dislocations and the{1012}TB can generate a~61°/25°asymmetric tilt boundary.The segregation of Gd and Zn atoms is closely related to the aggregateddislocations and the interfacial interstices of the asymmetric tilt boundary,which is energetically favorable in reducing the total system energy.
基金supported by the National Natural Science Foundation of China(grant no.52371029)the Science and Technology Development Program of Jilin Province,China(grant no.20210402083GH).
文摘It is difficult to generate coherent twin boundaries in bulk Al alloys due to their high intrinsic stacking fault energy. Here, we report a strategy to induce high-density growth twins in aluminum alloys through the heterogeneous nucleation of twinned Al grains on twin-structured TiC nucleants and the preferred growth of twinned dendrites by laser surface remelting of bulk metals. The solidification structure at the surface shows a mixture of lamellar twinned dendrites with ultra-fine twin boundary spacing (∼2 µm), isolated twinned dendrites, and regular dendrites. EBSD analysis and finite element method (FEM) simulations have been used to understand the competitive growth between twinned and regular dendrites, and the solidification conditions for the preferred growth of twinned dendrites during laser remelting and subsequent rapid solidification are established. It is shown that the reduction in the ratio of temperature gradient G to solidification rate V promotes the formation of lamellar twinned dendrites. The primary trunk spacing of lamellar twinned dendrites is refined by the high thermal gradient and solidification rate. The present work paves a new way to generate high-density growth twins in additive-manufactured Al alloys.
