[Objectives]This study was conducted to improve the seed production efficiency of water-saving and drought-resistant hybrid millet in production.[Methods]A high-efficiency seed production technology for water-saving a...[Objectives]This study was conducted to improve the seed production efficiency of water-saving and drought-resistant hybrid millet in production.[Methods]A high-efficiency seed production technology for water-saving and drought-resistant hybrid millet varieties was developed by integrating aspects such as parental line sources,botanical characteristics,biological traits,seed production yield structure,key technical points of seed production,and suitable planting regions.[Results]Under standardized pre-sowing preparation and field management,both parents are simultaneously sown around May 20 with a planting row ratio of 2:6(female:male),a row spacing of 20 cm and plant spacing of 10 cm for the female parent,and a row spacing of 35 cm and plant spacing of 15 cm for the male parent.Both parents are fertilized simultaneously with 375 kg/hm^(2) of urea at the booting stage combined with intertillage or rainfall,and 225 kg/hm^(2) of urea at the grain-filling stage combined with irrigation.Strict hybrid removal,proper pollination and timely harvesting can significantly increase the yield of seed production.[Conclusions]This technology can be fully applied to large-scale seed production of water-saving and drought-resistant hybrid millet,providing seed supply support for cultivation in arid and semi-arid regions.It helps alleviate issues such as excessive groundwater extraction and water scarcity while enhancing planting efficiency,increasing yield,and boosting increase of farmers income.展开更多
The moving morphable component(MMC)topology optimization method,as a typical explicit topology optimization method,has been widely concerned.In the MMC topology optimization framework,the surrogate material model is m...The moving morphable component(MMC)topology optimization method,as a typical explicit topology optimization method,has been widely concerned.In the MMC topology optimization framework,the surrogate material model is mainly used for finite element analysis at present,and the effectiveness of the surrogate material model has been fully confirmed.However,there are some accuracy problems when dealing with boundary elements using the surrogate material model,which will affect the topology optimization results.In this study,a boundary element reconstruction(BER)model is proposed based on the surrogate material model under the MMC topology optimization framework to improve the accuracy of topology optimization.The proposed BER model can reconstruct the boundary elements by refining the local meshes and obtaining new nodes in boundary elements.Then the density of boundary elements is recalculated using the new node information,which is more accurate than the original model.Based on the new density of boundary elements,the material properties and volume information of the boundary elements are updated.Compared with other finite element analysis methods,the BER model is simple and feasible and can improve computational accuracy.Finally,the effectiveness and superiority of the proposed method are verified by comparing it with the optimization results of the original surrogate material model through several numerical examples.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
Based on the educational evaluation reform,this study explores the construction of an evidence-based value-added evaluation system based on data-driven,aiming to solve the limitations of traditional evaluation methods...Based on the educational evaluation reform,this study explores the construction of an evidence-based value-added evaluation system based on data-driven,aiming to solve the limitations of traditional evaluation methods.The research adopts the method of combining theoretical analysis and practical application,and designs the evidence-based value-added evaluation framework,which includes the core elements of a multi-source heterogeneous data acquisition and processing system,a value-added evaluation agent based on a large model,and an evaluation implementation and application mechanism.Through empirical research verification,the evaluation system has remarkable effects in improving learning participation,promoting ability development,and supporting teaching decision-making,and provides a theoretical reference and practical path for educational evaluation reform in the new era.The research shows that the evidence-based value-added evaluation system based on data-driven can reflect students’actual progress more fairly and objectively by accurately measuring the difference in starting point and development range of students,and provide strong support for the realization of high-quality education development.展开更多
<div style="text-align:justify;"> When the vibration of diesel engine structure is measured, the signal is composed of a very complex superposition of the contributions of different vibratory sources m...<div style="text-align:justify;"> When the vibration of diesel engine structure is measured, the signal is composed of a very complex superposition of the contributions of different vibratory sources modified by their respective transmission paths. These sources originate from several internal phenomenon in the engine such as combustion pressure variation, unbalanced reciprocating and rotating parts. In a diesel engine, movement parts work in a specific order. Once the starting point is determined, occurrence of work order in different cycle phases can be determined. This could successfully use to identifying of impulses in complex vibration signal of a diesel engine. From the variation of features of those impulses, it is possible to determine the working condition of the engine. This can use to fault diagnosis of diesel engine, specially faults related to combustion process. </div>展开更多
The rapid development of portable electronics,wearable technologies,and healthcare monitoring systems necessitates the innovation of flexible energy storage systems.Considering environmental pollution and the depletio...The rapid development of portable electronics,wearable technologies,and healthcare monitoring systems necessitates the innovation of flexible energy storage systems.Considering environmental pollution and the depletion of fossil resources,the utilization of renewable resources to engineer advanced flexible materials has become especially crucial.Cellulose,the most abundant natural polymer,has emerged as a promising precursor for advanced functional materials due to its unique structure and properties.Typically,the easy processability,tunable chemical structure,self-assembly behavior,mechanical strength,and reinforcing capability enable its utilization as binder,substrate,hybrid electrode,separator,and electrolyte reservoir for flexible energy storage devices.This review comprehensively summarizes the design,fabrication,and mechanical and electrochemical performances of cellulose-based materials.The structure and unique properties of cellulose are first briefly introduced.Then,the construction of cellulose-based materials in the forms of 1D fibers/filaments,2D films/membranes,3D hydrogels and aerogels is discussed,and the merits of cellulose in these materials are emphasized.After that,the various advanced applications in supercapacitors,lithium-ion batteries,lithium-sulfur batteries,sodium-ion batteries,metal-air batteries,and Zn-ion batteries are presented in detail.Finally,an outlook of the potential challenges and future perspectives in advanced cellulose-based materials for flexible energy storage systems is discussed.展开更多
Biomacromolecules derived from plant-based traditional Chinese medicines play a pivotal role in natural drug research.Ginseng,the root of Panax ginseng C.A.Meyer,has attracted significant attention due to its diverse ...Biomacromolecules derived from plant-based traditional Chinese medicines play a pivotal role in natural drug research.Ginseng,the root of Panax ginseng C.A.Meyer,has attracted significant attention due to its diverse pharmacological activities and broad therapeutic applications.This review focuses on specific active macromolecules obtained from ginseng,including pectin,exosomes,proteins,and dietary fibers.These components possess unique structural characteristics and biological activities that offer novel insights into the multifaceted applications of ginseng.To systematically assess this field,we reviewed literature published over the past 60 years and identified 119 relevant studies investigating the structural composition,pharmacological activity,and potential applications of P.ginseng biomacromolecules.By highlighting their crucial role in promoting health and enhancing disease resistance,this review synthesizes the latest research findings on ginseng’s pharmacological effects,providing new perspectives and strong theoretical support for clinical drug development.展开更多
The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately iden...The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately identifying the rotor unbalance.This paper utilizes a high-frequency composite sensor to monitor the engine’s blade tip clearance(BTC)and extracts unbalanced information from BTC signals for rotor dynamic balancing,while avoiding the need for the once per revolution(OPR)sensor.First,the vibration characteristics of the rotor-blade system under multi-fault conditions are investigated.Then,based on BTC measurement,a none OPR method and an unbalance identification method are proposed,in which the radial vibration of the blade tip in the BTC signals at different speeds is extracted and operated in the time domain to obtain the rotor unbalanced vibration,the signal is reconstructed,and cross-correlation analysis is used to accurately identify the magnitude and phase of the unbalanced signal.Finally,a rotor test bench is utilized for experimental verification.The results reveal that the dynamic balancing method based on the BTC signal can more precisely identify the rotor unbalance than the traditional rotor dynamic balancing method.The application of this technique will effectively improve engine health management and fault prediction.展开更多
The extreme removal of SiO2 and MnO inclusions in 304 stainless steel in supergravity fields was investigated using an inhouse high-temperature supergravity equipment.The influences of the gravity coefficient and sepa...The extreme removal of SiO2 and MnO inclusions in 304 stainless steel in supergravity fields was investigated using an inhouse high-temperature supergravity equipment.The influences of the gravity coefficient and separation time on the removal efficiency of the inclusions were studied.After supergravity treatment,the inclusions migrated to the top of the sample and formed large aggregates.Meanwhile,the lower part of the sample was purified considerably and appeared significantly cleaner than the raw material.At the gravity coefficient of 500 and separation time of 600 s,the total oxygen content at the bottom of the sample(position E)decreased from 240 to 28 ppm.This corresponded to a total oxygen removal rate of 88.33%.The volume fraction and number density of inclusions exhibited a gradient distribution along the supergravity direction,with values of 8.5%and 106 mm^(-2) at the top of the sample(position A)and 0.06%and 22 mm^(-2) at its bottom.展开更多
The construction of rare earth(RE)alloy catalysts offers a route to harness the unique electronic structure of RE.Within the alloy,RE can fine-tune the electronic configuration of the active element,such as rhodium(Rh...The construction of rare earth(RE)alloy catalysts offers a route to harness the unique electronic structure of RE.Within the alloy,RE can fine-tune the electronic configuration of the active element,such as rhodium(Rh),via the ligand effect,optimizing the electrochemical reaction pathway.However,the challenging negative reduction potential of RE has impeded the progress in developing RE alloys,particularly nanoalloy catalysts.In this study,Rh_(3)Sc/C and Rh_(3)Y/C nanoalloys were synthesized using a sodium vapor reduction strategy for application as hydrogen evolution reaction(HER)catalysts.Elec-trochemical tests reveal that Rh-RE alloy catalysts exhibit significantly improved electrocatalytic activity in 1 mol/L KOH.Notably,Rh_(3)Y/C demonstrates exceptional HER performance,achieving a low over-potential of only 31 mV at 10 mA/cm^(2),surpassing the 50 mV observed for Rh/C.Furthermore,the current density of Rh_(3)Y/C at an 80 mV overpotential is 3.9 times that of Rh/C.This study sheds light on the remarkable catalytic potential of Rh-RE alloys,paving the way for the future expansion of RE nanoalloy systems.展开更多
Value-added evaluation focuses on individual student growth by tracking changes in academic performance,skills,literacy,etc.,at different time points.It weakens horizontal comparisons and emphasizes vertical progress ...Value-added evaluation focuses on individual student growth by tracking changes in academic performance,skills,literacy,etc.,at different time points.It weakens horizontal comparisons and emphasizes vertical progress to more fairly reflect educational effectiveness.This evaluation method is particularly suitable for vocational education,effectively motivating students’learning enthusiasm and enhancing their self-confidence.Foreign research is represented by the Tennessee Value-Added Assessment System(TVAAS),widely used in evaluating school quality and teacher performance.Domestic research currently focuses on the theoretical construction,model establishment,optimization,and practical application of value-added evaluation,still facing significant challenges in data collection comprehensiveness and model adaptability.Aiming at current issues,this study focuses on exploring the application of artificial intelligence large models in student value-added evaluation from an evidence-based perspective,committed to constructing an innovative evidence-based value-added evaluation system.It aims to achieve precise assessment of students’learning effect“net value-added”through multi-source data collection,intelligent analysis,and personalized feedback.The system integrates outcome evaluation,process evaluation,value-added evaluation,and comprehensive evaluation to form a“four-in-one”dynamic evaluation framework,considering students’starting points,process performance,and final achievements.In the future,value-added evaluation needs to further expand the assessment of non-academic dimensions(such as professional literacy and social-emotional skills)and explore the application of non-linear models to promote the deepening and innovation of educational evaluation reform.展开更多
The flow field characteristics of the conduit-matrix system(CMS)have consistently been a primary area of interest to researchers.However,under the long-term influence of water flow,the hydraulic conductivity of the ma...The flow field characteristics of the conduit-matrix system(CMS)have consistently been a primary area of interest to researchers.However,under the long-term influence of water flow,the hydraulic conductivity of the matrix surrounding the conduit often deforms differentially along the conduit axis,resulting in the development of a conduit-multilayer matrix system(CMMS).This renders conventional models inadequate in accurately describing the flow field characteristics of CMMS.In this study,a semi-analytical model with second-order accuracy is developed to investigate the velocity profile characteristics of CMMS by coupling the Navier-Stokes(N–S)equations in the conduit and the Darcy-Brinkman(D-B)equation in the multilayer matrices.In this model,the interface between the conduit and the matrix satisfies the velocity continuity and stress jumping condition.In contrast,different matrix interfaces require both velocity and stress to be equal.The model's validity is verified through Lattice Boltzmann Method(LBM)simulation,COMSOL simulation,and experimental data under different conduit apertures,matrix region numbers,and matrix permeability characteristics.Moreover,the current model predicts discharges with higher accuracy than the Hagen-Poiseuille law and Darcy's law(the maximum error between the present model and the test is 7.24%).Furthermore,the existing Poiseuille's law,conduit-matrix model,and conduit-matrix1-matrix2 model are all special cases of the current semi-analytical model,thereby indicating its broader applicability.Sensitivity results reveal that the flow velocities in the surrounding matrix and the conduit regions also increase when the permeability of the matrix in proximity to the conduit increases.Additionally,as the stress jumping coefficient at the interface approaches zero,the transition from free flow to seepage becomes smoother.展开更多
基金Supported by National Modern Agricultural Industry Technology System(CARS-06-14.5-A7)Hebei Provincial Agricultural Science and Technology Achievement Transformation Fund Project("Zhangzagu 19"Pilot Test and Demonstration).
文摘[Objectives]This study was conducted to improve the seed production efficiency of water-saving and drought-resistant hybrid millet in production.[Methods]A high-efficiency seed production technology for water-saving and drought-resistant hybrid millet varieties was developed by integrating aspects such as parental line sources,botanical characteristics,biological traits,seed production yield structure,key technical points of seed production,and suitable planting regions.[Results]Under standardized pre-sowing preparation and field management,both parents are simultaneously sown around May 20 with a planting row ratio of 2:6(female:male),a row spacing of 20 cm and plant spacing of 10 cm for the female parent,and a row spacing of 35 cm and plant spacing of 15 cm for the male parent.Both parents are fertilized simultaneously with 375 kg/hm^(2) of urea at the booting stage combined with intertillage or rainfall,and 225 kg/hm^(2) of urea at the grain-filling stage combined with irrigation.Strict hybrid removal,proper pollination and timely harvesting can significantly increase the yield of seed production.[Conclusions]This technology can be fully applied to large-scale seed production of water-saving and drought-resistant hybrid millet,providing seed supply support for cultivation in arid and semi-arid regions.It helps alleviate issues such as excessive groundwater extraction and water scarcity while enhancing planting efficiency,increasing yield,and boosting increase of farmers income.
基金supported by the Science and Technology Research Project of Henan Province(242102241055)the Industry-University-Research Collaborative Innovation Base on Automobile Lightweight of“Science and Technology Innovation in Central Plains”(2024KCZY315)the Opening Fund of State Key Laboratory of Structural Analysis,Optimization and CAE Software for Industrial Equipment(GZ2024A03-ZZU).
文摘The moving morphable component(MMC)topology optimization method,as a typical explicit topology optimization method,has been widely concerned.In the MMC topology optimization framework,the surrogate material model is mainly used for finite element analysis at present,and the effectiveness of the surrogate material model has been fully confirmed.However,there are some accuracy problems when dealing with boundary elements using the surrogate material model,which will affect the topology optimization results.In this study,a boundary element reconstruction(BER)model is proposed based on the surrogate material model under the MMC topology optimization framework to improve the accuracy of topology optimization.The proposed BER model can reconstruct the boundary elements by refining the local meshes and obtaining new nodes in boundary elements.Then the density of boundary elements is recalculated using the new node information,which is more accurate than the original model.Based on the new density of boundary elements,the material properties and volume information of the boundary elements are updated.Compared with other finite element analysis methods,the BER model is simple and feasible and can improve computational accuracy.Finally,the effectiveness and superiority of the proposed method are verified by comparing it with the optimization results of the original surrogate material model through several numerical examples.
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This paper is the research result of“Research on Innovation of Evidence-Based Teaching Paradigm in Vocational Education under the Background of New Quality Productivity”(2024JXQ176)the Shandong Province Artificial Intelligence Education Research Project(SDDJ202501035),which explores the application of artificial intelligence big models in student value-added evaluation from an evidence-based perspective。
文摘Based on the educational evaluation reform,this study explores the construction of an evidence-based value-added evaluation system based on data-driven,aiming to solve the limitations of traditional evaluation methods.The research adopts the method of combining theoretical analysis and practical application,and designs the evidence-based value-added evaluation framework,which includes the core elements of a multi-source heterogeneous data acquisition and processing system,a value-added evaluation agent based on a large model,and an evaluation implementation and application mechanism.Through empirical research verification,the evaluation system has remarkable effects in improving learning participation,promoting ability development,and supporting teaching decision-making,and provides a theoretical reference and practical path for educational evaluation reform in the new era.The research shows that the evidence-based value-added evaluation system based on data-driven can reflect students’actual progress more fairly and objectively by accurately measuring the difference in starting point and development range of students,and provide strong support for the realization of high-quality education development.
文摘<div style="text-align:justify;"> When the vibration of diesel engine structure is measured, the signal is composed of a very complex superposition of the contributions of different vibratory sources modified by their respective transmission paths. These sources originate from several internal phenomenon in the engine such as combustion pressure variation, unbalanced reciprocating and rotating parts. In a diesel engine, movement parts work in a specific order. Once the starting point is determined, occurrence of work order in different cycle phases can be determined. This could successfully use to identifying of impulses in complex vibration signal of a diesel engine. From the variation of features of those impulses, it is possible to determine the working condition of the engine. This can use to fault diagnosis of diesel engine, specially faults related to combustion process. </div>
基金supported by National Natural Science Foundation of China(Grant Nos.32201499,32222057,and 22478142)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023A1515012519,2023A0505050114,and 2024B1515040004)+1 种基金National Key Research and Development Project(Grant No 2023YFE0109600)State Key Laboratory of Advanced Papermaking and Paper-based Materials(2024C02).
文摘The rapid development of portable electronics,wearable technologies,and healthcare monitoring systems necessitates the innovation of flexible energy storage systems.Considering environmental pollution and the depletion of fossil resources,the utilization of renewable resources to engineer advanced flexible materials has become especially crucial.Cellulose,the most abundant natural polymer,has emerged as a promising precursor for advanced functional materials due to its unique structure and properties.Typically,the easy processability,tunable chemical structure,self-assembly behavior,mechanical strength,and reinforcing capability enable its utilization as binder,substrate,hybrid electrode,separator,and electrolyte reservoir for flexible energy storage devices.This review comprehensively summarizes the design,fabrication,and mechanical and electrochemical performances of cellulose-based materials.The structure and unique properties of cellulose are first briefly introduced.Then,the construction of cellulose-based materials in the forms of 1D fibers/filaments,2D films/membranes,3D hydrogels and aerogels is discussed,and the merits of cellulose in these materials are emphasized.After that,the various advanced applications in supercapacitors,lithium-ion batteries,lithium-sulfur batteries,sodium-ion batteries,metal-air batteries,and Zn-ion batteries are presented in detail.Finally,an outlook of the potential challenges and future perspectives in advanced cellulose-based materials for flexible energy storage systems is discussed.
基金supported by the grants of the National Natural Science Foundation of China(Grant No.82474070)Jilin Science&Technology Development Plan(Grant No.20230204003YY).
文摘Biomacromolecules derived from plant-based traditional Chinese medicines play a pivotal role in natural drug research.Ginseng,the root of Panax ginseng C.A.Meyer,has attracted significant attention due to its diverse pharmacological activities and broad therapeutic applications.This review focuses on specific active macromolecules obtained from ginseng,including pectin,exosomes,proteins,and dietary fibers.These components possess unique structural characteristics and biological activities that offer novel insights into the multifaceted applications of ginseng.To systematically assess this field,we reviewed literature published over the past 60 years and identified 119 relevant studies investigating the structural composition,pharmacological activity,and potential applications of P.ginseng biomacromolecules.By highlighting their crucial role in promoting health and enhancing disease resistance,this review synthesizes the latest research findings on ginseng’s pharmacological effects,providing new perspectives and strong theoretical support for clinical drug development.
基金supported by the Key Program of National Natural Science Foundation of China(No.92160203)National Natural Science Foundation of China(No.92360306).
文摘The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately identifying the rotor unbalance.This paper utilizes a high-frequency composite sensor to monitor the engine’s blade tip clearance(BTC)and extracts unbalanced information from BTC signals for rotor dynamic balancing,while avoiding the need for the once per revolution(OPR)sensor.First,the vibration characteristics of the rotor-blade system under multi-fault conditions are investigated.Then,based on BTC measurement,a none OPR method and an unbalance identification method are proposed,in which the radial vibration of the blade tip in the BTC signals at different speeds is extracted and operated in the time domain to obtain the rotor unbalanced vibration,the signal is reconstructed,and cross-correlation analysis is used to accurately identify the magnitude and phase of the unbalanced signal.Finally,a rotor test bench is utilized for experimental verification.The results reveal that the dynamic balancing method based on the BTC signal can more precisely identify the rotor unbalance than the traditional rotor dynamic balancing method.The application of this technique will effectively improve engine health management and fault prediction.
基金supported by the National Natural Science Foundation of China(No.52174275).
文摘The extreme removal of SiO2 and MnO inclusions in 304 stainless steel in supergravity fields was investigated using an inhouse high-temperature supergravity equipment.The influences of the gravity coefficient and separation time on the removal efficiency of the inclusions were studied.After supergravity treatment,the inclusions migrated to the top of the sample and formed large aggregates.Meanwhile,the lower part of the sample was purified considerably and appeared significantly cleaner than the raw material.At the gravity coefficient of 500 and separation time of 600 s,the total oxygen content at the bottom of the sample(position E)decreased from 240 to 28 ppm.This corresponded to a total oxygen removal rate of 88.33%.The volume fraction and number density of inclusions exhibited a gradient distribution along the supergravity direction,with values of 8.5%and 106 mm^(-2) at the top of the sample(position A)and 0.06%and 22 mm^(-2) at its bottom.
基金the National Natural Science Foundation of China(22371131)the 111 Project from China(B18030)+5 种基金the Beijing-Tianjin-Hebei Collaborative Innovation Project(19YFSLQY00030)the Outstanding Youth Project of Tianjin Natural Science Foundation(20JCJQJC00130)the Key Project of Tianjin Natural Science Foundation(20JCZDJC00650)the opening fund of Key Laboratory of Rare Earths,Chinese Academy of Sciencesthe Functional Research Funds for the Central Universities,Nankai University(63186005)Tianjin Key Lab for Rare Earth Materials and Applications(ZB19500202).
文摘The construction of rare earth(RE)alloy catalysts offers a route to harness the unique electronic structure of RE.Within the alloy,RE can fine-tune the electronic configuration of the active element,such as rhodium(Rh),via the ligand effect,optimizing the electrochemical reaction pathway.However,the challenging negative reduction potential of RE has impeded the progress in developing RE alloys,particularly nanoalloy catalysts.In this study,Rh_(3)Sc/C and Rh_(3)Y/C nanoalloys were synthesized using a sodium vapor reduction strategy for application as hydrogen evolution reaction(HER)catalysts.Elec-trochemical tests reveal that Rh-RE alloy catalysts exhibit significantly improved electrocatalytic activity in 1 mol/L KOH.Notably,Rh_(3)Y/C demonstrates exceptional HER performance,achieving a low over-potential of only 31 mV at 10 mA/cm^(2),surpassing the 50 mV observed for Rh/C.Furthermore,the current density of Rh_(3)Y/C at an 80 mV overpotential is 3.9 times that of Rh/C.This study sheds light on the remarkable catalytic potential of Rh-RE alloys,paving the way for the future expansion of RE nanoalloy systems.
基金Artificial Intelligence Education Research Project of Shandong Provincial Audio-Visual Education Center“Exploration of the Application of Large-scale AI Models in Student Value-added Evaluation from an Evidence-based Perspective”(SDDJ202501035)。
文摘Value-added evaluation focuses on individual student growth by tracking changes in academic performance,skills,literacy,etc.,at different time points.It weakens horizontal comparisons and emphasizes vertical progress to more fairly reflect educational effectiveness.This evaluation method is particularly suitable for vocational education,effectively motivating students’learning enthusiasm and enhancing their self-confidence.Foreign research is represented by the Tennessee Value-Added Assessment System(TVAAS),widely used in evaluating school quality and teacher performance.Domestic research currently focuses on the theoretical construction,model establishment,optimization,and practical application of value-added evaluation,still facing significant challenges in data collection comprehensiveness and model adaptability.Aiming at current issues,this study focuses on exploring the application of artificial intelligence large models in student value-added evaluation from an evidence-based perspective,committed to constructing an innovative evidence-based value-added evaluation system.It aims to achieve precise assessment of students’learning effect“net value-added”through multi-source data collection,intelligent analysis,and personalized feedback.The system integrates outcome evaluation,process evaluation,value-added evaluation,and comprehensive evaluation to form a“four-in-one”dynamic evaluation framework,considering students’starting points,process performance,and final achievements.In the future,value-added evaluation needs to further expand the assessment of non-academic dimensions(such as professional literacy and social-emotional skills)and explore the application of non-linear models to promote the deepening and innovation of educational evaluation reform.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52079068,52090081)the State Key Laboratory of Hydroscience and Engineering(Grant No.2021-KY-04).
文摘The flow field characteristics of the conduit-matrix system(CMS)have consistently been a primary area of interest to researchers.However,under the long-term influence of water flow,the hydraulic conductivity of the matrix surrounding the conduit often deforms differentially along the conduit axis,resulting in the development of a conduit-multilayer matrix system(CMMS).This renders conventional models inadequate in accurately describing the flow field characteristics of CMMS.In this study,a semi-analytical model with second-order accuracy is developed to investigate the velocity profile characteristics of CMMS by coupling the Navier-Stokes(N–S)equations in the conduit and the Darcy-Brinkman(D-B)equation in the multilayer matrices.In this model,the interface between the conduit and the matrix satisfies the velocity continuity and stress jumping condition.In contrast,different matrix interfaces require both velocity and stress to be equal.The model's validity is verified through Lattice Boltzmann Method(LBM)simulation,COMSOL simulation,and experimental data under different conduit apertures,matrix region numbers,and matrix permeability characteristics.Moreover,the current model predicts discharges with higher accuracy than the Hagen-Poiseuille law and Darcy's law(the maximum error between the present model and the test is 7.24%).Furthermore,the existing Poiseuille's law,conduit-matrix model,and conduit-matrix1-matrix2 model are all special cases of the current semi-analytical model,thereby indicating its broader applicability.Sensitivity results reveal that the flow velocities in the surrounding matrix and the conduit regions also increase when the permeability of the matrix in proximity to the conduit increases.Additionally,as the stress jumping coefficient at the interface approaches zero,the transition from free flow to seepage becomes smoother.
