Vocational undergraduate education has entered a new stage of high-quality development,making the cultivation of students'learning ability a core issue in enhancing talent cultivation quality.This study conducted ...Vocational undergraduate education has entered a new stage of high-quality development,making the cultivation of students'learning ability a core issue in enhancing talent cultivation quality.This study conducted a questionnaire survey with 177 students majoring in integrated circuits at Shenzhen Polytechnic University(SZPU),focusing on six dimensions:self-learning proficiency,academic competence,goal planning,self-discipline,learning initiative,and learning environment.The results indicate that while students possess a solid learning foundation and clear career planning,significant deficiencies exist in the execution of academic plans,self-discipline,and learning initiative.In response to these issues,this study proposes four systematic improvement pathways from the institutional perspective:establishing a closed-loop academic navigation system incorporating“goal-process-feedback”,creating an immersive“virtual-physical integrated”learning environment,implementing a multi-dimensional“cognitive-affective-practical”initiative activation plan,and building a synergistic cultivation mechanism for“self-discipline and core competencies”.The findings aim to provide references for talent cultivation and teaching reform in vocational undergraduate integrated circuit programs.展开更多
From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competiti...From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results.展开更多
The past two decades have seen formative assessment claim legitimacy in policy discourse and engender immense tensions within the testing-dominated assessment regimes of multiple educational settings.These tensions,al...The past two decades have seen formative assessment claim legitimacy in policy discourse and engender immense tensions within the testing-dominated assessment regimes of multiple educational settings.These tensions,along with the top-down approach of the policy process,have made the inroads of formative assessment in local contexts very complex.This study seeks to unveil the localized appropriation and actualization of a formative assessment initiative in the College English area at a Chinese local university.The focus is on how the key actors at the institutional and classroom levels appropriate and negotiate the policy meaning within their local community of practice.Analysis of an individual interview with the dean and a focus-group interview with six 1 teachers has revealed a“two-hand”approach to the national policy and a nested mediation from local constraints,“cultural tools for thinking”and,more importantly,power in the policymaking process at the institutional level.The classroom level,on the other hand,witnesses capable teachers exercising their agency within a limited space.As a result,we would caution that power and agency could be solid mediators in the policy process and need to be exercised with care to ensure a more coherent implementation of assessment innovations.展开更多
Overseas study for university teachers is a crucial path for their professional development and an effective means to enhance the level of education internationalization.However,the effectiveness of these studies is i...Overseas study for university teachers is a crucial path for their professional development and an effective means to enhance the level of education internationalization.However,the effectiveness of these studies is influenced by the various factors,including pre⁃study selection and preparation,management and support in the study period,application and assessment of study outcomes afterward,as well as personal factors such as age,family background,and education experience.This paper aims to explore the impact of these factors on the effectiveness of teachers′international education studies and propose the corresponding improvement suggestions,in order to provide a reference for improving the quality and effectiveness of teachers′studies.展开更多
In recent years,various efforts have been devoted to advancing university education through artificial intelligence(AI).To this end,this paper introduces KCUBE,a novel framework centered on knowledge graphs(KGs)design...In recent years,various efforts have been devoted to advancing university education through artificial intelligence(AI).To this end,this paper introduces KCUBE,a novel framework centered on knowledge graphs(KGs)designed to enhance student advising and career planning in university courses.Owing to KCUBE,we can improve university education in the AI era by leveraging the expressiveness,operability,and interpretability of KGs.We detail a bottom-up approach for KG construction,empowering professors to develop subject-specific KGs,augmented by tools like ChatGPT,which has demonstrated promising accuracy and coverage.Based on KGs,KCUBE supports KG reasoning for applications such as automated teaching plan generation with dynamic editing capabilities.Furthermore,KCUBE offers advanced KG manipulation through 2D and 3D visualization platforms,such as virtual reality(VR)for immersive exploration of academic subjects and potential career paths.A comparative study on collaborative learning highlights the benefits of VR and KG-enhanced environments in promoting student engagement,participation,and collaborative decision-making.展开更多
Purpose:This study investigates the impact of domestic mobility on Chinese scientists’academic performance and explores the predictors influencing their chances of moving to more prestigious institutions.Design/metho...Purpose:This study investigates the impact of domestic mobility on Chinese scientists’academic performance and explores the predictors influencing their chances of moving to more prestigious institutions.Design/methodology/approach:Using publication and affiliation data from OpenAlex,we identified 2,896 scientists who relocated between cities in China from 2014 to 2017.We applied propensity score matching(PSM)to compare their academic outcomes post-mobility with a matched group of non-mobile peers.Multiple performance metrics were examined,including publication count,citation impact,number of collaborators,and university prestige.Ordered logistic regression was used to analyze factors influencing moves to higher-level institutions.Findings:Mobility enhances collaboration by increasing the number of coauthors but is associated with a short-term decline in citation impact.Scientists were more likely to move to lower-prestige universities.However,prior collaboration breadth and citation count positively predicted transitions to more prestigious institutions,while the number of publications did not.Research limitations:This study focuses on intra-national mobility within China from 2014 to 2017 and relies on quantitative data,lacking personal or qualitative variables such as gender,discipline-specific norms,or institutional culture.Data coverage for Chinese-language publications may also be limited.Practical implications:This research provides insights into academic hiring patterns and the trade-offs involved in scientist mobility.It offers valuable guidance for institutions aiming to enhance faculty recruitment and retention,as well as for researchers considering career transitions.Originality/value:This is a quantitative analysis of domestic scientist mobility in China using matched comparison and multi-dimensional academic indicators.The integration of university prestige metrics(Double First-Class and citation-based rankings)offers a nuanced view of career dynamics within the Chinese higher education system.展开更多
With the rapid development of China’s economy,the demand for high-end talents in the field of engineering technology is becoming increasingly prominent.Engineering doctors,as an important force in this field,have a d...With the rapid development of China’s economy,the demand for high-end talents in the field of engineering technology is becoming increasingly prominent.Engineering doctors,as an important force in this field,have a direct impact on the progress of national technological innovation and the upgrading of industrial structure.Currently,there are still some issues in the university-enterprise collaboration for engineering doctor training in China,such as unclear cooperation mechanisms and responsibility divisions,insufficient corporate participation and enthusiasm,and imperfect evaluation and feedback mechanisms.This paper aims to explore the university-enterprise collaborative training path of engineering doctors from the perspective of deep integration,analyzing multiple dimensions including training objectives,curriculum design,practical sessions,mentor teams,and evaluation systems,in order to provide reference for the reform and practice of engineering doctor training in China.展开更多
China implemented its Action Plan of Air Pollution Prevention and Control(APAPPC)in 2013 as a major step in national air-quality management.This study treated the APAPPC as a quasi-experiment,drawing on the Grossman a...China implemented its Action Plan of Air Pollution Prevention and Control(APAPPC)in 2013 as a major step in national air-quality management.This study treated the APAPPC as a quasi-experiment,drawing on the Grossman and Cropper models,to examine how air pollution affected individual health capital and medical service demand.Using panel data from the China Health and Retirement Longitudinal Study for 2011,2013,2015,and 2018,the analysis applied a Heckman two-stage model and difference-in-differences estimation to identify the policy's effects on medical expenditure.The results showed that the APAPPC significantly reduced annual health spending,with stronger effects among women,older adults,and rural residents.The mechanism analysis indicated that the reduction in respiratory diseases played a key role.This study provides evidence that supports further airpollution control in China and offers useful insights for other developing countries.展开更多
Graphene/copper-based composite heat sinks demonstrate extensive application potential in military equipment thermal management,high-power electronic packaging,new energy vehicles,and 5G communication systems,due to t...Graphene/copper-based composite heat sinks demonstrate extensive application potential in military equipment thermal management,high-power electronic packaging,new energy vehicles,and 5G communication systems,due to their outstanding properties,including high thermal conductivity,tunable thermal expansion coefficients,excellent mechanical strength,and low density.However,the industrial-scale application of these composites faces critical challenges during the fabrication of components with complex structures,such as inhomogeneous dispersion of graphene within the copper matrix and poor interfacial bonding between the two phases,which substantially undermine the overall performance of graphene/copper-based composites.To address these issues,the preparation methods for graphene/copper-based composite heat sinks were reviewed.For each method,a rigorous analysis was presented to clarify its inherent advantages and unavoidable restrictions.Furthermore,the latest research progress in addressing three core scientific challenges was synthesized,including uniform dispersion of graphene,interfacial optimization mechanisms,and molecular dynamics simulations for elucidating the structure-property relationships.Finally,the future development directions of graphene/copper-based composite heat sinks in engineering applications were prospected.展开更多
Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(...Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid),phen(1,10-phenanthroline),bpb(1,4-bis(pyrid-4-yl)benzene),bpa(bis(4-pyridyl)amine),and copper,nickel and cadmium chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and singlecrystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three complexes crystallize in the monoclinic P21/n,tetragonal I42d,and orthorhombic P21212 space groups.The complexes exhibit molecular dimers(1)or 2D metal-organic networks(2 and 3).The catalytic performances in the Knoevenagel reaction of these complexes were investigated.Complex 1 exhibits an effective catalytic activity and excellent reusability as a heterogeneous catalyst in the Knoevenagel reaction at room temperature.CCDC:2463800,1;2463801,2;2463802,3.展开更多
For mission-oriented unmanned aerial vehicle(UAV)swarms,mission capability assessment provides an important reference in the design and development process,and is a precondition for mission success.For this multi-crit...For mission-oriented unmanned aerial vehicle(UAV)swarms,mission capability assessment provides an important reference in the design and development process,and is a precondition for mission success.For this multi-criteria decisionmaking(MCDM)problem,the current literature lacks a way to unambiguously present criteria and the popular fuzzy analytic network process(ANP)approaches neglect the hesitancy of subjective judgments.To fill these research gaps,an MCDM method based on unified architecture framework(UAF)and interval-valued spherical fuzzy ANP(IVSF-ANP)is proposed in this paper.Firstly,selected viewpoints in UAF are extended to construct criteria models with standardized representation.Secondly,interval-valued spherical fuzzy sets are introduced to ANP to weight interdependent criteria,handling fuzziness and hesitancy in pairwise comparisons.A method of adjusting weights of experts based on their decision similarities is also included in this process to reduce ambiguity brought by multiple experts.Next,performance characteristics are non-linearly transformed regarding to expectations to get final results.This proposition is applied to assess the mission capability of UAV swarms to search and strike surface vessels.Comparative analysis shows that the proposed method is valid and reasonable.展开更多
Myelination,the continuous ensheathment of neuronal axons,is a lifelong process in the nervous system that is essential for the precise,temporospatial conduction of action potentials between neurons.Myelin also provid...Myelination,the continuous ensheathment of neuronal axons,is a lifelong process in the nervous system that is essential for the precise,temporospatial conduction of action potentials between neurons.Myelin also provides intercellular metabolic support to axons.Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases.In fact,myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases,including multiple sclerosis and Alzheimer’s disease.In the central nervous system,compact myelin sheaths are formed by fully mature oligodendrocytes.However,the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages.In addition to their well-known role in action potential propagation,oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes.Therefore,myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases.Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals.In this review,we investigate the changes in myelin that are associated with aging and their underlying mechanisms.We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent,slow down,or even reverse age-related myelin degeneration.Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.展开更多
A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.T...A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.展开更多
The problem of maneuvering for a servicing spacecraft(inspector)to inspect a noncooperative spacecraft(evader)in cislunar space is investigated in this paper.The evader,which may be a malfunctioning or uncontrolled sa...The problem of maneuvering for a servicing spacecraft(inspector)to inspect a noncooperative spacecraft(evader)in cislunar space is investigated in this paper.The evader,which may be a malfunctioning or uncontrolled satellite,introduces uncertainties due to its potential maneuvering capabilities.To address this challenge,the scenario is modeled as a special orbital game,incorporating the unique complexities of the cislunar environment.A variable-duration,turn-based inspection and anti-inspection game model is designed.The model defines both players'rules,constraints,and victory conditions,providing a framework for non-cooperative inspection.Strategies for both players are developed and validated based on their dynamical properties.The inspector's strategy integrates two-body Lambert transfers with shooting methods,while the evader's strategy aims to maximize the inspector's fuel consumption.Simulation results show that the evader's optimal strategy involves deliberate fluctuations in its lunar periapsis altitude,with the inspector's requiredΔV up to eight times greater than the evader's.The impact of game constraints is evaluated,and the effectiveness of deploying the inspector in low lunar orbit is compared with the inspector at the Earth-Moon Lagrange point L1.The strengths and weaknesses of both are shown.These findings provide valuable insights for future orbital servicing and orbital games.展开更多
This paper proposes a threat assessment framework for non-cooperative satellites by analyzing their motion characteristics,developing a quantitative evaluation methodology,and demonstrating its effectiveness via repre...This paper proposes a threat assessment framework for non-cooperative satellites by analyzing their motion characteristics,developing a quantitative evaluation methodology,and demonstrating its effectiveness via representative scenarios with neural network acceleration.The framework first establishes a threat evaluation model that integrates three core parameters:capability,opportunity,and hidden values.Subsequently,this research systematically investigates the critical role of transfer windows in threat quantification and introduces a transfer window-based threat assessment approach.The proposed methodology is validated through multiple representative scenarios,with simulation results demonstrating superior performance compared to conventional methods relying solely on optimal transfer windows or minimum distance metrics,enabling more nuanced threat ranking in scenarios where traditional techniques prove inadequate.To address computational demands,a neural networkbased approximation system is implemented to achieve a 25,200×speedup(0.005 s vs.baseline 126 s per 1000-sample batch)through parallel processing,maintaining 99.3%accuracy.Finally,the study explores the framework's extensibility to diverse NCS objectives.It identifies discrepancies between intention inference models and threat evaluation paradigms,providing methodological insights for next-generation space domain awareness systems.展开更多
The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural ...The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure.展开更多
Coiled tube heat exchangers are widely preferred in shell structures due to their superior heat transfer performance,driven by favorable flow characteristics.This study investigates the effect of modifying coil and sh...Coiled tube heat exchangers are widely preferred in shell structures due to their superior heat transfer performance,driven by favorable flow characteristics.This study investigates the effect of modifying coil and shell configurations on heat transfer efficiency.Two key enhancements were examined:adding fins to the outer coil surface and integrating longitudinal slots within a hollowed shell.These modifications promote turbulence and extend heat transfer duration,thereby improving performance.However,they also introduce challenges,including increased pressure loss andmanufacturing complexity.Numerical simulationswere conducted usingANSYS Fluent 2024R1 under identical boundary conditions.With a fixed cold-side flow rate of 3 L/min,the input temperatures for the hot and cold fluids were 333.15 and 291.65 K,respectively.The hot-side flow rate varied between 2 and 6 L/min.Simulation outcomes were reported for the objectives of the study that included the improvement in heat exchangers’heat transfer enhancement.As it was indicated in the study outcomes,the average heat transfer rate increased by 15.56%,the overall heat transfer coefficient enhanced by about 29.51%,and the convective heat transfer coefficient improved by about 75.96%compared to the conventional shell-and-coil tube heat exchanger model.However,the modified technique resulted in a significant pressure drop.展开更多
The adjoint method is widely used in gradient-based optimization with high-dimensional design variables.However,the cost of solving the adjoint equations in each iteration is comparable to that of solving the flow fie...The adjoint method is widely used in gradient-based optimization with high-dimensional design variables.However,the cost of solving the adjoint equations in each iteration is comparable to that of solving the flow field,resulting in expensive computational costs.To improve the efficiency of solving adjoint equations,we propose a physics-constrained graph neural networks for solving adjoint equations,named ADJ-PCGN.ADJ-PCGN establishes a mapping relationship between flow characteristics and adjoint vector based on data,serving as a replacement for the computationally expensive numerical solution of adjoint equations.A physics-based graph structure and message-passing mechanism are designed to endow its strong fitting and generalization capabilities.Taking transonic drag reduction and maximum lift-drag ratio of the airfoil as examples,results indicate that ADJ-PCGN attains a similar optimal shape as the classical direct adjoint loop method.In addition,ADJ-PCGN demonstrates strong generalization capabilities across different mesh topologies,mesh densities,and out-of-distribution conditions.It holds the potential to become a universal model for aerodynamic shape optimization involving states,geometries,and meshes.展开更多
The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed...The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed to characterize the track irregularities under different circumstances.The first model is a novel explicit track spectrum function,which performs better in reflecting the inherent periodic components of track irregularities than the existing track spectra.On this foundation,the second model,a parameterized track spectrum random model,is proposed to represent the vast measured track irregularities from the probabilistic perspective.Finally,the third model,an imprecise track spectrum interval model based on a neighborhood uniform sampling Bootstrap method,is presented to identify the confidential interval of the track spectra when the track irregularity data are limited.Three examples are illustrated to demonstrate the feasibility of the three track irregularity models in characterizing the track irregularities in different conditions.This research can help capture the railway deformation status and optimize track maintenance strategies.展开更多
文摘Vocational undergraduate education has entered a new stage of high-quality development,making the cultivation of students'learning ability a core issue in enhancing talent cultivation quality.This study conducted a questionnaire survey with 177 students majoring in integrated circuits at Shenzhen Polytechnic University(SZPU),focusing on six dimensions:self-learning proficiency,academic competence,goal planning,self-discipline,learning initiative,and learning environment.The results indicate that while students possess a solid learning foundation and clear career planning,significant deficiencies exist in the execution of academic plans,self-discipline,and learning initiative.In response to these issues,this study proposes four systematic improvement pathways from the institutional perspective:establishing a closed-loop academic navigation system incorporating“goal-process-feedback”,creating an immersive“virtual-physical integrated”learning environment,implementing a multi-dimensional“cognitive-affective-practical”initiative activation plan,and building a synergistic cultivation mechanism for“self-discipline and core competencies”.The findings aim to provide references for talent cultivation and teaching reform in vocational undergraduate integrated circuit programs.
文摘From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results.
基金based on research projects sponsored by the National Social Science Fund of China(NSSFC)(No.17BYY100)the China Association of Higher Education—Foreign Language Teaching and Research Association[21WYJYYB24]。
文摘The past two decades have seen formative assessment claim legitimacy in policy discourse and engender immense tensions within the testing-dominated assessment regimes of multiple educational settings.These tensions,along with the top-down approach of the policy process,have made the inroads of formative assessment in local contexts very complex.This study seeks to unveil the localized appropriation and actualization of a formative assessment initiative in the College English area at a Chinese local university.The focus is on how the key actors at the institutional and classroom levels appropriate and negotiate the policy meaning within their local community of practice.Analysis of an individual interview with the dean and a focus-group interview with six 1 teachers has revealed a“two-hand”approach to the national policy and a nested mediation from local constraints,“cultural tools for thinking”and,more importantly,power in the policymaking process at the institutional level.The classroom level,on the other hand,witnesses capable teachers exercising their agency within a limited space.As a result,we would caution that power and agency could be solid mediators in the policy process and need to be exercised with care to ensure a more coherent implementation of assessment innovations.
基金supported by the Higher Education Research Fund Project of Northwestern Polytechnical(International Talent Cultivation Special Project)(GJGZMS202309).University。
文摘Overseas study for university teachers is a crucial path for their professional development and an effective means to enhance the level of education internationalization.However,the effectiveness of these studies is influenced by the various factors,including pre⁃study selection and preparation,management and support in the study period,application and assessment of study outcomes afterward,as well as personal factors such as age,family background,and education experience.This paper aims to explore the impact of these factors on the effectiveness of teachers′international education studies and propose the corresponding improvement suggestions,in order to provide a reference for improving the quality and effectiveness of teachers′studies.
文摘In recent years,various efforts have been devoted to advancing university education through artificial intelligence(AI).To this end,this paper introduces KCUBE,a novel framework centered on knowledge graphs(KGs)designed to enhance student advising and career planning in university courses.Owing to KCUBE,we can improve university education in the AI era by leveraging the expressiveness,operability,and interpretability of KGs.We detail a bottom-up approach for KG construction,empowering professors to develop subject-specific KGs,augmented by tools like ChatGPT,which has demonstrated promising accuracy and coverage.Based on KGs,KCUBE supports KG reasoning for applications such as automated teaching plan generation with dynamic editing capabilities.Furthermore,KCUBE offers advanced KG manipulation through 2D and 3D visualization platforms,such as virtual reality(VR)for immersive exploration of academic subjects and potential career paths.A comparative study on collaborative learning highlights the benefits of VR and KG-enhanced environments in promoting student engagement,participation,and collaborative decision-making.
基金supported by grants from Shenzhen Polytechnic University Research(Fund No.6025310042 K)the National Natural Science Foundation of China(No.NSFC62006109 and NSFC12031005).
文摘Purpose:This study investigates the impact of domestic mobility on Chinese scientists’academic performance and explores the predictors influencing their chances of moving to more prestigious institutions.Design/methodology/approach:Using publication and affiliation data from OpenAlex,we identified 2,896 scientists who relocated between cities in China from 2014 to 2017.We applied propensity score matching(PSM)to compare their academic outcomes post-mobility with a matched group of non-mobile peers.Multiple performance metrics were examined,including publication count,citation impact,number of collaborators,and university prestige.Ordered logistic regression was used to analyze factors influencing moves to higher-level institutions.Findings:Mobility enhances collaboration by increasing the number of coauthors but is associated with a short-term decline in citation impact.Scientists were more likely to move to lower-prestige universities.However,prior collaboration breadth and citation count positively predicted transitions to more prestigious institutions,while the number of publications did not.Research limitations:This study focuses on intra-national mobility within China from 2014 to 2017 and relies on quantitative data,lacking personal or qualitative variables such as gender,discipline-specific norms,or institutional culture.Data coverage for Chinese-language publications may also be limited.Practical implications:This research provides insights into academic hiring patterns and the trade-offs involved in scientist mobility.It offers valuable guidance for institutions aiming to enhance faculty recruitment and retention,as well as for researchers considering career transitions.Originality/value:This is a quantitative analysis of domestic scientist mobility in China using matched comparison and multi-dimensional academic indicators.The integration of university prestige metrics(Double First-Class and citation-based rankings)offers a nuanced view of career dynamics within the Chinese higher education system.
基金supported in part by the 2023 College Student Innovation and Entrepreneurship Training 430 Program Project of China(Grant No.202310699159)2024 Graduate Education Comprehensive Reform,Development and Innovation Project of Northwestern Polytechnical University(Grant No.KCJG202432)2023 Northwestern Polytechnical University Degree and Postgraduate Education Research Funding(Grant No.2023YMs014)。
文摘With the rapid development of China’s economy,the demand for high-end talents in the field of engineering technology is becoming increasingly prominent.Engineering doctors,as an important force in this field,have a direct impact on the progress of national technological innovation and the upgrading of industrial structure.Currently,there are still some issues in the university-enterprise collaboration for engineering doctor training in China,such as unclear cooperation mechanisms and responsibility divisions,insufficient corporate participation and enthusiasm,and imperfect evaluation and feedback mechanisms.This paper aims to explore the university-enterprise collaborative training path of engineering doctors from the perspective of deep integration,analyzing multiple dimensions including training objectives,curriculum design,practical sessions,mentor teams,and evaluation systems,in order to provide reference for the reform and practice of engineering doctor training in China.
基金Natural Science Foundation of Hubei Province(No.2025AFC041).
文摘China implemented its Action Plan of Air Pollution Prevention and Control(APAPPC)in 2013 as a major step in national air-quality management.This study treated the APAPPC as a quasi-experiment,drawing on the Grossman and Cropper models,to examine how air pollution affected individual health capital and medical service demand.Using panel data from the China Health and Retirement Longitudinal Study for 2011,2013,2015,and 2018,the analysis applied a Heckman two-stage model and difference-in-differences estimation to identify the policy's effects on medical expenditure.The results showed that the APAPPC significantly reduced annual health spending,with stronger effects among women,older adults,and rural residents.The mechanism analysis indicated that the reduction in respiratory diseases played a key role.This study provides evidence that supports further airpollution control in China and offers useful insights for other developing countries.
基金Research Start-Up Fund Project of Anhui Polytechnic University(S022023017)University Research Project of Anhui Province(2023AH050937)+1 种基金Anhui Polytechnic University Research Foundation for Introducing Talents(2022YQQ003)Anhui Province Key Laboratory of Intelligent Vehicle Chassis by Wire。
文摘Graphene/copper-based composite heat sinks demonstrate extensive application potential in military equipment thermal management,high-power electronic packaging,new energy vehicles,and 5G communication systems,due to their outstanding properties,including high thermal conductivity,tunable thermal expansion coefficients,excellent mechanical strength,and low density.However,the industrial-scale application of these composites faces critical challenges during the fabrication of components with complex structures,such as inhomogeneous dispersion of graphene within the copper matrix and poor interfacial bonding between the two phases,which substantially undermine the overall performance of graphene/copper-based composites.To address these issues,the preparation methods for graphene/copper-based composite heat sinks were reviewed.For each method,a rigorous analysis was presented to clarify its inherent advantages and unavoidable restrictions.Furthermore,the latest research progress in addressing three core scientific challenges was synthesized,including uniform dispersion of graphene,interfacial optimization mechanisms,and molecular dynamics simulations for elucidating the structure-property relationships.Finally,the future development directions of graphene/copper-based composite heat sinks in engineering applications were prospected.
文摘Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid),phen(1,10-phenanthroline),bpb(1,4-bis(pyrid-4-yl)benzene),bpa(bis(4-pyridyl)amine),and copper,nickel and cadmium chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and singlecrystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three complexes crystallize in the monoclinic P21/n,tetragonal I42d,and orthorhombic P21212 space groups.The complexes exhibit molecular dimers(1)or 2D metal-organic networks(2 and 3).The catalytic performances in the Knoevenagel reaction of these complexes were investigated.Complex 1 exhibits an effective catalytic activity and excellent reusability as a heterogeneous catalyst in the Knoevenagel reaction at room temperature.CCDC:2463800,1;2463801,2;2463802,3.
基金supported by the National Natural Science Foundation of China(62073267,61903305)the Fundamental Research Funds for the Central Universities(HXGJXM202214)。
文摘For mission-oriented unmanned aerial vehicle(UAV)swarms,mission capability assessment provides an important reference in the design and development process,and is a precondition for mission success.For this multi-criteria decisionmaking(MCDM)problem,the current literature lacks a way to unambiguously present criteria and the popular fuzzy analytic network process(ANP)approaches neglect the hesitancy of subjective judgments.To fill these research gaps,an MCDM method based on unified architecture framework(UAF)and interval-valued spherical fuzzy ANP(IVSF-ANP)is proposed in this paper.Firstly,selected viewpoints in UAF are extended to construct criteria models with standardized representation.Secondly,interval-valued spherical fuzzy sets are introduced to ANP to weight interdependent criteria,handling fuzziness and hesitancy in pairwise comparisons.A method of adjusting weights of experts based on their decision similarities is also included in this process to reduce ambiguity brought by multiple experts.Next,performance characteristics are non-linearly transformed regarding to expectations to get final results.This proposition is applied to assess the mission capability of UAV swarms to search and strike surface vessels.Comparative analysis shows that the proposed method is valid and reasonable.
基金supported by grants from Guangdong Basic and Applied Basic Research Foundation,No.2021A1515110801(to SW)the National Natural Science Foundation of China,No.82301511(to SW)+1 种基金“Double First-Class”Construction Project of NPU,Nos.0515023GH0202320(to JC),0515023SH0201320(to JC)973 Program,No.2011CB504100(to JC).
文摘Myelination,the continuous ensheathment of neuronal axons,is a lifelong process in the nervous system that is essential for the precise,temporospatial conduction of action potentials between neurons.Myelin also provides intercellular metabolic support to axons.Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases.In fact,myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases,including multiple sclerosis and Alzheimer’s disease.In the central nervous system,compact myelin sheaths are formed by fully mature oligodendrocytes.However,the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages.In addition to their well-known role in action potential propagation,oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes.Therefore,myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases.Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals.In this review,we investigate the changes in myelin that are associated with aging and their underlying mechanisms.We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent,slow down,or even reverse age-related myelin degeneration.Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.
基金supported by the National Science and Technology Major Project,China(No.2017-II-0006-0019)the National Natural Science Foundation of China(No.52375266)the Shaanxi Science Foundation for Distinguished Young Scholars,China(No.2022JC-36)。
文摘A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.
基金supported by the National Key R&D Pro-gram of China:Gravitational Wave Detection Project(Nos.2021YFC2026,2021YFC2202601,2021YFC2202603)the National Natural Science Foundation of China(Nos.12172288 and 12472046)。
文摘The problem of maneuvering for a servicing spacecraft(inspector)to inspect a noncooperative spacecraft(evader)in cislunar space is investigated in this paper.The evader,which may be a malfunctioning or uncontrolled satellite,introduces uncertainties due to its potential maneuvering capabilities.To address this challenge,the scenario is modeled as a special orbital game,incorporating the unique complexities of the cislunar environment.A variable-duration,turn-based inspection and anti-inspection game model is designed.The model defines both players'rules,constraints,and victory conditions,providing a framework for non-cooperative inspection.Strategies for both players are developed and validated based on their dynamical properties.The inspector's strategy integrates two-body Lambert transfers with shooting methods,while the evader's strategy aims to maximize the inspector's fuel consumption.Simulation results show that the evader's optimal strategy involves deliberate fluctuations in its lunar periapsis altitude,with the inspector's requiredΔV up to eight times greater than the evader's.The impact of game constraints is evaluated,and the effectiveness of deploying the inspector in low lunar orbit is compared with the inspector at the Earth-Moon Lagrange point L1.The strengths and weaknesses of both are shown.These findings provide valuable insights for future orbital servicing and orbital games.
基金supported by the National Key R&D Programof China:Gravitational Wave Detection Project(Grant Nos.2021YFC2026,2021YFC2202601,2021YFC2202603)the Na-tional Natural Science Foundation of China(Grant Nos.12172288and 12472046)。
文摘This paper proposes a threat assessment framework for non-cooperative satellites by analyzing their motion characteristics,developing a quantitative evaluation methodology,and demonstrating its effectiveness via representative scenarios with neural network acceleration.The framework first establishes a threat evaluation model that integrates three core parameters:capability,opportunity,and hidden values.Subsequently,this research systematically investigates the critical role of transfer windows in threat quantification and introduces a transfer window-based threat assessment approach.The proposed methodology is validated through multiple representative scenarios,with simulation results demonstrating superior performance compared to conventional methods relying solely on optimal transfer windows or minimum distance metrics,enabling more nuanced threat ranking in scenarios where traditional techniques prove inadequate.To address computational demands,a neural networkbased approximation system is implemented to achieve a 25,200×speedup(0.005 s vs.baseline 126 s per 1000-sample batch)through parallel processing,maintaining 99.3%accuracy.Finally,the study explores the framework's extensibility to diverse NCS objectives.It identifies discrepancies between intention inference models and threat evaluation paradigms,providing methodological insights for next-generation space domain awareness systems.
基金supported by the National Natural Science Foundation of China (Nos. 52075449, 51975480)。
文摘The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure.
文摘Coiled tube heat exchangers are widely preferred in shell structures due to their superior heat transfer performance,driven by favorable flow characteristics.This study investigates the effect of modifying coil and shell configurations on heat transfer efficiency.Two key enhancements were examined:adding fins to the outer coil surface and integrating longitudinal slots within a hollowed shell.These modifications promote turbulence and extend heat transfer duration,thereby improving performance.However,they also introduce challenges,including increased pressure loss andmanufacturing complexity.Numerical simulationswere conducted usingANSYS Fluent 2024R1 under identical boundary conditions.With a fixed cold-side flow rate of 3 L/min,the input temperatures for the hot and cold fluids were 333.15 and 291.65 K,respectively.The hot-side flow rate varied between 2 and 6 L/min.Simulation outcomes were reported for the objectives of the study that included the improvement in heat exchangers’heat transfer enhancement.As it was indicated in the study outcomes,the average heat transfer rate increased by 15.56%,the overall heat transfer coefficient enhanced by about 29.51%,and the convective heat transfer coefficient improved by about 75.96%compared to the conventional shell-and-coil tube heat exchanger model.However,the modified technique resulted in a significant pressure drop.
基金supported by the National Natural Science Foundation of China(Grant No.12272316).
文摘The adjoint method is widely used in gradient-based optimization with high-dimensional design variables.However,the cost of solving the adjoint equations in each iteration is comparable to that of solving the flow field,resulting in expensive computational costs.To improve the efficiency of solving adjoint equations,we propose a physics-constrained graph neural networks for solving adjoint equations,named ADJ-PCGN.ADJ-PCGN establishes a mapping relationship between flow characteristics and adjoint vector based on data,serving as a replacement for the computationally expensive numerical solution of adjoint equations.A physics-based graph structure and message-passing mechanism are designed to endow its strong fitting and generalization capabilities.Taking transonic drag reduction and maximum lift-drag ratio of the airfoil as examples,results indicate that ADJ-PCGN attains a similar optimal shape as the classical direct adjoint loop method.In addition,ADJ-PCGN demonstrates strong generalization capabilities across different mesh topologies,mesh densities,and out-of-distribution conditions.It holds the potential to become a universal model for aerodynamic shape optimization involving states,geometries,and meshes.
基金supported by the National Natural Science Foundation of China(Grant No.52208445,52478321,52378468)the Fundamental Research Funds for the Central Universities(Grant No.G2021KY05105)+7 种基金the Basic Research Program of Natural Science in Shaanxi Province(Grant No.2022JQ-369)the Open Foundation of National Engineering Laboratory for High Speed Railway Construction(No.HSR202001)the Youth Talent Support Program Project of Xi’an Association for Science and Technology(Grant No.959202413090)Science and Technology Research and Development Program Project of China railway group limited(Major Special Project,No.:2020-Special-022021-Special-082023-Special-07)Innovation-driven project of Central South University(2023CXQD072)the National Natural Science Foundation of Hunan Province(Grant No.:2022-JJ-20071).
文摘The characterization of track irregularities is crucial in railway dynamics,as track irregularities are the primary source of internal excitation in railway systems.In this paper,three mathematical models are proposed to characterize the track irregularities under different circumstances.The first model is a novel explicit track spectrum function,which performs better in reflecting the inherent periodic components of track irregularities than the existing track spectra.On this foundation,the second model,a parameterized track spectrum random model,is proposed to represent the vast measured track irregularities from the probabilistic perspective.Finally,the third model,an imprecise track spectrum interval model based on a neighborhood uniform sampling Bootstrap method,is presented to identify the confidential interval of the track spectra when the track irregularity data are limited.Three examples are illustrated to demonstrate the feasibility of the three track irregularity models in characterizing the track irregularities in different conditions.This research can help capture the railway deformation status and optimize track maintenance strategies.
