With the advent of the big data era,modern statistics has enjoyed unprecedented development opportunities and also faced numerous new challenges.Traditional statistical computing methods are often limited by issues su...With the advent of the big data era,modern statistics has enjoyed unprecedented development opportunities and also faced numerous new challenges.Traditional statistical computing methods are often limited by issues such as computer memory capacity and distributed storage of data across different locations,and are unable to directly apply to large-scale data sets.Therefore,in the context of big data,designing efficient and theoretically guaranteed statistical learning and inference algorithms has become a key issue that the current field of statistics urgently needs to address.In this paper,the application status of statistical analysis methods in the big data environment was systematically reviewed,and its future development directions were analyzed to provide reference and support for the further development of theory and methods of the statistical analysis of big data.展开更多
With the accelerating urbanization process,issues related to the urban ecological environment have become increasingly prominent.Among these,greenway optimization is regarded as one of the key approaches to improving ...With the accelerating urbanization process,issues related to the urban ecological environment have become increasingly prominent.Among these,greenway optimization is regarded as one of the key approaches to improving urban ecological quality.As the capital of Anhui Province,Hefei is striving to build a comprehensive greenway network in line with its“Park City”strategy.However,the current development of Hefei’s greenways faces challenges such as delayed planning,limited functions,inadequate facilities,and weak operation and maintenance management.In this study,comparative analysis and literature review were combined to comprehensively summarize the current characteristics of greenway development in Hefei,and improvement suggestions were proposed in areas such as ecological restoration,functional expansion,facility establishment,and long-term management.It is suggested that Hefei should enhance the systematic and synergistic nature of its greenway system,create a city green space network with regional characteristics,and optimize the city’s environmental carrying capacity,so as to meet the diverse needs of the public and thereby provide theoretical support and practical guidance for the sustainable development of Hefei’s greenway system.展开更多
With the accelerating pace of population aging in China,various issues related to elderly care have emerged one after another,becoming a severe social problem.Especially against the backdrop of increasing economic pre...With the accelerating pace of population aging in China,various issues related to elderly care have emerged one after another,becoming a severe social problem.Especially against the backdrop of increasing economic pressure,the traditional family-based elderly care model is facing significant challenges and can hardly meet the elderly care needs.At present,the geriatric nursing models are relatively backward,which directly affects the quality of daily life,physical health and mental well-being of the elderly.Therefore,it is necessary to explore an appropriate geriatric nursing model to address the aging problem.Based on this,this paper analyzes and studies the current situation of geriatric nursing models under the background of healthy aging,providing references for relevant research and practice.展开更多
With the increase of global climate change and extreme weather events,more and more attention has been paid to the protection of China's meteorological cultural heritage.Meteorological cultural heritage is an impo...With the increase of global climate change and extreme weather events,more and more attention has been paid to the protection of China's meteorological cultural heritage.Meteorological cultural heritage is an important part of China's cultural heritage,which is unique and non renewable.It is of great significance to the inheritance of China's excellent traditional culture and the construction of a meteorological power.Because it is more special than water conservancy cultural heritage in China's historical development,it is not only a national context,but also mixed with foreign activities.This paper focuses on the protection and research of China's meteorological cultural heritage.Based on the current situation of the protection and utilization of China's meteorological cultural heritage,it analyzes the problems and shortcomings in the current protection work.In response to these problems,some targeted protection measures are proposed,including strengthening the construction of laws and regulations,improving the level of protection technology,enhancing public participation,and promoting the protection and sustainable development of meteorological cultural heritage.The aim is to provide useful references for the protection of China's meteorological cultural heritage in the future.展开更多
This article takes the joint training model as the research object and focuses on the joint postgraduate training in vocational universities.Based on a brief overview of the connotation and significance of joint postg...This article takes the joint training model as the research object and focuses on the joint postgraduate training in vocational universities.Based on a brief overview of the connotation and significance of joint postgraduate training in vocational universities,a systematic summary of the current situation of such training is conducted through practical research.While elaborating on the implementation and characteristics of joint postgraduate training in vocational universities,the article emphasizes a systematic collection and analysis of existing problems.Finally,guided by these problems and considering the characteristics and issues of joint postgraduate training in vocational universities,several improvement strategies are proposed.It is emphasized that vocational universities need to actively optimize their management models,establish restraint mechanisms,and implement dynamic adjustments to achieve scientific management of joint postgraduate training.This approach aims to promote academic innovation and improve training quality simultaneously.展开更多
The digital economy has injected continuous momentum into the development of urban economy and plays a positive and important role in the transformation and upgrading of urban energy consumption.Specifically,the digit...The digital economy has injected continuous momentum into the development of urban economy and plays a positive and important role in the transformation and upgrading of urban energy consumption.Specifically,the digital economy can significantly improve the efficiency of urban energy consumption by virtue of its distinctive characteristics of low pollution and high efficiency.Moreover,empowered by the digital economy,the pace of transformation and upgrading of high-pollution traditional industries has been accelerated.Particularly importantly,the urban energy consumption structure has been optimized and adjusted through the indirect role of intermediate factors.From this perspective,studying the current situation and countermeasures of urban energy consumption under the digital economy holds important practical significance both in theory and practice.This paper first briefly summarizes the relevant literature on the impact of the digital economy on the energy consumption structure;then,it focuses on detailed data to explore the current situation of urban energy consumption under the digital economy model;finally,based on the summary of the current situation,it puts forward practical and feasible suggestions,hoping to provide a decision-making basis for the implementation of policies in different types of cities and offer innovative ideas for promoting the high-quality development of urban energy systems.展开更多
Objective To analyze the current situation of drug shortage in some western countries and their management strategies,and to put forward feasible suggestions for drug shortage management in China.Methods The methods o...Objective To analyze the current situation of drug shortage in some western countries and their management strategies,and to put forward feasible suggestions for drug shortage management in China.Methods The methods of literature research and comparative study were used to collect policy information and related data from official government websites and news websites,then,the current situation and management of drug shortage in some western countries were compared and studied to summarize their effective experience in dealing with drug shortage.Results and Conclusion The current situation and influencing factors of drug shortage in these western countries are different,but the management system established to deal with drug shortage is good,including the support of policies and regulations,the early warning of monitoring platform and the construction of organizational system.Drawing lessons from their experience,China should strengthen cooperation and consultation among stakeholders and rationally allocate powers and responsibilities.The transparency of drug shortage data disclosure should be increased.The important role of pharmacists should be played to strengthen the management.Further optimizing the drug shortage management system in China can ensure the safety of drug supply.展开更多
With the development of the international education environment and the continuous reform of higher education in China,the working pace in universities is accelerating,with higher requirements for university work and ...With the development of the international education environment and the continuous reform of higher education in China,the working pace in universities is accelerating,with higher requirements for university work and increasingly apparent pressure on teachers.Young teachers in Chinese universities are prone to occupational stress.In addition to undertaking teaching,research,and other tasks,they feel anxious and at a loss when facing personal issues such as job promotion and taking care of their families.This article selects young teachers from some universities in China as research subjects and uses a questionnaire survey method to understand the current situation and sources of pressure on young teachers in universities,so as to focus on and alleviate their stress in a targeted manner.展开更多
As one of the world's three major food crops and an important economic and oil crop,soybean plays a crucial role in ensuring food safety.In recent years,there are many problems in soybean cultivation,production an...As one of the world's three major food crops and an important economic and oil crop,soybean plays a crucial role in ensuring food safety.In recent years,there are many problems in soybean cultivation,production and processing.In view of this situation,this paper comprehensively expounded and decomposed the cultivation situation,existing problems,specific countermeasures and conclusions,so as to re-recognize them.This study provides reference materials for the sustainable and healthy development of the soybean industry.展开更多
The establishment of Hainan Free Trade Port provides a new opportunity for the financing of small and medium-sized enterprises.In the process of the country continuously promoting the development of a free trade port,...The establishment of Hainan Free Trade Port provides a new opportunity for the financing of small and medium-sized enterprises.In the process of the country continuously promoting the development of a free trade port,the financing environment of small and medium-sized enterprises has gradually improved,and the financing environment has been greatly improved.But the small and medium-sized enterprises“financing difficult”“financing expensive”problem still exists.The problems of difficult and expensive financing of small and medium-sized enterprises in Haikou city have their reasons as well as the influence of external environmental factors.Therefore,to better solve the financing problems of small and medium-sized enterprises in Haikou,this paper analyzes the reasons for the difficulty and expensive financing of small and medium-sized enterprises according to the existing research results and summarizes the financing experience of small and medium-sized enterprises at home and abroad.This article finds that the financing systems for small and medium-sized enterprises(SMEs)in developed countries are relatively well-established,and both the government and society offer significant support to SMEs.Therefore,this paper believes that the government should adjust the business strategy to improve the financing ecological environment and enhance the financing ability of SMEs.The government should take the lead in perfecting the guarantee system,continuously improving the credit information system of enterprises and various financial service institutions,promoting the opening and institutionalization of private credit,and developing Internet finance[1].展开更多
Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into...Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into the new β phase during the pulsed current-assisted aging process,and then the newly formed β phase is mainly transformed into the β_(t) phase,with occasional transition to new α_(p) phase,leading to a remarkable grain refinement,especially for the lamellarαs phases.In comparison to conventional aging treatment,the pulsed current-assisted aging approach achieves a significant enhancement in strength without degrading ductility,yielding an excellent mechanical property combination:a yield strength of 932 MPa,a tensile strength of 1042 MPa,and an elongation of 12.2%.It is primarily ascribed to the increased fraction of β_(t) phases,the obvious grain refinement effect,and the slip block effect induced by the multiple-variantαs colonies distributed within β_(t) phases.展开更多
This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper cons...This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper constructs an internal model to learn the information of the states and input of the grid-connected inverter under steady state.Second,by utilizing the internal model principle,the paper turns the tracking control problem into the robust stabilization control problem based on some appropriate coordinate transformations.Then,The paper designs a dynamics state feedback control law to deal with this robust stabilization problem,and thus the solution of the robust current tracking control problem of three-phase grid-connected inverters can be obtained.This control method can ensure the asymptotic stability of the closedloop system.Finally,the paper illustrates the effectiveness of the proposed control approach through several groups of simulations,and compares it with the feedforward control method to verify the robustness of the proposed control method to uncertain parameters.展开更多
Autonomous vehicles operate without direct human intervention,which introduces safety risks that differ from those of conventional vehicles.Although many studies have examined safety issues related to autonomous drivi...Autonomous vehicles operate without direct human intervention,which introduces safety risks that differ from those of conventional vehicles.Although many studies have examined safety issues related to autonomous driving,high-risk situations have often been defined using single indicators,making it difficult to capture the complex and evolving nature of accident risk.To address this limitation,this study proposes a structured framework for defining and analyzing high-risk situations throughout the traffic accident process.High-risk situations are described using three complementary indicators:accident likelihood,accident severity,and accident duration.These indicators explain how risk emerges,increases,and persists over time.Based on this concept,a framework for traffic accident visualization analysis is developed to support phase-specific risk assessment and visualization.The framework combines accident-phase information with factor-level risk contributions,allowing systematic identification of key factors and their interactions across different accident stages.Using combinations of the three indicators,high-risk situations are classified into twenty-seven distinct types,providing a clear typology for complex accident scenarios involving autonomous vehicles.The applicability of the proposed framework is demonstrated through two representative accident scenarioswith different risk characteristics.The results showthat the framework effectively captures interactions among multiple risk factors,explains how risk levels change from pre-crash to post-crash phases,and identifies contributing factors that are difficult to detect using conventional traffic accident investigation methods.Overall,the proposed framework offers a practical basis for autonomous vehicle accident analysis,safety evaluation,and policy-related decision-making.展开更多
Energy density and safety are two crucial parameters when evaluating lithium-metal batteries(LMBs).Herein,we present an ultralight polymer-based current collector,incorporating flame-retardant materials,designed speci...Energy density and safety are two crucial parameters when evaluating lithium-metal batteries(LMBs).Herein,we present an ultralight polymer-based current collector,incorporating flame-retardant materials,designed specifically for thin lithium-metal anodes.Compared to the traditional copper current collector(8.96 mg cm^(-2),10μm thick),the polymer-based current collector(12μm thick)has a significantly lower areal density of 1.41 mg cm^(-2),i.e.,only one-sixth of the copper collector,thus enabling substantially higher energy densities.Accordingly,when employed in Li||NMC_(622)full-cells,the polymer-based current collector enables a specific energy of 449 Wh kg^(-1),representing a notable improvement of about14.5%compared to cells employing a classic copper current collector.The inclusion of Al(OH)_(3) as a flame retardant into the current collector suppresses flammability and,thereby,significantly improves the safety of the resulting LMBs.展开更多
The transient synchronization stability of grid-forming converters(GFMCs)is significantly challenged under grid voltage sags.Continuous efforts have been devoted to analyzing the GFMC transient stability,with limited ...The transient synchronization stability of grid-forming converters(GFMCs)is significantly challenged under grid voltage sags.Continuous efforts have been devoted to analyzing the GFMC transient stability,with limited attention paid to the impacts of control loop dynamics.However,the complex control dynamics,especially the interactions between the active/reactive power control loops and the current saturation process(CSP),are crucial for accurately describing the transient behavior and evaluating the stability.Thus,in this study,a new large-signal GFMC model is established,considering the reactive power control(RPC)with different kinds of controllers and the CSP simultaneously.It is revealed that GFMC does not switch to the current-limited mode immediately,and the dynamics of RPC further affect the transient behavior before the current limiting significantly.Hence,the complex control dynamics can alter the mode switching point of current saturation,thereby increasing the risk of loss of synchronization(LOS).Based on the above findings,comprehensive comparisons of typical RPC controllers are presented to facilitate practical engineering applications.A unified stability enhancement method is proposed for solving the problem of LOS.Finally,experiments validate the correctness of the analysis and the effectiveness of the proposed control strategy.展开更多
Lithium metal batteries(LMBs)are promising candidates for next-generation high-energy-density storage devices.However,an unstable lithium metal anode poses significant issues that critically compromise battery safety ...Lithium metal batteries(LMBs)are promising candidates for next-generation high-energy-density storage devices.However,an unstable lithium metal anode poses significant issues that critically compromise battery safety and cycle life,including lithium dendrite formation,solid electrolyte interphase degradation,dead lithium accumulation,and substantial volume fluctuations during cycling.These problems can be addressed by regulating lithium deposition and suppressing side reactions through the modification of copper current collectors using three classes of materials:metal and metal oxide,carbon,and polymer materials.This review comprehensively examines recent advances in the application of these materials as current collector coatings.Particularly,their distinct roles in the lithium deposition process are analyzed to understand how they mitigate the issues associated with the lithium metal anode.Furthermore,their inherent limitations are considered to inform future research directions.While each class of materials offers specific advantages,multifunctionality is required to effectively regulate lithium deposition.In prospect,a novel composite copper current collector design that integrates the merits of the aforementioned advanced materials is proposed.The insights from this review provide valuable guidance for the rational design of modified copper current collectors,which would significantly improve the safety and cycle life of LMBs and advance their commercialization.展开更多
When the converter bus voltage of a voltage source converter-based high voltage direct current(VSC-HVDC)system drops below a certain predetermined threshold,the system enters low-voltage ride-through(LVRT)mode to avoi...When the converter bus voltage of a voltage source converter-based high voltage direct current(VSC-HVDC)system drops below a certain predetermined threshold,the system enters low-voltage ride-through(LVRT)mode to avoid overcurrent and potential equipment failure,during which it operates as a controlled current source.The influence mechanism of LVRT control strategies on short-circuit current and overall system stability remains not yet fully and systematically investigated.First,this paper provides an overview of several LVRT strategies for VSC-HVDC systems and examines their effects on short-circuit current contribution.Next,it analyzes in detail the mechanisms through which active and reactive currents injected during LVRT impact system frequency stability,voltage stability,and synchronization stability.To address these interrelated issues,an optimized and comprehensive LVRT strategy incorporating short-circuit current constraints is proposed.The approach determines the active current ratio based on system frequency stability requirements and dynamically adjusts the active current recovery rate via phase control of the VSC-HVDC bus.The remaining capacity is allocated to reactive current support,thereby enhancing voltage and synchronization stability while maintaining sufficient short-circuit current margin and system frequency stability.Finally,simulations conducted on the PSS/E platform,using actual grid data from a selected cross-section system,validate convincingly the effectiveness of the proposed parameter optimization strategy for VSC-HVDC low-voltage ride-through.展开更多
Transcranial direct current stimulation(tDCS)is a non-invasive technique that modifies cortical excitability and induces neuroplasticity using low-intensity electrical currents.Nuclear medicine technologies like posit...Transcranial direct current stimulation(tDCS)is a non-invasive technique that modifies cortical excitability and induces neuroplasticity using low-intensity electrical currents.Nuclear medicine technologies like positron emission tomography(PET)and single-photon emission computed tomography(SPECT)can quantify cerebral metabolism and other dynamics.Evidence suggests that combining tDCS with these imaging methods enhances understanding and outcomes for neurological and psychiatric conditions.This review highlights how nuclear medicine can objectively characterize tDCS eff ects,map network modulation,and identify predictive biomarkers.PET and SPECT indicate changes in glucose metabolism and neurotransmitter activity post-tDCS,demonstrating their value in validation.While the co-application of these methodologies is still in conceptual stages,their integration may advance precision neuromodulation and inform rehabilitation strategies.展开更多
To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electric...To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.展开更多
Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potentia...Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise.展开更多
文摘With the advent of the big data era,modern statistics has enjoyed unprecedented development opportunities and also faced numerous new challenges.Traditional statistical computing methods are often limited by issues such as computer memory capacity and distributed storage of data across different locations,and are unable to directly apply to large-scale data sets.Therefore,in the context of big data,designing efficient and theoretically guaranteed statistical learning and inference algorithms has become a key issue that the current field of statistics urgently needs to address.In this paper,the application status of statistical analysis methods in the big data environment was systematically reviewed,and its future development directions were analyzed to provide reference and support for the further development of theory and methods of the statistical analysis of big data.
基金Sponsored by Research Team Project of Anhui Xinhua University(kytd202202)Anhui Provincial College Student Innovation Training Program Support Project(S202212216138,S202212216133,S202212216147)+1 种基金National College Student Innovation Training Program Support Project(AH202112216114)Key Project for Scientific Research in Anhui Higher Education Institutions(Natural Sciences Category)(2024AH050601).
文摘With the accelerating urbanization process,issues related to the urban ecological environment have become increasingly prominent.Among these,greenway optimization is regarded as one of the key approaches to improving urban ecological quality.As the capital of Anhui Province,Hefei is striving to build a comprehensive greenway network in line with its“Park City”strategy.However,the current development of Hefei’s greenways faces challenges such as delayed planning,limited functions,inadequate facilities,and weak operation and maintenance management.In this study,comparative analysis and literature review were combined to comprehensively summarize the current characteristics of greenway development in Hefei,and improvement suggestions were proposed in areas such as ecological restoration,functional expansion,facility establishment,and long-term management.It is suggested that Hefei should enhance the systematic and synergistic nature of its greenway system,create a city green space network with regional characteristics,and optimize the city’s environmental carrying capacity,so as to meet the diverse needs of the public and thereby provide theoretical support and practical guidance for the sustainable development of Hefei’s greenway system.
文摘With the accelerating pace of population aging in China,various issues related to elderly care have emerged one after another,becoming a severe social problem.Especially against the backdrop of increasing economic pressure,the traditional family-based elderly care model is facing significant challenges and can hardly meet the elderly care needs.At present,the geriatric nursing models are relatively backward,which directly affects the quality of daily life,physical health and mental well-being of the elderly.Therefore,it is necessary to explore an appropriate geriatric nursing model to address the aging problem.Based on this,this paper analyzes and studies the current situation of geriatric nursing models under the background of healthy aging,providing references for relevant research and practice.
文摘With the increase of global climate change and extreme weather events,more and more attention has been paid to the protection of China's meteorological cultural heritage.Meteorological cultural heritage is an important part of China's cultural heritage,which is unique and non renewable.It is of great significance to the inheritance of China's excellent traditional culture and the construction of a meteorological power.Because it is more special than water conservancy cultural heritage in China's historical development,it is not only a national context,but also mixed with foreign activities.This paper focuses on the protection and research of China's meteorological cultural heritage.Based on the current situation of the protection and utilization of China's meteorological cultural heritage,it analyzes the problems and shortcomings in the current protection work.In response to these problems,some targeted protection measures are proposed,including strengthening the construction of laws and regulations,improving the level of protection technology,enhancing public participation,and promoting the protection and sustainable development of meteorological cultural heritage.The aim is to provide useful references for the protection of China's meteorological cultural heritage in the future.
基金SZPU Quality Engineering Project University-level Teaching and Research Project(2025-29),Exploration and Practice of Professional Degree Cultivation and Joint Graduate Training in Vocational Undergraduate CollegesThe Young Backbone Teacher Plan of Beijing Information Science and Technology University(Project No.:YBT202448)+1 种基金Industry-University Cooperation Education Project of the Ministry of Education,Research on the Application of Model-Based Viewpoint Selection in UAV 3D Modeling Course Teaching(Project No.:1007-7025210681J1)Research on the Path of Promoting the Reform of Scientific Research Evaluation in Vocational Undergraduate University(Project No.:GDKG2025ZC1)。
文摘This article takes the joint training model as the research object and focuses on the joint postgraduate training in vocational universities.Based on a brief overview of the connotation and significance of joint postgraduate training in vocational universities,a systematic summary of the current situation of such training is conducted through practical research.While elaborating on the implementation and characteristics of joint postgraduate training in vocational universities,the article emphasizes a systematic collection and analysis of existing problems.Finally,guided by these problems and considering the characteristics and issues of joint postgraduate training in vocational universities,several improvement strategies are proposed.It is emphasized that vocational universities need to actively optimize their management models,establish restraint mechanisms,and implement dynamic adjustments to achieve scientific management of joint postgraduate training.This approach aims to promote academic innovation and improve training quality simultaneously.
文摘The digital economy has injected continuous momentum into the development of urban economy and plays a positive and important role in the transformation and upgrading of urban energy consumption.Specifically,the digital economy can significantly improve the efficiency of urban energy consumption by virtue of its distinctive characteristics of low pollution and high efficiency.Moreover,empowered by the digital economy,the pace of transformation and upgrading of high-pollution traditional industries has been accelerated.Particularly importantly,the urban energy consumption structure has been optimized and adjusted through the indirect role of intermediate factors.From this perspective,studying the current situation and countermeasures of urban energy consumption under the digital economy holds important practical significance both in theory and practice.This paper first briefly summarizes the relevant literature on the impact of the digital economy on the energy consumption structure;then,it focuses on detailed data to explore the current situation of urban energy consumption under the digital economy model;finally,based on the summary of the current situation,it puts forward practical and feasible suggestions,hoping to provide a decision-making basis for the implementation of policies in different types of cities and offer innovative ideas for promoting the high-quality development of urban energy systems.
文摘Objective To analyze the current situation of drug shortage in some western countries and their management strategies,and to put forward feasible suggestions for drug shortage management in China.Methods The methods of literature research and comparative study were used to collect policy information and related data from official government websites and news websites,then,the current situation and management of drug shortage in some western countries were compared and studied to summarize their effective experience in dealing with drug shortage.Results and Conclusion The current situation and influencing factors of drug shortage in these western countries are different,but the management system established to deal with drug shortage is good,including the support of policies and regulations,the early warning of monitoring platform and the construction of organizational system.Drawing lessons from their experience,China should strengthen cooperation and consultation among stakeholders and rationally allocate powers and responsibilities.The transparency of drug shortage data disclosure should be increased.The important role of pharmacists should be played to strengthen the management.Further optimizing the drug shortage management system in China can ensure the safety of drug supply.
基金Key Project of Education Science Planning in Jiangsu Province in 2024“Research on Risk Generation and Governance of Education Intelligence from the Perspective of Social Narrative”(B-b/2024/01/192)。
文摘With the development of the international education environment and the continuous reform of higher education in China,the working pace in universities is accelerating,with higher requirements for university work and increasingly apparent pressure on teachers.Young teachers in Chinese universities are prone to occupational stress.In addition to undertaking teaching,research,and other tasks,they feel anxious and at a loss when facing personal issues such as job promotion and taking care of their families.This article selects young teachers from some universities in China as research subjects and uses a questionnaire survey method to understand the current situation and sources of pressure on young teachers in universities,so as to focus on and alleviate their stress in a targeted manner.
基金Supported by Special Fund for National Modern Agricultural Industry Technology System Construction(CARS-04-CES16).
文摘As one of the world's three major food crops and an important economic and oil crop,soybean plays a crucial role in ensuring food safety.In recent years,there are many problems in soybean cultivation,production and processing.In view of this situation,this paper comprehensively expounded and decomposed the cultivation situation,existing problems,specific countermeasures and conclusions,so as to re-recognize them.This study provides reference materials for the sustainable and healthy development of the soybean industry.
文摘The establishment of Hainan Free Trade Port provides a new opportunity for the financing of small and medium-sized enterprises.In the process of the country continuously promoting the development of a free trade port,the financing environment of small and medium-sized enterprises has gradually improved,and the financing environment has been greatly improved.But the small and medium-sized enterprises“financing difficult”“financing expensive”problem still exists.The problems of difficult and expensive financing of small and medium-sized enterprises in Haikou city have their reasons as well as the influence of external environmental factors.Therefore,to better solve the financing problems of small and medium-sized enterprises in Haikou,this paper analyzes the reasons for the difficulty and expensive financing of small and medium-sized enterprises according to the existing research results and summarizes the financing experience of small and medium-sized enterprises at home and abroad.This article finds that the financing systems for small and medium-sized enterprises(SMEs)in developed countries are relatively well-established,and both the government and society offer significant support to SMEs.Therefore,this paper believes that the government should adjust the business strategy to improve the financing ecological environment and enhance the financing ability of SMEs.The government should take the lead in perfecting the guarantee system,continuously improving the credit information system of enterprises and various financial service institutions,promoting the opening and institutionalization of private credit,and developing Internet finance[1].
基金National Key Research and Development Program of China(2021YFB3700801)。
文摘Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into the new β phase during the pulsed current-assisted aging process,and then the newly formed β phase is mainly transformed into the β_(t) phase,with occasional transition to new α_(p) phase,leading to a remarkable grain refinement,especially for the lamellarαs phases.In comparison to conventional aging treatment,the pulsed current-assisted aging approach achieves a significant enhancement in strength without degrading ductility,yielding an excellent mechanical property combination:a yield strength of 932 MPa,a tensile strength of 1042 MPa,and an elongation of 12.2%.It is primarily ascribed to the increased fraction of β_(t) phases,the obvious grain refinement effect,and the slip block effect induced by the multiple-variantαs colonies distributed within β_(t) phases.
基金Supported by the Fundamental Research Funds for the Central Universities(2024ZYGXZR047)the National Natural Science Foundation of China(62373156)the Guangdong Basic and Applied Basic Research Foundation(2024A1515011736)。
文摘This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper constructs an internal model to learn the information of the states and input of the grid-connected inverter under steady state.Second,by utilizing the internal model principle,the paper turns the tracking control problem into the robust stabilization control problem based on some appropriate coordinate transformations.Then,The paper designs a dynamics state feedback control law to deal with this robust stabilization problem,and thus the solution of the robust current tracking control problem of three-phase grid-connected inverters can be obtained.This control method can ensure the asymptotic stability of the closedloop system.Finally,the paper illustrates the effectiveness of the proposed control approach through several groups of simulations,and compares it with the feedforward control method to verify the robustness of the proposed control method to uncertain parameters.
基金supported by the Korea Institute of Police Technology(No.:RS-2024-00405603).
文摘Autonomous vehicles operate without direct human intervention,which introduces safety risks that differ from those of conventional vehicles.Although many studies have examined safety issues related to autonomous driving,high-risk situations have often been defined using single indicators,making it difficult to capture the complex and evolving nature of accident risk.To address this limitation,this study proposes a structured framework for defining and analyzing high-risk situations throughout the traffic accident process.High-risk situations are described using three complementary indicators:accident likelihood,accident severity,and accident duration.These indicators explain how risk emerges,increases,and persists over time.Based on this concept,a framework for traffic accident visualization analysis is developed to support phase-specific risk assessment and visualization.The framework combines accident-phase information with factor-level risk contributions,allowing systematic identification of key factors and their interactions across different accident stages.Using combinations of the three indicators,high-risk situations are classified into twenty-seven distinct types,providing a clear typology for complex accident scenarios involving autonomous vehicles.The applicability of the proposed framework is demonstrated through two representative accident scenarioswith different risk characteristics.The results showthat the framework effectively captures interactions among multiple risk factors,explains how risk levels change from pre-crash to post-crash phases,and identifies contributing factors that are difficult to detect using conventional traffic accident investigation methods.Overall,the proposed framework offers a practical basis for autonomous vehicle accident analysis,safety evaluation,and policy-related decision-making.
基金financial support from the Helmholtz Association and the German Federal Ministry of Education and Research(BMBF)within the ExcellBattUlm project(03XP0257D)the HighSafe-3 project(03XP0568A)。
文摘Energy density and safety are two crucial parameters when evaluating lithium-metal batteries(LMBs).Herein,we present an ultralight polymer-based current collector,incorporating flame-retardant materials,designed specifically for thin lithium-metal anodes.Compared to the traditional copper current collector(8.96 mg cm^(-2),10μm thick),the polymer-based current collector(12μm thick)has a significantly lower areal density of 1.41 mg cm^(-2),i.e.,only one-sixth of the copper collector,thus enabling substantially higher energy densities.Accordingly,when employed in Li||NMC_(622)full-cells,the polymer-based current collector enables a specific energy of 449 Wh kg^(-1),representing a notable improvement of about14.5%compared to cells employing a classic copper current collector.The inclusion of Al(OH)_(3) as a flame retardant into the current collector suppresses flammability and,thereby,significantly improves the safety of the resulting LMBs.
基金supported by the National Natural Science Foundation of China under Grant 52277184 and Grant 52277183.
文摘The transient synchronization stability of grid-forming converters(GFMCs)is significantly challenged under grid voltage sags.Continuous efforts have been devoted to analyzing the GFMC transient stability,with limited attention paid to the impacts of control loop dynamics.However,the complex control dynamics,especially the interactions between the active/reactive power control loops and the current saturation process(CSP),are crucial for accurately describing the transient behavior and evaluating the stability.Thus,in this study,a new large-signal GFMC model is established,considering the reactive power control(RPC)with different kinds of controllers and the CSP simultaneously.It is revealed that GFMC does not switch to the current-limited mode immediately,and the dynamics of RPC further affect the transient behavior before the current limiting significantly.Hence,the complex control dynamics can alter the mode switching point of current saturation,thereby increasing the risk of loss of synchronization(LOS).Based on the above findings,comprehensive comparisons of typical RPC controllers are presented to facilitate practical engineering applications.A unified stability enhancement method is proposed for solving the problem of LOS.Finally,experiments validate the correctness of the analysis and the effectiveness of the proposed control strategy.
基金supported by the National Natural Science Foundation of China(grant numbers 52071225,22179143,and 22002176)the European Union’s Horizon Europe research and innovation program Electron Beam Emergent Additive Manufacturing(EBEAM)(grant number 101087143)+2 种基金a Norway Grant through the National Science Centre(project number 2019/34/H/ST8/00547)the National Key R&D Program of China(grant number 2021YFB3800300)the Jiangsu Funding Program for Excellent Postdoctoral Talent。
文摘Lithium metal batteries(LMBs)are promising candidates for next-generation high-energy-density storage devices.However,an unstable lithium metal anode poses significant issues that critically compromise battery safety and cycle life,including lithium dendrite formation,solid electrolyte interphase degradation,dead lithium accumulation,and substantial volume fluctuations during cycling.These problems can be addressed by regulating lithium deposition and suppressing side reactions through the modification of copper current collectors using three classes of materials:metal and metal oxide,carbon,and polymer materials.This review comprehensively examines recent advances in the application of these materials as current collector coatings.Particularly,their distinct roles in the lithium deposition process are analyzed to understand how they mitigate the issues associated with the lithium metal anode.Furthermore,their inherent limitations are considered to inform future research directions.While each class of materials offers specific advantages,multifunctionality is required to effectively regulate lithium deposition.In prospect,a novel composite copper current collector design that integrates the merits of the aforementioned advanced materials is proposed.The insights from this review provide valuable guidance for the rational design of modified copper current collectors,which would significantly improve the safety and cycle life of LMBs and advance their commercialization.
基金funded by State Grid Corporation of China,grant number DQ30DK24001L。
文摘When the converter bus voltage of a voltage source converter-based high voltage direct current(VSC-HVDC)system drops below a certain predetermined threshold,the system enters low-voltage ride-through(LVRT)mode to avoid overcurrent and potential equipment failure,during which it operates as a controlled current source.The influence mechanism of LVRT control strategies on short-circuit current and overall system stability remains not yet fully and systematically investigated.First,this paper provides an overview of several LVRT strategies for VSC-HVDC systems and examines their effects on short-circuit current contribution.Next,it analyzes in detail the mechanisms through which active and reactive currents injected during LVRT impact system frequency stability,voltage stability,and synchronization stability.To address these interrelated issues,an optimized and comprehensive LVRT strategy incorporating short-circuit current constraints is proposed.The approach determines the active current ratio based on system frequency stability requirements and dynamically adjusts the active current recovery rate via phase control of the VSC-HVDC bus.The remaining capacity is allocated to reactive current support,thereby enhancing voltage and synchronization stability while maintaining sufficient short-circuit current margin and system frequency stability.Finally,simulations conducted on the PSS/E platform,using actual grid data from a selected cross-section system,validate convincingly the effectiveness of the proposed parameter optimization strategy for VSC-HVDC low-voltage ride-through.
文摘Transcranial direct current stimulation(tDCS)is a non-invasive technique that modifies cortical excitability and induces neuroplasticity using low-intensity electrical currents.Nuclear medicine technologies like positron emission tomography(PET)and single-photon emission computed tomography(SPECT)can quantify cerebral metabolism and other dynamics.Evidence suggests that combining tDCS with these imaging methods enhances understanding and outcomes for neurological and psychiatric conditions.This review highlights how nuclear medicine can objectively characterize tDCS eff ects,map network modulation,and identify predictive biomarkers.PET and SPECT indicate changes in glucose metabolism and neurotransmitter activity post-tDCS,demonstrating their value in validation.While the co-application of these methodologies is still in conceptual stages,their integration may advance precision neuromodulation and inform rehabilitation strategies.
基金supported by Natural Science Foundation of Wuhan(2024040701010051)Natural Science Foundation of Hubei(2023AFB111)and National Natural Science Foundation of China(52401108).
文摘To elucidate the accelerated degradation mechanisms of metallic interconnects in operational solid oxide fuel cells,the oxidation behavior of FSS430 ferritic stainless steel under the coupling of simultaneous electrical current and high-temperature exposure is investigated.Isothermal thermogravimetric analysis was employed to quantify oxidation kinetics,complemented by microstructural characterization using X-ray diffraction,scanning electron microscopy with energy-dispersive spectroscopy and transmission electron microscopy.Experimental results demonstrate that the applied current dramatically enhances oxidation rates,increasing specific mass gain from 0.25 mg/cm^(2)(0 A/cm^(2))to 5.20 mg/cm^(2)(0.2 A/cm^(2))and oxide scale thickness from 1.87 to 15.62μm after 200 h.This acceleration originates from current-induced electromigration forces that promote cationic transport through the oxide layer.The quantitative relationships between current density and oxidation parameters are established,enabling predictive modeling of interconnector degradation in solid oxide fuel cell(SOFC)systems.
文摘Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise.
