For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol ...For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol is proposed,which contains two components associated with the communication interactions between the leader and tracking intelligent agents and the communication interactions among tracking intelligent agents,respectively,and the aperiodic silence,the topology switching and the energy constraint index is introduced properly.Then,a two-step transformation method is presented to separate the whole dynamics of a networked system into the relative dynamics between the leader and tracking intelligent agents and the dynamics of the leader,and sufficient conditions for limited-energy output formation tracking for networked systems with limited energy and aperiodic silence are presented,which are extended into networked systems without the aperiodic silence.Especially,a partition checking algorithm is presented to check limitedenergy output formation tracking design criteria.Finally,a numerical example is illustrated to demonstrate the validness of theoretical results.展开更多
The State Science and Technology Commission, State Economic and Trade Commission, and State Planning Commission of China have jointly worked out the Program for the Development of Chinese New and Renewable Energy rece...The State Science and Technology Commission, State Economic and Trade Commission, and State Planning Commission of China have jointly worked out the Program for the Development of Chinese New and Renewable Energy recently.展开更多
Securing a drastic transformation from weakness to strength, China has climbed a rugged path over the past 70 years thanks to the nation’s spirit of constant selfimprovement through hard work. Starting with the Opium...Securing a drastic transformation from weakness to strength, China has climbed a rugged path over the past 70 years thanks to the nation’s spirit of constant selfimprovement through hard work. Starting with the Opium Wars in the mid-19th Century, the Chinese people endured more than a century of struggles to save the country until the People’s Republic of China was founded in 1949, finally making the people masters of their own destinies.展开更多
To address the issues of short setting time and high bleeding rate of A component,which easily cause pipe plugging and poor grouting performance when a two-component grout is injected synchronously behind the Segmenta...To address the issues of short setting time and high bleeding rate of A component,which easily cause pipe plugging and poor grouting performance when a two-component grout is injected synchronously behind the Segmental Lining,the inorganic retarder sodium pyrophosphate(TSPP)and three organic retarders were added to the A component:sodium citrate(SC),sodium tartrate(ST)and glycerol(GLY).The effect law and microscopic mechanism of viscosity,bleeding rate,setting time,gelling time,compressive strength,and stone rate were investigated.The results revealed that the addition of retarders could enhance the stability and setting time of the A component and increase the gelling time,stone rate,and compressive strength of two-component grout.Among them,the performance of the grout with an SC dosage of 0.1% was superior.The bleeding rate of this grout was reduced to 3.5%,the stone rate of the two-component grout was more than 99%,and the early compressive strength and late compressive strength of this grout were increased by approximately 35% and 7%,respectively.The initial and final setting time of the A component with a TSPP dosage of 0.3% was the longest,which was prolonged to 17 and 26 h,respectively.Microscopic analysis revealed that the four retarders hindered the hydration process of cement through complexation and adsorption,and inhibited the hydration of C_(3)S and the crystallisation of CH.Moreover,they reduced the defects caused by the rapid reaction of water glass and CH on the solid phase structure,enabled the microstructure of the stone body to be denser,and subsequently,enhanced the compressive strength.展开更多
BACKGROUND There has been an increasing focus in recent years on health-care disparities.Studies investigating return to work(RTW)or sports are often performed in large,urban areas.Relatively few studies have investig...BACKGROUND There has been an increasing focus in recent years on health-care disparities.Studies investigating return to work(RTW)or sports are often performed in large,urban areas.Relatively few studies have investigated rates of return to farming or other heavy labor that is of interest to patients in rural areas.AIM To evaluate the literature regarding RTW in farming or heavy labor after orthopedic hip,knee,or shoulder surgery.METHODS A search was performed in the PubMed and EMBASE databases using Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.Studies were included if they reported patients employed in farming or heavy labor,RTW rates after orthopedic surgery of the hip,knee,or shoulder,and had a minimum 6-month follow-up.A meta-analysis of proportions using a random-effects model was performed on three single-arm observational studies to estimate the pooled RTW rate following arthroscopic shoulder surgery.RESULTS Ten studies were included,and 101 farmers were identified among 440 total patients.One study involved hip surgery,two studies involved knee surgery,and seven studies involved shoulder surgery.RTW rates across studies varied by type of surgery and follow-up interval,ranging from 24%to 100%.The RTW rate was only 53.6%at 1 year following total hip arthroplasty.No studies investigated RTW in farmers following total knee arthroplasty.Among non-comparative studies,meta-analysis revealed a pooled RTW rate of 89%following arthroscopic shoulder surgery,with low heterogeneity(I^(2)=30.1%).Among comparative studies,one study reported significantly higher RTW odds for patients undergoing anatomic total shoulder arthroplasty compared to reverse shoulder arthroplasty(odds ratio=5.45).Overall,surgical intervention for shoulder pathology was associated with a high likelihood of RTW across multiple techniques,with particularly favorable outcomes for anatomic total shoulder arthroplasty.CONCLUSION This systematic review highlights the high rates of RTW in farmers and heavy laborers after shoulder surgery.However,our findings also underscore the need for more rural-specific research to guide patient counseling,rehabilitation expectations,and shared decision-making in this underserved population,particularly for orthopedic surgery of the hip and knee.展开更多
The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials off...The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials.展开更多
China 2009 World Philatelic Exhibition (‘China 2009’) Executive Committee sent its delegation to Geneva, Switzerland aiming for better results in invitation and publicity work,26 to 31, July,2008,when the Universal ...China 2009 World Philatelic Exhibition (‘China 2009’) Executive Committee sent its delegation to Geneva, Switzerland aiming for better results in invitation and publicity work,26 to 31, July,2008,when the Universal Postal Union Congress was underway,the delegation made an vivid introduction to‘China 2009’and the Host City Luo Yang.展开更多
Objective Systematically integrate nurses’experience with“Internet Nursing Service”to analysis the nurses’experiences with“Internet Nursing Service”,and to provide a theoretical reference for formulating a more ...Objective Systematically integrate nurses’experience with“Internet Nursing Service”to analysis the nurses’experiences with“Internet Nursing Service”,and to provide a theoretical reference for formulating a more rational“Internet Nursing Service”model.Methods A systematic search in PubMed,Embase,Web of Science,the Cochrane Library,CINAHL,China National Knowledge Infrastructure(CNKI),Wanfang Database,and Chinese Biomedical Literature Database was conducted to collect qualitative research on nurses’experiences with“Internet Nursing Service,”with a retrieval time limit from December 2019 to June 2024.Qualitative meta-synthesis was performed through line-by-line coding of relevant quotes,organization of codes into descriptive themes,and development of analytical themes.Results A total of 19 studies were included,one study was rated as Grade A in quality evaluation,and the remaining studies were rated as Grade B.Collectively synthesized into three integrated results:Harvest and growth,Difficulties and challenges,and Expectations and support.Harvest and growth,include 1)manifestation of self-value,2)enhancing nursing capabilities,3)optimizing nursing resources;Difficulties and challenges,include 1)lack of safety guarantee,2)role conflict;Expectations and support include,1)expectation for professional knowledge and skill training,2)expectations for service platform optimization,3)expectation for reasonable charges,4)expectation for related policy support.Conclusion“Internet Nursing Service”model benefits both nurses and patients,but still full of challenges.It aids in the decentralization of medical resources.Management departments still need to encourage nurses to actively invest in“Internet Nursing Service”while ensuring their safety and interests.展开更多
Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction(HER)but the effect of the crystal phase engineering of supports on their performance remains unclear.Here,the impact o...Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction(HER)but the effect of the crystal phase engineering of supports on their performance remains unclear.Here,the impact of the crystal phase of the support on the catalytic activity of Ru was probed by anchoring Ru nanoparticles onto precisely synthesized hexagonal(WO_(3)-H),orthorhombic(WO_(3)-O),and monoclinic(WO_(3)-M)supports followed by thorough evaluation for HER.Among them,WO_(3)-H demonstrated superior performance by providing enhanced Ru anchoring and uniform dispersion,maximizing active site availability.A critical finding is the small work function difference(ΔW_(F))between Ru and WO_(3)-H,which minimizes interfacial charge accumulation and facilitates efficient hydrogen spillover,thereby accelerating HER kinetics.In contrast,WO_(3)-O and WO_(3)-M exhibited largerΔW_(F)and less effective Ru dispersion,resulting in a larger hydrogen spillover barrier and suboptimal hydrogen adsorption/desorption dynamics.As a result,Ru/WO_(3)-H exhibited the best performance,achieving an overpotential of 43.8 mV at 10 mA cm^(-2)and a Tafel slope of 49.1 mV dec^(-1).This work highlights the critical role of the crystal phase in optimizing the intrinsic catalytic activity of catalysts,offering new insights for designing efficient HER catalysts.展开更多
Objectives:Teachers are facing unprecedented new challenges leading them to face an increasing number of tasks that are not part of their job,as well as having to cope with the additional skills acquisition that comes...Objectives:Teachers are facing unprecedented new challenges leading them to face an increasing number of tasks that are not part of their job,as well as having to cope with the additional skills acquisition that comes with non-traditional forms of teaching and learning,and increased work pressure leading to an increase in the rate of teachers leaving the profession.Therefore,this study aims to explore the mechanism of the career calling on job burnout through career adaptability and work engagement.Methods:This study conducted a cross-sectional survey of 465 primary and secondary school teachers(PSST)in China's Mainland from the perspective of work adjustment and used structural equation modeling(SEM)to examine the mediating roles of career adaptability and work engagement in the relationship between teachers’career calling and job burnout.Results:The results show that PSSTs are above average in career calling,career adaptability,and work engagement,while job burnout is below average.A significant positive or negative correlation exists between career calling,career adaptability,work engagement,and job burnout.The result of path analysis indicates that career adaptability and work engagement exert an indirect influence on the job burnout of PSST through three paths:namely,the independent intermediary role of career adaptability(EV=−0.144),the independent intermediary role of work engagement(EV=0.172)and the chain intermediary role of the two(EV=0.176).Conclusion:This study emphasizes the importance of career adaptability and work engagement in teacher development in regulating career calling and job burnout.Therefore,on the one hand,we think that if managers want to reduce teachers’job burnout,they need to pay more attention to teachers’career adaptability and work engagement,rather than relying solely on teachers’career calling.On the other hand,it is to remind teachers not to rely on their adjustment to adapt to the work,but also to need outside help as much as possible.展开更多
Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomer...Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomers(p-phenylenediamine(Pa),benzidine(BD),and 4,4"-diamino-p-terphenyl(DATP))were used to synthesize a series of two-dimensional covalent-organic frameworks(COFs).The resulting COFs were named TpPa,TpBD,and TpDATP,respectively,and they showed uniform zincophilic sites,different pore sizes,and high Young's moduli on the Zn anode.Among them,TpPa and TpBD showed lower surface work functions and higher ion transfer numbers,which were conducive to uniform galvanizing/stripping zinc and inhibited dendrite growth.Theoretical calculations showed that TpPa and TpBD had wider negative potential region and greater adsorption capacity for Zn2+than TpDATP,providing more electron donor sites to coordinate with Zn^(2+).Symmetric cells protected by TpPa and TpBD stably cycled for more than 2300 h,whereas TpDATP@Zn and the bare zinc symmetric cells failed after around 150 and200 h.The full cells containing TpPa and TpBD modification layers also showed excellent cycling capacity at 1 A/g.This study provides comprehensive insights into the construction of highly reversible Zn anodes via COF modification layers for advanced rechargeable ZIBs.展开更多
Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid ...Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid route and the solid-solid route.However,the formation of DCN structures in steel requires long processes and complex steps.So far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain unavoidable.Here,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field.Ti-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 s.These small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel matrix.Our findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.展开更多
Carbon can change the phase components of low-density steels and influence the mechanical properties.In this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization tre...Carbon can change the phase components of low-density steels and influence the mechanical properties.In this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was proposed.The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined.Crussard-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile test.During decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual phase.Meanwhile,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the same.In addition,the formation of other carbides restrained.Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution.For the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of microbands.For the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in ferrite.At the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.展开更多
In this paper,the work hardening and softening behavior of AZ31 magnesium alloy sheets by hard plate accumulative roll bonding(HP-ARB)process in a specific temperature range was studied for the first time,and the cycl...In this paper,the work hardening and softening behavior of AZ31 magnesium alloy sheets by hard plate accumulative roll bonding(HP-ARB)process in a specific temperature range was studied for the first time,and the cyclic stress relaxation test,EBSD,TEM and other characterization methods were used.When the rolling temperature is 350℃,the grain size of magnesium sheets is refined to 4.32(±0.36)μm on average,and it shows an excellent combination of strength and plasticity.The tensile strength reaches 307(±8.52)MPa and the elongation is 12.73(±0.84)%.At this time,the curve of work hardening rate decreases smoothly and the degree of hardening is the lowest,and the amplitude of stress drop △σ_(p) in work softening test is the smallest with the increase of cycle times,which shows that the well coordination between work hardening and softening behavior has been achieved.Research has found that the combined effect of grain boundary strengthening and fine grain strengthening enhances the yield and tensile strength of magnesium sheets after three passes HP-ARB process at 350℃.This is attributed to the high degree of dislocation slip opening in the pyramidal surfaceand<c+a>,which not only coordinates the c-axis strain of the entire grain,but also promotes the slip transfer of dislocations in the fine-grained region,significantly improving the elongation of the sheets.This study provides a new idea for the forming and manufacturing of high performance magnesium alloy sheets.展开更多
To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s ...To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s aspect ratio on the microstructure,mechanical properties,work hardening and softening behaviors of Ti_(p)/Mg-5Zn-0.3Ca composites was investigated.The results indicated that the Ti_(p)could be elongated obviously after low-temperature extrusion,and the aspect ratio of which would reach to 13.7:1 as the extrusion temperature deceased to 140℃.Then the“Ti/Mg”layer-like structure was formed in the Ti_(p)/Mg-5Zn-0.3Ca composite.Accompanied with the elongation of Ti_(p),the dynamic recrystallized grains and dynamic precipitates were both refined significantly,however,the dynamic recrystallization rate changed a little.The elongated Ti_(p)endowed the Ti_(p)/Mg-5Zn-0.3Ca composites with better matching of strength and toughness without the sacrifice of elongation and bending strain.Both the work hardening rate and softening rate of Ti_(p)/Mg-5Zn-0.3Ca composites increased with the increasing aspect ratio of Ti_(p).The formation of“Ti/Mg”layer-like structure contributed to the redistribution of strain from large aggregations to a network-like distribution,which effectively suppresses the initiation and propagation of micro-cracks,thus enhancing the plasticity of the Ti_(p)/Mg-5Zn-0.3Ca composites.展开更多
基金supported by the National Natural Science Foundation of China(Nos.62176263,62103434,62003363,61867005,61703411)the Science and Technology Nova Plan of Beijing,China(No.Z201100006820122)+4 种基金the Shaanxi Natural Science Foundation for Distinguished Young Scholars,China(No.2021JC-35)the Shaanxi Natural Science Foundation for Youths,China(No.2021JQ-375)China Postdoctoral Science Special Foundation(No.2021T140790)China Postdoctoral Research Foundation of China(No.271004)the Gansu Provincial First-Class Discipline Program of Northwest Minzu University,China(No.11080305)。
文摘For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol is proposed,which contains two components associated with the communication interactions between the leader and tracking intelligent agents and the communication interactions among tracking intelligent agents,respectively,and the aperiodic silence,the topology switching and the energy constraint index is introduced properly.Then,a two-step transformation method is presented to separate the whole dynamics of a networked system into the relative dynamics between the leader and tracking intelligent agents and the dynamics of the leader,and sufficient conditions for limited-energy output formation tracking for networked systems with limited energy and aperiodic silence are presented,which are extended into networked systems without the aperiodic silence.Especially,a partition checking algorithm is presented to check limitedenergy output formation tracking design criteria.Finally,a numerical example is illustrated to demonstrate the validness of theoretical results.
文摘The State Science and Technology Commission, State Economic and Trade Commission, and State Planning Commission of China have jointly worked out the Program for the Development of Chinese New and Renewable Energy recently.
文摘Securing a drastic transformation from weakness to strength, China has climbed a rugged path over the past 70 years thanks to the nation’s spirit of constant selfimprovement through hard work. Starting with the Opium Wars in the mid-19th Century, the Chinese people endured more than a century of struggles to save the country until the People’s Republic of China was founded in 1949, finally making the people masters of their own destinies.
基金Funded by the National Natural Science Foundation of China(No.52378394)the Fundamental Research Funds for the Central Universities(No.B230201037)。
文摘To address the issues of short setting time and high bleeding rate of A component,which easily cause pipe plugging and poor grouting performance when a two-component grout is injected synchronously behind the Segmental Lining,the inorganic retarder sodium pyrophosphate(TSPP)and three organic retarders were added to the A component:sodium citrate(SC),sodium tartrate(ST)and glycerol(GLY).The effect law and microscopic mechanism of viscosity,bleeding rate,setting time,gelling time,compressive strength,and stone rate were investigated.The results revealed that the addition of retarders could enhance the stability and setting time of the A component and increase the gelling time,stone rate,and compressive strength of two-component grout.Among them,the performance of the grout with an SC dosage of 0.1% was superior.The bleeding rate of this grout was reduced to 3.5%,the stone rate of the two-component grout was more than 99%,and the early compressive strength and late compressive strength of this grout were increased by approximately 35% and 7%,respectively.The initial and final setting time of the A component with a TSPP dosage of 0.3% was the longest,which was prolonged to 17 and 26 h,respectively.Microscopic analysis revealed that the four retarders hindered the hydration process of cement through complexation and adsorption,and inhibited the hydration of C_(3)S and the crystallisation of CH.Moreover,they reduced the defects caused by the rapid reaction of water glass and CH on the solid phase structure,enabled the microstructure of the stone body to be denser,and subsequently,enhanced the compressive strength.
文摘BACKGROUND There has been an increasing focus in recent years on health-care disparities.Studies investigating return to work(RTW)or sports are often performed in large,urban areas.Relatively few studies have investigated rates of return to farming or other heavy labor that is of interest to patients in rural areas.AIM To evaluate the literature regarding RTW in farming or heavy labor after orthopedic hip,knee,or shoulder surgery.METHODS A search was performed in the PubMed and EMBASE databases using Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.Studies were included if they reported patients employed in farming or heavy labor,RTW rates after orthopedic surgery of the hip,knee,or shoulder,and had a minimum 6-month follow-up.A meta-analysis of proportions using a random-effects model was performed on three single-arm observational studies to estimate the pooled RTW rate following arthroscopic shoulder surgery.RESULTS Ten studies were included,and 101 farmers were identified among 440 total patients.One study involved hip surgery,two studies involved knee surgery,and seven studies involved shoulder surgery.RTW rates across studies varied by type of surgery and follow-up interval,ranging from 24%to 100%.The RTW rate was only 53.6%at 1 year following total hip arthroplasty.No studies investigated RTW in farmers following total knee arthroplasty.Among non-comparative studies,meta-analysis revealed a pooled RTW rate of 89%following arthroscopic shoulder surgery,with low heterogeneity(I^(2)=30.1%).Among comparative studies,one study reported significantly higher RTW odds for patients undergoing anatomic total shoulder arthroplasty compared to reverse shoulder arthroplasty(odds ratio=5.45).Overall,surgical intervention for shoulder pathology was associated with a high likelihood of RTW across multiple techniques,with particularly favorable outcomes for anatomic total shoulder arthroplasty.CONCLUSION This systematic review highlights the high rates of RTW in farmers and heavy laborers after shoulder surgery.However,our findings also underscore the need for more rural-specific research to guide patient counseling,rehabilitation expectations,and shared decision-making in this underserved population,particularly for orthopedic surgery of the hip and knee.
基金supported by the IITP(Institute of Information & Communications Technology Planning & Evaluation)-ITRC(Information Technology Research Center) grant funded by the Korea government(Ministry of Science and ICT) (IITP-2025-RS-2024-00437191, and RS-2025-02303505)partly supported by the Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education. (No. 2022R1A6C101A774)the Deanship of Research and Graduate Studies at King Khalid University, Saudi Arabia, through Large Research Project under grant number RGP-2/527/46
文摘The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials.
文摘China 2009 World Philatelic Exhibition (‘China 2009’) Executive Committee sent its delegation to Geneva, Switzerland aiming for better results in invitation and publicity work,26 to 31, July,2008,when the Universal Postal Union Congress was underway,the delegation made an vivid introduction to‘China 2009’and the Host City Luo Yang.
基金supported by the General Project of the Cultivation Project of the Chinese Hospital Reform and Development Research Institute of Nanjing University(NDYG2022072)。
文摘Objective Systematically integrate nurses’experience with“Internet Nursing Service”to analysis the nurses’experiences with“Internet Nursing Service”,and to provide a theoretical reference for formulating a more rational“Internet Nursing Service”model.Methods A systematic search in PubMed,Embase,Web of Science,the Cochrane Library,CINAHL,China National Knowledge Infrastructure(CNKI),Wanfang Database,and Chinese Biomedical Literature Database was conducted to collect qualitative research on nurses’experiences with“Internet Nursing Service,”with a retrieval time limit from December 2019 to June 2024.Qualitative meta-synthesis was performed through line-by-line coding of relevant quotes,organization of codes into descriptive themes,and development of analytical themes.Results A total of 19 studies were included,one study was rated as Grade A in quality evaluation,and the remaining studies were rated as Grade B.Collectively synthesized into three integrated results:Harvest and growth,Difficulties and challenges,and Expectations and support.Harvest and growth,include 1)manifestation of self-value,2)enhancing nursing capabilities,3)optimizing nursing resources;Difficulties and challenges,include 1)lack of safety guarantee,2)role conflict;Expectations and support include,1)expectation for professional knowledge and skill training,2)expectations for service platform optimization,3)expectation for reasonable charges,4)expectation for related policy support.Conclusion“Internet Nursing Service”model benefits both nurses and patients,but still full of challenges.It aids in the decentralization of medical resources.Management departments still need to encourage nurses to actively invest in“Internet Nursing Service”while ensuring their safety and interests.
基金financial support from the National Natural Science Foundation of China(22272148)。
文摘Supported Ru nanoparticles with high utilization are promising for the hydrogen evolution reaction(HER)but the effect of the crystal phase engineering of supports on their performance remains unclear.Here,the impact of the crystal phase of the support on the catalytic activity of Ru was probed by anchoring Ru nanoparticles onto precisely synthesized hexagonal(WO_(3)-H),orthorhombic(WO_(3)-O),and monoclinic(WO_(3)-M)supports followed by thorough evaluation for HER.Among them,WO_(3)-H demonstrated superior performance by providing enhanced Ru anchoring and uniform dispersion,maximizing active site availability.A critical finding is the small work function difference(ΔW_(F))between Ru and WO_(3)-H,which minimizes interfacial charge accumulation and facilitates efficient hydrogen spillover,thereby accelerating HER kinetics.In contrast,WO_(3)-O and WO_(3)-M exhibited largerΔW_(F)and less effective Ru dispersion,resulting in a larger hydrogen spillover barrier and suboptimal hydrogen adsorption/desorption dynamics.As a result,Ru/WO_(3)-H exhibited the best performance,achieving an overpotential of 43.8 mV at 10 mA cm^(-2)and a Tafel slope of 49.1 mV dec^(-1).This work highlights the critical role of the crystal phase in optimizing the intrinsic catalytic activity of catalysts,offering new insights for designing efficient HER catalysts.
基金funded by Humanities and Social Sciences Foundation and Natural Science Foundation of Nanjing University of Posts and Telecommunications(NYY222055,NY224176)General Subject of Educational Science Planning in Jiangsu Province(C/2024/01/76)National Natural Science Foundation of China(62307025).
文摘Objectives:Teachers are facing unprecedented new challenges leading them to face an increasing number of tasks that are not part of their job,as well as having to cope with the additional skills acquisition that comes with non-traditional forms of teaching and learning,and increased work pressure leading to an increase in the rate of teachers leaving the profession.Therefore,this study aims to explore the mechanism of the career calling on job burnout through career adaptability and work engagement.Methods:This study conducted a cross-sectional survey of 465 primary and secondary school teachers(PSST)in China's Mainland from the perspective of work adjustment and used structural equation modeling(SEM)to examine the mediating roles of career adaptability and work engagement in the relationship between teachers’career calling and job burnout.Results:The results show that PSSTs are above average in career calling,career adaptability,and work engagement,while job burnout is below average.A significant positive or negative correlation exists between career calling,career adaptability,work engagement,and job burnout.The result of path analysis indicates that career adaptability and work engagement exert an indirect influence on the job burnout of PSST through three paths:namely,the independent intermediary role of career adaptability(EV=−0.144),the independent intermediary role of work engagement(EV=0.172)and the chain intermediary role of the two(EV=0.176).Conclusion:This study emphasizes the importance of career adaptability and work engagement in teacher development in regulating career calling and job burnout.Therefore,on the one hand,we think that if managers want to reduce teachers’job burnout,they need to pay more attention to teachers’career adaptability and work engagement,rather than relying solely on teachers’career calling.On the other hand,it is to remind teachers not to rely on their adjustment to adapt to the work,but also to need outside help as much as possible.
基金financially supported by the National Natural Science Foundation of China(62464010)Spring City Plan-Special Program for Young Talents(K202005007)+3 种基金Yunnan Talents Support Plan for Yong Talents(XDYC-QNRC-2022-0482)Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)Key Laboratory of Artificial Microstructures in Yunnan Higher EducationFrontier Research Team of Kunming University 2023。
文摘Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomers(p-phenylenediamine(Pa),benzidine(BD),and 4,4"-diamino-p-terphenyl(DATP))were used to synthesize a series of two-dimensional covalent-organic frameworks(COFs).The resulting COFs were named TpPa,TpBD,and TpDATP,respectively,and they showed uniform zincophilic sites,different pore sizes,and high Young's moduli on the Zn anode.Among them,TpPa and TpBD showed lower surface work functions and higher ion transfer numbers,which were conducive to uniform galvanizing/stripping zinc and inhibited dendrite growth.Theoretical calculations showed that TpPa and TpBD had wider negative potential region and greater adsorption capacity for Zn2+than TpDATP,providing more electron donor sites to coordinate with Zn^(2+).Symmetric cells protected by TpPa and TpBD stably cycled for more than 2300 h,whereas TpDATP@Zn and the bare zinc symmetric cells failed after around 150 and200 h.The full cells containing TpPa and TpBD modification layers also showed excellent cycling capacity at 1 A/g.This study provides comprehensive insights into the construction of highly reversible Zn anodes via COF modification layers for advanced rechargeable ZIBs.
基金financially supported by the National Natural Science Foundation of China(No.51771125)the Sichuan Province Science and Technology Support Program(No.2020YFG0102)。
文摘Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid route and the solid-solid route.However,the formation of DCN structures in steel requires long processes and complex steps.So far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain unavoidable.Here,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field.Ti-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 s.These small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel matrix.Our findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.
基金financially supported by the National Natural Science Foundation of China(Nos.U2141207,52171111,and 52001083)the Youth Talent Project of China National Nuclear Corporation(No.CNNC2021Y-TEPHEU01)+3 种基金the China Postdoctoral Science Foundation(No.2020M681077)the Natural Science Foundation of Heilongjiang,China(No.LH2019E030)the Heilongjiang Postdoctoral Science Foundation,China(No.LBH-Z19125)he Heilongjiang Touyan Innovation Team Program,China,and the Natural Science Foundation of Heilongjiang(No.LH2020E060)。
文摘Carbon can change the phase components of low-density steels and influence the mechanical properties.In this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was proposed.The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined.Crussard-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile test.During decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual phase.Meanwhile,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the same.In addition,the formation of other carbides restrained.Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution.For the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of microbands.For the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in ferrite.At the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.JQ2022E004).
文摘In this paper,the work hardening and softening behavior of AZ31 magnesium alloy sheets by hard plate accumulative roll bonding(HP-ARB)process in a specific temperature range was studied for the first time,and the cyclic stress relaxation test,EBSD,TEM and other characterization methods were used.When the rolling temperature is 350℃,the grain size of magnesium sheets is refined to 4.32(±0.36)μm on average,and it shows an excellent combination of strength and plasticity.The tensile strength reaches 307(±8.52)MPa and the elongation is 12.73(±0.84)%.At this time,the curve of work hardening rate decreases smoothly and the degree of hardening is the lowest,and the amplitude of stress drop △σ_(p) in work softening test is the smallest with the increase of cycle times,which shows that the well coordination between work hardening and softening behavior has been achieved.Research has found that the combined effect of grain boundary strengthening and fine grain strengthening enhances the yield and tensile strength of magnesium sheets after three passes HP-ARB process at 350℃.This is attributed to the high degree of dislocation slip opening in the pyramidal surfaceand<c+a>,which not only coordinates the c-axis strain of the entire grain,but also promotes the slip transfer of dislocations in the fine-grained region,significantly improving the elongation of the sheets.This study provides a new idea for the forming and manufacturing of high performance magnesium alloy sheets.
基金supported by the“National Natural Science Foundation of China”(Grants.52271109 and 52001223)Support from the“National Key Research and Development Program for Young Scientists”(Grant.2021YFB3703300)+1 种基金the Major Special Plan for Science and Technology in Shanxi Province(202201050201012)the Special Fund Project for Guiding Local Science and Technology Development by the Central Government(Grant.YDZJSX2021B019)。
文摘To obtain the Ti_(p)with different aspect ratios,the Ti_(p)/Mg-5Zn-0.3Ca composite prepared by semi-solid stir casting was subjected to extrusion at 220℃,180℃,and 140℃,respectively.Then,the effect of the Ti_(p)’s aspect ratio on the microstructure,mechanical properties,work hardening and softening behaviors of Ti_(p)/Mg-5Zn-0.3Ca composites was investigated.The results indicated that the Ti_(p)could be elongated obviously after low-temperature extrusion,and the aspect ratio of which would reach to 13.7:1 as the extrusion temperature deceased to 140℃.Then the“Ti/Mg”layer-like structure was formed in the Ti_(p)/Mg-5Zn-0.3Ca composite.Accompanied with the elongation of Ti_(p),the dynamic recrystallized grains and dynamic precipitates were both refined significantly,however,the dynamic recrystallization rate changed a little.The elongated Ti_(p)endowed the Ti_(p)/Mg-5Zn-0.3Ca composites with better matching of strength and toughness without the sacrifice of elongation and bending strain.Both the work hardening rate and softening rate of Ti_(p)/Mg-5Zn-0.3Ca composites increased with the increasing aspect ratio of Ti_(p).The formation of“Ti/Mg”layer-like structure contributed to the redistribution of strain from large aggregations to a network-like distribution,which effectively suppresses the initiation and propagation of micro-cracks,thus enhancing the plasticity of the Ti_(p)/Mg-5Zn-0.3Ca composites.
