This study examined the relationship between inclusive leadership and authenticity at work in racial minority groups of South Africa,taking into account the mediating role of psychological safety and the moderator rol...This study examined the relationship between inclusive leadership and authenticity at work in racial minority groups of South Africa,taking into account the mediating role of psychological safety and the moderator role of gender,in that relationship.The sample was composed of 94 employees predominantly working in the professional services sector from South Africa(41.5%females;mean age=37.1),who self-identified as racial minority groups(coloured/black/Indian).Results indicate that inclusive leadership has no direct effect on authenticity at work;however,psychological safety fully mediates this relationship.Regarding the moderation effect of gender,results showed that males are more likely to diminish their self-alienation(a specific component of authenticity at work)when levels of psychological safety are higher.These results are consistent with Social Identity Theory,which posits that individuals derive part of their self-concept from their membership in social groups.In contexts where inclusive leadership fosters psychological safety,individuals(particularly men in traditionally male-dominated work environments)may feel a stronger sense of belonging and group identity,which in turn enhances their willingness to express their authentic selves and reduces self-alienation.Practical implications for companies include the need to improve leadership styles to foster more of an inclusive and psychologically safe culture,where minority groups can be authentic and flourish.展开更多
Background:As an important indicator of subjective well-being(SWB),decent work is a key guarantee for the sustainable development of teachers and their psychological health and work quality.Faced with the rapid develo...Background:As an important indicator of subjective well-being(SWB),decent work is a key guarantee for the sustainable development of teachers and their psychological health and work quality.Faced with the rapid development of artificial intelligence and the global labor market,vocational college teachers are facing challenges such as workload pressure and limited career development,which may harm their well-being.This study aims to localize the measurement method of decent work in Chinese vocational education based on the theory of the Psychology of Working Theory,and explore the relationship mechanism between organizational support,career adaptability,decent work,and job satisfaction among vocational college teachers.Methods:A cross-sectional survey was conducted with 422 HVCU teachers in China(202 male,220 female)using the localized Perceived Organizational Support Scale,Career Adaptability Scale,Decent Work Scale,and Job Satisfaction Scale.Results:The overall level of HVCU teachers’decent work was above the median(Mean=4.09,SD=0.69),laying a foundation for their SWB.Decent work significantly and positively predicted job satisfaction(β=0.620,p<0.001).Organizational support(r=0.58,p<0.001)and career adaptability(r=0.82,p<0.001)can positively affect decent work,and further improve job satisfaction(collective R2 rising from 38.3%to 41.1%).Bootstrap analysis confirmed these mediating effects were robust.Conclusions:This study confirms that the combined effects of organizational support and career adaptability can enhance decent work,further improving teachers’job satisfaction and subsequent subjective well-being.Besides,this study provides an empirical basis for improving the well-being of higher vocational teachers and the sustainable development of vocational education,and has practical significance for improving the teacher incentive policy.展开更多
Surface properties of crystals are critical in many fields,including electrochemistry and photoelectronics,the efficient prediction of which can expedite the design and optimization of catalysts,batteries,alloys etc.H...Surface properties of crystals are critical in many fields,including electrochemistry and photoelectronics,the efficient prediction of which can expedite the design and optimization of catalysts,batteries,alloys etc.However,we are still far from realizing this vision due to the rarity of surface property-related databases,especially for multicomponent compounds,due to the large sample spaces and limited computing resources.In this work,we present a surface emphasized multi-task crystal graph convolutional neural network(SEM-CGCNN)to predict multiple surface properties simultaneously from crystal structures.The model is evaluated on a dataset of 3526 surface energies and work functions of binary magnesium intermetallics obtained through first-principles calculations,and obvious improvements are observed both in efficiency and accuracy over the original CGCNN model.By transferring the pre-trained model to the datasets of pure metals and other intermetallics,the fine-tuned SEM-CGCNN outperforms learning from scratch and can be further applied to other surface properties and materials systems.This study could be a paradigm for the end-to-end mapping of atomic structures to anisotropic surface properties of crystals,which provides an efficient framework to understand and screen materials with desired surface characteristics.展开更多
In the quest to enhance energy efficiency and reduce environmental impact in the transportation sector,the recovery of waste heat from diesel engines has become a critical area of focus.This study provided an exhausti...In the quest to enhance energy efficiency and reduce environmental impact in the transportation sector,the recovery of waste heat from diesel engines has become a critical area of focus.This study provided an exhaustive thermodynamic analysis optimizing Organic Rankine Cycle(ORC)systems forwaste heat recovery fromdiesel engines.Thestudy assessed the performance of five candidateworking fluids—R11,R123,R113,R245fa,and R141b—under a range of operating conditions,specifically varying overheat temperatures and evaporation pressures.The results indicated that the choice of working fluid substantially influences the system’s exergetic efficiency,net output power,and thermal efficiency.R245fa showed an outstanding net output power of 30.39 kW at high overheat conditions,outperforming R11,which is significant for high-temperature waste heat recovery.At lower temperatures,R11 and R113 demonstrated higher exergetic efficiencies,with R11 reaching a peak exergetic efficiency of 7.4%at an evaporation pressure of 10 bar and an overheat of 10℃.The study also revealed that controlling the overheat and optimizing the evaporation pressure are crucial for enhancing the net output power of the ORC system.Specifically,at an evaporation pressure of 30 bar and an overheat of 0℃,R113 exhibited the lowest exergetic destruction of 544.5 kJ/kg,making it a suitable choice for minimizing irreversible losses.These findings are instrumental for understanding the performance of ORC systems in waste heat recovery applications and offer valuable insights for the design and operation of more efficient and environmentally friendly diesel engine systems.展开更多
BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their...BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their RTW process.Hence,scientific research is necessary to explore the barriers and facilitating factors of returning to work for young and middle-aged CRC survivors.AIM To examine the current RTW status among young and middle-aged CRC survivors and to analyze the impact of RTW self-efficacy(RTW-SE),fear of progression(FoP),eHealth literacy(eHL),family resilience(FR),and financial toxicity(FT)on their RTW outcomes.METHODS A cross-sectional investigation was adopted in this study.From September 2022 to February 2023,a total of 209 participants were recruited through a convenience sampling method from the gastrointestinal surgery department of a class A tertiary hospital in Chongqing.The investigation utilized a general information questionnaire alongside scales assessing RTW-SE,FoP,eHL,FR,and FT.To analyze the factors that influence RTW outcomes among young and middle-aged CRC survivors,Cox regression modeling and Kaplan-Meier survival analysis were used.RESULTS A total of 43.54%of the participants successfully returned to work,with an average RTW time of 100 days.Cox regression univariate analysis revealed that RTW-SE,FoP,eHL,FR,and FT were significantly different between the non-RTW and RTW groups(P<0.05).Furthermore,Cox regression multivariate analysis identified per capita family monthly income,job type,RTW-SE,and FR as independent influencing factors for RTW(P<0.05).CONCLUSION The RTW rate requires further improvement.Elevated levels of RTW-SE and FR were found to significantly increase RTW among young and middle-aged CRC survivors.Health professionals should focus on modifiable factors,such as RTW-SE and FR,to design targeted RTW support programs,thereby facilitating their timely reintegration into mainstream society.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
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
Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct c...Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.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
文摘This study examined the relationship between inclusive leadership and authenticity at work in racial minority groups of South Africa,taking into account the mediating role of psychological safety and the moderator role of gender,in that relationship.The sample was composed of 94 employees predominantly working in the professional services sector from South Africa(41.5%females;mean age=37.1),who self-identified as racial minority groups(coloured/black/Indian).Results indicate that inclusive leadership has no direct effect on authenticity at work;however,psychological safety fully mediates this relationship.Regarding the moderation effect of gender,results showed that males are more likely to diminish their self-alienation(a specific component of authenticity at work)when levels of psychological safety are higher.These results are consistent with Social Identity Theory,which posits that individuals derive part of their self-concept from their membership in social groups.In contexts where inclusive leadership fosters psychological safety,individuals(particularly men in traditionally male-dominated work environments)may feel a stronger sense of belonging and group identity,which in turn enhances their willingness to express their authentic selves and reduces self-alienation.Practical implications for companies include the need to improve leadership styles to foster more of an inclusive and psychologically safe culture,where minority groups can be authentic and flourish.
基金funded by Nanjing University of Posts and Telecommunications Humanities and Social Sciences Research Fund Project(NYY222055)Special research project on teaching reform of innovation and entrepreneurship education in Nanjing University of Posts and Telecommunications(GCSJG202528)+2 种基金General Subject of Educational Science Planning in Jiangsu Province(C/2024/01/76)General project of educational science research in Shanghai(C24288)Key funded project of Shandong Vocational Education Teaching Reform Research in 2022(2022052).
文摘Background:As an important indicator of subjective well-being(SWB),decent work is a key guarantee for the sustainable development of teachers and their psychological health and work quality.Faced with the rapid development of artificial intelligence and the global labor market,vocational college teachers are facing challenges such as workload pressure and limited career development,which may harm their well-being.This study aims to localize the measurement method of decent work in Chinese vocational education based on the theory of the Psychology of Working Theory,and explore the relationship mechanism between organizational support,career adaptability,decent work,and job satisfaction among vocational college teachers.Methods:A cross-sectional survey was conducted with 422 HVCU teachers in China(202 male,220 female)using the localized Perceived Organizational Support Scale,Career Adaptability Scale,Decent Work Scale,and Job Satisfaction Scale.Results:The overall level of HVCU teachers’decent work was above the median(Mean=4.09,SD=0.69),laying a foundation for their SWB.Decent work significantly and positively predicted job satisfaction(β=0.620,p<0.001).Organizational support(r=0.58,p<0.001)and career adaptability(r=0.82,p<0.001)can positively affect decent work,and further improve job satisfaction(collective R2 rising from 38.3%to 41.1%).Bootstrap analysis confirmed these mediating effects were robust.Conclusions:This study confirms that the combined effects of organizational support and career adaptability can enhance decent work,further improving teachers’job satisfaction and subsequent subjective well-being.Besides,this study provides an empirical basis for improving the well-being of higher vocational teachers and the sustainable development of vocational education,and has practical significance for improving the teacher incentive policy.
基金supported by the National Key R&D Program(No.2021YFB3501002)supported by the Ministry of Science and Technology of China,National Natural Science Foundation of China(No.51825101,52127801).
文摘Surface properties of crystals are critical in many fields,including electrochemistry and photoelectronics,the efficient prediction of which can expedite the design and optimization of catalysts,batteries,alloys etc.However,we are still far from realizing this vision due to the rarity of surface property-related databases,especially for multicomponent compounds,due to the large sample spaces and limited computing resources.In this work,we present a surface emphasized multi-task crystal graph convolutional neural network(SEM-CGCNN)to predict multiple surface properties simultaneously from crystal structures.The model is evaluated on a dataset of 3526 surface energies and work functions of binary magnesium intermetallics obtained through first-principles calculations,and obvious improvements are observed both in efficiency and accuracy over the original CGCNN model.By transferring the pre-trained model to the datasets of pure metals and other intermetallics,the fine-tuned SEM-CGCNN outperforms learning from scratch and can be further applied to other surface properties and materials systems.This study could be a paradigm for the end-to-end mapping of atomic structures to anisotropic surface properties of crystals,which provides an efficient framework to understand and screen materials with desired surface characteristics.
基金funded by the Huaiyin Institute of Technology—Institute of Smart Energy.
文摘In the quest to enhance energy efficiency and reduce environmental impact in the transportation sector,the recovery of waste heat from diesel engines has become a critical area of focus.This study provided an exhaustive thermodynamic analysis optimizing Organic Rankine Cycle(ORC)systems forwaste heat recovery fromdiesel engines.Thestudy assessed the performance of five candidateworking fluids—R11,R123,R113,R245fa,and R141b—under a range of operating conditions,specifically varying overheat temperatures and evaporation pressures.The results indicated that the choice of working fluid substantially influences the system’s exergetic efficiency,net output power,and thermal efficiency.R245fa showed an outstanding net output power of 30.39 kW at high overheat conditions,outperforming R11,which is significant for high-temperature waste heat recovery.At lower temperatures,R11 and R113 demonstrated higher exergetic efficiencies,with R11 reaching a peak exergetic efficiency of 7.4%at an evaporation pressure of 10 bar and an overheat of 10℃.The study also revealed that controlling the overheat and optimizing the evaporation pressure are crucial for enhancing the net output power of the ORC system.Specifically,at an evaporation pressure of 30 bar and an overheat of 0℃,R113 exhibited the lowest exergetic destruction of 544.5 kJ/kg,making it a suitable choice for minimizing irreversible losses.These findings are instrumental for understanding the performance of ORC systems in waste heat recovery applications and offer valuable insights for the design and operation of more efficient and environmentally friendly diesel engine systems.
基金国家高技术研究发展计划( 863)( the National High- Tech Research and Development Plan of China under Grant No.2006AA02Z499)兰州交通大学校科研基金( the Science Research Foundation of Lanzhou Jiaotong Uiversity)
基金Supported by the Chongqing Medical University Program for Youth Innovation in Future Medicine,No.W0019Chongqing Municipal Education Commission’s 14th Five-Year Key Discipline Support Project,No.20240101 and No.20240102。
文摘BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their RTW process.Hence,scientific research is necessary to explore the barriers and facilitating factors of returning to work for young and middle-aged CRC survivors.AIM To examine the current RTW status among young and middle-aged CRC survivors and to analyze the impact of RTW self-efficacy(RTW-SE),fear of progression(FoP),eHealth literacy(eHL),family resilience(FR),and financial toxicity(FT)on their RTW outcomes.METHODS A cross-sectional investigation was adopted in this study.From September 2022 to February 2023,a total of 209 participants were recruited through a convenience sampling method from the gastrointestinal surgery department of a class A tertiary hospital in Chongqing.The investigation utilized a general information questionnaire alongside scales assessing RTW-SE,FoP,eHL,FR,and FT.To analyze the factors that influence RTW outcomes among young and middle-aged CRC survivors,Cox regression modeling and Kaplan-Meier survival analysis were used.RESULTS A total of 43.54%of the participants successfully returned to work,with an average RTW time of 100 days.Cox regression univariate analysis revealed that RTW-SE,FoP,eHL,FR,and FT were significantly different between the non-RTW and RTW groups(P<0.05).Furthermore,Cox regression multivariate analysis identified per capita family monthly income,job type,RTW-SE,and FR as independent influencing factors for RTW(P<0.05).CONCLUSION The RTW rate requires further improvement.Elevated levels of RTW-SE and FR were found to significantly increase RTW among young and middle-aged CRC survivors.Health professionals should focus on modifiable factors,such as RTW-SE and FR,to design targeted RTW support programs,thereby facilitating their timely reintegration into mainstream society.
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.
文摘Bifunctional Ir catalysts for proton exchange membrane(PEM)water electrolysis offer transformative potential by streamlining electrolyzer while achieving efficient performance remains challenging due to the distinct conditions required for oxygen and hydrogen evolution reaction(OER and HER).Herein,we propose a theory-directed design of Ir-based bifunctional catalysts,Ir nanoparticles supported on mesoporous carbon spheres embedded with MoSe_(2)(Ir/MoSe_(2)@MCS),leveraging a work function(WF)-induced spontaneous built-in electric field to enhance catalytic performance.They demonstrate exceptional kinetics for both OER and HER,and potential application in the practical PEM electrolyzer,showcasing the effectiveness of this innovative approach.Low overpotentials of 252 mV for OER and 28 mV for HER to drive 10 mA cm^(-2)were observed,and the PEM electrolyzer showed the current density of 2 A cm^(-2)at 1.87 V and maintained stable activity at 1.65 V for over 30 h to deliver 1 A cm^(-2).Density functional theory calculations reveal that the WF difference at Ir/MoSe_(2)interface induces a spontaneous built-in electric field with asymmetric charge distributions,that modulate the electronic environment and d-band center of Ir promoting bifunctional active phase formation.This significantly lowers reaction barriers for water splitting by balancing intermediate adsorption,endowing the bifunctional activity.
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.
