As educational reforms intensify and societal emphasis shifts towards empowerment,the traditional discourse paradigm of management and control in educational supervision faces growing challenges.This paper explores th...As educational reforms intensify and societal emphasis shifts towards empowerment,the traditional discourse paradigm of management and control in educational supervision faces growing challenges.This paper explores the transformation of this discourse paradigm through the lens of empowerment,analyzing its distinct characteristics,potential pathways,and effective strategies.This paper begins by reviewing the concept of empowerment and examining the current research landscape surrounding the discourse paradigm in educational supervision.Subsequently,we conduct a comparative analysis of the“control”and“empowerment”paradigms,highlighting their essential differences.This analysis illuminates the key characteristics of an empowerment-oriented approach to educational supervision,particularly its emphasis on dialogue,collaboration,participation,and,crucially,empowerment itself.Ultimately,this research advocates for a shift in educational supervision towards an empowerment-oriented discourse system.This entails a multi-pronged approach:transforming ingrained beliefs,embracing renewed pedagogical concepts,fostering methodological innovation,and optimizing existing mechanisms and strategies within educational supervision.These changes are proposed to facilitate the more effective alignment of educational supervision with the pursuit of high-quality education.展开更多
This article explores the key role of intelligent computing in driving the paradigm shift of scientific discovery.The article first outlines the five paradigms of scientific discovery,from empirical observation to the...This article explores the key role of intelligent computing in driving the paradigm shift of scientific discovery.The article first outlines the five paradigms of scientific discovery,from empirical observation to theoretical models,then to computational simulation and data intensive science,and finally introduces intelligent computing as the core of the fifth paradigm.Intelligent computing enhances the ability to understand,predict,and automate scientific discoveries of complex systems through technologies such as deep learning and machine learning.The article further analyzes the applications of intelligent computing in fields such as bioinformatics,astronomy,climate science,materials science,and medical image analysis,demonstrating its practical utility in solving scientific problems and promoting knowledge development.Finally,the article predicts that intelligent computing will play a more critical role in future scientific research,promoting interdisciplinary integration,open science,and collaboration,providing new solutions for solving complex problems.展开更多
With the development of English as an international language,English speakers are widely spread in the world.The English learning fashion has been greatly changed since the culture background of English as a langauge ...With the development of English as an international language,English speakers are widely spread in the world.The English learning fashion has been greatly changed since the culture background of English as a langauge has shifted to a mixed cultures instead of just British and American. But the standard varieties of British and American English have been accepted as the only generally accepted forms of standard English in China.The language learning fashion in China is about to undertake a big paradigm shift.This paper is an analysis of the English learning pattern shift in Chinese setting and therefore suggests a practical activities to apply this concept in English learning classes.展开更多
Significant effort including field work has been devoted to develop a natural gas extraction technology from natural gas hydrate reservoirs through the injection of carbon dioxide. Natural gas hydrate is practically m...Significant effort including field work has been devoted to develop a natural gas extraction technology from natural gas hydrate reservoirs through the injection of carbon dioxide. Natural gas hydrate is practically methane hydrate. The hypothesis is that carbon dioxide will be stored as hydrate owing to its favorable stability conditions compared to methane hydrate. Although the dynamics of the CO2/CH4 exchange process are not entirely understood it is established that the exchange process is feasible. The extent is limited but even if the CH4 recovery is optimized there is a need for a CH4/CO2 separation plant to enable a complete cyclic sequence of CO2 capture, injection and CH4 recovery. In this paper we propose an alternative paradigm to the Inject(CO2)/Exchange with(CH4)/Recover(CH4) one namely Recover(CH4) first and then Inject(CO2) for Storage.展开更多
From AlphaGo to ChatGPT,the field of AI has launched a series of remarkable achievements in recent years.Analyzing,comparing,and summarizing these achievements at the paradigm level is important for future AI innovati...From AlphaGo to ChatGPT,the field of AI has launched a series of remarkable achievements in recent years.Analyzing,comparing,and summarizing these achievements at the paradigm level is important for future AI innovation,but has not received sufficient attention.In this paper,we give an overview and perspective on machine learning paradigms.First,we propose a paradigm taxonomy with three levels and seven dimensions from a knowledge perspective.Accordingly,we give an overview on three basic and twelve extended learning paradigms,such as Ensemble Learning,Transfer Learning,etc.,with figures in unified style.We further analyze three advanced paradigms,i.e.,AlphaGo,AlphaFold and ChatGPT.Second,to enable more efficient and effective scientific discovery,we propose to build a new ecosystem that drives AI paradigm shifts through the decentralized science(DeSci)movement based on decentralized autonomous organization(DAO).To this end,we design the Hanoi framework,which integrates human factors,parallel intelligence based on a combination of artificial systems and the natural world,and the DAO to inspire AI innovations.展开更多
This paper presents a discussion about paradigm shift from following aspects: the paradigm shift and sustainability,traditional paradigm in China,experience from developed countries and the new planning paradigm shift...This paper presents a discussion about paradigm shift from following aspects: the paradigm shift and sustainability,traditional paradigm in China,experience from developed countries and the new planning paradigm shift. Also,the paper mainly focuses on the topic of urbanrural relationship in China and argues the possibility of paradigm shift to achieve urban-rural integration. The traditional urbanization paradigm has city-oriented policy and always focuses on industrialization to promote urbanization,which leads to the village hollowing and many other sacrifices in rural areas. Thus,new shifting of the urban-rural integration is essential. The paper mentions the new planning from policy and spatial aspects appearing some ways to achieve the new paradigm shift in urban-rural integration.展开更多
Chinese President Xi Jinping's visit to Bangladesh in October2016 has dramatically uplifted the strategic value of Bangladesh to the world and presented new opportunities to Bangladeshs' security,political and...Chinese President Xi Jinping's visit to Bangladesh in October2016 has dramatically uplifted the strategic value of Bangladesh to the world and presented new opportunities to Bangladeshs' security,political and economic interests.Bangladesh and China have agreed to elevate‘the closer comprehensive partnership of cooperation'to a ‘strategic partnership'.China's B&R initiative is perhaps a major project for Bangladesh to promote economic development and to connect itself with global markets.展开更多
This paper examines the impacts of information technology (IT) on LDCs' competitive conditions, especially the impacts on intra-organization's linkage and technology capability formation via innovation, as the...This paper examines the impacts of information technology (IT) on LDCs' competitive conditions, especially the impacts on intra-organization's linkage and technology capability formation via innovation, as the rising of the new paradigms of system integration. And some strategic implications are made.展开更多
Learner autonomy and attribution impact English language acquisition. Learners should be encouraged to take the responsibility for their success or failure, and achievement or underperformance in the acquisition of En...Learner autonomy and attribution impact English language acquisition. Learners should be encouraged to take the responsibility for their success or failure, and achievement or underperformance in the acquisition of English as an L2 (second language). A paradigm shift can be visible on the part of teachers and students of English only when they are metamorphosed voluntarily into classroom facilitators and autonomous learners with changed duties and responsibilities. As facilitators, teachers closely monitor learners' attributions to their success/failure in English language courses. "Attribution" means "how learners learn about themselves and order uncertain environments". Teachers are very often unaware of learner attributions; so it becomes essential for them to increase their awareness of learner attributions so that they can become facilitators. Interaction is the only medium for acquisition of English in the classroom, and teachers can play the role of a catalyst only when they allow students to become leamers with autonomy and right kind of learner attributions. Autonomy implies accountability. Very often, learner attributions clash with teacher attributions. As long as there is a clash, teachers can never claim themselves as facilitators of learning. This paper identifies the attributions of Indian learners of English, and studies if they clash with those of teachers. It also finds out the means of minimizing the negative and undesirable attributions of both facilitators and learners. Two standardized research questionnaires were developed and administered among students and teachers to identify the attributions, and to detect the desirability and feasibility of learner autonomy in the Indian context.展开更多
Orthogonal Time Frequency and Space(OTFS) modulation is expected to provide high-speed and ultra-reliable communications for emerging mobile applications, including low-orbit satellite communications. Using the Dopple...Orthogonal Time Frequency and Space(OTFS) modulation is expected to provide high-speed and ultra-reliable communications for emerging mobile applications, including low-orbit satellite communications. Using the Doppler frequency for positioning is a promising research direction on communication and navigation integration. To tackle the high Doppler frequency and low signal-to-noise ratio(SNR) in satellite communication, this paper proposes a Red and Blue Frequency Shift Discriminator(RBFSD) based on the pseudo-noise(PN) sequence.The paper derives that the cross-correlation function on the Doppler domain exhibits the characteristic of a Sinc function. Therefore, it applies modulation onto the Delay-Doppler domain using PN sequence and adjusts Doppler frequency estimation by red-shifting or blue-shifting. Simulation results show that the performance of Doppler frequency estimation is close to the Cramér-Rao Lower Bound when the SNR is greater than -15dB. The proposed algorithm is about 1/D times less complex than the existing PN pilot sequence algorithm, where D is the resolution of the fractional Doppler.展开更多
Objectives:Newly graduated nurses commence night shifts during a phase of heightened vulnerability to reality shock,exacerbating the challenges faced by these graduates.Therefore,this study aimed to identify the chall...Objectives:Newly graduated nurses commence night shifts during a phase of heightened vulnerability to reality shock,exacerbating the challenges faced by these graduates.Therefore,this study aimed to identify the challenges experienced by newly graduated nurses when undertaking night shifts in order to help identify a strategy for supporting their adaptation to these shifts.Methods:Semi-structured personal interviews were used to collect data.Fifteen newly graduated nurses were selected to participate in the study by purposive sampling method from November 2021 to March 2022 in one of four general hospitals situated in the southwestern region of Japan.Semi-structured interviews were analyzed by using thematic analysis.Results:The analysis revealedfive central themes and nine subthemes:challenges in task efficiency(task organization challenges,challenges in time-constrained task performance),challenges in responding to patients’changing conditions(challenges in responding to patients’irregular conditions,challenges in responding to nighttime changes in patients’behaviors),challenges in independent practice(challenges in engaging in independent nursing practice,challenges in dealing with unexpected events),challenges in establishing collaborative relationships(challenges in working closely with other staff,challenges in establishing collaborative relationships during night shifts with limited resources),challenges in adapting to shift work(challenges in managing physical conditions for shift work).Conclusions:Newly graduated nurses often encounter challenges in performing their tasks during the transition period.When working night shifts,they face additional hurdles unique to nocturnal duties.Thefindings underscore the necessity for these graduates to develop night shift-specific readiness to effectively navigate the demands inherent in such work schedules.展开更多
In this paper,we mainly study the propagation properties of a nonlocal dispersal predator-prey system in a shifting environment.It is known that Choi et al.[J Differ Equ,2021,302:807-853]studied the persistence or ext...In this paper,we mainly study the propagation properties of a nonlocal dispersal predator-prey system in a shifting environment.It is known that Choi et al.[J Differ Equ,2021,302:807-853]studied the persistence or extinction of the prey and of the predator separately in various moving frames.In particular,they achieved a complete picture in the local diffusion case.However,the question of the persistence of the prey and of the predator in some intermediate moving frames in the nonlocal diffusion case was left open in Choi et al.'s paper.By using some a prior estimates,the Arzelà-Ascoli theorem and a diagonal extraction process,we can extend and improve the main results of Choi et al.to achieve a complete picture in the nonlocal diffusion case.展开更多
We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position...We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position in the harmonic emission by adjusting the absolute phase parameter within the frequency domain of the shaping pulse.This phenomenon holds potential significance for experimental setups necessitating precisely tuned single harmonics.Notably,we observe a modulated shift in the created harmonic photon energy,spanning an impressive range of 1.2 eV.This frequency peak shift is rooted in the asymmetry exhibited by the rising and falling edges of the laser pulse,directly influencing the position of the peak frequency emission.Our study quantifies the dependence of this tuning range and the asymmetry of the laser pulse,offering valuable insights into the underlying mechanisms driving this phenomenon.Furthermore,our investigation uncovers the emergence of semi-integer order harmonics as the phase parameter is altered.We attribute this discovery to the intricate interference between harmonics generated by the primary and secondary return cores.This observation introduces an innovative approach for generating semi-integer order harmonics,thus expanding our understanding of high-order harmonic generation.Ultimately,our work contributes to the broader comprehension of complex phenomena in laser-matter interactions and provides a foundation for harnessing these effects in various applications,particularly those involving precise spectral control and the generation of unique harmonic patterns.展开更多
The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported catalysts.Here,we report a synthetic strategy to upgrade Cu-CeO_(2)i...The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported catalysts.Here,we report a synthetic strategy to upgrade Cu-CeO_(2)interfacial interaction by the pyrolysis of mixed metal-organic framework(MOF)structure.The obtained highly dispersed Cu/CeO_(2)-MOF catalyst via this strategy was used to catalyze water-gas shift reaction(WGSR),which exhibited high activity of 40.5μmolCOgcat^(-1).s^(-1)at 300℃and high stability of about 120 h.Based on comprehensive studies of electronic structure,pyrolysis strategy has significant effect on enhancing metal-support interaction and then stabilizing interfacial Cu^(+)species under reaction conditions.Abundant Cu^(+)species and generated oxygen vacancies over Cu/CeO_(2)-MOF catalyst played a key role in CO molecule activation and H2O molecule dissociation,respectively.Both collaborated closely and then promoted WGSR catalytic performance in comparison with traditio nal supported catalysts.This study shall offer a robust approach to harvest highly dispersed catalysts with finely-tuned metal-support interactions for stabilizing the most interfacial active metal species in diverse heterogeneous catalytic reactions.展开更多
In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence sp...In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence spectrum detected by the PCR system exhibits an asymmetry and induced Doppler shift f_(D)during the internal kink mode(IKM)rotation phase.This Doppler shift f_(D)is the target measurement of Doppler reflectometry,but captured by conventional reflectometry.Results show that the Doppler shift f_(D)is modulated by the periodic changes in the effective angle between the probing wave and cutoff layer normal,but not by plasma turbulence.The fishbone mode and saturated long-lived mode are typical IKMs,and this modulation phenomenon is observed in both cases.Moreover,the value of the Doppler shift f_(D)is positively correlated with the amplitude of the IKM,even when the latter is small.However,the positive and negative frequency components of the Doppler shift f_(D)can be asymmetric,which is related to the plasma configuration.A simulated analysis is performed by ray tracing to verify these observations.These results establish a clear link between f_(D)and IKM rotation,and are helpful for studying the characteristics of IKM and related physical phenomena.展开更多
文摘As educational reforms intensify and societal emphasis shifts towards empowerment,the traditional discourse paradigm of management and control in educational supervision faces growing challenges.This paper explores the transformation of this discourse paradigm through the lens of empowerment,analyzing its distinct characteristics,potential pathways,and effective strategies.This paper begins by reviewing the concept of empowerment and examining the current research landscape surrounding the discourse paradigm in educational supervision.Subsequently,we conduct a comparative analysis of the“control”and“empowerment”paradigms,highlighting their essential differences.This analysis illuminates the key characteristics of an empowerment-oriented approach to educational supervision,particularly its emphasis on dialogue,collaboration,participation,and,crucially,empowerment itself.Ultimately,this research advocates for a shift in educational supervision towards an empowerment-oriented discourse system.This entails a multi-pronged approach:transforming ingrained beliefs,embracing renewed pedagogical concepts,fostering methodological innovation,and optimizing existing mechanisms and strategies within educational supervision.These changes are proposed to facilitate the more effective alignment of educational supervision with the pursuit of high-quality education.
文摘This article explores the key role of intelligent computing in driving the paradigm shift of scientific discovery.The article first outlines the five paradigms of scientific discovery,from empirical observation to theoretical models,then to computational simulation and data intensive science,and finally introduces intelligent computing as the core of the fifth paradigm.Intelligent computing enhances the ability to understand,predict,and automate scientific discoveries of complex systems through technologies such as deep learning and machine learning.The article further analyzes the applications of intelligent computing in fields such as bioinformatics,astronomy,climate science,materials science,and medical image analysis,demonstrating its practical utility in solving scientific problems and promoting knowledge development.Finally,the article predicts that intelligent computing will play a more critical role in future scientific research,promoting interdisciplinary integration,open science,and collaboration,providing new solutions for solving complex problems.
文摘With the development of English as an international language,English speakers are widely spread in the world.The English learning fashion has been greatly changed since the culture background of English as a langauge has shifted to a mixed cultures instead of just British and American. But the standard varieties of British and American English have been accepted as the only generally accepted forms of standard English in China.The language learning fashion in China is about to undertake a big paradigm shift.This paper is an analysis of the English learning pattern shift in Chinese setting and therefore suggests a practical activities to apply this concept in English learning classes.
基金The financial support from NSERC is acknowledged
文摘Significant effort including field work has been devoted to develop a natural gas extraction technology from natural gas hydrate reservoirs through the injection of carbon dioxide. Natural gas hydrate is practically methane hydrate. The hypothesis is that carbon dioxide will be stored as hydrate owing to its favorable stability conditions compared to methane hydrate. Although the dynamics of the CO2/CH4 exchange process are not entirely understood it is established that the exchange process is feasible. The extent is limited but even if the CH4 recovery is optimized there is a need for a CH4/CO2 separation plant to enable a complete cyclic sequence of CO2 capture, injection and CH4 recovery. In this paper we propose an alternative paradigm to the Inject(CO2)/Exchange with(CH4)/Recover(CH4) one namely Recover(CH4) first and then Inject(CO2) for Storage.
基金This work was supported by the National Key Research and Development Program of China(2020YFB2104001)the National Natural Science Foundation of China(62271485,61903363,U1811463)Open Project of the State Key Laboratory for Management and Control of Complex Systems(20220117).
文摘From AlphaGo to ChatGPT,the field of AI has launched a series of remarkable achievements in recent years.Analyzing,comparing,and summarizing these achievements at the paradigm level is important for future AI innovation,but has not received sufficient attention.In this paper,we give an overview and perspective on machine learning paradigms.First,we propose a paradigm taxonomy with three levels and seven dimensions from a knowledge perspective.Accordingly,we give an overview on three basic and twelve extended learning paradigms,such as Ensemble Learning,Transfer Learning,etc.,with figures in unified style.We further analyze three advanced paradigms,i.e.,AlphaGo,AlphaFold and ChatGPT.Second,to enable more efficient and effective scientific discovery,we propose to build a new ecosystem that drives AI paradigm shifts through the decentralized science(DeSci)movement based on decentralized autonomous organization(DAO).To this end,we design the Hanoi framework,which integrates human factors,parallel intelligence based on a combination of artificial systems and the natural world,and the DAO to inspire AI innovations.
文摘This paper presents a discussion about paradigm shift from following aspects: the paradigm shift and sustainability,traditional paradigm in China,experience from developed countries and the new planning paradigm shift. Also,the paper mainly focuses on the topic of urbanrural relationship in China and argues the possibility of paradigm shift to achieve urban-rural integration. The traditional urbanization paradigm has city-oriented policy and always focuses on industrialization to promote urbanization,which leads to the village hollowing and many other sacrifices in rural areas. Thus,new shifting of the urban-rural integration is essential. The paper mentions the new planning from policy and spatial aspects appearing some ways to achieve the new paradigm shift in urban-rural integration.
文摘Chinese President Xi Jinping's visit to Bangladesh in October2016 has dramatically uplifted the strategic value of Bangladesh to the world and presented new opportunities to Bangladeshs' security,political and economic interests.Bangladesh and China have agreed to elevate‘the closer comprehensive partnership of cooperation'to a ‘strategic partnership'.China's B&R initiative is perhaps a major project for Bangladesh to promote economic development and to connect itself with global markets.
文摘This paper examines the impacts of information technology (IT) on LDCs' competitive conditions, especially the impacts on intra-organization's linkage and technology capability formation via innovation, as the rising of the new paradigms of system integration. And some strategic implications are made.
文摘Learner autonomy and attribution impact English language acquisition. Learners should be encouraged to take the responsibility for their success or failure, and achievement or underperformance in the acquisition of English as an L2 (second language). A paradigm shift can be visible on the part of teachers and students of English only when they are metamorphosed voluntarily into classroom facilitators and autonomous learners with changed duties and responsibilities. As facilitators, teachers closely monitor learners' attributions to their success/failure in English language courses. "Attribution" means "how learners learn about themselves and order uncertain environments". Teachers are very often unaware of learner attributions; so it becomes essential for them to increase their awareness of learner attributions so that they can become facilitators. Interaction is the only medium for acquisition of English in the classroom, and teachers can play the role of a catalyst only when they allow students to become leamers with autonomy and right kind of learner attributions. Autonomy implies accountability. Very often, learner attributions clash with teacher attributions. As long as there is a clash, teachers can never claim themselves as facilitators of learning. This paper identifies the attributions of Indian learners of English, and studies if they clash with those of teachers. It also finds out the means of minimizing the negative and undesirable attributions of both facilitators and learners. Two standardized research questionnaires were developed and administered among students and teachers to identify the attributions, and to detect the desirability and feasibility of learner autonomy in the Indian context.
文摘Orthogonal Time Frequency and Space(OTFS) modulation is expected to provide high-speed and ultra-reliable communications for emerging mobile applications, including low-orbit satellite communications. Using the Doppler frequency for positioning is a promising research direction on communication and navigation integration. To tackle the high Doppler frequency and low signal-to-noise ratio(SNR) in satellite communication, this paper proposes a Red and Blue Frequency Shift Discriminator(RBFSD) based on the pseudo-noise(PN) sequence.The paper derives that the cross-correlation function on the Doppler domain exhibits the characteristic of a Sinc function. Therefore, it applies modulation onto the Delay-Doppler domain using PN sequence and adjusts Doppler frequency estimation by red-shifting or blue-shifting. Simulation results show that the performance of Doppler frequency estimation is close to the Cramér-Rao Lower Bound when the SNR is greater than -15dB. The proposed algorithm is about 1/D times less complex than the existing PN pilot sequence algorithm, where D is the resolution of the fractional Doppler.
基金supported by Japan Society for the Promotion of Science,Grants-in-Aid for Scientific Research[grant number 23K09804]The JSPS has had any roles in the survey's design,implementation,and analysis.
文摘Objectives:Newly graduated nurses commence night shifts during a phase of heightened vulnerability to reality shock,exacerbating the challenges faced by these graduates.Therefore,this study aimed to identify the challenges experienced by newly graduated nurses when undertaking night shifts in order to help identify a strategy for supporting their adaptation to these shifts.Methods:Semi-structured personal interviews were used to collect data.Fifteen newly graduated nurses were selected to participate in the study by purposive sampling method from November 2021 to March 2022 in one of four general hospitals situated in the southwestern region of Japan.Semi-structured interviews were analyzed by using thematic analysis.Results:The analysis revealedfive central themes and nine subthemes:challenges in task efficiency(task organization challenges,challenges in time-constrained task performance),challenges in responding to patients’changing conditions(challenges in responding to patients’irregular conditions,challenges in responding to nighttime changes in patients’behaviors),challenges in independent practice(challenges in engaging in independent nursing practice,challenges in dealing with unexpected events),challenges in establishing collaborative relationships(challenges in working closely with other staff,challenges in establishing collaborative relationships during night shifts with limited resources),challenges in adapting to shift work(challenges in managing physical conditions for shift work).Conclusions:Newly graduated nurses often encounter challenges in performing their tasks during the transition period.When working night shifts,they face additional hurdles unique to nocturnal duties.Thefindings underscore the necessity for these graduates to develop night shift-specific readiness to effectively navigate the demands inherent in such work schedules.
基金supported by the National Natural Science Foundation of China(12171039,12271044)。
文摘In this paper,we mainly study the propagation properties of a nonlocal dispersal predator-prey system in a shifting environment.It is known that Choi et al.[J Differ Equ,2021,302:807-853]studied the persistence or extinction of the prey and of the predator separately in various moving frames.In particular,they achieved a complete picture in the local diffusion case.However,the question of the persistence of the prey and of the predator in some intermediate moving frames in the nonlocal diffusion case was left open in Choi et al.'s paper.By using some a prior estimates,the Arzelà-Ascoli theorem and a diagonal extraction process,we can extend and improve the main results of Choi et al.to achieve a complete picture in the nonlocal diffusion case.
基金This project was supported by the National Key Research and Development Program of China(Grant Nos.2022YFE134200 and 2019YFA0307700)the National Natural Science Foundation of China(Grant Nos.11604119,12104177,11904192,12074145,and 11704147)the Fundamental Research Funds for the Central Universities(Grant Nos.GK202207012 and QCYRCXM-2022-241).
文摘We delve into the phenomenon of high-order harmonic generation within a helium atom under the influence of a plasmon-assisted shaping pulse.Our findings reveal an intriguing manipulation of the frequency peak position in the harmonic emission by adjusting the absolute phase parameter within the frequency domain of the shaping pulse.This phenomenon holds potential significance for experimental setups necessitating precisely tuned single harmonics.Notably,we observe a modulated shift in the created harmonic photon energy,spanning an impressive range of 1.2 eV.This frequency peak shift is rooted in the asymmetry exhibited by the rising and falling edges of the laser pulse,directly influencing the position of the peak frequency emission.Our study quantifies the dependence of this tuning range and the asymmetry of the laser pulse,offering valuable insights into the underlying mechanisms driving this phenomenon.Furthermore,our investigation uncovers the emergence of semi-integer order harmonics as the phase parameter is altered.We attribute this discovery to the intricate interference between harmonics generated by the primary and secondary return cores.This observation introduces an innovative approach for generating semi-integer order harmonics,thus expanding our understanding of high-order harmonic generation.Ultimately,our work contributes to the broader comprehension of complex phenomena in laser-matter interactions and provides a foundation for harnessing these effects in various applications,particularly those involving precise spectral control and the generation of unique harmonic patterns.
基金sponsored by the National Key R&D Program of China(2021YFA1501100)the National Natural Science Foundation of China(21832001 and 22293042)the Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202104)。
文摘The modulation of metal-support interfacial interaction is significant but challenging in the design of high-efficiency and high-stability supported catalysts.Here,we report a synthetic strategy to upgrade Cu-CeO_(2)interfacial interaction by the pyrolysis of mixed metal-organic framework(MOF)structure.The obtained highly dispersed Cu/CeO_(2)-MOF catalyst via this strategy was used to catalyze water-gas shift reaction(WGSR),which exhibited high activity of 40.5μmolCOgcat^(-1).s^(-1)at 300℃and high stability of about 120 h.Based on comprehensive studies of electronic structure,pyrolysis strategy has significant effect on enhancing metal-support interaction and then stabilizing interfacial Cu^(+)species under reaction conditions.Abundant Cu^(+)species and generated oxygen vacancies over Cu/CeO_(2)-MOF catalyst played a key role in CO molecule activation and H2O molecule dissociation,respectively.Both collaborated closely and then promoted WGSR catalytic performance in comparison with traditio nal supported catalysts.This study shall offer a robust approach to harvest highly dispersed catalysts with finely-tuned metal-support interactions for stabilizing the most interfacial active metal species in diverse heterogeneous catalytic reactions.
基金supported by the National Key R&D Program of China(Nos.2022YFE03050003,2022YFE03020004,2019YFE03080200 and 2022YFE03070004)National Natural Science Foundation of China(Nos.12275315,11875289,12175277 and 11975271)+3 种基金partly supported by the Youth Science and Technology Talents Support Program(2020)by Anhui Association for Science and Technology(No.RCTJ202009)the Science Foundation of Institute of Plasma Physics,Chinese Academy of Sciences(No.DSJJ2021-08)the China Postdoctoral Science Foundation(No.2021M703256)the Director Funding of Hefei Institutes of Physical Science,Chinese Academy of Sciences(No.YZJJ2022QN16)。
文摘In this paper we present a new experimental observation using a conventional reflectometry technique,poloidal correlation reflectometry(PCR),in the Experimental Advanced Superconducting Tokamak(EAST).The turbulence spectrum detected by the PCR system exhibits an asymmetry and induced Doppler shift f_(D)during the internal kink mode(IKM)rotation phase.This Doppler shift f_(D)is the target measurement of Doppler reflectometry,but captured by conventional reflectometry.Results show that the Doppler shift f_(D)is modulated by the periodic changes in the effective angle between the probing wave and cutoff layer normal,but not by plasma turbulence.The fishbone mode and saturated long-lived mode are typical IKMs,and this modulation phenomenon is observed in both cases.Moreover,the value of the Doppler shift f_(D)is positively correlated with the amplitude of the IKM,even when the latter is small.However,the positive and negative frequency components of the Doppler shift f_(D)can be asymmetric,which is related to the plasma configuration.A simulated analysis is performed by ray tracing to verify these observations.These results establish a clear link between f_(D)and IKM rotation,and are helpful for studying the characteristics of IKM and related physical phenomena.