Distribution transformers play a vital role in power distribution systems,and their reliable operation is crucial for grid stability.This study presents a simulation-based framework for active fault diagnosis and earl...Distribution transformers play a vital role in power distribution systems,and their reliable operation is crucial for grid stability.This study presents a simulation-based framework for active fault diagnosis and early warning of distribution transformers,integrating Sample Ensemble Learning(SEL)with a Self-Optimizing Support Vector Machine(SO-SVM).The SEL technique enhances data diversity and mitigates class imbalance,while SO-SVM adaptively tunes its hyperparameters to improve classification accuracy.A comprehensive transformer model was developed in MATLAB/Simulink to simulate diverse fault scenarios,including inter-turn winding faults,core saturation,and thermal aging.Feature vectors were extracted from voltage,current,and temperature measurements to train and validate the proposed hybrid model.Quantitative analysis shows that the SEL–SO-SVM framework achieves a classification accuracy of 97.8%,a precision of 96.5%,and an F1-score of 97.2%.Beyond classification,the model effectively identified incipient faults,providing an early warning lead time of up to 2.5 s before significant deviations in operational parameters.This predictive capability underscores its potential for preventing catastrophic transformer failures and enabling timely maintenance actions.The proposed approach demonstrates strong applicability for enhancing the reliability and operational safety of distribution transformers in simulated environments,offering a promising foundation for future real-time and field-level implementations.展开更多
The susceptibility of ore particles to electrical breakdown plays a critical role for high voltage pulse(HVP)breakage,yet its quantitative characterization still lacks deep understanding.Two indicators,namely breakdow...The susceptibility of ore particles to electrical breakdown plays a critical role for high voltage pulse(HVP)breakage,yet its quantitative characterization still lacks deep understanding.Two indicators,namely breakdown delay time(T_(d))and breakdown strength(E_(b))were compared,based on analysis on the two breakdown modes namely wavefront mode and post-wave mode.It was found that T_(d) is more suitable to characterize the susceptibility of ore particles to electrical breakdown in HVP breakage than E_(b).A probabilistic model based on the Weibull distribution is developed to describe the relation of breakdown probability to T_(d).Regression analyses were conducted to investigate how operating parameters and particle properties influence Td and size reduction degree of ore particles in HVP breakage.The regressed models demonstrate potential capability to predict metallic minerals content and HVP breakage degree based on operating parameters and particle properties.展开更多
Accurately forecasting the triple point(TP)path is essential for analyzing blast loads and assessing the destructive effectiveness of the height of burst explosion.Empirical models that describe the TP path under norm...Accurately forecasting the triple point(TP)path is essential for analyzing blast loads and assessing the destructive effectiveness of the height of burst explosion.Empirical models that describe the TP path under normal temperature and pressure environments are commonly employed;however,in certain configurations,such as at high-altitudes(HAs),the environment may involve low temperature and pressure conditions.The present study develops a theoretical prediction model for the TP path under reduced pressure and temperature conditions,utilizing the image bursts method,reflected polar analysis,and dimensional analysis.The model's accuracy is evaluated through numerical simulations and experimental data.Results indicate that the prediction model effectively evaluates the TP path under diminished temperature and pressure conditions,with most predictions falling within a±15%deviation.It was found that the TP height increases with altitude.As the altitude rises from 0 m to 10,000 m,the average TP height increases by 61.7%,87.9%,109.0%,and 134.3%for the scaled height of burst of 1.5 m,2.0 m,2.5 m,and 3.0 m,respectively.Moreover,the variation in TP height under HA environments closely mirrors that observed under corresponding reduced pressure conditions.In HA environments,only the effect of low-pressure conditions on the TP path needs to be considered,as the environmental lowtemperature has a minimal effect.展开更多
Laser powder bed fusion(L-PBF)is an advanced metal additive manufacturing process with an excellent capability for fabricating nickel-based superalloys.After solution aging(SA),the l-PBF nickel-based superalloys can m...Laser powder bed fusion(L-PBF)is an advanced metal additive manufacturing process with an excellent capability for fabricating nickel-based superalloys.After solution aging(SA),the l-PBF nickel-based superalloys can match the tensile properties with the conventional manufacturing process;however,its performance under long-life regime service conditions,especially at an elevated temperature of 650℃,has not yet been well understood,which restricts its promotion in industrial applications.In this study,combined with various techniques including X-ray diffraction(XRD),electron backscatter diffraction(EBSD),and micro-computed tomography(micro-CT),the microstructure,phases,micro-texture,and internal defects of SA l-PBF nickel-based superalloys were analyzed,and tensile and cutting-edge fatigue tests with stress ratios R=-1 and 0.1 were performed at 25℃ and 650℃ to investigate the fatigue failure behavior.The results showed that the SA treatment promoted microstructural homogenization with vague laser scanning tracks.The synergistic effect of the γ',γ",and δ phases improved the mechanical and fatigue properties.Elevated temperatures and positive stress ratios promoted the occurrence of subsurface or internal failures.The four cracking modes include crack nucleation from the crystallographic facets,pore-assisted facetted crack nucleation,lack of fusion-induced crack nucleation,and inclusion-induced crack nucleation.At 650℃,the grains fractured along the maximum shear plane,formed a large number of highly inhomogeneous facets,which caused significant fluctuations.Finally,the phase transition processes during SA treatment and defect-related fatigue failure mechanisms were elucidated.This study provides key quality and testing data to support the advancement of l-PBF nickel-based superalloys and provides a foundation for their optimized design and industrial applications.展开更多
The efficient storage and application of sustainable solar energy has drawn significant attention from both academic and industrial points of view.However,most developed catalytic materials still suffer from insuffici...The efficient storage and application of sustainable solar energy has drawn significant attention from both academic and industrial points of view.However,most developed catalytic materials still suffer from insufficient mass diffusion and unsatisfactory durability due to the lack of interconnected and regulatable porosity.Developing catalytic architectures with engineered active sites and prominent stability through rational synthesis strategies has become one of the core projects in solar-driven applications.The unique properties of mesoporous silicas render them among the most valuable functional materials for industrial applications,such as high specific surface area,regulatable porosity,adjustable surface properties,tunable particle sizes,and great thermal and mechanical stability.Mesoporous silicas serve as structural templates or catalytic supports to enhance light harvesting via the scattering effect and provide large surface areas for active site generation.These advantages have been widely utilized in solar applications,including hydrogen production,CO_(2)conversion,photovoltaics,biomass utilization,and pollutant degradation.To achieve the specific functionalities and desired activity,various types of mesoporous silicas from different synthesis methods have been customized and synthesized.Moreover,morphology regulation and component modification strategies have also been performed to endow mesoporous silica-based materials with unprecedented efficiency for solar energy storage and utilization.Nevertheless,reviews about synthesis,morphology regulation,and component modification strategies for mesoporous silica-based catalyst design in solar-driven applications are still limited.Herein,the latest progress concerning mesoporous silica-based catalysis in solar-driven applications is comprehensively reviewed.Synthesis principles,formation mechanisms,and rational functionalities of mesoporous silica are systematically summarized.Some typical catalysts with impressive activities in different solar-driven applications are highlighted.Furthermore,challenges and future potential opportunities in this study field are also discussed and proposed.This present review guides the design of mesoporous silica catalysts for efficient solar energy management for solar energy storage and conversion applications.展开更多
Compressed air energy storage(CAES)caverns transformed from horseshoe-shaped roadways in abandoned coal mines still face unclear mechanisms of force transfer,especially in the presence of initial damage in the surroun...Compressed air energy storage(CAES)caverns transformed from horseshoe-shaped roadways in abandoned coal mines still face unclear mechanisms of force transfer,especially in the presence of initial damage in the surrounding rock.The shape and size of the initial damage area as well as their effect on cavern stability remain unclear.Due to the complex geometry and multiphysical couplings,traditional numerical algorithms encounter problems of nonconvergence and low accuracy.These challenges can be addressed through numerical simulations with robust convergence and high accuracy.In this study,the damage area shapes of a CAES cavern are first computed using the concept of damage levels.Then,an iteration algorithm is improved using the generalization a method through the error control and one-way coupling loop for fully coupling equations.Finally,the stability of the CAES cavern with different damage zone shapes is numerically simulated in the thermodynamic process.It is found that this improved algorithm can greatly enhance numerical convergence and accuracy.The nonuniformity of the elastic modulus has a significant impact on the mechanical responses of the CAES cavern.The cavern shape with different damage zones has significant impacts on cavern stability.The initial damage area can delay the responses of temperature and stress.It induces variations of temperature in the range of approximately 1.2 m and variations of stress in the range of 1.5 m from the damage area.展开更多
Cr^(3+)-activated spinel-type phosphors have great potential in different application scenes due to their unique sharp and far-red(FR)emission.However,the multi-functionalization of these phosphors is still limited by...Cr^(3+)-activated spinel-type phosphors have great potential in different application scenes due to their unique sharp and far-red(FR)emission.However,the multi-functionalization of these phosphors is still limited by their unsatisfied comprehensive properties.Herein,a simple composition engineering was used to explore versatile phosphors,using Ga^(3+)to substitute Al^(3+)to improve the optical performances of spinel LiAl5-xGa_(x)O_(8):Cr^(3+).The substitution of Ga^(3+)evidently affects the crystal field environment of Cr^(3+)and further accounts for the luminescence optimization.Using the optimized phosphor,two sensitive thermometers based on fluorescence intensity ratio(FIR)technique were explored on account of the different temperature dependencies of^(4)T_(2)→^(4)A_(2)and2E→^(4)A_(2)emission and of R2and R1emission.The maximum relative sensitivity Sr are 1.29%/K at 323 K and 1.94%/K at 298 K,respectively,which are superior to that of the Ga^(3+)-unsubstituted one.Besides,the Ga^(3+)→Al^(3+)substitutions endow the resultant phosphors with larger atomic number(Zeff)and theoretical density,which is more conducive to improving X-ray-stimulated emission for X-ray detection.Finally,the potential applications of the developed phosphor are also reflected in plant growth and night vision surveillance,as it is shown to be capable of matching with the absorption of phytochrome PFRand visualizing objects in the dark.This contribution not only proves that the developed LiAl5-xGa_(x)O_(8):Cr^(3+)FR phosphors are promising versatile platforms,but also provides an essential guidance for designing more novel multi-functional materials.展开更多
Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy...Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).展开更多
Microplastics are a widely distributed pollutant that threatens the growth and health of marine organisms.Compared to the mainland,island ecosystems with unique characteristics are fragile and sensitive to natural and...Microplastics are a widely distributed pollutant that threatens the growth and health of marine organisms.Compared to the mainland,island ecosystems with unique characteristics are fragile and sensitive to natural and human interference.We investigated the characteristics and ecological risks of microplastics in the soils of Wuzhizhou Island,Hainan,China,and its surrounding nearshore sediments affected by human activities.Results show that the microplastic abundance in soil was 1116.67 items/kg;the particles were fragmented in size of less than 2 mm,the main polymer types were polypropylene(PP),polyethylene(PE),and polybutylene(PB),in transparent,gray,green,or white.The microplastic abundances in nearshore sediments of Wuzhizhou Island and the surrounding Haitang Bay were 274.67 and 755.17 items/kg,respectively;the particles were mainly fibrous,less than 1 mm in size,the main polymer types were rayon and polyethylene terephthalate(PET),mostly transparent.The abundance of microplastics showed a decreasing trend from shore to sea.Microplastics in the supratidal and intertidal zones differed in mainly the abundance and size.The microplastics in land soil were from tourism activities and infrastructure while the those in nearshore sediments came from not only tourism but also domestic sewage and fishing activities.The ecological risk of microplastics in the terrestrial soils of Wuzhizhou Island was higher than that in its surrounding nearshore sediments.These findings help to gain a deeper understanding of microplastic pollution in the island subjected to intensive human activities,and provide a scientific basis for subsequent in-situ toxicology research on microplastics and plastic pollution control.展开更多
Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structura...Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structural design to optimize the blend morphology remains challenging.Herein,we present a simple yet effective design strategy to modulate the aggregation behavior of the Y-series-based polymer acceptor PY-V-γby introducing a pendant-fluorinated Y-series acceptor(Y2F-ET)into the main-conjugated backbone.Two random copolymer acceptors(PY-EY-5 and PY-EY-20)were synthesized with varying molar fractions of Y2F-ET pendant monomers.Our findings revealed that both the solution-phase and solid-state aggregation behaviors were progressively suppressed as the Y2F-ET content increased.Compared to the highly self-aggregating PY-V-γ-based all-PSCs,the more amorphous PY-EY-5 enabled devices to achieve an increased device efficiency from 17.31%to 18.45%,which is attributed to the slightly smaller polymer phase-separation domain sizes and reduced molecular aggregation in the PM6:PY-EY-5 blend.Moreover,the finely tuned blend morphology exhibited superior thermal stability,underscoring the significant advantages of the Y-series pendant random copolymerization approach.展开更多
AIM: To investigate the protective effect of glutamine (Gln) on intestinal injury and the bacterial community in rats exposed to hypobaric hypoxia environment.
文摘Distribution transformers play a vital role in power distribution systems,and their reliable operation is crucial for grid stability.This study presents a simulation-based framework for active fault diagnosis and early warning of distribution transformers,integrating Sample Ensemble Learning(SEL)with a Self-Optimizing Support Vector Machine(SO-SVM).The SEL technique enhances data diversity and mitigates class imbalance,while SO-SVM adaptively tunes its hyperparameters to improve classification accuracy.A comprehensive transformer model was developed in MATLAB/Simulink to simulate diverse fault scenarios,including inter-turn winding faults,core saturation,and thermal aging.Feature vectors were extracted from voltage,current,and temperature measurements to train and validate the proposed hybrid model.Quantitative analysis shows that the SEL–SO-SVM framework achieves a classification accuracy of 97.8%,a precision of 96.5%,and an F1-score of 97.2%.Beyond classification,the model effectively identified incipient faults,providing an early warning lead time of up to 2.5 s before significant deviations in operational parameters.This predictive capability underscores its potential for preventing catastrophic transformer failures and enabling timely maintenance actions.The proposed approach demonstrates strong applicability for enhancing the reliability and operational safety of distribution transformers in simulated environments,offering a promising foundation for future real-time and field-level implementations.
基金The financial supports from National Natural Science Foundation of China(Nos.52574313,52204272 and 52074091)to this project。
文摘The susceptibility of ore particles to electrical breakdown plays a critical role for high voltage pulse(HVP)breakage,yet its quantitative characterization still lacks deep understanding.Two indicators,namely breakdown delay time(T_(d))and breakdown strength(E_(b))were compared,based on analysis on the two breakdown modes namely wavefront mode and post-wave mode.It was found that T_(d) is more suitable to characterize the susceptibility of ore particles to electrical breakdown in HVP breakage than E_(b).A probabilistic model based on the Weibull distribution is developed to describe the relation of breakdown probability to T_(d).Regression analyses were conducted to investigate how operating parameters and particle properties influence Td and size reduction degree of ore particles in HVP breakage.The regressed models demonstrate potential capability to predict metallic minerals content and HVP breakage degree based on operating parameters and particle properties.
基金funding from Anhui Engineering Laboratory of Explosive Materials and Technology Foundation(No.AHBP2022B-04)Natural Science Research Project of Anhui Educational Committee(No.2023AH051221)+1 种基金Anhui Provincial Natural Science Foundation(No.2208085QA26)Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology for the project related to this work.
文摘Accurately forecasting the triple point(TP)path is essential for analyzing blast loads and assessing the destructive effectiveness of the height of burst explosion.Empirical models that describe the TP path under normal temperature and pressure environments are commonly employed;however,in certain configurations,such as at high-altitudes(HAs),the environment may involve low temperature and pressure conditions.The present study develops a theoretical prediction model for the TP path under reduced pressure and temperature conditions,utilizing the image bursts method,reflected polar analysis,and dimensional analysis.The model's accuracy is evaluated through numerical simulations and experimental data.Results indicate that the prediction model effectively evaluates the TP path under diminished temperature and pressure conditions,with most predictions falling within a±15%deviation.It was found that the TP height increases with altitude.As the altitude rises from 0 m to 10,000 m,the average TP height increases by 61.7%,87.9%,109.0%,and 134.3%for the scaled height of burst of 1.5 m,2.0 m,2.5 m,and 3.0 m,respectively.Moreover,the variation in TP height under HA environments closely mirrors that observed under corresponding reduced pressure conditions.In HA environments,only the effect of low-pressure conditions on the TP path needs to be considered,as the environmental lowtemperature has a minimal effect.
基金supported by National Natural Science Foundation of China(Grant No.52175128)the State Key Laboratory for the Mechanical Behavior of Materials of China(Grant No.20232501).
文摘Laser powder bed fusion(L-PBF)is an advanced metal additive manufacturing process with an excellent capability for fabricating nickel-based superalloys.After solution aging(SA),the l-PBF nickel-based superalloys can match the tensile properties with the conventional manufacturing process;however,its performance under long-life regime service conditions,especially at an elevated temperature of 650℃,has not yet been well understood,which restricts its promotion in industrial applications.In this study,combined with various techniques including X-ray diffraction(XRD),electron backscatter diffraction(EBSD),and micro-computed tomography(micro-CT),the microstructure,phases,micro-texture,and internal defects of SA l-PBF nickel-based superalloys were analyzed,and tensile and cutting-edge fatigue tests with stress ratios R=-1 and 0.1 were performed at 25℃ and 650℃ to investigate the fatigue failure behavior.The results showed that the SA treatment promoted microstructural homogenization with vague laser scanning tracks.The synergistic effect of the γ',γ",and δ phases improved the mechanical and fatigue properties.Elevated temperatures and positive stress ratios promoted the occurrence of subsurface or internal failures.The four cracking modes include crack nucleation from the crystallographic facets,pore-assisted facetted crack nucleation,lack of fusion-induced crack nucleation,and inclusion-induced crack nucleation.At 650℃,the grains fractured along the maximum shear plane,formed a large number of highly inhomogeneous facets,which caused significant fluctuations.Finally,the phase transition processes during SA treatment and defect-related fatigue failure mechanisms were elucidated.This study provides key quality and testing data to support the advancement of l-PBF nickel-based superalloys and provides a foundation for their optimized design and industrial applications.
基金financially supported by the Ningbo Institute of Digital Twin,Eastern Institute of Technology,Ningbo.We also acknowledge supportfrom the Young Innovative Talent of Yongjiang Talent Project(2023A‐387‐G).
文摘The efficient storage and application of sustainable solar energy has drawn significant attention from both academic and industrial points of view.However,most developed catalytic materials still suffer from insufficient mass diffusion and unsatisfactory durability due to the lack of interconnected and regulatable porosity.Developing catalytic architectures with engineered active sites and prominent stability through rational synthesis strategies has become one of the core projects in solar-driven applications.The unique properties of mesoporous silicas render them among the most valuable functional materials for industrial applications,such as high specific surface area,regulatable porosity,adjustable surface properties,tunable particle sizes,and great thermal and mechanical stability.Mesoporous silicas serve as structural templates or catalytic supports to enhance light harvesting via the scattering effect and provide large surface areas for active site generation.These advantages have been widely utilized in solar applications,including hydrogen production,CO_(2)conversion,photovoltaics,biomass utilization,and pollutant degradation.To achieve the specific functionalities and desired activity,various types of mesoporous silicas from different synthesis methods have been customized and synthesized.Moreover,morphology regulation and component modification strategies have also been performed to endow mesoporous silica-based materials with unprecedented efficiency for solar energy storage and utilization.Nevertheless,reviews about synthesis,morphology regulation,and component modification strategies for mesoporous silica-based catalyst design in solar-driven applications are still limited.Herein,the latest progress concerning mesoporous silica-based catalysis in solar-driven applications is comprehensively reviewed.Synthesis principles,formation mechanisms,and rational functionalities of mesoporous silica are systematically summarized.Some typical catalysts with impressive activities in different solar-driven applications are highlighted.Furthermore,challenges and future potential opportunities in this study field are also discussed and proposed.This present review guides the design of mesoporous silica catalysts for efficient solar energy management for solar energy storage and conversion applications.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFE0129100National Natural Science Foundation of China,Grant/Award Number:51674246+1 种基金Graduate Innovation Program of China University of Mining and Technology,Grant/Award Number:2023WLJCRCZL046Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX23_2660。
文摘Compressed air energy storage(CAES)caverns transformed from horseshoe-shaped roadways in abandoned coal mines still face unclear mechanisms of force transfer,especially in the presence of initial damage in the surrounding rock.The shape and size of the initial damage area as well as their effect on cavern stability remain unclear.Due to the complex geometry and multiphysical couplings,traditional numerical algorithms encounter problems of nonconvergence and low accuracy.These challenges can be addressed through numerical simulations with robust convergence and high accuracy.In this study,the damage area shapes of a CAES cavern are first computed using the concept of damage levels.Then,an iteration algorithm is improved using the generalization a method through the error control and one-way coupling loop for fully coupling equations.Finally,the stability of the CAES cavern with different damage zone shapes is numerically simulated in the thermodynamic process.It is found that this improved algorithm can greatly enhance numerical convergence and accuracy.The nonuniformity of the elastic modulus has a significant impact on the mechanical responses of the CAES cavern.The cavern shape with different damage zones has significant impacts on cavern stability.The initial damage area can delay the responses of temperature and stress.It induces variations of temperature in the range of approximately 1.2 m and variations of stress in the range of 1.5 m from the damage area.
基金Project supported by the National Natural Science Foundation of China(52272143,51902063)the Guangdong Basic and Applied Basic Research Foundation(2023A1515010166,2023A1515010866,2021A1515110404)the Major Science and Technology Project of Jiangxi Province(20223AAE01003)。
文摘Cr^(3+)-activated spinel-type phosphors have great potential in different application scenes due to their unique sharp and far-red(FR)emission.However,the multi-functionalization of these phosphors is still limited by their unsatisfied comprehensive properties.Herein,a simple composition engineering was used to explore versatile phosphors,using Ga^(3+)to substitute Al^(3+)to improve the optical performances of spinel LiAl5-xGa_(x)O_(8):Cr^(3+).The substitution of Ga^(3+)evidently affects the crystal field environment of Cr^(3+)and further accounts for the luminescence optimization.Using the optimized phosphor,two sensitive thermometers based on fluorescence intensity ratio(FIR)technique were explored on account of the different temperature dependencies of^(4)T_(2)→^(4)A_(2)and2E→^(4)A_(2)emission and of R2and R1emission.The maximum relative sensitivity Sr are 1.29%/K at 323 K and 1.94%/K at 298 K,respectively,which are superior to that of the Ga^(3+)-unsubstituted one.Besides,the Ga^(3+)→Al^(3+)substitutions endow the resultant phosphors with larger atomic number(Zeff)and theoretical density,which is more conducive to improving X-ray-stimulated emission for X-ray detection.Finally,the potential applications of the developed phosphor are also reflected in plant growth and night vision surveillance,as it is shown to be capable of matching with the absorption of phytochrome PFRand visualizing objects in the dark.This contribution not only proves that the developed LiAl5-xGa_(x)O_(8):Cr^(3+)FR phosphors are promising versatile platforms,but also provides an essential guidance for designing more novel multi-functional materials.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602200)the National Natural Science Foundation of China(Nos.12341501 and 12405174)the Hefei Comprehensive National Science Center for the strong support on the STCF key technology research project.
文摘Electron-positron colliders operating in the GeV center-of-mass range,or tau-charm energy region,have been proved to enable competitive frontier research due to several unique features.With the progress of high-energy physics in the last two decades,a new-generation Tau-Charm factory,called the Super Tau-Charm Facility(STCF),has been actively promoted by the particle physics community in China.STCF has the potential to address fundamental questions such as the essence of color confinement and the matter-antimatter asymmetry within the next decades.The main design goals of the STCF are a center-of-mass energy ranging from 2 to 7 GeV and a luminosity surpassing 5×10^(34)cm^(−2)s^(−1)that is optimized at a center-of-mass energy of 4 GeV,which is approximately 50 times that of the currently operating Tau-Charm factory-BEPCII.The STCF accelerator has two main parts:a double-ring collider with a crab-waist collision scheme and an injector that provides top-up injections for both electron and positron beams.As a typical third-generation electron-positron circular collider,the STCF accelerator faces many challenges in both accelerator physics and technology.In this paper,the conceptual design of the STCF accelerator complex is presented,including the ongoing efforts and plans for technological research and develop-ment,as well as the required infrastructure.The STCF project aims to secure support from the Chinese central government for its construction during the 15th Five-Year Plan(2026-2030).
基金the Hainan Provincial Natural Science Foundation of China(No.422MS082)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(No.2021CXLH0009)+2 种基金the Funding Scheme for High-level Overseas Chinese Students’Return of Ministry of Human Resources and Social Security of China and ScienceOpen Project Program of Yazhou Bay Innovation Institute of Hainan Tropical Ocean University(No.2022RHDKFKT08)Technology Project of Yazhou Bay Innovation Institute of Hainan Tropical Ocean University(No.2022CXYZD002)。
文摘Microplastics are a widely distributed pollutant that threatens the growth and health of marine organisms.Compared to the mainland,island ecosystems with unique characteristics are fragile and sensitive to natural and human interference.We investigated the characteristics and ecological risks of microplastics in the soils of Wuzhizhou Island,Hainan,China,and its surrounding nearshore sediments affected by human activities.Results show that the microplastic abundance in soil was 1116.67 items/kg;the particles were fragmented in size of less than 2 mm,the main polymer types were polypropylene(PP),polyethylene(PE),and polybutylene(PB),in transparent,gray,green,or white.The microplastic abundances in nearshore sediments of Wuzhizhou Island and the surrounding Haitang Bay were 274.67 and 755.17 items/kg,respectively;the particles were mainly fibrous,less than 1 mm in size,the main polymer types were rayon and polyethylene terephthalate(PET),mostly transparent.The abundance of microplastics showed a decreasing trend from shore to sea.Microplastics in the supratidal and intertidal zones differed in mainly the abundance and size.The microplastics in land soil were from tourism activities and infrastructure while the those in nearshore sediments came from not only tourism but also domestic sewage and fishing activities.The ecological risk of microplastics in the terrestrial soils of Wuzhizhou Island was higher than that in its surrounding nearshore sediments.These findings help to gain a deeper understanding of microplastic pollution in the island subjected to intensive human activities,and provide a scientific basis for subsequent in-situ toxicology research on microplastics and plastic pollution control.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22279094 and 22409149)Hubei Provincial Natural Science Foundation(No.2024 AFB068)Fundamental Research Funds for the Central Universities。
文摘Polymer acceptor configuration and aggregation behavior are critical in determining the photovoltaic performance of all-polymer solar cells(all-PSCs).Effectively manipulating polymer self-aggregation through structural design to optimize the blend morphology remains challenging.Herein,we present a simple yet effective design strategy to modulate the aggregation behavior of the Y-series-based polymer acceptor PY-V-γby introducing a pendant-fluorinated Y-series acceptor(Y2F-ET)into the main-conjugated backbone.Two random copolymer acceptors(PY-EY-5 and PY-EY-20)were synthesized with varying molar fractions of Y2F-ET pendant monomers.Our findings revealed that both the solution-phase and solid-state aggregation behaviors were progressively suppressed as the Y2F-ET content increased.Compared to the highly self-aggregating PY-V-γ-based all-PSCs,the more amorphous PY-EY-5 enabled devices to achieve an increased device efficiency from 17.31%to 18.45%,which is attributed to the slightly smaller polymer phase-separation domain sizes and reduced molecular aggregation in the PM6:PY-EY-5 blend.Moreover,the finely tuned blend morphology exhibited superior thermal stability,underscoring the significant advantages of the Y-series pendant random copolymerization approach.
基金Supported by National Natural Science Foundation of China,No.31001012 and No.31101304Programs for Agricultural Science and Technology Development of Shaanxi Province,China,No.2013K02-16Northwestern Polytechnical University Foundation Science Research Fund,No.JC201278
文摘AIM: To investigate the protective effect of glutamine (Gln) on intestinal injury and the bacterial community in rats exposed to hypobaric hypoxia environment.
