The second most important cause of lung cancer after smoking is radon gas. Thus, the determination of indoor radon concentrations in residential buildings and workplaces is an important public health concern. The purp...The second most important cause of lung cancer after smoking is radon gas. Thus, the determination of indoor radon concentrations in residential buildings and workplaces is an important public health concern. The purpose of this research was to measure the concentration of radon gas in the offices of the Institute of Science and Technology and to evaluate the effective dose in the lungs and the risk of cancer. This study used Corentium’s AIR THINGS digital radon detector to determine the radon concentration in sixteen (16) offices. The digital radon detector air Things of Corentium was placed in each office for a minimum period of one week and the concentration values were recorded every 24 hours. The values recorded in each office were the short-term average and the long-term average during seven days of measurement. The short-term radon concentrations vary between 5.286 Bq/m<sup>3</sup> and 192.714 Bq/m3</sup> with an average of 48.01 Bq/m3</sup> and those in the long-term were between 6.143 Bq/m3</sup> and 172.571 Bq/m3</sup> with an average of 52.46 Bq/m3</sup>. The measurements in office N°6 and 13 were above the lower limit of 100 Bq/m3</sup> proposed by the WHO. The short-term and long-term effective doses in the lungs for offices N°6 and 13 were above the “normal” background level of 1.1 mSv/year proposed by UNSCEAR-2000. The short-term effective dose in the lungs for office N°6 was above the lower limit of 3 mSv per the ICRP-23 recommendation. The average number of lung cancer cases per year per million people was 15.展开更多
Displays represent information visually,so they have become the fundamental building block to visualize the data of current electronics including smartphones.Recently,electronics have been advanced toward flexible and...Displays represent information visually,so they have become the fundamental building block to visualize the data of current electronics including smartphones.Recently,electronics have been advanced toward flexible and wearable electronics that can be bent,folded,or stretched while maintaining their performance under various deformations.Here,recent advances in research to demonstrate flexible and wearable displays are reviewed.We introduce these results by dividing them into several categories according to the components of the display:active-matrix backplane,touch screen panel,light sources,integrated circuit for fingerprint touch screen panel,and characterization tests;and we also present mechanical tests in nano-meter scale and visual ergonomics research.展开更多
Corresponding author’s name was incorrectly written as“Dadang Guo”instead of“Dagang Guo”.The correct author name should be“Dagang Guo”.The authors would like to apologise for any inconvenience caused.
Organic and pharmaceutical synthesis have traditionally relied on the stepwise transformation ofactivated functional groups to synthesize cyclic molecules.The design of valuable heterocyclic compounds,for instance,has...Organic and pharmaceutical synthesis have traditionally relied on the stepwise transformation ofactivated functional groups to synthesize cyclic molecules.The design of valuable heterocyclic compounds,for instance,has depended on multi-step routes such as polar or radical cyclization,cycloadditions,and the manipulation of various functional groups to achieve ring formation or connection[1,2].展开更多
Electroslag remelting(ESR) is an important metallurgical process for producing high-purity materials with homogeneous compositions and sound microstructures,and its typical products are ingots or simple castings.The c...Electroslag remelting(ESR) is an important metallurgical process for producing high-purity materials with homogeneous compositions and sound microstructures,and its typical products are ingots or simple castings.The core principle involves the resistive melting of a consumable electrode within a slag pool,followed by the refining of molten metal droplets as they traverse the slag,and subsequent sequential solidification in a water-cooled mold.However,conventional ESR processes face limitations in producing large or complex-shaped components,enhancing production efficiency,achieving highly specialized microstructures,and meeting ultra-high purity demands for advanced applications.Advanced composite ESR technologies have been developed to overcome these limitations by innovatively modifying key process aspects.For instance,electrode systems are improved using vibration,rotation,or multiple electrodes.Enhanced mold design and solidification control are achieved through techniques including conductive molds,mold rotation,and ingot withdrawal.Precise control of the process is realized through the use of protective gas,vacuum,or elevated pressure,as well as the application of external fields such as magnetic fields or ultrasonic vibration.This review comprehensively summarizes these advanced techniques,examining their principles and characteristics,and discussing their specific advantages and challenges.展开更多
Suffusion refers to the loss of fineparticles within the soil matrix without any associated volume change,induced by hydrodynamic forces.This study investigated the suffusion of sand-clay mixtures through one-dimensio...Suffusion refers to the loss of fineparticles within the soil matrix without any associated volume change,induced by hydrodynamic forces.This study investigated the suffusion of sand-clay mixtures through one-dimensional soil column experiments under a stepwise increase in hydraulic gradient(i),aiming to evaluate the critical hydraulic gradient(icrit)as a function of the size ratio between sand and clay,clay type,and ionic concentration.It was found that icrit was less than 0.1 for all sand-clay mixtures examined in this study.In addition,the lower peak concentrations of filtrated clay observed in sand-illite mixtures,compared to those of sand-kaolinite mixtures at the same level of i,suggest that illite particles are more susceptible to suffusion.Overall,the observed breakthrough curves,mass fraction of filtrated clay,volume of outflow,and total injection time presented in this study highlight the importance of considering clay type,sand-to-clay size ratio,and ionic concentration when assessing the suffusion behavior of clay-containing soils under a stepwise increase in hydraulic gradient.展开更多
The nervous system function requires a precise but plastic neural architecture.The neuronal shape dictates how neurons interact with each other and with other cells,being the morphology of dendrites and axons the cent...The nervous system function requires a precise but plastic neural architecture.The neuronal shape dictates how neurons interact with each other and with other cells,being the morphology of dendrites and axons the central determinant of the functional properties of neurons and neural circuits.The topological and structural morphology of axons and dendrites defines and determines how synapses are conformed.The morphological diversity of axon and dendrite arborization governs the neuron’s inputs,synaptic integration,neuronal computation,signal transmission,and network circuitry,hence defining the particular connectivity and function of the different brain areas.展开更多
Radical cycloaddition reactions(RCRs) are highly effective methods for constructing complex carbo-and heterocycles,which are frequently encountered in natural products that exhibit intriguing biological properties and...Radical cycloaddition reactions(RCRs) are highly effective methods for constructing complex carbo-and heterocycles,which are frequently encountered in natural products that exhibit intriguing biological properties and hold significant potential for applications in medicinal chemistry.Radical-mediated cycloaddition strategies,which recycle radical character,are particularly appealing because they require only a catalytic amount of reagent and promise reactions with theoretically high atom economy.This review focuses on recent developments and synthetic applications in RCRs,with an emphasis on visible lightinduced radical photocycloaddition reactions(RPCRs),transition metal-catalyzed approaches,and small molecule-catalyzed methods.By highlighting some outstanding innovations and addressing current challenges,this review aims to identify potential areas for improvement.These advancements will provide more efficient pathways for the synthesis of natural product molecules and offer valuable insights for the development of new synthetic methodologies.展开更多
Thiswork explores aMagnetohydrodynamic(MHD)flowin a triangular cavitywith a thermally insulated baffle.Enclosure’s inclined wall is hotter,whereas the vertical border is adiabatic and the bottom is cooler.The study a...Thiswork explores aMagnetohydrodynamic(MHD)flowin a triangular cavitywith a thermally insulated baffle.Enclosure’s inclined wall is hotter,whereas the vertical border is adiabatic and the bottom is cooler.The study aims to clarify how geometric changes affect thermal performance and offers new perspectives on how to improve heat dissipation mechanisms.A COMSOL Multiphysics version 6.2 has been used to solve numerical solutions.Streamlines and thermal distributions are examined systematically in order to understand how the unique geometry and baffle size of triangular cavities can influence the fluid flow.This influence can result in optimized flow patterns,promoting efficient heat transfer by directing the fluid to specific areas that require more cooling.In comparison with conventional designs,this optimization results in more efficient convective heat transfer,which raises cooling efficiency and lowers thermal resistance.Furthermore,by strengthening heat transfer characteristics in heat transfer systems,these geometries increase thermal efficiency,which helps several sectors,including the production of electricity,HVAC,and the automobile industry.展开更多
The safe driving and operation of trains is a necessary condition for ensuring the safe operation of trains.In particular,heavy-haul trains are characterized by the difficulty in driving and operation.Considering the ...The safe driving and operation of trains is a necessary condition for ensuring the safe operation of trains.In particular,heavy-haul trains are characterized by the difficulty in driving and operation.Considering the uncertainties in train driving and operation,this paper analyzes the relationship between the safety of heavy-haul electric locomotive hauled trains and driving and operation.It studies the auxiliary intelligent driving safety operation control methods.Through K-means to identify the characteristics of drivers'driving manipulation,the hidden Markov model adaptively adjusts the train driving and operation sequence,and conducts auxiliary driving reconstruction for heavy-haul locomotive driving and operation.Based on the train running curve and the locomotive traction/braking characteristics,it smoothly controls the exertion of the traction/braking force of heavy-haul locomotives,thereby optimizing the driving safety control of heavy-haul trains in the vehicle-environment-track system.Finally,the train operation simulation and optimized driving verification are carried out by simulating some track sections.The results show that the proposed method can correct and pre-optimize driving operations,improving the smoothness of heavy-haul trains by approximately 10%.It verifies the effectiveness of the proposed train assisted driving control reconstruction method,facilitating the smooth and safe operation of heavy-haul trains.展开更多
Structural instability and sluggish lithium-ion(Li+) kinetics of spinel NiCo_(2)O_(4) anodes severely hinder their applications in high-energy-density lithium-ion batteries.Mesocrystalline structures exhibit promising...Structural instability and sluggish lithium-ion(Li+) kinetics of spinel NiCo_(2)O_(4) anodes severely hinder their applications in high-energy-density lithium-ion batteries.Mesocrystalline structures exhibit promising potential in balancing structural stability and enhancing reaction kinetics.However,their controlled synthesis mechanisms remain elusive.Herein,a substrate interface engineering strategy is developed to achieve controllable synthesis of mesocrystalline and polycrystalline NiCo_(2)O_(4) nanorods.Remarkably,mesocrystalline NiCo_(2)O_(4) exhibits a high capacity retention rate of 85.7% after 500 cycles at 2 A/g,attributed to its porous structure facilitating Li^(+) transport kinetics and unique stress-buffering effect validated by ex-situ TEM.Theoretical calculations and interfacial chemical analysis reveal that substratecrystal surface engineering regulates the nucleation-growth pathways:Acid-treated nickel foam enables epitaxial growth via lattice matching,acting as a low-interfacial-energy template to reduce nucleation barriers and promote low-temperature oriented crystallization.In contrast,carbon cloth requires hightemperature thermal activation to overcome surface diffusion barriers induced by elevated interfacial energy.This substrate-driven crystallization kinetic modulation overcomes the limitations of random nucleation in conventional hydrothermal synthesis.The established substrate-crystal interfacial interaction model not only clarifies the kinetic essence of crystal orientation regulation but also provides a universal theoretical framework for lattice-matching design and mesostructural optimization of advanced electrode materials.展开更多
The high voltage of Li||LiCoO_(2) battery can increase the energy density.However,the cycling performance associated with cathode structural stability remains challenging.To address this question,we proposed an electr...The high voltage of Li||LiCoO_(2) battery can increase the energy density.However,the cycling performance associated with cathode structural stability remains challenging.To address this question,we proposed an electrolyte strategy for improving the performance of 4.6 V Li||LiCoO_(2) battery by using trimethylsilyl isocyanate(TMIS)as electrolyte additive.The trimethylsilyl group of TMIS can trap HF while the isocyanate group brings polyamide components to the CEI and the SEI.By the synergistic action,the Co3+dissolution problem of the LiCoO_(2) cathode was effectively curbed.Furthermore,TMIS regulates the construction of anion-dominated LiF-rich SEI by influencing the solvation structure of Li+.As expected,the 4.6 V Li||LiCoO_(2) battery with TMIS retains 77.9% initial capacity after 200 cycles at 0.5 C.展开更多
Lithium manganese silicate(Li-Mn-Si-O)cathodes are key components of lithium-ion batteries,and their physical and mechanical properties are strongly influenced by their underlying crystal structures.In this study,a ra...Lithium manganese silicate(Li-Mn-Si-O)cathodes are key components of lithium-ion batteries,and their physical and mechanical properties are strongly influenced by their underlying crystal structures.In this study,a range of machine learning(ML)algorithms were developed and compared to predict the crystal systems of Li-Mn-Si-O cathode materials using density functional theory(DFT)data obtained from the Materials Project database.The dataset comprised 211 compositions characterized by key descriptors,including formation energy,energy above the hull,bandgap,atomic site number,density,and unit cell volume.These features were utilized to classify the materials into monoclinic(0)and triclinic(1)crystal systems.A comprehensive comparison of various classification algorithms including Decision Tree,Random Forest,XGBoost,Support VectorMachine,k-Nearest Neighbor,Stochastic Gradient Descent,Gaussian Naive Bayes,Gaussian Process,and Artificial Neural Network(ANN)was conducted.Among these,the optimized ANN architecture(6–14-14-14-1)exhibited the highest predictive performance,achieving an accuracy of 95.3%,aMatthews correlation coefficient(MCC)of 0.894,and an F-score of 0.963,demonstrating excellent consistency with DFT-predicted crystal structures.Meanwhile,RandomForest and Gaussian Processmodels also exhibited reliable and consistent predictive capability,indicating their potential as complementary approaches,particularly when data are limited or computational efficiency is required.This comparative framework provides valuable insights into model selection for crystal system classification in complex cathode materials.展开更多
Vibrio harveyi,a Gram-negative bacterium ubiquitous in marine environments,is recognized as an opportunistic pathogen affecting various aquatic organisms such as fish,shrimp,and shellfish.To enhance its environmental ...Vibrio harveyi,a Gram-negative bacterium ubiquitous in marine environments,is recognized as an opportunistic pathogen affecting various aquatic organisms such as fish,shrimp,and shellfish.To enhance its environmental resilience and adaptive capacity,V.harveyi employs a complex quorum sensing mechanism to modulate its virulence factors,such as bioluminescence,biofilm formation,and motility.Therefore,targeting the quorum sensing of V.harveyi could be a promising strategy to develop novel approaches to ensure the microbial safety of seafood products.This study aims to evaluate the impact of curcumin-mediated photo/sonodynamic treatment on quorum sensing in V.harveyi and its regulated functions.The results indicate a significant decrease of luminescence in V.harveyi following curcumin-mediated photo/sonodynamic treatment.Correspondingly,the biofilm formation ability and bacterial motility of V.harveyi were also greatly impaired by the treatment.Notably,the production of reactive oxygen species in bacteria induced by the photo/sonodynamic treatment could be the underlying mechanism involved in the observed disruption of quorum sensing.These findings underscore the great potential of photo/sonodynamic treatment as a promising strategy to disrupt quorum sensing and mitigate the virulence of V.harveyi,thereby contributing to the development of effective control strategies against this pervasive pathogen.展开更多
α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to syn...α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to synthesizeα-chiral amides from benzyl ammonium salts and isocyanates.The key to success is using a chiral 2,2-bipyridine ligand(-)-Ph-SBpy,enabling high yield(up to 95%)and enantiomeric ratio(up to 98:2 er)under mild conditions.Addition of phenol prevents isocyanate polymerization by reversibly forming a carbamate intermediate,enhancing selectivity and efficiency.The synthetic utility is showcased through transformations of the enantioenriched amides,and the mechanism and enantioselectivity are supported by experimental and computational studies.展开更多
The lateral transport of labile organic carbon represents a critical pathway for soil organic carbon(SOC) loss,reducing organic carbon sequestration and increasing the risk of waterbody pollution.Livestock manure appl...The lateral transport of labile organic carbon represents a critical pathway for soil organic carbon(SOC) loss,reducing organic carbon sequestration and increasing the risk of waterbody pollution.Livestock manure application on croplands serves as a common fertilizer reduction practice to sustain crop yields,enhance SOC sequestration,and reduce water erosion.However,limited quantitative assessments have examined the effects of livestock manure substitution on labile organic carbon lateral loss and fluxes in long-term experiments.This study conducted a three-year field investigation on subtropical sloping croplands to assess the impact of livestock manure substitution on dissolved organic carbon(DOC) and particulate organic carbon(POC) loss via surface runoff,interflow and eroded sediments.There are four treatments:no fertilization(CK);chemical nitrogen fertilizer(SF),40% nitrogen substitution with pig manure(PMF),and 100% nitrogen substitution from pig manure(PM).Compared to SF treatment,long-term livestock manure substitution in PMF and PM treatments significantly(P<0.05) reduced annual cumulative surface runoff fluxes by 13.5 and 21.6%,respectively.Manure applications decreased annual sediment fluxes by 12.9 and 19.1%,respectively.Soil water stable aggregates for mean weight diameter(MWD) increased significantly by 37.7 and 73.6%.Annual cumulative POC loss flux via eroded sediment under PMF and PM treatments increased significantly(P<0.05) by 61.1 and 47.9%,respectively.The labile organic carbon loss fluxes,including DOC and POC losses,under PMF and PM treatments increased significantly(P<0.05) by 11.9 and 31.4%,respectively.These results demonstrate that while water erosion intensity decreases due to enhanced soil aggregate stability,the risk of labile organic carbon loss increases after long-term livestock manure substitution in subtropical sloping croplands.Future research should examine labile organic carbon lateral migration under various soil types and slope gradients for livestock manure application in subtropical agricultural ecosystem croplands to better understand extreme rainfall effects.展开更多
The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials off...The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials.展开更多
Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and of...Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and offering the highest theoretical energy density(~3.5 k Wh kg^(-1))among discussed candidates.Contributing to the poor cycle life of currently reported Li-O_(2)cells is singlet oxygen(1O_(2))formation,inducing parasitic reactions,degrading key components,and severely deteriorating cell performance.Here,we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets(Co_(3)O_(4)NSs)as cathode materials to suppress 1O_(2)in Li-O_(2)batteries for the first time.Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in 1O_(2)during discharge and charge,respectively,compared to conventional carbon paperbased cells,consistent with differential electrochemical mass spectrometry results,which indicate a near-theoretical charge-to-O_(2)ratio(2.04 e-/O_(2)).Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level,enhancing Co 3d-O 2p hybridization,stabilizing reaction intermediates,and lowering activation barriers for Li_(2)O_(2)formation and decomposition.These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O_(2)batteries,abridging the current gap to commercialization.展开更多
This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywo...This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywords after indexing national R＆D information in Korea （human resources, project and outcome） and applying expertise calculation algorithm. In consideration of the characteristics of national R＆D information, weight values have been selected. Then, expertise points were calculated by applying weighted values. In addition, joint research and collaborative relations were implemented in a knowledge map format through network analysis using national R＆D information.展开更多
Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review arti...Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review articles in Web of Science,Scopus and Publisher’s websites on a large scale.Design/methodology/approach:27,616 papers from 160 journals from 10 review journal series indexed in SCI are analyzed.The document types of these papers labeled on journals’websites,and assigned by WoS and Scopus are retrieved and compared to determine the assigning accuracy and identify the possible reasons for wrongly assigning.For the document type labeled on the website,we further differentiate them into explicit review and implicit review based on whether the website directly indicates it is a review or not.Findings:Overall,WoS and Scopus performed similarly,with an average precision of about 99% and recall of about 80%.However,there were some differences between WoS and Scopus across different journal series and within the same journal series.The assigning accuracy of WoS and Scopus for implicit reviews dropped significantly,especially for Scopus.Research limitations:The document types we used as the gold standard were based on the journal websites’labeling which were not manually validated one by one.We only studied the labeling performance for review articles published during 2017-2018 in review journals.Whether this conclusion can be extended to review articles published in non-review journals and most current situation is not very clear.Practical implications:This study provides a reference for the accuracy of document type assigning of review articles in WoS and Scopus,and the identified pattern for assigning implicit reviews may be helpful to better labeling on websites,WoS and Scopus.Originality/value:This study investigated the assigning accuracy of document type of reviews and identified the some patterns of wrong assignments.展开更多
文摘The second most important cause of lung cancer after smoking is radon gas. Thus, the determination of indoor radon concentrations in residential buildings and workplaces is an important public health concern. The purpose of this research was to measure the concentration of radon gas in the offices of the Institute of Science and Technology and to evaluate the effective dose in the lungs and the risk of cancer. This study used Corentium’s AIR THINGS digital radon detector to determine the radon concentration in sixteen (16) offices. The digital radon detector air Things of Corentium was placed in each office for a minimum period of one week and the concentration values were recorded every 24 hours. The values recorded in each office were the short-term average and the long-term average during seven days of measurement. The short-term radon concentrations vary between 5.286 Bq/m<sup>3</sup> and 192.714 Bq/m3</sup> with an average of 48.01 Bq/m3</sup> and those in the long-term were between 6.143 Bq/m3</sup> and 172.571 Bq/m3</sup> with an average of 52.46 Bq/m3</sup>. The measurements in office N°6 and 13 were above the lower limit of 100 Bq/m3</sup> proposed by the WHO. The short-term and long-term effective doses in the lungs for offices N°6 and 13 were above the “normal” background level of 1.1 mSv/year proposed by UNSCEAR-2000. The short-term effective dose in the lungs for office N°6 was above the lower limit of 3 mSv per the ICRP-23 recommendation. The average number of lung cancer cases per year per million people was 15.
文摘Displays represent information visually,so they have become the fundamental building block to visualize the data of current electronics including smartphones.Recently,electronics have been advanced toward flexible and wearable electronics that can be bent,folded,or stretched while maintaining their performance under various deformations.Here,recent advances in research to demonstrate flexible and wearable displays are reviewed.We introduce these results by dividing them into several categories according to the components of the display:active-matrix backplane,touch screen panel,light sources,integrated circuit for fingerprint touch screen panel,and characterization tests;and we also present mechanical tests in nano-meter scale and visual ergonomics research.
文摘Corresponding author’s name was incorrectly written as“Dadang Guo”instead of“Dagang Guo”.The correct author name should be“Dagang Guo”.The authors would like to apologise for any inconvenience caused.
基金supported by the MSIT(2022R1F1A106268,RS-2023-00213491,RS-2023-00219859,RS-2024-00405261,RS-2024-00409589,RS-2025-25460522,and RS-2025-00642970)Republic of Korea,the InnoCORE program of the Ministry of Science and ICT of Korea(N10250153 and 1.250022.01)the Creative Research Program and KAIST Cross-Generation Collaborative Lab Project.
文摘Organic and pharmaceutical synthesis have traditionally relied on the stepwise transformation ofactivated functional groups to synthesize cyclic molecules.The design of valuable heterocyclic compounds,for instance,has depended on multi-step routes such as polar or radical cyclization,cycloadditions,and the manipulation of various functional groups to achieve ring formation or connection[1,2].
基金supported by the National Natural Science Foundation of China (NSFC 52175352)。
文摘Electroslag remelting(ESR) is an important metallurgical process for producing high-purity materials with homogeneous compositions and sound microstructures,and its typical products are ingots or simple castings.The core principle involves the resistive melting of a consumable electrode within a slag pool,followed by the refining of molten metal droplets as they traverse the slag,and subsequent sequential solidification in a water-cooled mold.However,conventional ESR processes face limitations in producing large or complex-shaped components,enhancing production efficiency,achieving highly specialized microstructures,and meeting ultra-high purity demands for advanced applications.Advanced composite ESR technologies have been developed to overcome these limitations by innovatively modifying key process aspects.For instance,electrode systems are improved using vibration,rotation,or multiple electrodes.Enhanced mold design and solidification control are achieved through techniques including conductive molds,mold rotation,and ingot withdrawal.Precise control of the process is realized through the use of protective gas,vacuum,or elevated pressure,as well as the application of external fields such as magnetic fields or ultrasonic vibration.This review comprehensively summarizes these advanced techniques,examining their principles and characteristics,and discussing their specific advantages and challenges.
基金supported by the National Research Foundation of Korea(NRF)grants(Grant Nos.RS-2020-NR049594 and RS-2022-NR071877)the Korea Agency for Infrastructure Technology Advancement under the Ministry of Land,Infrastructure and Transport(Grant No.RS-2024-00410248).
文摘Suffusion refers to the loss of fineparticles within the soil matrix without any associated volume change,induced by hydrodynamic forces.This study investigated the suffusion of sand-clay mixtures through one-dimensional soil column experiments under a stepwise increase in hydraulic gradient(i),aiming to evaluate the critical hydraulic gradient(icrit)as a function of the size ratio between sand and clay,clay type,and ionic concentration.It was found that icrit was less than 0.1 for all sand-clay mixtures examined in this study.In addition,the lower peak concentrations of filtrated clay observed in sand-illite mixtures,compared to those of sand-kaolinite mixtures at the same level of i,suggest that illite particles are more susceptible to suffusion.Overall,the observed breakthrough curves,mass fraction of filtrated clay,volume of outflow,and total injection time presented in this study highlight the importance of considering clay type,sand-to-clay size ratio,and ionic concentration when assessing the suffusion behavior of clay-containing soils under a stepwise increase in hydraulic gradient.
基金supported by the Wellcome Trust(grant No.103852).
文摘The nervous system function requires a precise but plastic neural architecture.The neuronal shape dictates how neurons interact with each other and with other cells,being the morphology of dendrites and axons the central determinant of the functional properties of neurons and neural circuits.The topological and structural morphology of axons and dendrites defines and determines how synapses are conformed.The morphological diversity of axon and dendrite arborization governs the neuron’s inputs,synaptic integration,neuronal computation,signal transmission,and network circuitry,hence defining the particular connectivity and function of the different brain areas.
基金The financial support from the National Natural Science Foundation of China (Nos.22150410339,W2432012,22301237 and 22171218)the Ministry of Science and Technology China (No.wgxz2022188) is greatly acknowledged。
文摘Radical cycloaddition reactions(RCRs) are highly effective methods for constructing complex carbo-and heterocycles,which are frequently encountered in natural products that exhibit intriguing biological properties and hold significant potential for applications in medicinal chemistry.Radical-mediated cycloaddition strategies,which recycle radical character,are particularly appealing because they require only a catalytic amount of reagent and promise reactions with theoretically high atom economy.This review focuses on recent developments and synthetic applications in RCRs,with an emphasis on visible lightinduced radical photocycloaddition reactions(RPCRs),transition metal-catalyzed approaches,and small molecule-catalyzed methods.By highlighting some outstanding innovations and addressing current challenges,this review aims to identify potential areas for improvement.These advancements will provide more efficient pathways for the synthesis of natural product molecules and offer valuable insights for the development of new synthetic methodologies.
文摘Thiswork explores aMagnetohydrodynamic(MHD)flowin a triangular cavitywith a thermally insulated baffle.Enclosure’s inclined wall is hotter,whereas the vertical border is adiabatic and the bottom is cooler.The study aims to clarify how geometric changes affect thermal performance and offers new perspectives on how to improve heat dissipation mechanisms.A COMSOL Multiphysics version 6.2 has been used to solve numerical solutions.Streamlines and thermal distributions are examined systematically in order to understand how the unique geometry and baffle size of triangular cavities can influence the fluid flow.This influence can result in optimized flow patterns,promoting efficient heat transfer by directing the fluid to specific areas that require more cooling.In comparison with conventional designs,this optimization results in more efficient convective heat transfer,which raises cooling efficiency and lowers thermal resistance.Furthermore,by strengthening heat transfer characteristics in heat transfer systems,these geometries increase thermal efficiency,which helps several sectors,including the production of electricity,HVAC,and the automobile industry.
基金Project(U2034211)supported by the National Natural Science Foundation of ChinaProject(20232ACE01013)supported by the Major Scientific and Technological Research and Development Special Project of Jiangxi Province,China。
文摘The safe driving and operation of trains is a necessary condition for ensuring the safe operation of trains.In particular,heavy-haul trains are characterized by the difficulty in driving and operation.Considering the uncertainties in train driving and operation,this paper analyzes the relationship between the safety of heavy-haul electric locomotive hauled trains and driving and operation.It studies the auxiliary intelligent driving safety operation control methods.Through K-means to identify the characteristics of drivers'driving manipulation,the hidden Markov model adaptively adjusts the train driving and operation sequence,and conducts auxiliary driving reconstruction for heavy-haul locomotive driving and operation.Based on the train running curve and the locomotive traction/braking characteristics,it smoothly controls the exertion of the traction/braking force of heavy-haul locomotives,thereby optimizing the driving safety control of heavy-haul trains in the vehicle-environment-track system.Finally,the train operation simulation and optimized driving verification are carried out by simulating some track sections.The results show that the proposed method can correct and pre-optimize driving operations,improving the smoothness of heavy-haul trains by approximately 10%.It verifies the effectiveness of the proposed train assisted driving control reconstruction method,facilitating the smooth and safe operation of heavy-haul trains.
基金financially supported by the National Nature Science Foundation of China (No.52401273)Science and Technology Department of Henan (Nos.242102241007,252102320178 and 252102321067)Training Program for Young Backbone Teachers in Higher Education Institutions in Henan Province (No.2024GGJS101)。
文摘Structural instability and sluggish lithium-ion(Li+) kinetics of spinel NiCo_(2)O_(4) anodes severely hinder their applications in high-energy-density lithium-ion batteries.Mesocrystalline structures exhibit promising potential in balancing structural stability and enhancing reaction kinetics.However,their controlled synthesis mechanisms remain elusive.Herein,a substrate interface engineering strategy is developed to achieve controllable synthesis of mesocrystalline and polycrystalline NiCo_(2)O_(4) nanorods.Remarkably,mesocrystalline NiCo_(2)O_(4) exhibits a high capacity retention rate of 85.7% after 500 cycles at 2 A/g,attributed to its porous structure facilitating Li^(+) transport kinetics and unique stress-buffering effect validated by ex-situ TEM.Theoretical calculations and interfacial chemical analysis reveal that substratecrystal surface engineering regulates the nucleation-growth pathways:Acid-treated nickel foam enables epitaxial growth via lattice matching,acting as a low-interfacial-energy template to reduce nucleation barriers and promote low-temperature oriented crystallization.In contrast,carbon cloth requires hightemperature thermal activation to overcome surface diffusion barriers induced by elevated interfacial energy.This substrate-driven crystallization kinetic modulation overcomes the limitations of random nucleation in conventional hydrothermal synthesis.The established substrate-crystal interfacial interaction model not only clarifies the kinetic essence of crystal orientation regulation but also provides a universal theoretical framework for lattice-matching design and mesostructural optimization of advanced electrode materials.
基金supported by the National Natural Science Foundation of China(Nos.U21A20311 and 52400163).
文摘The high voltage of Li||LiCoO_(2) battery can increase the energy density.However,the cycling performance associated with cathode structural stability remains challenging.To address this question,we proposed an electrolyte strategy for improving the performance of 4.6 V Li||LiCoO_(2) battery by using trimethylsilyl isocyanate(TMIS)as electrolyte additive.The trimethylsilyl group of TMIS can trap HF while the isocyanate group brings polyamide components to the CEI and the SEI.By the synergistic action,the Co3+dissolution problem of the LiCoO_(2) cathode was effectively curbed.Furthermore,TMIS regulates the construction of anion-dominated LiF-rich SEI by influencing the solvation structure of Li+.As expected,the 4.6 V Li||LiCoO_(2) battery with TMIS retains 77.9% initial capacity after 200 cycles at 0.5 C.
基金supported by the Learning&Academic Research Institution for Master’s,PhD students,and Postdocs LAMP Program of the National Research Foundation of Korea(NRF)grant funded by the Ministry of Education(No.RS-2023-00301974)This work was also supported by the Glocal University 30 Project fund of Gyeongsang National University in 2025.
文摘Lithium manganese silicate(Li-Mn-Si-O)cathodes are key components of lithium-ion batteries,and their physical and mechanical properties are strongly influenced by their underlying crystal structures.In this study,a range of machine learning(ML)algorithms were developed and compared to predict the crystal systems of Li-Mn-Si-O cathode materials using density functional theory(DFT)data obtained from the Materials Project database.The dataset comprised 211 compositions characterized by key descriptors,including formation energy,energy above the hull,bandgap,atomic site number,density,and unit cell volume.These features were utilized to classify the materials into monoclinic(0)and triclinic(1)crystal systems.A comprehensive comparison of various classification algorithms including Decision Tree,Random Forest,XGBoost,Support VectorMachine,k-Nearest Neighbor,Stochastic Gradient Descent,Gaussian Naive Bayes,Gaussian Process,and Artificial Neural Network(ANN)was conducted.Among these,the optimized ANN architecture(6–14-14-14-1)exhibited the highest predictive performance,achieving an accuracy of 95.3%,aMatthews correlation coefficient(MCC)of 0.894,and an F-score of 0.963,demonstrating excellent consistency with DFT-predicted crystal structures.Meanwhile,RandomForest and Gaussian Processmodels also exhibited reliable and consistent predictive capability,indicating their potential as complementary approaches,particularly when data are limited or computational efficiency is required.This comparative framework provides valuable insights into model selection for crystal system classification in complex cathode materials.
基金financially supported by National Natural Science Foundation of China(32272450)Science Fund for Distinguished Young Scholars of Fujian Province(2023J06020)Special Funds for Science and Technology Innovation of Fujian Agriculture and Forestry University(KFB23132A)。
文摘Vibrio harveyi,a Gram-negative bacterium ubiquitous in marine environments,is recognized as an opportunistic pathogen affecting various aquatic organisms such as fish,shrimp,and shellfish.To enhance its environmental resilience and adaptive capacity,V.harveyi employs a complex quorum sensing mechanism to modulate its virulence factors,such as bioluminescence,biofilm formation,and motility.Therefore,targeting the quorum sensing of V.harveyi could be a promising strategy to develop novel approaches to ensure the microbial safety of seafood products.This study aims to evaluate the impact of curcumin-mediated photo/sonodynamic treatment on quorum sensing in V.harveyi and its regulated functions.The results indicate a significant decrease of luminescence in V.harveyi following curcumin-mediated photo/sonodynamic treatment.Correspondingly,the biofilm formation ability and bacterial motility of V.harveyi were also greatly impaired by the treatment.Notably,the production of reactive oxygen species in bacteria induced by the photo/sonodynamic treatment could be the underlying mechanism involved in the observed disruption of quorum sensing.These findings underscore the great potential of photo/sonodynamic treatment as a promising strategy to disrupt quorum sensing and mitigate the virulence of V.harveyi,thereby contributing to the development of effective control strategies against this pervasive pathogen.
基金the National Natural Science Foundation of China(Nos.22150410339,W2432012,22301233 and 22171218)the Ministry of Science and Technology China(No.wgxz2022188)。
文摘α-Chiral amides are common in pharmaceuticals,agrochemicals,natural products,and peptides,prompting the need for new synthetic methods.Here,we introduce a nickel-catalyzed asymmetric reductive amidation method to synthesizeα-chiral amides from benzyl ammonium salts and isocyanates.The key to success is using a chiral 2,2-bipyridine ligand(-)-Ph-SBpy,enabling high yield(up to 95%)and enantiomeric ratio(up to 98:2 er)under mild conditions.Addition of phenol prevents isocyanate polymerization by reversibly forming a carbamate intermediate,enhancing selectivity and efficiency.The synthetic utility is showcased through transformations of the enantioenriched amides,and the mechanism and enantioselectivity are supported by experimental and computational studies.
基金funded by the Joint Funds of the National Natural Science Foundation of China (U20A20107 and U22A20562)the National Key Research and Development Program of China (2023YFD1900201-3)the International Cooperation Project,Ministry of Science and Technology of China (G2023019005L)。
文摘The lateral transport of labile organic carbon represents a critical pathway for soil organic carbon(SOC) loss,reducing organic carbon sequestration and increasing the risk of waterbody pollution.Livestock manure application on croplands serves as a common fertilizer reduction practice to sustain crop yields,enhance SOC sequestration,and reduce water erosion.However,limited quantitative assessments have examined the effects of livestock manure substitution on labile organic carbon lateral loss and fluxes in long-term experiments.This study conducted a three-year field investigation on subtropical sloping croplands to assess the impact of livestock manure substitution on dissolved organic carbon(DOC) and particulate organic carbon(POC) loss via surface runoff,interflow and eroded sediments.There are four treatments:no fertilization(CK);chemical nitrogen fertilizer(SF),40% nitrogen substitution with pig manure(PMF),and 100% nitrogen substitution from pig manure(PM).Compared to SF treatment,long-term livestock manure substitution in PMF and PM treatments significantly(P<0.05) reduced annual cumulative surface runoff fluxes by 13.5 and 21.6%,respectively.Manure applications decreased annual sediment fluxes by 12.9 and 19.1%,respectively.Soil water stable aggregates for mean weight diameter(MWD) increased significantly by 37.7 and 73.6%.Annual cumulative POC loss flux via eroded sediment under PMF and PM treatments increased significantly(P<0.05) by 61.1 and 47.9%,respectively.The labile organic carbon loss fluxes,including DOC and POC losses,under PMF and PM treatments increased significantly(P<0.05) by 11.9 and 31.4%,respectively.These results demonstrate that while water erosion intensity decreases due to enhanced soil aggregate stability,the risk of labile organic carbon loss increases after long-term livestock manure substitution in subtropical sloping croplands.Future research should examine labile organic carbon lateral migration under various soil types and slope gradients for livestock manure application in subtropical agricultural ecosystem croplands to better understand extreme rainfall effects.
基金supported by the IITP(Institute of Information & Communications Technology Planning & Evaluation)-ITRC(Information Technology Research Center) grant funded by the Korea government(Ministry of Science and ICT) (IITP-2025-RS-2024-00437191, and RS-2025-02303505)partly supported by the Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education. (No. 2022R1A6C101A774)the Deanship of Research and Graduate Studies at King Khalid University, Saudi Arabia, through Large Research Project under grant number RGP-2/527/46
文摘The growing global energy demand and worsening climate change highlight the urgent need for clean,efficient and sustainable energy solutions.Among emerging technologies,atomically thin two-dimensional(2D)materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties,high surface area and efficient charge transport capabilities.This review explores recent progress in photovoltaics incorporating 2D materials,focusing on their application as hole and electron transport layers to optimize bandgap alignment,enhance carrier mobility and improve chemical stability.A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials,with a particular focus on strategies to enhance crystallization,passivate defects and improve overall cell efficiency.Additionally,the application of 2D materials in organic solar cells is examined,particularly for reducing recombination losses and enhancing charge extraction through work function modification.Their impact on dye-sensitized solar cells,including catalytic activity and counter electrode performance,is also explored.Finally,the review outlines key challenges,material limitations and performance metrics,offering insight into the future development of nextgeneration photovoltaic devices encouraged by 2D materials.
基金supported by Basic Science Research Program(Priority Research Institute)through the NRF of Korea funded by the Ministry of Education(2021R1A6A1A10039823)by the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(2020R1A6C101B194)。
文摘Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and offering the highest theoretical energy density(~3.5 k Wh kg^(-1))among discussed candidates.Contributing to the poor cycle life of currently reported Li-O_(2)cells is singlet oxygen(1O_(2))formation,inducing parasitic reactions,degrading key components,and severely deteriorating cell performance.Here,we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets(Co_(3)O_(4)NSs)as cathode materials to suppress 1O_(2)in Li-O_(2)batteries for the first time.Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in 1O_(2)during discharge and charge,respectively,compared to conventional carbon paperbased cells,consistent with differential electrochemical mass spectrometry results,which indicate a near-theoretical charge-to-O_(2)ratio(2.04 e-/O_(2)).Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level,enhancing Co 3d-O 2p hybridization,stabilizing reaction intermediates,and lowering activation barriers for Li_(2)O_(2)formation and decomposition.These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O_(2)batteries,abridging the current gap to commercialization.
基金Project(N-12-NM-LU01-C01) supported by Construction of NTIS (National Science & Technology Information Service) Program Funded by the National Science & Technology Commission (NSTC), Korea
文摘This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywords after indexing national R＆D information in Korea （human resources, project and outcome） and applying expertise calculation algorithm. In consideration of the characteristics of national R＆D information, weight values have been selected. Then, expertise points were calculated by applying weighted values. In addition, joint research and collaborative relations were implemented in a knowledge map format through network analysis using national R＆D information.
文摘Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review articles in Web of Science,Scopus and Publisher’s websites on a large scale.Design/methodology/approach:27,616 papers from 160 journals from 10 review journal series indexed in SCI are analyzed.The document types of these papers labeled on journals’websites,and assigned by WoS and Scopus are retrieved and compared to determine the assigning accuracy and identify the possible reasons for wrongly assigning.For the document type labeled on the website,we further differentiate them into explicit review and implicit review based on whether the website directly indicates it is a review or not.Findings:Overall,WoS and Scopus performed similarly,with an average precision of about 99% and recall of about 80%.However,there were some differences between WoS and Scopus across different journal series and within the same journal series.The assigning accuracy of WoS and Scopus for implicit reviews dropped significantly,especially for Scopus.Research limitations:The document types we used as the gold standard were based on the journal websites’labeling which were not manually validated one by one.We only studied the labeling performance for review articles published during 2017-2018 in review journals.Whether this conclusion can be extended to review articles published in non-review journals and most current situation is not very clear.Practical implications:This study provides a reference for the accuracy of document type assigning of review articles in WoS and Scopus,and the identified pattern for assigning implicit reviews may be helpful to better labeling on websites,WoS and Scopus.Originality/value:This study investigated the assigning accuracy of document type of reviews and identified the some patterns of wrong assignments.
