The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were t...The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were to analyze yield stability and adaptability of proso millets and to evaluate the discrimination and representativeness of locations by analysis of vari- ance （ANOVA） and genotype and genotype by environment interaction （GGE） biplot methods. Grain yields of proso millet genotypes were significantly influenced by environment （E）, genotype （G） and their interaction （GxE） （P〈0.1%）. GxE inter- action effect was six times higher than G effect in non-waxy group and seven times in waxy group. N04-339 in non-waxy and Neimi 6 （NM6） in waxy showed higher grain yields and stability compared with other genotypes. Also, Neimi 9 （NM9, a non-waxy cultivar） and 90322-2-33 （a waxy cultivar） showed higher adaptability in 7 and in 11 locations, respectively. For non-waxy, Dalat, Inner Mongolia （E2） and Wuzhai, Shanxi （E5） were the best sites among all the locations for maximizing the variance among candidate cultivars, and Yanchi, Ningxia （El0） had the best representativeness. Wuzhai, Shanxi （e9） and Yanchi, Ningxia （e14） were the best representative locations, and Baicheng, Jilin （e2） was better discriminating location than others for waxy genotypes. Based on our results, El0 and e14 have enhanced efficiency and accuracy for non-waxy genotypes and waxy genotypes selection, respectively in national regional test of proso millet varieties.展开更多
Air pollution has seriously endangered human health and the natural ecosystem during the last decades.Air quality monitoring stations(AQMS)have played a critical role in providing valuable data sets for recording regi...Air pollution has seriously endangered human health and the natural ecosystem during the last decades.Air quality monitoring stations(AQMS)have played a critical role in providing valuable data sets for recording regional air pollutants.The spatial representativeness of AQMS is a critical parameter when choosing the location of stations and assessing effects on the population to long-term exposure to air pollution.In this paper,we proposed a methodological framework for assessing the spatial representativeness of the regional air quality monitoring network and applied it to ground-based PM_(2.5)observation in the mainland of China.Weighted multidimensional Euclidean distance between each pixel and the stations was used to determine the representativeness of the existing monitoring network.In addition,the K-means clustering method was adopted to improve the spatial representativeness of the existing AQMS.The results showed that there were obvious differences among the representative area of 1820 stations in the mainland of China.The monitoring stations could well represent the PM_(2.5)spatial distribution of the entire region,and the effectively represented area(i.e.the area where the Euclidean distance between the pixels and the stations was lower than the average value)accounted for 67.32%of the total area and covered 93.12%of the population.Forty additional stations were identified in the Northwest,North China,and Northeast regions,which could improve the spatial representativeness by 14.31%.展开更多
Objective:To compare the characteristics of suspected measles cases at the health facilities and to determine the representativeness of the data.Methods:We visited 25 hospitals in the Aniocha Local Government Area(LGA...Objective:To compare the characteristics of suspected measles cases at the health facilities and to determine the representativeness of the data.Methods:We visited 25 hospitals in the Aniocha Local Government Area(LGA) of Delta State,Nigeria,from which information on reportable diseases was collected.In particular,the suspected measles cases in their registries between January 1,2007,and June 30,2008,were reviewed.We compared the characteristics,including age,sex,location,and month of reporting,of the suspected cases with the LGA surveillance records.Results:In the LGA records,10%cases involved individuals older than 14 years, compared with 20%in the same age group in the health facility records.Based on geographic location,53%of the measles cases among the hospital records came from a single location,in contrast to only 30%of the cases among the LGA records.An analysis considering time revealed that 30%of the cases in the LGA records occurred in August 2007,whereas 20%of hospital cases were reported in February and May 2008 combined.Conclusions:The two record types differed considerably in all of the characteristics used in this comparison.展开更多
The investigation of whether sediment samples contain representative grain size distribution information is important for the accurate extraction of sediment characteristics and conduct of related sedimentary record s...The investigation of whether sediment samples contain representative grain size distribution information is important for the accurate extraction of sediment characteristics and conduct of related sedimentary record studies.This study comparatively analyzed the numerical and qualitative differences and the degree of correlation of 36 sets of the characteristic parameters of surface sediment parallel sample grain size distribution from three sampling profiles at Jinsha Bay Beach in Zhanjiang,western Guangdong.At each sampling point,five parallel subsamples were established at intervals of 0,10,20,50,and 100 cm along the coastline.The research findings indicate the following:1)relatively large differences in the mean values of the different parallel samples(0.19–0.34Φ),with smaller differences observed in other characteristic grain sizes(D_(10),D_(50),and D_(90));2)small differences in characteristic values among various parallel sample grain size parameters,with at least 33%of the combinations of qualitative results showing inconsistency;3)50%of the regression equations between the skewness of different parallel samples displaying no significant correlation;4)relative deviations of−47.91%to 27.63%and−49.20%to 2.08%existing between the particle size parameters of a single sample and parallel samples(with the average obtained)at intervals of 10 and 50 cm,respectively.As such,small spatial differences,even within 100 cm,can considerably affect grain size parameters.Given the uncertain reasons underlying the representativeness of the samples,which may only cover the area immediately surrounding the sampling station,researchers are advised to design parallel sample collection strategies based on the spatiotemporal distribution characteristics of the parameters of interest during sediment sample collection.This study provides a typical case of the comparative analysis of parallel sample grain size parameters,with a focus on small spatial beach sediment,which contributes to the enhanced understanding of the accuracy and reliability of sediment sample collection strategies and extraction of grain size information.展开更多
Lanzhou is a typical mountainous city with severe air pollution in northwestern China. This study uses hourly observational data of air pollutants at five air quality monitoring sites in Lanzhou from July to December ...Lanzhou is a typical mountainous city with severe air pollution in northwestern China. This study uses hourly observational data of air pollutants at five air quality monitoring sites in Lanzhou from July to December 2015 to discuss data quality control and the representativeness of the monitoring sites(four urban sites and one suburban site). A fuzzy matrix is applied to study primary air pollutants. The results show that of the six routinely monitored pollutants,the primary pollutant is PM_10 during the study period. Based on lag correlation analysis and one-way analysis of variance, it is concluded that there are redundant observations at the four urban sites for the timely diffusion and transport of air pollutants from the same general area. The coefficient of divergence(COD) method is then used to evaluate the spatial distribution differences, and the primary air pollutant PM_10 shows differences at each site. COD can be used as a positive indicator to describe site representativeness. To evaluate the overall air pollution in the valley, correlation analysis is performed between the PM_10 concentration retrieved from aerosol optical depth satellite data and the concentration from the four urban monitoring sites. Among these, the correlation between the workers' hospital site data and the retrieval data is the highest, passing the 90% confidence level. A new representative evaluation model for air quality monitoring sites, R_s = 0.77 COD + 0.23R_(retrieval), is established by using COD and correlation coefficients between routine observations and satellite retrieval products. From this model, it can be concluded that the biological products institute site in Lanzhou is the most representative site for the evaluation of air pollution out of the four urban air quality monitoring sites from July to December 2015.展开更多
Rechargeable zinc-air batteries(ZABs) have recently drawn great attention in energy research due to their high theoretical capacity,low costs, and inherently safe nature [1–3]. However, the sluggish cathode reactions...Rechargeable zinc-air batteries(ZABs) have recently drawn great attention in energy research due to their high theoretical capacity,low costs, and inherently safe nature [1–3]. However, the sluggish cathode reactions necessitate the development of bifunctional oxygen electrocatalysts with lower ΔE indicator values. The ΔE indicator is commonly employed to quantitatively evaluate the electrocatalytic activity of a bifunctional oxygen electrocatalyst,representing the overall overpotential from oxygen reduction reaction(ORR) to oxygen evolution reaction(OER).展开更多
The first plenary meeting of ISO/TC 8/SC 27,Ports and terminals,was held on October 21 in Shanghai,which attracted representatives from 15 member states and 5 international organizations,as well as over 100 experts an...The first plenary meeting of ISO/TC 8/SC 27,Ports and terminals,was held on October 21 in Shanghai,which attracted representatives from 15 member states and 5 international organizations,as well as over 100 experts and scholars.展开更多
Agroup of young representatives and scholars from more than 10 foreign countries had great fun collecting water samples from the Grand Canal in Sanwan Park,Yangzhou City,east China’s Jiangsu Province,on June 3,2025.T...Agroup of young representatives and scholars from more than 10 foreign countries had great fun collecting water samples from the Grand Canal in Sanwan Park,Yangzhou City,east China’s Jiangsu Province,on June 3,2025.The samples were poured into a“pot of civilization,”which symbolized the integration of cultures.In addition to the canal,the young people also visited places such as Yangzhou University,China Grand Canal Museum,and the Slender West Lake,learning the culture of the Grand Canal and the canal city of Yangzhou.展开更多
This study conducts a thorough examination of honeycomb sandwich panels with a lattice core,adopting advanced computational techniques for their modeling.The research extends its analysis to investigate the natural fr...This study conducts a thorough examination of honeycomb sandwich panels with a lattice core,adopting advanced computational techniques for their modeling.The research extends its analysis to investigate the natural frequency behavior of sandwich panels,encompassing the comprehensive assessment of the entire panel structure.At its core,the research applies the Representative Volume Element(RVE)theory to establish the equivalent material properties,thereby enhancing the predictive capabilities of lattice structure simulations.Themethodology applies these properties in the core of infinite panels,which are modeled using double periodic boundary conditions to explore their natural frequencies.Expanding beyond mere material characterization,the study introduces a novel approach to defining the material within the panel cores.By incorporating alternate materials such as steel and AlSiC,and by strategically modifying their ratios,the research streamlines the process of material variation without resorting to repetitive 3D operations on the constituent cells.This optimizes not only the computational resources but also offers insights into the structural response under diverse material compositions.Furthermore,the investigation extends its scope to analyze the influence of curvature on the structural behavior of lattice structures.Panels are modeled with varying degrees of curvature,ranging from single to double curvatures,including cylindrical and spherical configurations,across a spectrum of radii.A rigorous analysis is performed to study the effect of curvature on the mechanical performance and stability of lattice structures,offering valuable insights for design optimization and structural engineering applications.By building upon the existing knowledge and introducing innovative methodologies,this study contributes to improving the understanding of lattice structures and their applicability in diverse engineering contexts.展开更多
China’s economy reached its 2024 growth target despite a complex domestic and global landscape,providing much needed certainty and confidence to the global economy.The annual Gross Domestic Product(GDP)reached RMB 13...China’s economy reached its 2024 growth target despite a complex domestic and global landscape,providing much needed certainty and confidence to the global economy.The annual Gross Domestic Product(GDP)reached RMB 13,490.84 billion,representing a 5.0%increase over the previous year in constant prices.By sector,the added value of the primary sector was RMB 914.14 billion,up by 3.5%year-on year;the secondary sector’s added value was RMB 4,920.87 billion,up by 5.3%;and the tertiary sector’s added value was RMB 7,655.83 billion,up by 5.0%.展开更多
High-pressure synthesis of lutetium hydrides from molecular hydrogen(H_(2))and lutetium(Lu)is systematically investigated using synchrotron X-ray diffraction,Raman spectroscopy,and visual observations.We demonstrate t...High-pressure synthesis of lutetium hydrides from molecular hydrogen(H_(2))and lutetium(Lu)is systematically investigated using synchrotron X-ray diffraction,Raman spectroscopy,and visual observations.We demonstrate that the reaction pathway between H_(2)and Lu invariably follows the sequence Lu→LuH_(2)→LuH_(3)and exhibits a notable time dependence.A comprehensive diagram representing the formation and synthesis of lutetium hydrides as a function of pressure and time is constructed.Our findings indicate that the synthesis can be accelerated by elevated temperature and decelerated by increased pressure.Notably,two critical pressure thresholds at ambient temperature are identified:the synthesis of LuH_(2)from Lu commences at a minimum pressure of~3 GPa,while~28 GPa is the minimum pressure at which LuH_(2)fails to transform into LuH_(3)within a time scale of months.This underscores the significant impact of temporal factors on synthesis,with the reaction completion time increasing sub-linearly with rising pressure.Furthermore,the cubic phase of LuH_(3)can be obtained exclusively through compressing the trigonal LuH_(3)phase at~11.5 GPa.We also demonstrate that the bandgap of LuH_(3)slowly closes under pressure and is noticeably lower than that of LuH_(2).展开更多
The correlation between the microstructure,properties,and strain partitioning behavior in a medium-carbon carbide-free bainitic steel was investigated through a combination of experiments and representative volume ele...The correlation between the microstructure,properties,and strain partitioning behavior in a medium-carbon carbide-free bainitic steel was investigated through a combination of experiments and representative volume element simulations.The results reveal that as the austempering temperature increases from low to intermediate,the optimal balance of properties shifts from strength-toughness to plasticity-toughness.The formation of fine bainitic ferrite plates and bainite sheaves under low austempering temperature(270℃)enhances both strength and toughness.Conversely,the wide size and shape distribution of the retained austenite(RA)obtained through austempering at intermediate temperature(350℃)contribute to increased work-hardening capacity,resulting in enhanced plasticity.The volume fraction of the ductile film-like RA plays a crucial role in enhancing impact toughness under relatively higher austempering temperatures.In the simulations of tensile deformation,the concentration of equivalent plastic strain predominantly manifests in the bainitic ferrite neighboring the martensite,whereas the equivalent plastic strain evenly spreads between the thin film-like retained austenite and bainitic ferrite.It is predicted that the cracks will occur at the interface between martensite and bainitic ferrite where the strain is concentrated,and eventually propagate along the strain failure zone.展开更多
Cardiovascular disease(CVD)represents the foremost cause of mortality globally,imposing a substantial economic burden.In 2021,approximately 19.4 million deaths were attributed to cardiovascular conditions,constituting...Cardiovascular disease(CVD)represents the foremost cause of mortality globally,imposing a substantial economic burden.In 2021,approximately 19.4 million deaths were attributed to cardiovascular conditions,constituting 32%of global mortality[1].Over three-quarters of these fatalities occurred in low and middle-income nations.Notably,ischemic heart disease and stroke were responsible for 84%of CVD-related deaths.Among them,the number of cases of ischemic cardiomyopathy increased by 68%in 2021 compared to 1990(Figure 1A).展开更多
In late May,the city of Dunhuang,a key historical hub of Eastern and Western cultures in Northwest China's Gansu Province,basked in clear and refreshing weather under a brilliant blue sky.The rugged Mingsha Mounta...In late May,the city of Dunhuang,a key historical hub of Eastern and Western cultures in Northwest China's Gansu Province,basked in clear and refreshing weather under a brilliant blue sky.The rugged Mingsha Mountain,renowned for the musical sounds produced by wind-blown sands when the wind blows,stood in silent majesty.To the close north of the mountain's massive golden dunes stood the city's international convention centre,where some 400 vips from 60 countries host cultural exchanges and mutual learning.展开更多
304H austenitic stainless steel wire was investigated,emphasizing microstructural deformation,martensite phase transformation,and residual magnetic properties during drawing.Utilizing several microstructural observati...304H austenitic stainless steel wire was investigated,emphasizing microstructural deformation,martensite phase transformation,and residual magnetic properties during drawing.Utilizing several microstructural observation techniques,the volume fraction of martensite,modes of grain deformation in distinct regions,and the phase relationship between austenite and martensite were comprehensively characterized.In addition,a finite element simulation with representative volume elements specific to different zones also offers insights into strain responses during the drawing process.Results from the first-pass drawing reveal that there exists a higher volume fraction of martensite in the central region of 304H austenitic stainless steel wire compared to edge areas.This discrepancy is attributed to a concentrated presence of shear slip system{111}<110>γcrystallographic orientation,primarily accumulating in the central region obeying the Kurdjumov-Sachs path.Subsequent to the second drawing pass,the cumulative shear deformation within distinct regions of the steel wire became more pronounced.This resulted in a progressive augmentation of the volume fraction of martensite in both the central and peripheral regions of the steel wire.Concurrently,this led to a discernible elevation in the overall residual magnetism of the steel wire.展开更多
Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution.As a result,a comprehensive understanding of the di...Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution.As a result,a comprehensive understanding of the different scale variation on microstructure evolution during bending deformation is essential.The advanced high strength dual-phase(DP1180)steel was investigated using multiscale microstructure-based 3D representative volume element(RVE)modelling technology with emphasis on understanding the relationship between the microstructure,localised stress-strain evolution as well as the deformation characteristics in the bending process.It is demonstrated that the localised development in bending can be more accurately described by microscopic deformation when taking into account microstructural properties.Microstructure-based 3D RVEs from each chosen bending condition generally have comparable localisation properties,whilst the magnitudes and intensities differ.In addition,the most severe localised bands are predicted to occur close to the ferrite and martensite phase boundaries where the martensite grains are close together or have a somewhat sharp edge.The numerically predicted results for the microstructure evolution,shear bands development and stress and strain distribution after 3-point bending exhibit a good agreement with the relevant experimental observations.展开更多
In this paper,a two-stage light detection and ranging(LiDAR) three-dimensional(3D) object detection framework is presented,namely point-voxel dual transformer(PV-DT3D),which is a transformer-based method.In the propos...In this paper,a two-stage light detection and ranging(LiDAR) three-dimensional(3D) object detection framework is presented,namely point-voxel dual transformer(PV-DT3D),which is a transformer-based method.In the proposed PV-DT3D,point-voxel fusion features are used for proposal refinement.Specifically,keypoints are sampled from entire point cloud scene and used to encode representative scene features via a proposal-aware voxel set abstraction module.Subsequently,following the generation of proposals by the region proposal networks(RPN),the internal encoded keypoints are fed into the dual transformer encoder-decoder architecture.In 3D object detection,the proposed PV-DT3D takes advantage of both point-wise transformer and channel-wise architecture to capture contextual information from the spatial and channel dimensions.Experiments conducted on the highly competitive KITTI 3D car detection leaderboard show that the PV-DT3D achieves superior detection accuracy among state-of-the-art point-voxel-based methods.展开更多
Hypertrophic cardiomyopathy(HCM)is a primary myocardial disease characterized by myocardial hypertrophy,excluding other cardiovascular or systemic/metabolic causes of ventricular wall thickening.Apical hypertrophic ca...Hypertrophic cardiomyopathy(HCM)is a primary myocardial disease characterized by myocardial hypertrophy,excluding other cardiovascular or systemic/metabolic causes of ventricular wall thickening.Apical hypertrophic cardiomyopathy(ApHCM)represents a special form of ventricular hypertrophy predominantly affecting the left ventricular apex below the papillary muscles,typically without significant left ventricular outflow tract obstruction.[1,2]ApHCM often coexists with mild coronary artery abnormalities,[3]and reports of acute myocardial infarction with coronary artery stenosis in ApHCM or HCM patients are uncommon.展开更多
The addition of nanoparticles serves as an effective reinforcement strategy for polymeric coatings,utilizing their unique characteristics as well as extraordinary mechanical,thermal,and electrical properties.The excep...The addition of nanoparticles serves as an effective reinforcement strategy for polymeric coatings,utilizing their unique characteristics as well as extraordinary mechanical,thermal,and electrical properties.The exceptionally high surface-to-volume ratio of nanoparticles imparts remarkable reinforcing potentials,yet it simultaneously gives rise to a prevalent tendency for nanoparticles to agglomerate into clusters within nanocomposites.The agglomeration behavior of the nanoparticles is predominantly influenced by their distinct microstructures and varied weight concentrations.This study investigated the synergistic effects of nanoparticle geometric shape and weight concentration on the dispersion characteristics of nanoparticles and the physical-mechanical performances of nano-reinforced epoxy coatings.Three carbon-based nanoparticles,nanodiamonds(NDs),carbon nanotubes(CNTs),and graphenes(GNPs),were incorporated into epoxy coatings at three weight concentrations(0.5%,1.0%,and 2.0%).The experimental findings reveal that epoxy coatings reinforced with NDs demonstrated the most homogenous dispersion characteristics,lowest viscosity,and reduced porosity among all the nanoparticles,which could be attributed to the spherical geometry shape.Due to the superior physical properties,ND-reinforced nanocomposites displayed the highest abrasion resistance and tensile properties.Specifically,the 1.0wt%ND-reinforced nanocomposites exhibited 60%,52%,and 97%improvements in mass lost,tensile strength,and failure strain,respectively,compared to pure epoxy.Furthermore,the representative volume element(RVE)modeling was employed to validate the experimental results,while highlighting the critical role of nanoparticle agglomeration,orientation,and the presence of voids on the mechanical properties of the nanocomposites.Nano-reinforced epoxy coatings with enhanced mechanical properties are well-suited for application in protective coatings for pipelines,industrial equipment,and automotive parts,where high wear resistance is essential.展开更多
基金funded by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2014BAD07B03)the National Natural Science Foundation of China (31371529)+2 种基金the Postdoctoral Science Foundation of Heilongjiang Province, China (LBH-Z14177)the project of Education Department in Heilongjiang Province, China (12541599)the China Agricultural Research System (CARS07-13.5-A9)
文摘The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were to analyze yield stability and adaptability of proso millets and to evaluate the discrimination and representativeness of locations by analysis of vari- ance （ANOVA） and genotype and genotype by environment interaction （GGE） biplot methods. Grain yields of proso millet genotypes were significantly influenced by environment （E）, genotype （G） and their interaction （GxE） （P〈0.1%）. GxE inter- action effect was six times higher than G effect in non-waxy group and seven times in waxy group. N04-339 in non-waxy and Neimi 6 （NM6） in waxy showed higher grain yields and stability compared with other genotypes. Also, Neimi 9 （NM9, a non-waxy cultivar） and 90322-2-33 （a waxy cultivar） showed higher adaptability in 7 and in 11 locations, respectively. For non-waxy, Dalat, Inner Mongolia （E2） and Wuzhai, Shanxi （E5） were the best sites among all the locations for maximizing the variance among candidate cultivars, and Yanchi, Ningxia （El0） had the best representativeness. Wuzhai, Shanxi （e9） and Yanchi, Ningxia （e14） were the best representative locations, and Baicheng, Jilin （e2） was better discriminating location than others for waxy genotypes. Based on our results, El0 and e14 have enhanced efficiency and accuracy for non-waxy genotypes and waxy genotypes selection, respectively in national regional test of proso millet varieties.
基金funded by the National Natural Science Foundation of China (41977399)the National Key Research and Development Program (2017YFC0505800)
文摘Air pollution has seriously endangered human health and the natural ecosystem during the last decades.Air quality monitoring stations(AQMS)have played a critical role in providing valuable data sets for recording regional air pollutants.The spatial representativeness of AQMS is a critical parameter when choosing the location of stations and assessing effects on the population to long-term exposure to air pollution.In this paper,we proposed a methodological framework for assessing the spatial representativeness of the regional air quality monitoring network and applied it to ground-based PM_(2.5)observation in the mainland of China.Weighted multidimensional Euclidean distance between each pixel and the stations was used to determine the representativeness of the existing monitoring network.In addition,the K-means clustering method was adopted to improve the spatial representativeness of the existing AQMS.The results showed that there were obvious differences among the representative area of 1820 stations in the mainland of China.The monitoring stations could well represent the PM_(2.5)spatial distribution of the entire region,and the effectively represented area(i.e.the area where the Euclidean distance between the pixels and the stations was lower than the average value)accounted for 67.32%of the total area and covered 93.12%of the population.Forty additional stations were identified in the Northwest,North China,and Northeast regions,which could improve the spatial representativeness by 14.31%.
文摘Objective:To compare the characteristics of suspected measles cases at the health facilities and to determine the representativeness of the data.Methods:We visited 25 hospitals in the Aniocha Local Government Area(LGA) of Delta State,Nigeria,from which information on reportable diseases was collected.In particular,the suspected measles cases in their registries between January 1,2007,and June 30,2008,were reviewed.We compared the characteristics,including age,sex,location,and month of reporting,of the suspected cases with the LGA surveillance records.Results:In the LGA records,10%cases involved individuals older than 14 years, compared with 20%in the same age group in the health facility records.Based on geographic location,53%of the measles cases among the hospital records came from a single location,in contrast to only 30%of the cases among the LGA records.An analysis considering time revealed that 30%of the cases in the LGA records occurred in August 2007,whereas 20%of hospital cases were reported in February and May 2008 combined.Conclusions:The two record types differed considerably in all of the characteristics used in this comparison.
基金supported by the Innovation Driven Development Foundation of Guangxi(No.AD22080035)the Open Project Funding of the Key Laboratory of Tropical Marine Ecosystem and Bioresource,Ministry of Natural Resources(No.2023-QN04)+1 种基金the Guangdong Provincial Ordinary University Youth Innovative Talent Project in 2024(No.2024KQNCX134)the Guangdong Provincial Special Fund Project for Talent Development Strategy in 2024(No.2024R3005).
文摘The investigation of whether sediment samples contain representative grain size distribution information is important for the accurate extraction of sediment characteristics and conduct of related sedimentary record studies.This study comparatively analyzed the numerical and qualitative differences and the degree of correlation of 36 sets of the characteristic parameters of surface sediment parallel sample grain size distribution from three sampling profiles at Jinsha Bay Beach in Zhanjiang,western Guangdong.At each sampling point,five parallel subsamples were established at intervals of 0,10,20,50,and 100 cm along the coastline.The research findings indicate the following:1)relatively large differences in the mean values of the different parallel samples(0.19–0.34Φ),with smaller differences observed in other characteristic grain sizes(D_(10),D_(50),and D_(90));2)small differences in characteristic values among various parallel sample grain size parameters,with at least 33%of the combinations of qualitative results showing inconsistency;3)50%of the regression equations between the skewness of different parallel samples displaying no significant correlation;4)relative deviations of−47.91%to 27.63%and−49.20%to 2.08%existing between the particle size parameters of a single sample and parallel samples(with the average obtained)at intervals of 10 and 50 cm,respectively.As such,small spatial differences,even within 100 cm,can considerably affect grain size parameters.Given the uncertain reasons underlying the representativeness of the samples,which may only cover the area immediately surrounding the sampling station,researchers are advised to design parallel sample collection strategies based on the spatiotemporal distribution characteristics of the parameters of interest during sediment sample collection.This study provides a typical case of the comparative analysis of parallel sample grain size parameters,with a focus on small spatial beach sediment,which contributes to the enhanced understanding of the accuracy and reliability of sediment sample collection strategies and extraction of grain size information.
基金Supported by the National Key R&D Program of China(2017YFC1501805)Drought Meteorology Research Project(IAM201603)Gansu Province Natural Science Foundation(18JR3RA278)
文摘Lanzhou is a typical mountainous city with severe air pollution in northwestern China. This study uses hourly observational data of air pollutants at five air quality monitoring sites in Lanzhou from July to December 2015 to discuss data quality control and the representativeness of the monitoring sites(four urban sites and one suburban site). A fuzzy matrix is applied to study primary air pollutants. The results show that of the six routinely monitored pollutants,the primary pollutant is PM_10 during the study period. Based on lag correlation analysis and one-way analysis of variance, it is concluded that there are redundant observations at the four urban sites for the timely diffusion and transport of air pollutants from the same general area. The coefficient of divergence(COD) method is then used to evaluate the spatial distribution differences, and the primary air pollutant PM_10 shows differences at each site. COD can be used as a positive indicator to describe site representativeness. To evaluate the overall air pollution in the valley, correlation analysis is performed between the PM_10 concentration retrieved from aerosol optical depth satellite data and the concentration from the four urban monitoring sites. Among these, the correlation between the workers' hospital site data and the retrieval data is the highest, passing the 90% confidence level. A new representative evaluation model for air quality monitoring sites, R_s = 0.77 COD + 0.23R_(retrieval), is established by using COD and correlation coefficients between routine observations and satellite retrieval products. From this model, it can be concluded that the biological products institute site in Lanzhou is the most representative site for the evaluation of air pollution out of the four urban air quality monitoring sites from July to December 2015.
基金National Research Foundation (NRF Investigatorship NRF-NRFI09-0002)Agency for Science,Technology and Research (MTC Programmatic Fund M23L9b0052)。
文摘Rechargeable zinc-air batteries(ZABs) have recently drawn great attention in energy research due to their high theoretical capacity,low costs, and inherently safe nature [1–3]. However, the sluggish cathode reactions necessitate the development of bifunctional oxygen electrocatalysts with lower ΔE indicator values. The ΔE indicator is commonly employed to quantitatively evaluate the electrocatalytic activity of a bifunctional oxygen electrocatalyst,representing the overall overpotential from oxygen reduction reaction(ORR) to oxygen evolution reaction(OER).
文摘The first plenary meeting of ISO/TC 8/SC 27,Ports and terminals,was held on October 21 in Shanghai,which attracted representatives from 15 member states and 5 international organizations,as well as over 100 experts and scholars.
文摘Agroup of young representatives and scholars from more than 10 foreign countries had great fun collecting water samples from the Grand Canal in Sanwan Park,Yangzhou City,east China’s Jiangsu Province,on June 3,2025.The samples were poured into a“pot of civilization,”which symbolized the integration of cultures.In addition to the canal,the young people also visited places such as Yangzhou University,China Grand Canal Museum,and the Slender West Lake,learning the culture of the Grand Canal and the canal city of Yangzhou.
文摘This study conducts a thorough examination of honeycomb sandwich panels with a lattice core,adopting advanced computational techniques for their modeling.The research extends its analysis to investigate the natural frequency behavior of sandwich panels,encompassing the comprehensive assessment of the entire panel structure.At its core,the research applies the Representative Volume Element(RVE)theory to establish the equivalent material properties,thereby enhancing the predictive capabilities of lattice structure simulations.Themethodology applies these properties in the core of infinite panels,which are modeled using double periodic boundary conditions to explore their natural frequencies.Expanding beyond mere material characterization,the study introduces a novel approach to defining the material within the panel cores.By incorporating alternate materials such as steel and AlSiC,and by strategically modifying their ratios,the research streamlines the process of material variation without resorting to repetitive 3D operations on the constituent cells.This optimizes not only the computational resources but also offers insights into the structural response under diverse material compositions.Furthermore,the investigation extends its scope to analyze the influence of curvature on the structural behavior of lattice structures.Panels are modeled with varying degrees of curvature,ranging from single to double curvatures,including cylindrical and spherical configurations,across a spectrum of radii.A rigorous analysis is performed to study the effect of curvature on the mechanical performance and stability of lattice structures,offering valuable insights for design optimization and structural engineering applications.By building upon the existing knowledge and introducing innovative methodologies,this study contributes to improving the understanding of lattice structures and their applicability in diverse engineering contexts.
文摘China’s economy reached its 2024 growth target despite a complex domestic and global landscape,providing much needed certainty and confidence to the global economy.The annual Gross Domestic Product(GDP)reached RMB 13,490.84 billion,representing a 5.0%increase over the previous year in constant prices.By sector,the added value of the primary sector was RMB 914.14 billion,up by 3.5%year-on year;the secondary sector’s added value was RMB 4,920.87 billion,up by 5.3%;and the tertiary sector’s added value was RMB 7,655.83 billion,up by 5.0%.
基金supported by research grants of the Youth Innovation Promotion Association of CAS(Grant No.2021446)the National Science Foundation of China(Grant Nos.12204484,51672279,12174398 and 11874361)+1 种基金the Anhui Key Research and Development Program(Grant No.2022h11020007)the HFIPS Director’s Fund of the Chinese Academy of Sciences(Grant Nos.BJPY2022B02,YZJJ202102,YZJJ-GGZX-2022-01,and 2021YZGH03).
文摘High-pressure synthesis of lutetium hydrides from molecular hydrogen(H_(2))and lutetium(Lu)is systematically investigated using synchrotron X-ray diffraction,Raman spectroscopy,and visual observations.We demonstrate that the reaction pathway between H_(2)and Lu invariably follows the sequence Lu→LuH_(2)→LuH_(3)and exhibits a notable time dependence.A comprehensive diagram representing the formation and synthesis of lutetium hydrides as a function of pressure and time is constructed.Our findings indicate that the synthesis can be accelerated by elevated temperature and decelerated by increased pressure.Notably,two critical pressure thresholds at ambient temperature are identified:the synthesis of LuH_(2)from Lu commences at a minimum pressure of~3 GPa,while~28 GPa is the minimum pressure at which LuH_(2)fails to transform into LuH_(3)within a time scale of months.This underscores the significant impact of temporal factors on synthesis,with the reaction completion time increasing sub-linearly with rising pressure.Furthermore,the cubic phase of LuH_(3)can be obtained exclusively through compressing the trigonal LuH_(3)phase at~11.5 GPa.We also demonstrate that the bandgap of LuH_(3)slowly closes under pressure and is noticeably lower than that of LuH_(2).
基金supported by the National Key R&D Program Young Scientists Project(2021YFB3703500)National Natural Science Foundation of China(52001110,52122410,52374406),S&T Program of Hebei(23311004D)+1 种基金Natural Science Foundation of Hebei Province(E2023203259)Science and Technology Project of Yantai(2022ZDCX002).
文摘The correlation between the microstructure,properties,and strain partitioning behavior in a medium-carbon carbide-free bainitic steel was investigated through a combination of experiments and representative volume element simulations.The results reveal that as the austempering temperature increases from low to intermediate,the optimal balance of properties shifts from strength-toughness to plasticity-toughness.The formation of fine bainitic ferrite plates and bainite sheaves under low austempering temperature(270℃)enhances both strength and toughness.Conversely,the wide size and shape distribution of the retained austenite(RA)obtained through austempering at intermediate temperature(350℃)contribute to increased work-hardening capacity,resulting in enhanced plasticity.The volume fraction of the ductile film-like RA plays a crucial role in enhancing impact toughness under relatively higher austempering temperatures.In the simulations of tensile deformation,the concentration of equivalent plastic strain predominantly manifests in the bainitic ferrite neighboring the martensite,whereas the equivalent plastic strain evenly spreads between the thin film-like retained austenite and bainitic ferrite.It is predicted that the cracks will occur at the interface between martensite and bainitic ferrite where the strain is concentrated,and eventually propagate along the strain failure zone.
基金supported by the National Natural Science Foundation of China(No.82270364)Science and Technology Program of Guizhou Province(No.ZK[2023]321)+3 种基金Guizhou Provincial Youth Science and Technology Talents Growth Project(No.KY[2022]214)Excellent Young Talents Plan of Guizhou Medical University(No.[2023]112)Guizhou Medical University Key Laboratory of Cardiovascular Disease Basic and Clinical Research(No.2024001)Start-up Fund of Guizhou Medical University(No.J2021032).
文摘Cardiovascular disease(CVD)represents the foremost cause of mortality globally,imposing a substantial economic burden.In 2021,approximately 19.4 million deaths were attributed to cardiovascular conditions,constituting 32%of global mortality[1].Over three-quarters of these fatalities occurred in low and middle-income nations.Notably,ischemic heart disease and stroke were responsible for 84%of CVD-related deaths.Among them,the number of cases of ischemic cardiomyopathy increased by 68%in 2021 compared to 1990(Figure 1A).
文摘In late May,the city of Dunhuang,a key historical hub of Eastern and Western cultures in Northwest China's Gansu Province,basked in clear and refreshing weather under a brilliant blue sky.The rugged Mingsha Mountain,renowned for the musical sounds produced by wind-blown sands when the wind blows,stood in silent majesty.To the close north of the mountain's massive golden dunes stood the city's international convention centre,where some 400 vips from 60 countries host cultural exchanges and mutual learning.
基金funded by National Natural Science Foundation of China(52201084 and 52231003)Major Program(JD)of Hubei Province(2023BAA019)+2 种基金China Scholarship Council(CSC)Postdoctoral Station of metallurgical Engineering of Wuhan University of Science and Technology(WUST)Postdoctoral workstation of Zhejiang Jincheng New Material Co.,Ltd.
文摘304H austenitic stainless steel wire was investigated,emphasizing microstructural deformation,martensite phase transformation,and residual magnetic properties during drawing.Utilizing several microstructural observation techniques,the volume fraction of martensite,modes of grain deformation in distinct regions,and the phase relationship between austenite and martensite were comprehensively characterized.In addition,a finite element simulation with representative volume elements specific to different zones also offers insights into strain responses during the drawing process.Results from the first-pass drawing reveal that there exists a higher volume fraction of martensite in the central region of 304H austenitic stainless steel wire compared to edge areas.This discrepancy is attributed to a concentrated presence of shear slip system{111}<110>γcrystallographic orientation,primarily accumulating in the central region obeying the Kurdjumov-Sachs path.Subsequent to the second drawing pass,the cumulative shear deformation within distinct regions of the steel wire became more pronounced.This resulted in a progressive augmentation of the volume fraction of martensite in both the central and peripheral regions of the steel wire.Concurrently,this led to a discernible elevation in the overall residual magnetism of the steel wire.
基金supported by HBIS Group under the Grant No.IRIS 200506003.
文摘Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution.As a result,a comprehensive understanding of the different scale variation on microstructure evolution during bending deformation is essential.The advanced high strength dual-phase(DP1180)steel was investigated using multiscale microstructure-based 3D representative volume element(RVE)modelling technology with emphasis on understanding the relationship between the microstructure,localised stress-strain evolution as well as the deformation characteristics in the bending process.It is demonstrated that the localised development in bending can be more accurately described by microscopic deformation when taking into account microstructural properties.Microstructure-based 3D RVEs from each chosen bending condition generally have comparable localisation properties,whilst the magnitudes and intensities differ.In addition,the most severe localised bands are predicted to occur close to the ferrite and martensite phase boundaries where the martensite grains are close together or have a somewhat sharp edge.The numerically predicted results for the microstructure evolution,shear bands development and stress and strain distribution after 3-point bending exhibit a good agreement with the relevant experimental observations.
基金supported by the Natural Science Foundation of China (No.62103298)the South African National Research Foundation (Nos.132797 and 137951)。
文摘In this paper,a two-stage light detection and ranging(LiDAR) three-dimensional(3D) object detection framework is presented,namely point-voxel dual transformer(PV-DT3D),which is a transformer-based method.In the proposed PV-DT3D,point-voxel fusion features are used for proposal refinement.Specifically,keypoints are sampled from entire point cloud scene and used to encode representative scene features via a proposal-aware voxel set abstraction module.Subsequently,following the generation of proposals by the region proposal networks(RPN),the internal encoded keypoints are fed into the dual transformer encoder-decoder architecture.In 3D object detection,the proposed PV-DT3D takes advantage of both point-wise transformer and channel-wise architecture to capture contextual information from the spatial and channel dimensions.Experiments conducted on the highly competitive KITTI 3D car detection leaderboard show that the PV-DT3D achieves superior detection accuracy among state-of-the-art point-voxel-based methods.
文摘Hypertrophic cardiomyopathy(HCM)is a primary myocardial disease characterized by myocardial hypertrophy,excluding other cardiovascular or systemic/metabolic causes of ventricular wall thickening.Apical hypertrophic cardiomyopathy(ApHCM)represents a special form of ventricular hypertrophy predominantly affecting the left ventricular apex below the papillary muscles,typically without significant left ventricular outflow tract obstruction.[1,2]ApHCM often coexists with mild coronary artery abnormalities,[3]and reports of acute myocardial infarction with coronary artery stenosis in ApHCM or HCM patients are uncommon.
基金supported by the National Science Foundation(NSF)(No.CMMI-1750316)Pipeline and Hazardous Materials Safety Administration(PHMSA)of U.S.Department of Transportation(No.693JK31950008CAAP).
文摘The addition of nanoparticles serves as an effective reinforcement strategy for polymeric coatings,utilizing their unique characteristics as well as extraordinary mechanical,thermal,and electrical properties.The exceptionally high surface-to-volume ratio of nanoparticles imparts remarkable reinforcing potentials,yet it simultaneously gives rise to a prevalent tendency for nanoparticles to agglomerate into clusters within nanocomposites.The agglomeration behavior of the nanoparticles is predominantly influenced by their distinct microstructures and varied weight concentrations.This study investigated the synergistic effects of nanoparticle geometric shape and weight concentration on the dispersion characteristics of nanoparticles and the physical-mechanical performances of nano-reinforced epoxy coatings.Three carbon-based nanoparticles,nanodiamonds(NDs),carbon nanotubes(CNTs),and graphenes(GNPs),were incorporated into epoxy coatings at three weight concentrations(0.5%,1.0%,and 2.0%).The experimental findings reveal that epoxy coatings reinforced with NDs demonstrated the most homogenous dispersion characteristics,lowest viscosity,and reduced porosity among all the nanoparticles,which could be attributed to the spherical geometry shape.Due to the superior physical properties,ND-reinforced nanocomposites displayed the highest abrasion resistance and tensile properties.Specifically,the 1.0wt%ND-reinforced nanocomposites exhibited 60%,52%,and 97%improvements in mass lost,tensile strength,and failure strain,respectively,compared to pure epoxy.Furthermore,the representative volume element(RVE)modeling was employed to validate the experimental results,while highlighting the critical role of nanoparticle agglomeration,orientation,and the presence of voids on the mechanical properties of the nanocomposites.Nano-reinforced epoxy coatings with enhanced mechanical properties are well-suited for application in protective coatings for pipelines,industrial equipment,and automotive parts,where high wear resistance is essential.
