Rural tourism plays a crucial role in driving the sustainable development of rural economies.With the rise of the digital economy,user-generated content(UGC)videos on platforms such as TikTok have become a significant...Rural tourism plays a crucial role in driving the sustainable development of rural economies.With the rise of the digital economy,user-generated content(UGC)videos on platforms such as TikTok have become a significant factor influencing consumer decision-making,creating new opportunities for the growth of rural tourism.Using the TikTok app as the research platform,this study examines the relationship between UGC short videos,tourists’intentions to engage in rural tourism,and their perception of destination image.Specifically,it explores the impact of UGC short videos on tourists’willingness to participate in rural tourism and the mediating role of destination image perception.The findings indicate that UGC short videos positively influence tourists’willingness to engage in rural tourism.Destination image perception mediates this relationship,shaping tourists’decisions through cognitive and emotional image perceptions.Based on these findings,this paper recommends rural tourism destination managers enhance promotional strategies and improve destination image perception through UGC short video content.展开更多
User-generated content(UGC) such as blogs and twitters are exploding in modern Internet services. In such systems, recommender systems are needed to help people filter vast amount of UGC generated by other users. Howe...User-generated content(UGC) such as blogs and twitters are exploding in modern Internet services. In such systems, recommender systems are needed to help people filter vast amount of UGC generated by other users. However, traditional recommendation models do not use user authorship of items. In this paper, we show that with this additional information, we can significantly improve the performance of recommendations. A generative model that combines hierarchical topic modeling and matrix factorization is proposed. Empirical results show that our model outperforms other state-of-the-art models, and can provide interpretable topic structures for users and items. Furthermore, since user interests can be inferred from their productions, recommendations can be made for users that do not have any ratings to solve the cold-start problem.展开更多
Rice is a poor source of folate,an essential micronutrient for the body.Biofortification offers an effective way to enhance the folate content of rice and alleviate folate deficiencies in humans.In this study,we confi...Rice is a poor source of folate,an essential micronutrient for the body.Biofortification offers an effective way to enhance the folate content of rice and alleviate folate deficiencies in humans.In this study,we confirmed that OsADCS and OsGTPCHI,encoding the initial enzymes necessary for folate synthesis,positively regulate folate accumulation in knockout mutants of both japonica and indica rice backgrounds.The folate content in the low-folate japonica variety was slightly increased by the expression of the indica alleles driven by the endosperm-specific promoter.We further obtained co-expression lines by stacking OsADCS and OsGTPCHI genes;the folate accumulation in brown rice and polished rice reached 5.65μg/g and 2.95μg/g,respectively,representing 37.9-fold and 26.5-fold increases compared with the wild type.Transcriptomic analysis of rice grains from six transgenic lines showed that folate changes affected biological pathways involved in the synthesis and metabolism of rice seed storage substances,while the expression of other folate synthesis genes was weakly regulated.In addition,we identified Aus rice as a high-folate germplasm carrying superior haplotypes of OsADCS and OsGTPCHI through natural variation.This study provides an alternative and effective complementary strategy for rice biofortification,promoting the rational combination of metabolic engineering and conventional breeding to breed high-folate varieties.展开更多
Carbon can change the phase components of low-density steels and influence the mechanical properties.In this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization tre...Carbon can change the phase components of low-density steels and influence the mechanical properties.In this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was proposed.The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined.Crussard-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile test.During decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual phase.Meanwhile,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the same.In addition,the formation of other carbides restrained.Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution.For the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of microbands.For the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in ferrite.At the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.展开更多
In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMC)are prepared by taking the manufactured sand li...In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMC)are prepared by taking the manufactured sand lithology(tuff,limestone,basalt,granite),stone powder content(0,5%,10%,15%)and concrete strength grade(C60,C80,C100)as variables.The evolution of mechanical properties of HMC and the correlation between cubic compressive strength and other mechanical properties are studied.Compared to river sand,manufactured sand enhances the cubic compressive strength,axial compressive strength and elastic modulus of concrete,while its potential microcracks weaken the flexural strength and splitting tensile strength of concrete.Stone powder content displays both positive and negative effects on mechanical properties of HMC,and the stone powder content is suggested to be less than 10%.The empirical formulas between cubic compressive strength and other mechanical properties are proposed.展开更多
Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks.However,existing sampling technologies face challenges in maintaining the...Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks.However,existing sampling technologies face challenges in maintaining the integrity of gas content within samples and are often constrained by estimation errors inherent in empirical formulas,which results in inaccurate gas content measurements.This study introduces a lightweight,in-situ pressure-and gas-preserved corer designed to collect coal samples under the pressure conditions at the sampling point,effectively preventing gas loss during transfer and significantly improving measurement accuracy.Additionally,a gas migration model for deep coal mines was developed to elucidate gas migration characteristics under pressure-preserved coring conditions.The model offers valuable insights for optimizing coring parameters,demonstrating that both minimizing the coring hole diameter and reducing the pressure difference between the coring-point pressure and the original pore pressure can effectively improve the precision of gas content measurements.Coring tests conducted at an experimental base validated the performance of the corer and its effectiveness in sample collection.Furthermore,successful horizontal coring tests conducted in an underground coal mine roadway demonstrated that the measured gas content using pressure-preserved coring was 34%higher than that obtained through open sampling methods.展开更多
This study presents an innovative approach to enhancing the security of visual medical data in the generative AI environment through the integration of blockchain technology.By combining the strengths of blockchain an...This study presents an innovative approach to enhancing the security of visual medical data in the generative AI environment through the integration of blockchain technology.By combining the strengths of blockchain and generative AI,the research team aimed to address the timely challenge of safeguarding visual medical content.The participating researchers conducted a comprehensive analysis,examining the vulnerabilities of medical AI services,personal information protection issues,and overall security weaknesses.This multi faceted exploration led to an indepth evaluation of the model’s performance and security.Notably,the correlation between accuracy,detection rate,and error rate was scrutinized.This analysis revealed insights into the model’s strengths and limitations,while the consideration of standard deviation shed light on the model’s stability and performance variability.The study proposed practical improvements,emphasizing the reduction of false negatives to enhance detection rate and leveraging blockchain technology to ensure visual data integrity in medical applications.Applying blockchain to generative AI-created medical content addresses key personal information protection issues.By utilizing the distributed ledger system of blockchain,the research team aimed to protect the privacy and integrity of medical data especially medical images.This approach not only enhances security but also enables transparent and tamperproof record-keeping.Additionally,the use of generative AI models ensures the creation of novel medical content without compromising personal information,further safeguarding patient privacy.In conclusion,this study showcases the potential of blockchain-based solutions in the medical field,particularly in securing sensitive medical data and protecting patient privacy.The proposed approach,combining blockchain and generative AI,offers a promising direction toward more robust and secure medical content management.Further research and advancements in this area will undoubtedly contribute to the development of robust and privacy-preserving healthcare systems,and visual diagnostic systems.展开更多
Zirconium alloy cladding materials inevitably undergo hydrogen absorption in the processing and operation process of the reactor,and its static and dynamic mechanical properties are closely related to the hydrogen con...Zirconium alloy cladding materials inevitably undergo hydrogen absorption in the processing and operation process of the reactor,and its static and dynamic mechanical properties are closely related to the hydrogen content.Samples with hydrogen content ranging from 23μg/g to 132μg/g were obtained using the method of gas-phase hydrogen charging,and the influence of hydrogen content on static/dynamic mechanical properties of Zr-Sn-Nb-Fe alloy was studied.The results show that the effect of weak hydrogen charging on the ultimate tensile strength,yield strength,and elongation of zirconium alloy is not obvious.There are a large number of dimples on the fracture surface of the tensile sample before and after hydrogen charging,which is a typical ductile fracture.However,the impact toughness of Zr-Sn-Nb-Fe alloy decreases significantly after trace hydrogen charging.The impact sample without hydrogen charging shows the mixed fracture mechanism of ductile fracture and microcleavage fracture.The increase in hydrogen permeability leads to the emergence of hydride,and the deformation of high strain rate under the impact loading condition leads to secondary cracks in the microstructure.The initiation and expansion of the secondary cracks is the main reason for the reduction of the impact toughness.展开更多
Aseries of [(Fe_(0.6)Co_(0.2)Ni_(0.2))_(0.75-0.03x)B_(0.2)Si_(0.05+0.03x)]_(96)Nb_(4) amorphous alloy composite coatings were prepared by adjusting the silicon content(x=0,1,2,3,4,5,and 6)and their microstructures and...Aseries of [(Fe_(0.6)Co_(0.2)Ni_(0.2))_(0.75-0.03x)B_(0.2)Si_(0.05+0.03x)]_(96)Nb_(4) amorphous alloy composite coatings were prepared by adjusting the silicon content(x=0,1,2,3,4,5,and 6)and their microstructures and tribological properties were investigated by laser cladding technique.Additionally,the effect of Si on the glass forming ability(GFA)of the layers was understood.Results show that an appropriate Si content can refine the microstructure of the FeCoNiBSiNb laser cladding layers and improve the mechanical and tribological properties.The hardness of the coating layer increases monotonically with the Si content.At the Si content of 4.8at%(x=0),the coating layer exhibits a relatively low hardness(734.2HV 0.1).Conversely,at the silicon content of 13.44at%(x=3),the coating layer exhibits the highest hardness(1106HV 0.1).The non-crystalline content and tensile strength exhibit an initial increase,followed by a subsequent decrease.At x=2,the coating exhibits its maximum fracture strength(2880 MPa).However,when x>2,the fracture strength of the coating decreases with an increase in x.Conversely,with an increase in Si content,the wear volume loss initially decreases and then increases.At a Si content of 10.56at%(x=2),the coating exhibits the highest non-crystalline content(42%),the highest tensile strength(2880 MPa),and the most favorable dry friction performance.展开更多
In this study,compacted loess samples with varying compaction water content but identical dry density were prepared to investigate the evolution of their hydraulic conductivity and compression behavior.Additionally,en...In this study,compacted loess samples with varying compaction water content but identical dry density were prepared to investigate the evolution of their hydraulic conductivity and compression behavior.Additionally,environmental scanning electron microscopy(ESEM)and nuclear magnetic resonance(NMR)analyses were conducted to gain microstructural insights into loess behavior at the laboratory scale.The results indicate that the maximum saturated hydraulic conductivity is observed at the lowest compaction water content,particularly in the early stage of permeability tests.In particular,for loess compacted at water contents below the optimum(as determined by the modified Proctor compaction test),the hydraulic conductivity decreases throughout the permeability tests.Conversely,when the water content exceeds the optimum level,the hydraulic conductivity shows an increasing trend.In terms of compression behavior,when the as-compacted samples are loaded in oedometer conditions,an increase in material compressibility is observed with increasing compaction water content.Again,a different phenomenological behavior was observed when the compaction water content exceeded the optimum,i.e.an abrupt increase in loess compressibility.ESEM tests provide microstructural confirmation of this evidence,as the surface morphology of the compacted loess changes significantly with increasing compaction water content.The microstructural evolution was also quantified in terms of area ratio using image processing software.Finally,NMR was used to quantify the intra-and inter-aggregate water at different compaction water contents,once again highlighting a threshold for the presence or absence of inter-aggregate water similar to the optimum water content.展开更多
Salt stress significantly inhibits crop growth and development,and mitigating this can enhance salt tolerance in various crops.Previous studies have shown that regulating saccharide biosynthesis is a key aspect of pla...Salt stress significantly inhibits crop growth and development,and mitigating this can enhance salt tolerance in various crops.Previous studies have shown that regulating saccharide biosynthesis is a key aspect of plant salt tolerance;however,the underlying molecular mechanisms remain largely unexplored.In this study,we demonstrate that overexpression of a salt-inducible galactinol synthase gene,ZmGolS1,alleviates salt-induced growth inhibition,likely by promoting raffinose synthesis.Additionally,we show that natural variation in ZmGolS1 transcript levels contributes to the diversity of raffinose content and salt tolerance in maize.We further reveal that ZmRR18,a type-B response regulator transcription factor,binds to the AATC element in the promoter of ZmGolS1,with this binding increases the transcript levels of ZmGolS1 under salt conditions.Moreover,a single nucleotide polymorphism(termed SNP-302T)within the ZmGolS1 promoter significantly reduces its binding affinity for ZmRR18,resulting in decreased ZmGolS1 expression and diminished raffinose content,ultimately leading to a salt-hypersensitive phenotype.Collectively,our findings reveal the molecular mechanisms by which the ZmRR18-ZmGolS1 module enhances raffinose biosynthesis,thereby promoting maize growth under salt conditions.This research provides important insights into salt tolerance mechanisms associated with saccharide biosynthesis and identifies valuable genetic loci for breeding salt-tolerant maize varieties.展开更多
Protein content plays a crucial role in determining the eating and cooking quality of rice.However,the genetic and molecular basis underlying grain protein content remains to be elucidated.In this study,we identified ...Protein content plays a crucial role in determining the eating and cooking quality of rice.However,the genetic and molecular basis underlying grain protein content remains to be elucidated.In this study,we identified a genomic region associated with grain protein content in rice chromosome segment substitution lines containing the flowering gene Ghd7.1,which reduced grain protein content by repressing the transcription of the gene OsAAP6.Knockout of Ghd7.1 increased grain protein content and decreased the eating and cooking quality of rice.Introduction of the functional haplotype of Ghd7.1 into two elite rice cultivars reduced their protein content and increased their eating quality and grain yield with no effect on the regulation of flowering time.Ghd7.1 might be used for regulating the protein content and improving the eating quality of rice varieties.展开更多
Crude fat is an important nutritional component of maize kernels.However,the genetic mechanisms underlying crude fat content in maize kernels remain elusive.Previous studies used single-model genome-wide association s...Crude fat is an important nutritional component of maize kernels.However,the genetic mechanisms underlying crude fat content in maize kernels remain elusive.Previous studies used single-model genome-wide association studies(GWAS)with limited population sizes,which can result in false loci positives and hinder functional gene identification.Therefore,this study used a population consisting of 495 maize inbred lines,combined with 1.25 million single nucleotide polymorphisms(SNPs),and implemented GWAS using six models to identify quantitative trait nucleotides(QTNs)controlling crude fat content and to mine key genes.The results revealed a wide variation in crude fat content(0.62-16.03%)and broad-sense heritability(H^(2))(96.23%).In total,744 significant QTNs were detected,with 147 co-located across different models,environments,and methods.Based on the 147 colocated QTNs,candidate genes were searched at 50 kb up-and down-stream intervals of each QTN.We finally screened eight candidate genes(GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,GRMZM2G368838,GRMZM2G058496,GRMZM2G090669,GRMZM2G001241,and GRMZM2G333454)related to crude fat content that exhibited high expression levels during kernel development in maize inbred line B73.Notably,GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,and GRMZM2G368838 are involved in the linoleic acid metabolic pathway,oil metabolism,kernel growth,and development in maize.Furthermore,co-expression network analysis revealed that the eight candidate genes strongly correlated with 30 known genes.Proteins encoded by candidate genes interact with other proteins and play an important role in oil content and oleic acid metabolism in maize kernels.The best haplotypes of candidate genes might increase crude fat content without decreasing maize yield.These results broaden the understanding of the genetic mechanism of crude fat content and facilitate marker-assisted selection for high-crude fat breeding programs for maize.展开更多
The present teaching content of the power electronics course is insufficient to cover the power electronics technology used in building electrical engineering.This paper analyzes the relationship between building elec...The present teaching content of the power electronics course is insufficient to cover the power electronics technology used in building electrical engineering.This paper analyzes the relationship between building electrical engineering and power electronics technology,investigates the main power electronics technology used in building electrical engineering,introduces the teaching content of current power electronics course,analyzes the insufficiency of current teaching content related to the practice of electrical engineering,and proposes the principles and directions for the reformation and innovation of the teaching content of the course of power electronics for the major of building electricity and intelligence.展开更多
Tight oil is the most viable target for unconventional oil and gas exploration, but the complexity of micro-/nanopore throat systems significantly affects the oil content of reservoirs. To investigate the causes of he...Tight oil is the most viable target for unconventional oil and gas exploration, but the complexity of micro-/nanopore throat systems significantly affects the oil content of reservoirs. To investigate the causes of heterogeneity in oil-bearing reservoirs, a high-pressure mercury injection experiment combined with fractal theory was conducted to analyze the micro pore throat structure characteristics of the tight sandstone of Chang 7 Member reservoirs in the Ordos Basin. The factors controlling the variations in oil content among tight sandstone samples were identified based on mineral composition characteristics. The results indicate that the pore throat radius distribution is mainly unimodal an bimodal. In oil-bearing samples, the pore throat distributions align well with the corresponding permeability contribution curves, while in oil-free samples, there is a clear deviation from these curves. Mesopore throats exert the greatest influence on seepage capacity. Differences in fractal characteristics are primarily reflected in D1 values, with oil-free samples exhibiting D1 values close to 3, indicating an extremely nonuniform pore throat structure at this scale. The content of quartz, plagioclase, and chlorite is significantly higher in oil-bearing samples than in oil-free samples, whereas calcite content is lower in oil-bearing samples. There is a positive correlation between the contents of quartz, plagioclase, and chlorite with D1;their increased presence contributes to a more favorable pore throat structure.Conversely, the calcite contents show an inverse relationship with D1. Cementation increases the complexity of pore throat structures, while multiple diagenetic processes simultaneously control these characteristics, leading to variations in oil content.展开更多
Peanut kernels rich in oil,particularly those with oleic acid as their primary fatty acid,are in high demand among consumers,the food industry,and farmers due to their superior nutritional content,extended shelf life,...Peanut kernels rich in oil,particularly those with oleic acid as their primary fatty acid,are in high demand among consumers,the food industry,and farmers due to their superior nutritional content,extended shelf life,and health benefits.The oil content and fatty acid composition are governed by multiple genetic factors.Identifying the quantitative trait loci(QTLs)related to these attributes will facilitate marker-assisted selection and genomic selection,thus enhancing quality-focused peanut breeding programs.For this purpose,we developed a population of 521 recombinant inbred lines(RILs)and tested their kernel quality traits across five different environments.We identified two major and stable QTLs for oil content,qOCAh12.1 and qOCAh16.1.The markers linked to these QTLs were designed by Kompetitive allele-specific PCR(KASP)and subsequently validated.Moreover,we found that the superior haplotype of oil content in the qOCAh16.1 region was conserved within the plant introduction(PI)germplasm cluster,as evidenced by a diverse peanut accession panel.In addition,we determined that qAh09 and qAh19.1,which harbor the key gene encoding fatty acid desaturase 2(FAD2),influence all seven fatty acids,palmitic,stearic,oleic,linoleic,arachidic,gadoleic,and behenic acids.Regarding the protein content and the long-chain saturated fatty acid behenic acid,qAh07 emerged as the major and stable QTL,accounting for over 10%of the phenotypic variation explained(PVE).These findings can enhance marker-assisted selection in peanut breeding,with the aim of improving the oil content,and deepen our understanding of the genetic mechanisms that shape fatty acid composition.展开更多
Currently,in STEM environments,female employees are often recognized as minorities due to their positioning or occupancy rate,which may lead to experiences of“imposter syndrome”.This study applies frameworks of mixe...Currently,in STEM environments,female employees are often recognized as minorities due to their positioning or occupancy rate,which may lead to experiences of“imposter syndrome”.This study applies frameworks of mixed-gender discourse,such as limited involvement in activity as an agent,markedness,and gender-differentiated roles,to clarify how women in STEM position themselves or are positioned by the society.Using corpus linguistics and content analysis,it is clarified that female researchers are usually linguistically marked or tend to distinguish themselves as non-experts.Thus,their portrayal within a misogynistic society may considerably interact with how female researchers represent themselves.展开更多
Surface albedo,as one of the important properties of the underlying surface,has a significant impact on the surface energy balance in cold regions.However,due to the complexity of the factors affecting surface albedo,...Surface albedo,as one of the important properties of the underlying surface,has a significant impact on the surface energy balance in cold regions.However,due to the complexity of the factors affecting surface albedo,existing calculations still contain inaccuracies.Therefore,this study conducted surface albedo experiments on loess with different water contents and temperatures.By analyzing the surface albedo measurements of samples with varying temperature and water content levels,as well as the soil freezing characteristic curve(SFCC)and soil-water characteristic curve(SWCC)of loess,the study explores the influence of soil temperature and water content on the surface albedo of loess.The results indicate that both the temperature and water content of loess jointly affect surface albedo.During the process of albedo change,there exists a water content threshold that alters the trend of surface albedo.Soil temperature influences surface albedo by affecting the content of pore ice and liquid water within the soil.When the water content of loess is relatively low,the surface albedo decreases as the unfrozen water content decreases.However,this trend changes as the water content of loess increases.Additionally,a decrease in soil temperature lowers the moisture content threshold during the changes in surface albedo.This study provides a reference for exploring and determining the surface energy balance in cold regions under the background of warm and humid climates,as well as for establishing thermal calculation boundaries.展开更多
Vehicular networks enable seamless connectivity for exchanging emergency and infotainment content.However,retrieving infotainment data from remote servers often introduces high delays,degrading the Quality of Service(...Vehicular networks enable seamless connectivity for exchanging emergency and infotainment content.However,retrieving infotainment data from remote servers often introduces high delays,degrading the Quality of Service(QoS).To overcome this,caching frequently requested content at fog-enabled Road Side Units(RSUs)reduces communication latency.Yet,the limited caching capacity of RSUs makes it impractical to store all contents with varying sizes and popularity.This research proposes an efficient content caching algorithm that adapts to dynamic vehicular demands on highways to maximize request satisfaction.The scheme is evaluated against Intelligent Content Caching(ICC)and Random Caching(RC).The obtained results show that our proposed scheme entertains more contentrequesting vehicles as compared to ICC and RC,with 33%and 41%more downloaded data in 28%and 35%less amount of time from ICC and RC schemes,respectively.展开更多
基金The Liaoning Provincial Social Science Planning Fund Project(L23CGL002)。
文摘Rural tourism plays a crucial role in driving the sustainable development of rural economies.With the rise of the digital economy,user-generated content(UGC)videos on platforms such as TikTok have become a significant factor influencing consumer decision-making,creating new opportunities for the growth of rural tourism.Using the TikTok app as the research platform,this study examines the relationship between UGC short videos,tourists’intentions to engage in rural tourism,and their perception of destination image.Specifically,it explores the impact of UGC short videos on tourists’willingness to participate in rural tourism and the mediating role of destination image perception.The findings indicate that UGC short videos positively influence tourists’willingness to engage in rural tourism.Destination image perception mediates this relationship,shaping tourists’decisions through cognitive and emotional image perceptions.Based on these findings,this paper recommends rural tourism destination managers enhance promotional strategies and improve destination image perception through UGC short video content.
基金Project supported by the Monitoring Statistics Project on Agricultural and Rural Resources,MOA,Chinathe Innovative Talents Project,MOA,Chinathe Science and Technology Innovation Project Fund of Chinese Academy of Agricultural Sciences(No.CAAS-ASTIP-2015-AI I-02)
文摘User-generated content(UGC) such as blogs and twitters are exploding in modern Internet services. In such systems, recommender systems are needed to help people filter vast amount of UGC generated by other users. However, traditional recommendation models do not use user authorship of items. In this paper, we show that with this additional information, we can significantly improve the performance of recommendations. A generative model that combines hierarchical topic modeling and matrix factorization is proposed. Empirical results show that our model outperforms other state-of-the-art models, and can provide interpretable topic structures for users and items. Furthermore, since user interests can be inferred from their productions, recommendations can be made for users that do not have any ratings to solve the cold-start problem.
基金supported by the Central Public-Interest Scientific Institution Basal Research Fund,China(Grant No.CPSIBRF-CNRRI-202403)。
文摘Rice is a poor source of folate,an essential micronutrient for the body.Biofortification offers an effective way to enhance the folate content of rice and alleviate folate deficiencies in humans.In this study,we confirmed that OsADCS and OsGTPCHI,encoding the initial enzymes necessary for folate synthesis,positively regulate folate accumulation in knockout mutants of both japonica and indica rice backgrounds.The folate content in the low-folate japonica variety was slightly increased by the expression of the indica alleles driven by the endosperm-specific promoter.We further obtained co-expression lines by stacking OsADCS and OsGTPCHI genes;the folate accumulation in brown rice and polished rice reached 5.65μg/g and 2.95μg/g,respectively,representing 37.9-fold and 26.5-fold increases compared with the wild type.Transcriptomic analysis of rice grains from six transgenic lines showed that folate changes affected biological pathways involved in the synthesis and metabolism of rice seed storage substances,while the expression of other folate synthesis genes was weakly regulated.In addition,we identified Aus rice as a high-folate germplasm carrying superior haplotypes of OsADCS and OsGTPCHI through natural variation.This study provides an alternative and effective complementary strategy for rice biofortification,promoting the rational combination of metabolic engineering and conventional breeding to breed high-folate varieties.
基金financially supported by the National Natural Science Foundation of China(Nos.U2141207,52171111,and 52001083)the Youth Talent Project of China National Nuclear Corporation(No.CNNC2021Y-TEPHEU01)+3 种基金the China Postdoctoral Science Foundation(No.2020M681077)the Natural Science Foundation of Heilongjiang,China(No.LH2019E030)the Heilongjiang Postdoctoral Science Foundation,China(No.LBH-Z19125)he Heilongjiang Touyan Innovation Team Program,China,and the Natural Science Foundation of Heilongjiang(No.LH2020E060)。
文摘Carbon can change the phase components of low-density steels and influence the mechanical properties.In this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was proposed.The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined.Crussard-Jaoul(C-J)analysis was employed to examine the work hardening characteristics during the tensile test.During decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual phase.Meanwhile,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the same.In addition,the formation of other carbides restrained.Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution.For the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of microbands.For the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in ferrite.At the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.
基金Funded by the National Natural Science Foundation of China(Nos.U1934206,52108260)China Academy of Railway Sciences Fund(No.2021YJ078)+1 种基金Railway Engineering Construction Standard Project(No.2023-BZWW-006)New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMC)are prepared by taking the manufactured sand lithology(tuff,limestone,basalt,granite),stone powder content(0,5%,10%,15%)and concrete strength grade(C60,C80,C100)as variables.The evolution of mechanical properties of HMC and the correlation between cubic compressive strength and other mechanical properties are studied.Compared to river sand,manufactured sand enhances the cubic compressive strength,axial compressive strength and elastic modulus of concrete,while its potential microcracks weaken the flexural strength and splitting tensile strength of concrete.Stone powder content displays both positive and negative effects on mechanical properties of HMC,and the stone powder content is suggested to be less than 10%.The empirical formulas between cubic compressive strength and other mechanical properties are proposed.
基金supported by the National Natural Science Foundation of China(Nos.51827901,42477191,and 52304033)the Fundamental Research Funds for the Central Universities(No.YJ202449)+1 种基金the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(No.SKLGME022009)the China Postdoctoral Science Foundation(No.2023M742446).
文摘Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks.However,existing sampling technologies face challenges in maintaining the integrity of gas content within samples and are often constrained by estimation errors inherent in empirical formulas,which results in inaccurate gas content measurements.This study introduces a lightweight,in-situ pressure-and gas-preserved corer designed to collect coal samples under the pressure conditions at the sampling point,effectively preventing gas loss during transfer and significantly improving measurement accuracy.Additionally,a gas migration model for deep coal mines was developed to elucidate gas migration characteristics under pressure-preserved coring conditions.The model offers valuable insights for optimizing coring parameters,demonstrating that both minimizing the coring hole diameter and reducing the pressure difference between the coring-point pressure and the original pore pressure can effectively improve the precision of gas content measurements.Coring tests conducted at an experimental base validated the performance of the corer and its effectiveness in sample collection.Furthermore,successful horizontal coring tests conducted in an underground coal mine roadway demonstrated that the measured gas content using pressure-preserved coring was 34%higher than that obtained through open sampling methods.
文摘This study presents an innovative approach to enhancing the security of visual medical data in the generative AI environment through the integration of blockchain technology.By combining the strengths of blockchain and generative AI,the research team aimed to address the timely challenge of safeguarding visual medical content.The participating researchers conducted a comprehensive analysis,examining the vulnerabilities of medical AI services,personal information protection issues,and overall security weaknesses.This multi faceted exploration led to an indepth evaluation of the model’s performance and security.Notably,the correlation between accuracy,detection rate,and error rate was scrutinized.This analysis revealed insights into the model’s strengths and limitations,while the consideration of standard deviation shed light on the model’s stability and performance variability.The study proposed practical improvements,emphasizing the reduction of false negatives to enhance detection rate and leveraging blockchain technology to ensure visual data integrity in medical applications.Applying blockchain to generative AI-created medical content addresses key personal information protection issues.By utilizing the distributed ledger system of blockchain,the research team aimed to protect the privacy and integrity of medical data especially medical images.This approach not only enhances security but also enables transparent and tamperproof record-keeping.Additionally,the use of generative AI models ensures the creation of novel medical content without compromising personal information,further safeguarding patient privacy.In conclusion,this study showcases the potential of blockchain-based solutions in the medical field,particularly in securing sensitive medical data and protecting patient privacy.The proposed approach,combining blockchain and generative AI,offers a promising direction toward more robust and secure medical content management.Further research and advancements in this area will undoubtedly contribute to the development of robust and privacy-preserving healthcare systems,and visual diagnostic systems.
文摘Zirconium alloy cladding materials inevitably undergo hydrogen absorption in the processing and operation process of the reactor,and its static and dynamic mechanical properties are closely related to the hydrogen content.Samples with hydrogen content ranging from 23μg/g to 132μg/g were obtained using the method of gas-phase hydrogen charging,and the influence of hydrogen content on static/dynamic mechanical properties of Zr-Sn-Nb-Fe alloy was studied.The results show that the effect of weak hydrogen charging on the ultimate tensile strength,yield strength,and elongation of zirconium alloy is not obvious.There are a large number of dimples on the fracture surface of the tensile sample before and after hydrogen charging,which is a typical ductile fracture.However,the impact toughness of Zr-Sn-Nb-Fe alloy decreases significantly after trace hydrogen charging.The impact sample without hydrogen charging shows the mixed fracture mechanism of ductile fracture and microcleavage fracture.The increase in hydrogen permeability leads to the emergence of hydride,and the deformation of high strain rate under the impact loading condition leads to secondary cracks in the microstructure.The initiation and expansion of the secondary cracks is the main reason for the reduction of the impact toughness.
文摘Aseries of [(Fe_(0.6)Co_(0.2)Ni_(0.2))_(0.75-0.03x)B_(0.2)Si_(0.05+0.03x)]_(96)Nb_(4) amorphous alloy composite coatings were prepared by adjusting the silicon content(x=0,1,2,3,4,5,and 6)and their microstructures and tribological properties were investigated by laser cladding technique.Additionally,the effect of Si on the glass forming ability(GFA)of the layers was understood.Results show that an appropriate Si content can refine the microstructure of the FeCoNiBSiNb laser cladding layers and improve the mechanical and tribological properties.The hardness of the coating layer increases monotonically with the Si content.At the Si content of 4.8at%(x=0),the coating layer exhibits a relatively low hardness(734.2HV 0.1).Conversely,at the silicon content of 13.44at%(x=3),the coating layer exhibits the highest hardness(1106HV 0.1).The non-crystalline content and tensile strength exhibit an initial increase,followed by a subsequent decrease.At x=2,the coating exhibits its maximum fracture strength(2880 MPa).However,when x>2,the fracture strength of the coating decreases with an increase in x.Conversely,with an increase in Si content,the wear volume loss initially decreases and then increases.At a Si content of 10.56at%(x=2),the coating exhibits the highest non-crystalline content(42%),the highest tensile strength(2880 MPa),and the most favorable dry friction performance.
基金the China Postdoctoral Science Foundation(Grant No.2024MD753992)Shaanxi Geotechnical Mechanics and Engineering Young Talent Support Program Project(Grant No.YESS2024005)the National Natural Science Foundation of China(Grant No.41931285).
文摘In this study,compacted loess samples with varying compaction water content but identical dry density were prepared to investigate the evolution of their hydraulic conductivity and compression behavior.Additionally,environmental scanning electron microscopy(ESEM)and nuclear magnetic resonance(NMR)analyses were conducted to gain microstructural insights into loess behavior at the laboratory scale.The results indicate that the maximum saturated hydraulic conductivity is observed at the lowest compaction water content,particularly in the early stage of permeability tests.In particular,for loess compacted at water contents below the optimum(as determined by the modified Proctor compaction test),the hydraulic conductivity decreases throughout the permeability tests.Conversely,when the water content exceeds the optimum level,the hydraulic conductivity shows an increasing trend.In terms of compression behavior,when the as-compacted samples are loaded in oedometer conditions,an increase in material compressibility is observed with increasing compaction water content.Again,a different phenomenological behavior was observed when the compaction water content exceeded the optimum,i.e.an abrupt increase in loess compressibility.ESEM tests provide microstructural confirmation of this evidence,as the surface morphology of the compacted loess changes significantly with increasing compaction water content.The microstructural evolution was also quantified in terms of area ratio using image processing software.Finally,NMR was used to quantify the intra-and inter-aggregate water at different compaction water contents,once again highlighting a threshold for the presence or absence of inter-aggregate water similar to the optimum water content.
基金support from the National Key R&D Program of China(2022YFF1001601)the National Science Fund for Distinguished Young Scholars(32325037)+2 种基金the National Natural Science Foundation of China(32201718 and 32401756)the Postdoctoral Innovation Talents Support Program(BX20240420)the China Postdoctoral Science Foundation(2024T171011 and 2023M743817).
文摘Salt stress significantly inhibits crop growth and development,and mitigating this can enhance salt tolerance in various crops.Previous studies have shown that regulating saccharide biosynthesis is a key aspect of plant salt tolerance;however,the underlying molecular mechanisms remain largely unexplored.In this study,we demonstrate that overexpression of a salt-inducible galactinol synthase gene,ZmGolS1,alleviates salt-induced growth inhibition,likely by promoting raffinose synthesis.Additionally,we show that natural variation in ZmGolS1 transcript levels contributes to the diversity of raffinose content and salt tolerance in maize.We further reveal that ZmRR18,a type-B response regulator transcription factor,binds to the AATC element in the promoter of ZmGolS1,with this binding increases the transcript levels of ZmGolS1 under salt conditions.Moreover,a single nucleotide polymorphism(termed SNP-302T)within the ZmGolS1 promoter significantly reduces its binding affinity for ZmRR18,resulting in decreased ZmGolS1 expression and diminished raffinose content,ultimately leading to a salt-hypersensitive phenotype.Collectively,our findings reveal the molecular mechanisms by which the ZmRR18-ZmGolS1 module enhances raffinose biosynthesis,thereby promoting maize growth under salt conditions.This research provides important insights into salt tolerance mechanisms associated with saccharide biosynthesis and identifies valuable genetic loci for breeding salt-tolerant maize varieties.
基金supported by the National Natural Science Foundation of China(32272071,No.32261143466)the Major Program of Science and Technology Development of Wuhan,China(2022021302024850)the Key Project for Research and Development of Hubei Province,China(2023BBB027)。
文摘Protein content plays a crucial role in determining the eating and cooking quality of rice.However,the genetic and molecular basis underlying grain protein content remains to be elucidated.In this study,we identified a genomic region associated with grain protein content in rice chromosome segment substitution lines containing the flowering gene Ghd7.1,which reduced grain protein content by repressing the transcription of the gene OsAAP6.Knockout of Ghd7.1 increased grain protein content and decreased the eating and cooking quality of rice.Introduction of the functional haplotype of Ghd7.1 into two elite rice cultivars reduced their protein content and increased their eating quality and grain yield with no effect on the regulation of flowering time.Ghd7.1 might be used for regulating the protein content and improving the eating quality of rice varieties.
基金supported by the National Natural Science Foundation of China(32101700)the China Postdoctoral Science Foundation(2022M7111220)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(2021RC2082)and the Postgraduate Scientific Research Innovation Project of Hunan Province,China(CX20230697)。
文摘Crude fat is an important nutritional component of maize kernels.However,the genetic mechanisms underlying crude fat content in maize kernels remain elusive.Previous studies used single-model genome-wide association studies(GWAS)with limited population sizes,which can result in false loci positives and hinder functional gene identification.Therefore,this study used a population consisting of 495 maize inbred lines,combined with 1.25 million single nucleotide polymorphisms(SNPs),and implemented GWAS using six models to identify quantitative trait nucleotides(QTNs)controlling crude fat content and to mine key genes.The results revealed a wide variation in crude fat content(0.62-16.03%)and broad-sense heritability(H^(2))(96.23%).In total,744 significant QTNs were detected,with 147 co-located across different models,environments,and methods.Based on the 147 colocated QTNs,candidate genes were searched at 50 kb up-and down-stream intervals of each QTN.We finally screened eight candidate genes(GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,GRMZM2G368838,GRMZM2G058496,GRMZM2G090669,GRMZM2G001241,and GRMZM2G333454)related to crude fat content that exhibited high expression levels during kernel development in maize inbred line B73.Notably,GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,and GRMZM2G368838 are involved in the linoleic acid metabolic pathway,oil metabolism,kernel growth,and development in maize.Furthermore,co-expression network analysis revealed that the eight candidate genes strongly correlated with 30 known genes.Proteins encoded by candidate genes interact with other proteins and play an important role in oil content and oleic acid metabolism in maize kernels.The best haplotypes of candidate genes might increase crude fat content without decreasing maize yield.These results broaden the understanding of the genetic mechanism of crude fat content and facilitate marker-assisted selection for high-crude fat breeding programs for maize.
基金Cloud Course of Beijing University of Civil Engineering and Architecture at Super Star Learning(YC240109)。
文摘The present teaching content of the power electronics course is insufficient to cover the power electronics technology used in building electrical engineering.This paper analyzes the relationship between building electrical engineering and power electronics technology,investigates the main power electronics technology used in building electrical engineering,introduces the teaching content of current power electronics course,analyzes the insufficiency of current teaching content related to the practice of electrical engineering,and proposes the principles and directions for the reformation and innovation of the teaching content of the course of power electronics for the major of building electricity and intelligence.
基金supported by the National Natural Science Foundation of China (Grant No. 42002139)the Basic Prospective Project of SINOPEC (Grant No. P23240-3)。
文摘Tight oil is the most viable target for unconventional oil and gas exploration, but the complexity of micro-/nanopore throat systems significantly affects the oil content of reservoirs. To investigate the causes of heterogeneity in oil-bearing reservoirs, a high-pressure mercury injection experiment combined with fractal theory was conducted to analyze the micro pore throat structure characteristics of the tight sandstone of Chang 7 Member reservoirs in the Ordos Basin. The factors controlling the variations in oil content among tight sandstone samples were identified based on mineral composition characteristics. The results indicate that the pore throat radius distribution is mainly unimodal an bimodal. In oil-bearing samples, the pore throat distributions align well with the corresponding permeability contribution curves, while in oil-free samples, there is a clear deviation from these curves. Mesopore throats exert the greatest influence on seepage capacity. Differences in fractal characteristics are primarily reflected in D1 values, with oil-free samples exhibiting D1 values close to 3, indicating an extremely nonuniform pore throat structure at this scale. The content of quartz, plagioclase, and chlorite is significantly higher in oil-bearing samples than in oil-free samples, whereas calcite content is lower in oil-bearing samples. There is a positive correlation between the contents of quartz, plagioclase, and chlorite with D1;their increased presence contributes to a more favorable pore throat structure.Conversely, the calcite contents show an inverse relationship with D1. Cementation increases the complexity of pore throat structures, while multiple diagenetic processes simultaneously control these characteristics, leading to variations in oil content.
基金supported by the National Key R&D Program of China(2022YFD1200400)the earmarked fund for CARS-13,the Major Science and Technology Projects of Henan Province,China(221100110300)the Henan Provincial R&D Program of Interregional Cooperation for Local Scientific and Technological Development Guided by Central Government,China(YDZX20214100004191)。
文摘Peanut kernels rich in oil,particularly those with oleic acid as their primary fatty acid,are in high demand among consumers,the food industry,and farmers due to their superior nutritional content,extended shelf life,and health benefits.The oil content and fatty acid composition are governed by multiple genetic factors.Identifying the quantitative trait loci(QTLs)related to these attributes will facilitate marker-assisted selection and genomic selection,thus enhancing quality-focused peanut breeding programs.For this purpose,we developed a population of 521 recombinant inbred lines(RILs)and tested their kernel quality traits across five different environments.We identified two major and stable QTLs for oil content,qOCAh12.1 and qOCAh16.1.The markers linked to these QTLs were designed by Kompetitive allele-specific PCR(KASP)and subsequently validated.Moreover,we found that the superior haplotype of oil content in the qOCAh16.1 region was conserved within the plant introduction(PI)germplasm cluster,as evidenced by a diverse peanut accession panel.In addition,we determined that qAh09 and qAh19.1,which harbor the key gene encoding fatty acid desaturase 2(FAD2),influence all seven fatty acids,palmitic,stearic,oleic,linoleic,arachidic,gadoleic,and behenic acids.Regarding the protein content and the long-chain saturated fatty acid behenic acid,qAh07 emerged as the major and stable QTL,accounting for over 10%of the phenotypic variation explained(PVE).These findings can enhance marker-assisted selection in peanut breeding,with the aim of improving the oil content,and deepen our understanding of the genetic mechanisms that shape fatty acid composition.
文摘Currently,in STEM environments,female employees are often recognized as minorities due to their positioning or occupancy rate,which may lead to experiences of“imposter syndrome”.This study applies frameworks of mixed-gender discourse,such as limited involvement in activity as an agent,markedness,and gender-differentiated roles,to clarify how women in STEM position themselves or are positioned by the society.Using corpus linguistics and content analysis,it is clarified that female researchers are usually linguistically marked or tend to distinguish themselves as non-experts.Thus,their portrayal within a misogynistic society may considerably interact with how female researchers represent themselves.
基金supported by the National Natural Science Foundation of China(42261028)the Chinese Academy of Sciences“Light of West China”Program for Western Young Scholars(23JR6KA027)+3 种基金the Science Foundation for Distinguished Young Scholars of Gansu Province(24JRRA167)the Key Research and Development Program on Ecological Civilization Construction of Gansu Province(25YFFA012)Gansu Provincial Science and Technology Plan Fund Project(24CXGA063)Scientific Research Projects on Ecological and Environmental Protection in Heilongjiang Province in 2023(Grant No.:HST2023ZR005)。
文摘Surface albedo,as one of the important properties of the underlying surface,has a significant impact on the surface energy balance in cold regions.However,due to the complexity of the factors affecting surface albedo,existing calculations still contain inaccuracies.Therefore,this study conducted surface albedo experiments on loess with different water contents and temperatures.By analyzing the surface albedo measurements of samples with varying temperature and water content levels,as well as the soil freezing characteristic curve(SFCC)and soil-water characteristic curve(SWCC)of loess,the study explores the influence of soil temperature and water content on the surface albedo of loess.The results indicate that both the temperature and water content of loess jointly affect surface albedo.During the process of albedo change,there exists a water content threshold that alters the trend of surface albedo.Soil temperature influences surface albedo by affecting the content of pore ice and liquid water within the soil.When the water content of loess is relatively low,the surface albedo decreases as the unfrozen water content decreases.However,this trend changes as the water content of loess increases.Additionally,a decrease in soil temperature lowers the moisture content threshold during the changes in surface albedo.This study provides a reference for exploring and determining the surface energy balance in cold regions under the background of warm and humid climates,as well as for establishing thermal calculation boundaries.
基金supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)(grant number IMSIU-DDRSP2504).
文摘Vehicular networks enable seamless connectivity for exchanging emergency and infotainment content.However,retrieving infotainment data from remote servers often introduces high delays,degrading the Quality of Service(QoS).To overcome this,caching frequently requested content at fog-enabled Road Side Units(RSUs)reduces communication latency.Yet,the limited caching capacity of RSUs makes it impractical to store all contents with varying sizes and popularity.This research proposes an efficient content caching algorithm that adapts to dynamic vehicular demands on highways to maximize request satisfaction.The scheme is evaluated against Intelligent Content Caching(ICC)and Random Caching(RC).The obtained results show that our proposed scheme entertains more contentrequesting vehicles as compared to ICC and RC,with 33%and 41%more downloaded data in 28%and 35%less amount of time from ICC and RC schemes,respectively.
