Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects ...Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.展开更多
Population growth and expanding urbanization have caused persistent shortages and contamination of groundwater resources in Mali,Africa.The increase in groundwater salinity makes it more difficult for residents to obt...Population growth and expanding urbanization have caused persistent shortages and contamination of groundwater resources in Mali,Africa.The increase in groundwater salinity makes it more difficult for residents to obtain drinking water,it is necessary to clarify the causes and control factors of groundwater mineralization in Gao region,northern Mali.Based on the analysis of the hydrochemical composition of groundwater in 24 boreholes,Piper and Sch?eller diagrams,principal component analysis(PCA)and hierarchical cluster analysis(HCA)are used to carry out multivariate statistical analysis on the main ions.The results show that the groundwater samples are weakly alkaline,with pH values ranging from 5.83 to 8.40,and the average values of boreholes are 7.50,respectively.The average electrical conductivity(EC)value is 354.4(μS/cm),and the extreme value is between 124.0 and 1247(μS/cm).Water is usually mineralized and presents nine types of water phase.The three principal components explain 84.42%of the total variance for 13 parameters.The factor F1(58.85%),the factor F2(16.88%)and the factor F3(8.69%)present for the majority of the total data set.In addition,multivariate statistical analysis confirmed the genetic relationship among aquifers and identified three main clusters.Clustering related to groundwater mineralization(F1),clustering related to oxide reduction and iron enrichment(F2),and clustering of groundwater pollution caused by nitrate and magnesium(F3).We found that agriculture,weathering activities and dissolution of geological materials promote the mineralization of groundwater.Groundwater quality in the Gao region is becoming less and less potable because of increasing salinity.展开更多
Glaciers,as“solid reservoirs”,are precious resources in arid areas.The study of glaciers is of great significance to the sustainable development and management of agriculture and the economy in northern Xinjiang.The...Glaciers,as“solid reservoirs”,are precious resources in arid areas.The study of glaciers is of great significance to the sustainable development and management of agriculture and the economy in northern Xinjiang.The area of glacier distribution on the 1963 topographic map data,1975 MSS data,2000 ETM data,2008 CBERS-2 data,2014 and 2018 ETM+were collected as secondary data.According to the remote sensing survey,the glacier areas in Northern Xinjiang are identified during 1963-2018.Based on the evolution of glacier area in the past 55 years,and using two scenarios,the average annual decrease area of a region during the whole 1963-2018 and the period with the minimum reduction area,the glacier areas of Southern Tianshan Mountains,Western Tianshan Mountains,Eastern Tianshan Mountains,the Sawuer Mountains and Altai Mountains in Northern Xinjiang,and the whole northern Xinjiang in 2030,2040,2050,and 2100 are examined and predicted.In 2100,the glacier area in Northern Xinjiang may decrease by 43%-59%.展开更多
[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phyl...[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phylogenetic tree of G6PDH gene were analyzed by BLAST and other bioinformatics software within Eucalyptus grandsis whole genome database.[Result] Six G6PDH genes,including one cytomic type and five plastids,were detected in the E.grandsis genome.All the G6PDHs have conserved motifs of motif 1,motif 2,motif 3,motif 7,motif 9 and motif 11.Furthermore,promoter sequences of all E.grandsis G6PDH contain TATA box,enhancer,light-responsive,hormone-responsive and stress-responsive regulatory elements.[Conclusion] This study provided reference for the further revealing molecular function of E.grandsis G6PDH gene family展开更多
In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identifie...In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identified） during 1949-2011 in Fujian Province were analyzed. Results showed that, 45 parents were used as parents for peanut breeding, and 22 parents were originated from Fujian Province, 24 parents were registered varieties; Shitouqi, Yueyou 92, Shanyou 523, Quanhua No.10 and Quanhua 327 were milestone parents of peanut varieties in Fujian Province, and the phylogenetic relationship of varieties mainly came from Guangdong. Systematic se- lection was the main breeding method during 1951-1980 in Fujian Province, while crossbreeding became the main method of peanut breeding since 1991. With the variety update of peanuts, the yield levels were constantly increasing. The gradual increase of 100-pod weight and 100-kernel weight played an important role in the improvement of peanut yield. Fat content increased slightly with time, while protein content changed in contrast. Plant height was gradually decreased, and anti-lodging and fertilizer-tolerance capacity was improved, which were suitable for close planting. The total number of branches was decreased slightly, while the number of bearing branches barely changed.展开更多
Background:Facelift procedures represent a critical area of aesthetic and reconstructive surgery that addresses the physical and psychological impacts of facial aging.Advancements in techniques and technologies over t...Background:Facelift procedures represent a critical area of aesthetic and reconstructive surgery that addresses the physical and psychological impacts of facial aging.Advancements in techniques and technologies over time have transformed the field,making it essential to assess the evolution of research trends.This study performed a bibliometric analysis of facelift research by examining the top 50 most cited publications to evaluate their contributions,thematic evolution,and collaborative networks.Methods:The Scopus database was used to identify relevant publications.A total of 50 documents were selected,comprising 47 articles and 3 reviews published across 16 academic sources.The inclusion criteria focused on publications with substantial relevance to facelift research;this ensured comprehensive coverage of the topic.Key performance indicators(for the authors)such as the number of papers,total citations,h-index,g-index,m-index,HG composite,and Q2 index were calculated.Citation analysis and collaborative network mapping were conducted to identify the leading contributors,including authors,universities,countries,and sources.Results:The findings indicated an annual growth rate of 1.34%,with an average document age of 29.4 years and an average citation count per document of 134.9.The analysis identified the top authors and their collaborative networks,along with key contributions from various universities,countries,and sources.The thematic evolution of facelift research was examined across these 50 papers;this revealed important trends and shifts within the field.Conclusion:This bibliometric analysis offers valuable insights into the development and influence of facelift research over a 52-year span.It highlights significant contributors and outlines thematic shifts,providing directions for future research and collaboration in this field.展开更多
The pitch bearing is a component in wind turbine units used to adjust the angle of the fan blades to adapt to the wind direction,so as to maximize the utilization of wind energy.Due to the different working mode of th...The pitch bearing is a component in wind turbine units used to adjust the angle of the fan blades to adapt to the wind direction,so as to maximize the utilization of wind energy.Due to the different working mode of the pitch bearing itself compared with ordinary small bearings and the harsh working environment,the pitch bearing is prone to faults such as cracking and deformation.In severe cases,it will lead to overall damage to the pitch bearing,causing the blade to fall from a high altitude and even injuring personnel.Therefore,this paper conducts a patent analysis and technical decomposition of the deformation monitoring device for pitch bearings,analyzes and summarizes the development process of existing deformation monitoring devices for pitch bearings.Combined with the TRIZ evolution theory and based on the S-curve,it is concluded that the current deformation monitoring device for pitch bearings is in the transitional stage between the infant period and the growth period,and discusses the possible subsequent evolution directions.Through reviewing relevant literature,it is found that inner ring cracks first appear near the upper and lower surfaces of the bolt holes in the inner ring of the pitch bearing.To this end,a new type of deformation monitoring device for pitch bearings is designed.The fiber optic displacement sensor is used for qualitative monitoring of initial cracks near the surface of the bolt holes in the inner ring of the pitch bearing.After cracks are detected,the eddy current sensor is used for quantitative monitoring of whether there are extended cracks between the cracked bolt holes and adjacent bolt holes.Finally,the work done in this paper is summarized and prospected.展开更多
A large multi-country outbreak of Oropouche virus(OROV),a segmented negative-sense RNA virus,is emerging in Latin America.By analyzing publicly available whole-genome sequences spanning 1955 to 2024,this study reveals...A large multi-country outbreak of Oropouche virus(OROV),a segmented negative-sense RNA virus,is emerging in Latin America.By analyzing publicly available whole-genome sequences spanning 1955 to 2024,this study reveals accelerated spatiotemporal evolution of OROV,cooperatively driven by genome mutagenesis and segment reassortment.The strains responsible for the 2023-2024 outbreak are universally reassortants,but form two divergent lineages,namely the Brazil and western Amazon basin lineages.This epidemic spreading is primarily fueled by localized transmission within countries and cross-border spread.Phylogenomic analysis further suggests that the S segment of the viral genome originated in Brazil around the 1740s,underwent diversification into five distinct clusters by the 1970s,and experienced rapid proliferation during 2020-2024.In contrast,the L segment originated in Peru around the 1630s and evolved into two independent clusters by the 1850s.Divergent evolutionary pressures have driven distinct patterns of amino acid changes in viral proteins between the Brazil and the western Amazon basin lineages.These mutations are predicted to alter the protein structures and bear functional consequences for viral fitness and transmission.These findings provide critical insights into the evolutionary dynamics of OROV and underscore the necessity of genome surveillance to track the transmission pathways and spatiotemporal evolution.展开更多
The geomorphic evolution of the Xindiangou small watershed on the Loess Plateau in China is influenced by many factors,resulting in very complex evolutionary characteristics of erosion,morphology,and development.Since...The geomorphic evolution of the Xindiangou small watershed on the Loess Plateau in China is influenced by many factors,resulting in very complex evolutionary characteristics of erosion,morphology,and development.Since 1952,a number of soil and water conservation projects have been implemented in the watershed,especially the largescale project of returning farmland to forest and grass since 1999,which has significant impact on the erosion characteristics of the loess.This paper takes a unique perspective of the watershed geomorphic system and its watershed geomorphic entropy(WGE)and clarifies the geomorphic erosion characteristics of the Xindiangou small watershed.The results show that in the past 45 years,the entropy change of WGE of this watershed has generally shown the characteristics of entropy decrease and local entropy increase.The watershed is dominated by erosion in general,but due to the large-scale implementation of various soil and water conservation projects,especially the Project of Returning Farmland to Forests and Grasslands(RFFG),the landform erosion intensity has been greatly reduced and local increase in the entropy change of WGE has appeared.These projects have achieved good ecological effects after 11 years of implementation.展开更多
This paper analysed the evolution of landslide research and research foci in different countries. The data comprise 3105 landslide SCI articles published between January 1977 and June 2015 from the Web of Science. The...This paper analysed the evolution of landslide research and research foci in different countries. The data comprise 3105 landslide SCI articles published between January 1977 and June 2015 from the Web of Science. The data are extracted under interaction constraints of the journal title, category, and keywords. The complex network method is used for the analysis. First, from the perspective of topics and methods, the evolution is systematically assessed by generating a co-citation network of the articles and a semantic cluster analysis. Second, from the perspective of topics and landsliderelated disasters, the focus in different countries is discussed by generating co-occurrence networks. These networks are the co-occurrence of the countries and keywords, and the co-occurrence of countries and landslide-related disaster phrases. The main conclusions are as follows:(1) landslide susceptibility analysis and methods of machine learning are popular research topics and methods, respectively. The topics change through time, and the article output is influenced by increasing landslide-related disasters, increasing economic losses and casualties, a desire for a more complete and accurate landslide inventory, and the use of effective methods, such as geographical information Science(GIS) and machine learning.(2) The research focus in each country is related with the country-specific disasters or economic costs caused by landslides to some degree. In addition to Italy and the USA, China is the country most commonly affected by landslides, and it should develop its own landslide database and complete in-depth studies of disaster mitigation.展开更多
Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design...Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design is an important way to improve PHM capability. Testability modeling and analysis are the foundation of DFT. This paper proposes a novel approach of testability modeling and analysis based on failure evolution mechanisms. At the component level, the fault progression-related information of each unit under test （UUT） in a system is obtained by means of failure modes, evolution mechanisms, effects and criticality analysis （FMEMECA）, and then the failure-symptom dependency can be generated. At the system level, the dynamic attributes of UUTs are assigned by using the bond graph methodology, and then the symptom-test dependency can be obtained by means of the functional flow method. Based on the failure-symptom and symptom-test dependencies, testability analysis for PHM systems can be realized. A shunt motor is used to verify the application of the approach proposed in this paper. Experimental results show that this approach is able to be applied to testability modeling and analysis for PHM systems very well, and the analysis results can provide a guide for engineers to design for testability in order to improve PHM performance.展开更多
Influenced by globalization,rural transition in developed Western countries has experienced processes of productivism,post-productivism,and multifunctional development.By contrast,rural transition in most developing c...Influenced by globalization,rural transition in developed Western countries has experienced processes of productivism,post-productivism,and multifunctional development.By contrast,rural transition in most developing countries has been accompanied by rapid urbanization,which has become a core topic in geography research.As the world’s largest developing country,China has undergone profound development since the reform and opening-up.Moreover,rural spaces in some eastern coastal areas have entered the stage of reconstruction after decades of industrialization and urbanization.This paper takes Suzhou as the case area and measures the process of rural transition from 1990 to 2015 by constructing an index system.It then analyzes the characteristics of space-time evolution using exploratory spatial data analysis(ESDA)methods to reveal the influence of economic and social development on rural transition.The results show that rural transition,which generally entails the weakening of rurality and enhancing of urbanity on a macro scale,tends to be heterogeneous across different regions on a micro scale.This paper argues that multifunctionality will be the main future trend of rural transition in rapidly urbanizing areas.The experience in Suzhou could provide an example for establishing policies on sustainable development in rural spaces and achieving urban-rural co-governance.展开更多
In this paper, we make use of the functional spectral analysis to infer the periodicity of paleoclimate in the Hongzuisi section since about 15 ka. Through combined analysis of organic carbon isotope and CaCO\-3 conte...In this paper, we make use of the functional spectral analysis to infer the periodicity of paleoclimate in the Hongzuisi section since about 15 ka. Through combined analysis of organic carbon isotope and CaCO\-3 content, the law of paleoclimatic evolution of the Hongzuisi section is obtained. There were climatic changes from 10 ka to about 0.1 ka over the last 15 ka. Among these cycles, the cycle of several ka is most remarkable. The result indicates that functional spectral analysis is helpful for paleoclimatic study, which can provide useful information about paleoclimatic reconstruction and future forecast.展开更多
Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the worl...Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the world.In this study,we shall firstly carry out an in-depth quantitative research to analyze the patterns and evolution of global production networks,using a long time-sequenced multi-region input-output table and the network analysis approach.Then based on the method of value-added decomposition,we will develop an index system to measure the degree of participation of regions in global production networks.Finally,we will try to identify the factors affecting the degree of participation of countries in global production networks by constructing a regression model.The results show that from 1995 to 2015,the evolution of global production networks measured by input-output linkages experienced four stages:expansion,contraction,re-expansion,and re-contraction.In addition,the core communities of global production networks evolved from two major production communities(Europe and the Americas)to three pillars(Europe,Americas,and Asia)while more segmented communities are mainly affected by geographical proximity.The latter consists of European,North American,South American,African and Asian communities.The evolution of the global production network pattern primarily manifests as a process of cooperation strengthening or weakening among communities,based on changes in the external environment and the need for individual development strategies.Meanwhile,the United States,Germany,and the United Kingdom have consistently ranked among the top entities in global production networks,whereas China,Russia,and Southeast Asia have the fastest rises in ranking.In addition,government efficiency,resources endowment,infrastructure conditions and technology levels play important roles in the participation in global production networks.展开更多
Assimilating satellite radiances into Numerical Weather Prediction(NWP) models has become an important approach to increase the accuracy of numerical weather forecasting. In this study, the assimilation technique sche...Assimilating satellite radiances into Numerical Weather Prediction(NWP) models has become an important approach to increase the accuracy of numerical weather forecasting. In this study, the assimilation technique scheme was employed in NOAA's STMAS(Space-Time Multiscale Analysis System) to assimilate AMSU-A radiances data.Channel selection sensitivity experiments were conducted on assimilated satellite data in the first place. Then, real case analysis of AMSU-A data assimilation was performed. The analysis results showed that, following assimilating of AMSU-A channels 5-11 in STMAS, the objective function quickly converged, and the channel vertical response was consistent with the AMSU-A weighting function distribution, which suggests that the channels can be used in the assimilation of satellite data in STMAS. With the case of the Typhoon Morakot in Taiwan Island in August 2009 as an example, experiments on assimilated and unassimilated AMSU-A radiances data were designed to analyze the impact of the assimilation of satellite data on STMAS. The results demonstrated that assimilation of AMSU-A data provided more accurate prediction of the precipitation region and intensity, and especially, it improved the 0-6h precipitation forecast significantly.展开更多
MicroRNA（miRNA） is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evo...MicroRNA（miRNA） is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evolution of gma-MIR166 gene family in order to understand the evolutionary mechanisms of miRNAs in soybean. In this study, we implemented soybean wide genome block analysis, the molecular phylogeny of gma-MIR166 and block analysis of gma-MIR166 family. The results showed that both chromosome big segmental duplications and tandem duplications were main reasons contributed to the expanding of gmaMIR166 gene family. These findings suggested that gma-MIR166 gene family might originate from one or two ancient miRNA genes. The results of research provided a support for evolutionary study of miRNAs in soybean and related species in Fabaceae.展开更多
Group A human rotaviruses(RVAs)annually cause the deaths of 215,000 infants and young children.To understand the epidemiological characteristics and genetic evolution of RVAs,we performed sentinel surveillance on RVA ...Group A human rotaviruses(RVAs)annually cause the deaths of 215,000 infants and young children.To understand the epidemiological characteristics and genetic evolution of RVAs,we performed sentinel surveillance on RVA prevalence in a rotavirus-surveillance network in Hubei,China.From 2013 to 2016,a total of 2007 fecal samples from hospital outpatients with acute gastroenteritis were collected from four cities of Hubei Province.Of the 2007 samples,153(7.62%)were identified positive for RVA by real-time RT-PCR.RVA infection in Hubei mainly occurred in autumn and winter.The highest detection rate of RVA infection was in 1–2 years old of outpatients(16.97%).No significant difference of RVA positive rate was observed between females and males.We performed a phylogenetic analysis of the G/P genotypes based on the partial VP7/VP4 gene sequences of RVAs.G9P[8]was the most predominant strain in all four years but the prevalence of G2P[4]genotype increased rapidly since 2014.We reconstructed the evolutionary time scale of RVAs in Hubei,and found that the evolutionary rates of the G9,G2,P[8],and P[4]genotypes of RVA were 1.069×10^(-3),1.029×10^(-3),1.283×10^(-3)and 1.172×10^(-3)nucleotide substitutions/site/year,respectively.Importantly,using a molecular clock model,we showed that most G9,G2,P[8],and P[4]genotype strains dated from the recent ancestor in 2005,2005,1993,and 2013,respectively.The finding of the distribution of RVAs in infants and young children in Hubei Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of RVAs in China.展开更多
This paper examines the temporal change and spatial variation of population pressure on the ecological environment in China.We have collected sufficient data from the statistical yearbooks of 31 provincial administrat...This paper examines the temporal change and spatial variation of population pressure on the ecological environment in China.We have collected sufficient data from the statistical yearbooks of 31 provincial administrative areas in 1990,1995,2000,2005,and 2010.Using a geographic information system(GIS) and relevant models,we analyzed the trend of the population pressure on ecological environment and the change of the gravity center of ecological environment quality.We conclude that:(1) generally,population pressure on the ecological environment in China was becoming higher during1990-2010,especially in some areas where the population and environment were in serious imbalance and the ecological environment experienced severe pollution;(2) during a certain period,population pressure on the ecological environment was becoming lower in some areas,but the ecological environment was getting worse;(3) the areas with super-high population pressure on the ecological environment were Beijing,Tianjin,and Shanghai;(4) the gravity center of population pressure on the ecological environment and the center of ecological environment quality move differently during the study time period,but the general trend was similar- both of them were moving from west to east.Based on the analysis,this paper also provides some policy suggestions on the control of ecological environment quality.展开更多
The photo absorbing, photo transmitting and photoluminescence performances of WiO2 photocatalysts compounded with V2O5 or WO3 were investigated by UV-Vis spectra, transmitting spectra, and PL spectra, respectively. Th...The photo absorbing, photo transmitting and photoluminescence performances of WiO2 photocatalysts compounded with V2O5 or WO3 were investigated by UV-Vis spectra, transmitting spectra, and PL spectra, respectively. The energy band structures of TiO2 photocatalysts were analyzed. The photocatalytic activities of the TiO2 photocatalysts were investigated by splitting of water for 02 evolution. The results indicate that the band gaps of WO3 and V205 are about 2.8 and 2.14 eV, respectively, and the band gap of rutile TiO2 is about 3.08 eV. Speeds of water splitting for 2%WO3-TiO2 and 8%V2O5-TiO2 photocatalysts are 420 and 110 μmol/（L.h）, respectively, under UV light irradiation. V2O5 and WO3 compounded with suitable concentration can improve the photocatalytic activity of TiO2 with Fe3＋ as electron acceptor.展开更多
Although both Astasia longa and Euglena gracilis belong to different genera, they share many morphological characters except that A. longa has no chloroplast. In the 1940’s, on the basis of the finding that in darkne...Although both Astasia longa and Euglena gracilis belong to different genera, they share many morphological characters except that A. longa has no chloroplast. In the 1940’s, on the basis of the finding that in darkness or upon addition of some chemicals, E. gracilis would fade reversibly or irreversibly, some scholars hypothesised that A. longa evolved from E. gracilis by losing chloroplast. The authors’ use of RAPD and cladistic analyses in a study on the evolutionary relationship between A .longa and E. gracilis showed that the A. longa ’s relationship with E. gracilis was closer than that with other green euglenoids. This proves the hypothesis that A. longa evolved from E. gracilis is reasonable. The results of this study suggest that saprophytic colorless euglenoids were transformed from green euglenoids by losing their choroplasts.展开更多
基金supported by grants from the Human Resources Development program(Grant No.20204010600250)the Training Program of CCUS for the Green Growth(Grant No.20214000000500)by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)funded by the Ministry of Trade,Industry,and Energy of the Korean Government(MOTIE).
文摘Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.
基金funded by the China's National Natural Science Foundation(No.41440027)。
文摘Population growth and expanding urbanization have caused persistent shortages and contamination of groundwater resources in Mali,Africa.The increase in groundwater salinity makes it more difficult for residents to obtain drinking water,it is necessary to clarify the causes and control factors of groundwater mineralization in Gao region,northern Mali.Based on the analysis of the hydrochemical composition of groundwater in 24 boreholes,Piper and Sch?eller diagrams,principal component analysis(PCA)and hierarchical cluster analysis(HCA)are used to carry out multivariate statistical analysis on the main ions.The results show that the groundwater samples are weakly alkaline,with pH values ranging from 5.83 to 8.40,and the average values of boreholes are 7.50,respectively.The average electrical conductivity(EC)value is 354.4(μS/cm),and the extreme value is between 124.0 and 1247(μS/cm).Water is usually mineralized and presents nine types of water phase.The three principal components explain 84.42%of the total variance for 13 parameters.The factor F1(58.85%),the factor F2(16.88%)and the factor F3(8.69%)present for the majority of the total data set.In addition,multivariate statistical analysis confirmed the genetic relationship among aquifers and identified three main clusters.Clustering related to groundwater mineralization(F1),clustering related to oxide reduction and iron enrichment(F2),and clustering of groundwater pollution caused by nitrate and magnesium(F3).We found that agriculture,weathering activities and dissolution of geological materials promote the mineralization of groundwater.Groundwater quality in the Gao region is becoming less and less potable because of increasing salinity.
基金jointly supported by the“Technology and Demonstration Applications for Monitoring High Snow-glacier and Geological Hazards in Asia and the Arctic”of Earth Observations Group Project Funding(2021YFE0116800)。
文摘Glaciers,as“solid reservoirs”,are precious resources in arid areas.The study of glaciers is of great significance to the sustainable development and management of agriculture and the economy in northern Xinjiang.The area of glacier distribution on the 1963 topographic map data,1975 MSS data,2000 ETM data,2008 CBERS-2 data,2014 and 2018 ETM+were collected as secondary data.According to the remote sensing survey,the glacier areas in Northern Xinjiang are identified during 1963-2018.Based on the evolution of glacier area in the past 55 years,and using two scenarios,the average annual decrease area of a region during the whole 1963-2018 and the period with the minimum reduction area,the glacier areas of Southern Tianshan Mountains,Western Tianshan Mountains,Eastern Tianshan Mountains,the Sawuer Mountains and Altai Mountains in Northern Xinjiang,and the whole northern Xinjiang in 2030,2040,2050,and 2100 are examined and predicted.In 2100,the glacier area in Northern Xinjiang may decrease by 43%-59%.
基金Supported by Seeding Raising Project from Guangdong Provincial Department(LYM10040)Open Research Project of Key Laboratory for Genetics and Breeding in Forest Trees and Ornamental Plants,MOE,Beijing Forestry University(FOP2010-4)~~
文摘[Objective] The aim of this study was to perform genome-wide analysis of glucose-6-phosphate dehydrogenase（G6PDH） and reveal its evolution in Eucalyptus grandsis.[Method] The gene character,protein sequence and phylogenetic tree of G6PDH gene were analyzed by BLAST and other bioinformatics software within Eucalyptus grandsis whole genome database.[Result] Six G6PDH genes,including one cytomic type and five plastids,were detected in the E.grandsis genome.All the G6PDHs have conserved motifs of motif 1,motif 2,motif 3,motif 7,motif 9 and motif 11.Furthermore,promoter sequences of all E.grandsis G6PDH contain TATA box,enhancer,light-responsive,hormone-responsive and stress-responsive regulatory elements.[Conclusion] This study provided reference for the further revealing molecular function of E.grandsis G6PDH gene family
基金Supported by Science and Technology Spark Program of Fujian Province(2010S0018)Putian Science and Technology Project of Fujian Province(2012N05)~~
文摘In order to provide reference for the breeding of new peanut varieties and introduction of peanut cultivars in Fujian Province, the pedigree and trait evolution of 33 peanut varieties registered （certified, identified） during 1949-2011 in Fujian Province were analyzed. Results showed that, 45 parents were used as parents for peanut breeding, and 22 parents were originated from Fujian Province, 24 parents were registered varieties; Shitouqi, Yueyou 92, Shanyou 523, Quanhua No.10 and Quanhua 327 were milestone parents of peanut varieties in Fujian Province, and the phylogenetic relationship of varieties mainly came from Guangdong. Systematic se- lection was the main breeding method during 1951-1980 in Fujian Province, while crossbreeding became the main method of peanut breeding since 1991. With the variety update of peanuts, the yield levels were constantly increasing. The gradual increase of 100-pod weight and 100-kernel weight played an important role in the improvement of peanut yield. Fat content increased slightly with time, while protein content changed in contrast. Plant height was gradually decreased, and anti-lodging and fertilizer-tolerance capacity was improved, which were suitable for close planting. The total number of branches was decreased slightly, while the number of bearing branches barely changed.
文摘Background:Facelift procedures represent a critical area of aesthetic and reconstructive surgery that addresses the physical and psychological impacts of facial aging.Advancements in techniques and technologies over time have transformed the field,making it essential to assess the evolution of research trends.This study performed a bibliometric analysis of facelift research by examining the top 50 most cited publications to evaluate their contributions,thematic evolution,and collaborative networks.Methods:The Scopus database was used to identify relevant publications.A total of 50 documents were selected,comprising 47 articles and 3 reviews published across 16 academic sources.The inclusion criteria focused on publications with substantial relevance to facelift research;this ensured comprehensive coverage of the topic.Key performance indicators(for the authors)such as the number of papers,total citations,h-index,g-index,m-index,HG composite,and Q2 index were calculated.Citation analysis and collaborative network mapping were conducted to identify the leading contributors,including authors,universities,countries,and sources.Results:The findings indicated an annual growth rate of 1.34%,with an average document age of 29.4 years and an average citation count per document of 134.9.The analysis identified the top authors and their collaborative networks,along with key contributions from various universities,countries,and sources.The thematic evolution of facelift research was examined across these 50 papers;this revealed important trends and shifts within the field.Conclusion:This bibliometric analysis offers valuable insights into the development and influence of facelift research over a 52-year span.It highlights significant contributors and outlines thematic shifts,providing directions for future research and collaboration in this field.
文摘The pitch bearing is a component in wind turbine units used to adjust the angle of the fan blades to adapt to the wind direction,so as to maximize the utilization of wind energy.Due to the different working mode of the pitch bearing itself compared with ordinary small bearings and the harsh working environment,the pitch bearing is prone to faults such as cracking and deformation.In severe cases,it will lead to overall damage to the pitch bearing,causing the blade to fall from a high altitude and even injuring personnel.Therefore,this paper conducts a patent analysis and technical decomposition of the deformation monitoring device for pitch bearings,analyzes and summarizes the development process of existing deformation monitoring devices for pitch bearings.Combined with the TRIZ evolution theory and based on the S-curve,it is concluded that the current deformation monitoring device for pitch bearings is in the transitional stage between the infant period and the growth period,and discusses the possible subsequent evolution directions.Through reviewing relevant literature,it is found that inner ring cracks first appear near the upper and lower surfaces of the bolt holes in the inner ring of the pitch bearing.To this end,a new type of deformation monitoring device for pitch bearings is designed.The fiber optic displacement sensor is used for qualitative monitoring of initial cracks near the surface of the bolt holes in the inner ring of the pitch bearing.After cracks are detected,the eddy current sensor is used for quantitative monitoring of whether there are extended cracks between the cracked bolt holes and adjacent bolt holes.Finally,the work done in this paper is summarized and prospected.
基金supported by the National Natural Science Foundation of China,32270161,82302506.Research Grant of Jiangsu Commission of Health,ZD2021036The Starting Grant for Talents of Xuzhou Medical University,D2021007,D2021008,D2024017The Natural Science Foundation of the Jiangsu Higher Education Institutions of China(23KJD310005,23KJB310028,24KJD310005).
文摘A large multi-country outbreak of Oropouche virus(OROV),a segmented negative-sense RNA virus,is emerging in Latin America.By analyzing publicly available whole-genome sequences spanning 1955 to 2024,this study reveals accelerated spatiotemporal evolution of OROV,cooperatively driven by genome mutagenesis and segment reassortment.The strains responsible for the 2023-2024 outbreak are universally reassortants,but form two divergent lineages,namely the Brazil and western Amazon basin lineages.This epidemic spreading is primarily fueled by localized transmission within countries and cross-border spread.Phylogenomic analysis further suggests that the S segment of the viral genome originated in Brazil around the 1740s,underwent diversification into five distinct clusters by the 1970s,and experienced rapid proliferation during 2020-2024.In contrast,the L segment originated in Peru around the 1630s and evolved into two independent clusters by the 1850s.Divergent evolutionary pressures have driven distinct patterns of amino acid changes in viral proteins between the Brazil and the western Amazon basin lineages.These mutations are predicted to alter the protein structures and bear functional consequences for viral fitness and transmission.These findings provide critical insights into the evolutionary dynamics of OROV and underscore the necessity of genome surveillance to track the transmission pathways and spatiotemporal evolution.
基金funded by the National Natural Science Foundation of China(Grant No.42271417)the financial support from the National Natural Science Foundation of China。
文摘The geomorphic evolution of the Xindiangou small watershed on the Loess Plateau in China is influenced by many factors,resulting in very complex evolutionary characteristics of erosion,morphology,and development.Since 1952,a number of soil and water conservation projects have been implemented in the watershed,especially the largescale project of returning farmland to forest and grass since 1999,which has significant impact on the erosion characteristics of the loess.This paper takes a unique perspective of the watershed geomorphic system and its watershed geomorphic entropy(WGE)and clarifies the geomorphic erosion characteristics of the Xindiangou small watershed.The results show that in the past 45 years,the entropy change of WGE of this watershed has generally shown the characteristics of entropy decrease and local entropy increase.The watershed is dominated by erosion in general,but due to the large-scale implementation of various soil and water conservation projects,especially the Project of Returning Farmland to Forests and Grasslands(RFFG),the landform erosion intensity has been greatly reduced and local increase in the entropy change of WGE has appeared.These projects have achieved good ecological effects after 11 years of implementation.
基金under the auspices of National Key Research and Development Plan of China (Grant No. 2017YFB0504102)the Fundamental Research Funds for the Central Universities
文摘This paper analysed the evolution of landslide research and research foci in different countries. The data comprise 3105 landslide SCI articles published between January 1977 and June 2015 from the Web of Science. The data are extracted under interaction constraints of the journal title, category, and keywords. The complex network method is used for the analysis. First, from the perspective of topics and methods, the evolution is systematically assessed by generating a co-citation network of the articles and a semantic cluster analysis. Second, from the perspective of topics and landsliderelated disasters, the focus in different countries is discussed by generating co-occurrence networks. These networks are the co-occurrence of the countries and keywords, and the co-occurrence of countries and landslide-related disaster phrases. The main conclusions are as follows:(1) landslide susceptibility analysis and methods of machine learning are popular research topics and methods, respectively. The topics change through time, and the article output is influenced by increasing landslide-related disasters, increasing economic losses and casualties, a desire for a more complete and accurate landslide inventory, and the use of effective methods, such as geographical information Science(GIS) and machine learning.(2) The research focus in each country is related with the country-specific disasters or economic costs caused by landslides to some degree. In addition to Italy and the USA, China is the country most commonly affected by landslides, and it should develop its own landslide database and complete in-depth studies of disaster mitigation.
基金the National Natural Science Foundation of China(No.51175502)
文摘Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design is an important way to improve PHM capability. Testability modeling and analysis are the foundation of DFT. This paper proposes a novel approach of testability modeling and analysis based on failure evolution mechanisms. At the component level, the fault progression-related information of each unit under test （UUT） in a system is obtained by means of failure modes, evolution mechanisms, effects and criticality analysis （FMEMECA）, and then the failure-symptom dependency can be generated. At the system level, the dynamic attributes of UUTs are assigned by using the bond graph methodology, and then the symptom-test dependency can be obtained by means of the functional flow method. Based on the failure-symptom and symptom-test dependencies, testability analysis for PHM systems can be realized. A shunt motor is used to verify the application of the approach proposed in this paper. Experimental results show that this approach is able to be applied to testability modeling and analysis for PHM systems very well, and the analysis results can provide a guide for engineers to design for testability in order to improve PHM performance.
基金National Social Science Foundation of China,No.21FSHB014National Natural Science Foundation of China,No.42001196。
文摘Influenced by globalization,rural transition in developed Western countries has experienced processes of productivism,post-productivism,and multifunctional development.By contrast,rural transition in most developing countries has been accompanied by rapid urbanization,which has become a core topic in geography research.As the world’s largest developing country,China has undergone profound development since the reform and opening-up.Moreover,rural spaces in some eastern coastal areas have entered the stage of reconstruction after decades of industrialization and urbanization.This paper takes Suzhou as the case area and measures the process of rural transition from 1990 to 2015 by constructing an index system.It then analyzes the characteristics of space-time evolution using exploratory spatial data analysis(ESDA)methods to reveal the influence of economic and social development on rural transition.The results show that rural transition,which generally entails the weakening of rurality and enhancing of urbanity on a macro scale,tends to be heterogeneous across different regions on a micro scale.This paper argues that multifunctionality will be the main future trend of rural transition in rapidly urbanizing areas.The experience in Suzhou could provide an example for establishing policies on sustainable development in rural spaces and achieving urban-rural co-governance.
基金GrantedbytheNationalNaturalScienceFoundationofChina (No .4 9972 0 5 7)
文摘In this paper, we make use of the functional spectral analysis to infer the periodicity of paleoclimate in the Hongzuisi section since about 15 ka. Through combined analysis of organic carbon isotope and CaCO\-3 content, the law of paleoclimatic evolution of the Hongzuisi section is obtained. There were climatic changes from 10 ka to about 0.1 ka over the last 15 ka. Among these cycles, the cycle of several ka is most remarkable. The result indicates that functional spectral analysis is helpful for paleoclimatic study, which can provide useful information about paleoclimatic reconstruction and future forecast.
基金Strategic Priority Research Program of Chinese Academy of Sciences,No.XDA20080000National Natural Science Foundation of China,No.41901154。
文摘Global production networks have become the most important organizational platforms for coordinating international production activities,and their evolution patterns profoundly affect value distribution across the world.In this study,we shall firstly carry out an in-depth quantitative research to analyze the patterns and evolution of global production networks,using a long time-sequenced multi-region input-output table and the network analysis approach.Then based on the method of value-added decomposition,we will develop an index system to measure the degree of participation of regions in global production networks.Finally,we will try to identify the factors affecting the degree of participation of countries in global production networks by constructing a regression model.The results show that from 1995 to 2015,the evolution of global production networks measured by input-output linkages experienced four stages:expansion,contraction,re-expansion,and re-contraction.In addition,the core communities of global production networks evolved from two major production communities(Europe and the Americas)to three pillars(Europe,Americas,and Asia)while more segmented communities are mainly affected by geographical proximity.The latter consists of European,North American,South American,African and Asian communities.The evolution of the global production network pattern primarily manifests as a process of cooperation strengthening or weakening among communities,based on changes in the external environment and the need for individual development strategies.Meanwhile,the United States,Germany,and the United Kingdom have consistently ranked among the top entities in global production networks,whereas China,Russia,and Southeast Asia have the fastest rises in ranking.In addition,government efficiency,resources endowment,infrastructure conditions and technology levels play important roles in the participation in global production networks.
基金National Natural Science Foundation of China(41375027,41130960,41275114,41275039)Public Benefit Research Foundation of China Meteorological Administration(GYHY201406001,GYHY201106044)+1 种基金"863"Program(2012AA120903)National Key Research and Development Program of China(2016YFB0502501)
文摘Assimilating satellite radiances into Numerical Weather Prediction(NWP) models has become an important approach to increase the accuracy of numerical weather forecasting. In this study, the assimilation technique scheme was employed in NOAA's STMAS(Space-Time Multiscale Analysis System) to assimilate AMSU-A radiances data.Channel selection sensitivity experiments were conducted on assimilated satellite data in the first place. Then, real case analysis of AMSU-A data assimilation was performed. The analysis results showed that, following assimilating of AMSU-A channels 5-11 in STMAS, the objective function quickly converged, and the channel vertical response was consistent with the AMSU-A weighting function distribution, which suggests that the channels can be used in the assimilation of satellite data in STMAS. With the case of the Typhoon Morakot in Taiwan Island in August 2009 as an example, experiments on assimilated and unassimilated AMSU-A radiances data were designed to analyze the impact of the assimilation of satellite data on STMAS. The results demonstrated that assimilation of AMSU-A data provided more accurate prediction of the precipitation region and intensity, and especially, it improved the 0-6h precipitation forecast significantly.
基金Supported by Heilongjiang Postdoctoral Fund(LBH-Z12045)Northeast Agricultural University Innovation Foundation For Postgraduate(yjscx14053)
文摘MicroRNA（miRNA） is a class of important regulating non-coding small molecular RNA. The gma-MIR166 gene family consists of 21 members and their expression patterns diversify widely. It is important to analyze the evolution of gma-MIR166 gene family in order to understand the evolutionary mechanisms of miRNAs in soybean. In this study, we implemented soybean wide genome block analysis, the molecular phylogeny of gma-MIR166 and block analysis of gma-MIR166 family. The results showed that both chromosome big segmental duplications and tandem duplications were main reasons contributed to the expanding of gmaMIR166 gene family. These findings suggested that gma-MIR166 gene family might originate from one or two ancient miRNA genes. The results of research provided a support for evolutionary study of miRNAs in soybean and related species in Fabaceae.
基金the National Natural Science Foundation of China(Grant Numbers 31770833 and 32071212)the Natural Science Foundation of Hubei Province(Grant Number 2018CFB716)+1 种基金the Health and Family Planning Scientific Research Project of Hubei Province(Grant Number WJ2017M137)the China Postdoctoral Science Foundation(Grant Numbers 2021TQ0252 and 2021M700103)。
文摘Group A human rotaviruses(RVAs)annually cause the deaths of 215,000 infants and young children.To understand the epidemiological characteristics and genetic evolution of RVAs,we performed sentinel surveillance on RVA prevalence in a rotavirus-surveillance network in Hubei,China.From 2013 to 2016,a total of 2007 fecal samples from hospital outpatients with acute gastroenteritis were collected from four cities of Hubei Province.Of the 2007 samples,153(7.62%)were identified positive for RVA by real-time RT-PCR.RVA infection in Hubei mainly occurred in autumn and winter.The highest detection rate of RVA infection was in 1–2 years old of outpatients(16.97%).No significant difference of RVA positive rate was observed between females and males.We performed a phylogenetic analysis of the G/P genotypes based on the partial VP7/VP4 gene sequences of RVAs.G9P[8]was the most predominant strain in all four years but the prevalence of G2P[4]genotype increased rapidly since 2014.We reconstructed the evolutionary time scale of RVAs in Hubei,and found that the evolutionary rates of the G9,G2,P[8],and P[4]genotypes of RVA were 1.069×10^(-3),1.029×10^(-3),1.283×10^(-3)and 1.172×10^(-3)nucleotide substitutions/site/year,respectively.Importantly,using a molecular clock model,we showed that most G9,G2,P[8],and P[4]genotype strains dated from the recent ancestor in 2005,2005,1993,and 2013,respectively.The finding of the distribution of RVAs in infants and young children in Hubei Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of RVAs in China.
基金supported by National Natural Science Foundation of China[Grant No.41171134]Peking University-Lincoln Institute Center for Urban Development and land Policy2013 Jiangsu Province Graduate Student Research Innovation project[Grant No.CXLX13_034]
文摘This paper examines the temporal change and spatial variation of population pressure on the ecological environment in China.We have collected sufficient data from the statistical yearbooks of 31 provincial administrative areas in 1990,1995,2000,2005,and 2010.Using a geographic information system(GIS) and relevant models,we analyzed the trend of the population pressure on ecological environment and the change of the gravity center of ecological environment quality.We conclude that:(1) generally,population pressure on the ecological environment in China was becoming higher during1990-2010,especially in some areas where the population and environment were in serious imbalance and the ecological environment experienced severe pollution;(2) during a certain period,population pressure on the ecological environment was becoming lower in some areas,but the ecological environment was getting worse;(3) the areas with super-high population pressure on the ecological environment were Beijing,Tianjin,and Shanghai;(4) the gravity center of population pressure on the ecological environment and the center of ecological environment quality move differently during the study time period,but the general trend was similar- both of them were moving from west to east.Based on the analysis,this paper also provides some policy suggestions on the control of ecological environment quality.
基金Project(11JJ5010) supported by the Natural Science Foundation of Hunan Province, ChinaProject(2011RS4069) supported by the Planned Science and Technology Program of Hunan Province, ChinaProject supported by the Postdoctoral Science Foundation of Central South University,China
文摘The photo absorbing, photo transmitting and photoluminescence performances of WiO2 photocatalysts compounded with V2O5 or WO3 were investigated by UV-Vis spectra, transmitting spectra, and PL spectra, respectively. The energy band structures of TiO2 photocatalysts were analyzed. The photocatalytic activities of the TiO2 photocatalysts were investigated by splitting of water for 02 evolution. The results indicate that the band gaps of WO3 and V205 are about 2.8 and 2.14 eV, respectively, and the band gap of rutile TiO2 is about 3.08 eV. Speeds of water splitting for 2%WO3-TiO2 and 8%V2O5-TiO2 photocatalysts are 420 and 110 μmol/（L.h）, respectively, under UV light irradiation. V2O5 and WO3 compounded with suitable concentration can improve the photocatalytic activity of TiO2 with Fe3＋ as electron acceptor.
文摘Although both Astasia longa and Euglena gracilis belong to different genera, they share many morphological characters except that A. longa has no chloroplast. In the 1940’s, on the basis of the finding that in darkness or upon addition of some chemicals, E. gracilis would fade reversibly or irreversibly, some scholars hypothesised that A. longa evolved from E. gracilis by losing chloroplast. The authors’ use of RAPD and cladistic analyses in a study on the evolutionary relationship between A .longa and E. gracilis showed that the A. longa ’s relationship with E. gracilis was closer than that with other green euglenoids. This proves the hypothesis that A. longa evolved from E. gracilis is reasonable. The results of this study suggest that saprophytic colorless euglenoids were transformed from green euglenoids by losing their choroplasts.
