In this paper,the Taixin Integrated Economic Zone in Shanxi Province is taken as the research object,and the coupling coordination degree model and bivariate spatial autocorrelation model are used to judge the couplin...In this paper,the Taixin Integrated Economic Zone in Shanxi Province is taken as the research object,and the coupling coordination degree model and bivariate spatial autocorrelation model are used to judge the coupling coordination and spatial-temporal correlation between urbanization and ecosystem service,and the hotspot analysis is used to judge the spatial-temporal trend of urbanization and ecosystem service.The results show that:(1)The urbanization level from 2000 to 2020 continued to rise,the areas with relatively high urbanization were concentrated in the central part of the study area,and the relatively high terrain areas on both sides of the study area,the urbanization was relatively slow,and the hotspot areas with highly significant and significant urbanization level from 2000 to 2020 were distributed as bands in the central part of the study area and the area was rising,and there was no Cold spot area distribution;between 2000 and 2020,the ecosystem service value in the study area increased by 2.6800×10^(8) yuan.Over these two decades,it exhibited a development trend that first rose and then declined.The woodland and grassland agglomeration areas were located on the two sides of the study area,forming highly significant and significant hotspots.Conversely,the central and northeastern parts of the study area were characterized by concentrated man-made land surfaces and croplands,resulting in the formation of highly significant and significant cold spots.(2)In the central part of the study area where man-made land surface and cultivated land are concentrated,the coupling coordination between urbanization and ecosystem service is in the intermediate dislocation and mild dislocation interval;the woodland and grassland concentration areas on both sides of the study area are ecologically fragile,and the coupling coordination between the two is in the level of less than intermediate dislocation.(3)From 2000 to 2020,urbanization and the value of ecosystem services were both negatively correlated,although the correlation coefficient was low.In the central and northeastern parts,urbanization and ecosystem service exhibited patterns of high-low,high-high,and low-low clustering.Conversely,on both sides of the study area,most of the clusters showed a low-high pattern.展开更多
Objective： To describe the revolution and research status of Advances in Psychological Science. Methods： A total of 3060 articles published in Advances in Psychological Science from 1983 to 2014 were analyzed with t...Objective： To describe the revolution and research status of Advances in Psychological Science. Methods： A total of 3060 articles published in Advances in Psychological Science from 1983 to 2014 were analyzed with the information visualization method using Citespace software from the aspects of pub- lications, cited frequency and downloads, funding, organizations, authors and keywords. Results： The results showed that the amount of literature published annually had an upward tendency, and 49.4% of the papers were supported by national or provincial projects. Institutions such as the Chinese Academy of Sciences （CAS） and the normal universities were rated in the forefront of the sci- entific research output. Xiting Huang, Hong Li and Yuejia Luo were at the top of the list of prolific authors. Conclusions： A new pattern of cooperative development of the theory and application in the field of psychological research is forming.展开更多
Road traffic crashes are becoming thorny issues being faced worldwide.Traffic crashes are spatiotemporal events and the research on the spatiotemporal patterns and variation trends of traffic crashes has been carried ...Road traffic crashes are becoming thorny issues being faced worldwide.Traffic crashes are spatiotemporal events and the research on the spatiotemporal patterns and variation trends of traffic crashes has been carried out.However,the impact of built environment on traffic crash spatiotemporal trends has not received much attention.Moreover,the spatial non-stationarity between the variation trends of traffic crashes and their influencing factors is usually neglected.To make up for the lack of analysis of built environment factors influencing spatiotemporal hotspot trends in traffic crashes,this paper proposed a method of“ST-GWLR”for analyzing the influence of built environment factors on spatiotemporal hotspot trends of traffic crashes by combining the spatiotemporal hotspot trend analysis and Geographically Weighted Logistic Regression(GWLR)modeling methods.Firstly,the traffic crash spatiotemporal hotspot trends were explored using the space-time cube model,hotspot analysis,and Mann-Kendall trend test.Then,the GWLR was introduced to capture the spatial non-stationarity neglected by the classic Global Logistic Regression(GLR)model,to improve the accuracy of the model estimation.GWLR model is used for the first time to analyze the significant local correlation between the traffic crash spatiotemporal hotspot trends and the built environment factors,to accurately and effectively identify the built environment factors that have significant influences on the hotspot trends of traffic crashes.The performance of the GWLR models and GLR models was examined and compared sufficiently.The results showed that the proposed ST-GWLR,which captured spatial non-stationarity,performed better than the classic GLR combined with spatiotemporal analysis,and improved the prediction accuracy of the models by 14.9%,13.9%,and 15.1%,respectively.There were significant local correlations between intensifying hotspots and persistent hotspots of traffic crashes and the built environment factors.The findings of this paper have positive implications for traffic safety management and urban built environment planning.展开更多
[Objective]In order to reflect the relationship between literatures quickly and efficiently and reveal the evolutionary path and hotspot,and predict the future trend of Lycoris researches.[Methods]In 19902019,CiteSpac...[Objective]In order to reflect the relationship between literatures quickly and efficiently and reveal the evolutionary path and hotspot,and predict the future trend of Lycoris researches.[Methods]In 19902019,CiteSpace software was used for visual graphic analysis authors,institutes and key words related to Lycoris research based on data sources of WOS and CNKI.[Results](1)Domestic researchers have formed a core group of authors in East China,but the cooperation between the different teams is relatively dispersed.(2)From the perspective of international cooperation level,the cocontribution in China is the largest.Among them,the Chinese Academy of Sciences published has the largest number of papers,and higher research level.(3)The research on Lycoris has experienced three stages:slow accumulation period,rapid growth period and stable growth period.And its research direction develops along the route of“interspecific relationship within genuspropagation and cultivationpharmacology and pharmacodynamicscytology and molecular biologycross breeding”.[Conclusion]The research of Lycoris mainly distributed in Asian countries such as China and Japan.On the whole,its research direction is developing from macro to micro.展开更多
To reduce the risk of traffic accidents significantly caused by the speeding behavior of electric bicycles,this study focuses on the Beijing Yizhuang Economic and Tech-nological Development Zone.This work relies on hi...To reduce the risk of traffic accidents significantly caused by the speeding behavior of electric bicycles,this study focuses on the Beijing Yizhuang Economic and Tech-nological Development Zone.This work relies on high-precision shared electric bicycle Global Positioning System trajectory data,integrating a spatiotemporal analysis model and geographic information system(GIS)technol-ogy to explore the spatial and temporal variability law and formation mechanism of speeding behavior.Through data preprocessing,speeding events are identified,and weekday features are extracted.Four periods are identified:morning peak,midday minipeak,evening peak,and nighttime flat peak.Using the GIS platform,global spatial autocorrela-tion and local clustering analysis are conducted to identify the spatial clustering characteristics of speeding behaviors and hotspot areas.The coldspot and hotspot patterns of speeding events and the dynamic trajectories of their evolu-tion are analyzed using spatiotemporal cube technology.The results show that speeding behaviors are strongly corre-lated with the commuting peak in time and spatially concen-trated in the intersections of urban main roads,the periphery of commercial complexes,and industrial parks,with a dif-fusion tendency.The results of this study provide novel in-sights into the research and analysis of the spatial and tempo-ral characteristics of speeding risk behaviors of electric bi-cycles and effective technical support for nonmotorized traf-fic safety management.展开更多
In the 21st century,climate change has exacerbated global instability,leading to a rise in landslide occurrences.In Bangladesh,mountainous areas such as Bandarban experience significant landslides during the monsoon s...In the 21st century,climate change has exacerbated global instability,leading to a rise in landslide occurrences.In Bangladesh,mountainous areas such as Bandarban experience significant landslides during the monsoon season.This study seeks to evaluate landslide susceptibility in Bandarban and identify hotspots for optimal landslide hazard mitigation.This study examined landslide susceptibility using the analytical hierarchy process(AHP)and spatial weighted overlay(SWO).Ten conditioning factors were considered,with AHP based on responses from 100 key respondents.Using field surveys and high-resolution satellite images,280 landslide occurrence samples were collected to rank the subfactors.Using AHP-derived weights of factors and subfactors,the SWO approach was used to create the landslide susceptibility map(LSM).The Getis-Ord(Gi*)spatial statistics was then used to generate landslide susceptibility hotspots.The result showed that human influence weight 17.02%,making it the most crucial factor in landslide susceptibility.AHP-derived weights were reliable because their consistency ratio was<0.1.According to the study,59.86% of the area is moderately susceptible,20.06%is high,and 4.31%is very high.The validation of LSM by ROC curve found excellent performance(AUC=0.93)of the approaches.Specifically,63.8%of very high susceptibility areas and 33.26%of high susceptibility areas were found within the hotspot zones with 99%confidence.The research showed the combined use of field samples and remote sensing-based spatial variables improved the accuracy of LSM.These findings can be useful for ensuring proper land use planning and implementation of landslide hazard mitigation measures.展开更多
Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land ...Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land cover(LULC)changes on LST and determined the intensity of urban heat island(UHI)in New Town Kolkata(a smart city),eastern India,from 1991 to 2021 at 10-a intervals using various series of Landsat multi-spectral and thermal bands.This study used the maximum likelihood algorithm for image classification and other methods like the correlation analysis and hotspot analysis(Getis–Ord Gi^(*) method)to examine the impact of LULC changes on urban thermal environment.This study noticed that the area percentage of built-up land increased rapidly from 21.91%to 45.63%during 1991–2021,with a maximum positive change in built-up land and a maximum negative change in sparse vegetation.The mean temperature significantly increased during the study period(1991–2021),from 16.31℃to 22.48℃in winter,29.18℃to 34.61℃in summer,and 19.18℃to 27.11℃in autumn.The result showed that impervious surfaces contribute to higher LST,whereas vegetation helps decrease it.Poor ecological status has been found in built-up land,and excellent ecological status has been found in vegetation and water body.The hot spot and cold spot areas shifted their locations every decade due to random LULC changes.Even after New Town Kolkata became a smart city,high LST has been observed.Overall,this study indicated that urbanization and changes in LULC patterns can influence the urban thermal environment,and appropriate planning is needed to reduce LST.This study can help policy-makers create sustainable smart cities.展开更多
As a prerequisite for groundwater protection and contamination control, evaluation of groundwater con- tamination risk was the extension of groundwater vulnerability assessment. Based on disaster theory and using shal...As a prerequisite for groundwater protection and contamination control, evaluation of groundwater con- tamination risk was the extension of groundwater vulnerability assessment. Based on disaster theory and using shallow groundwater of the lower reaches of Liaohe River Plain as the study area, we built an evaluation index system and a contamination index model for groundwater contamination risks from the perspectives of intrinsic vulnerability, external stresses, and functional value. We used data acquisition technology （remote sensing） and spatial analysis technology （GIS） to calculate the value of groundwater contamination risks. The spatial distribution of hotspots was obtained by calculating G index. Results show that groundwater contamination is above a mid-level risk in most of the study area. Areas with extreme high risk account for 37.86%, areas with high risk 32.47%, areas with moderate risk 12.07%, areas with light risk 3.17%, and areas with slight risk 14.43%. Hotspots areas are mainly located in central Shenyang City, northwest of Xinmin City, Beizhen City and Liaozhong County. Coldspots are mainly in Panjin City, Yingkou City, Dashiqiao City, Dawa County and Panshan County. The results reflect the spatial distribution and mechanism of groundwater contamination risk in the study area and provide relative references for land use planning and groundwater resource protection in the lower reaches of the Liaohe River Plain.展开更多
Exosomes are membrane vesicles that exist in pathological or normal cells and are considered to be specifically secreted,contain complex RNAs and proteins,participate in intercellular communication functions,and have ...Exosomes are membrane vesicles that exist in pathological or normal cells and are considered to be specifically secreted,contain complex RNAs and proteins,participate in intercellular communication functions,and have functions in organismal immune response,antigen presentation,cell migration,cell differentiation,and tumor invasion.In recent years,with the explosion of the development of minimally invasive diagnostics,the research of exosomes has been rapidly developed,and the number of articles published in this field has increased dramatically,and many articles summarize the published papers in a review-type analysis.In this paper,we use bibliometric analysis combined with theoretical analysis and pathfinding network scaling to visualize data and objectively count the development process,current research,and development trend of the corresponding field by analyzing the literature of the specified field.This paper presents the data visualization by analyzing the literature of the specified field to objectively count the development process,current research and development trend of the corresponding field.This paper presents a retrospective analysis and review of the articles on exosomes in the last 20 years(2001–2021)based on the bibliometric analysis method of CiteSpace software,while presenting the problems of current research and discussing the challenges encountered in the future,hoping to provide new ideas for the development of research in this field.展开更多
Biochar is the carbon-rich product obtained from the thermochemical conversion of biomass under oxygen-limited condi-tions.Preparation methods contribute to biochar properties,which are widely concerned in the agronom...Biochar is the carbon-rich product obtained from the thermochemical conversion of biomass under oxygen-limited condi-tions.Preparation methods contribute to biochar properties,which are widely concerned in the agronomic and environmental benefits of agro-ecosystems.This research aims to use bibliometrics methods to comprehensively and objectively analyze the research trends in the global biochar production field from 2006 to 2019 based on the Web of Science Core Collection database.The results showed that 1434 papers related to biochar preparation were published,which gradually increased each year.The research topics were diversified,which were mainly divided into“Environmental Sciences and Ecology,”“Engineering”and“Agriculture”.Moreover,Bioresource Technology was the most published journal contained biochar preparation.Authors from China had the most publications,followed by the US,Australia and the UK.Meanwhile,Yong Sik Ok from Korea University contributed most of the publications and had the highest H-index.Keywords analysis indicated that biochar preparation by pyrolysis was a current hotspot,of which microwave and hydrothermal were a future research trend.Besides,gasification would be used to develop new biomass energy.Biochar has the characteristics of high pH,high specific surface area,high carbon content,and rich functional groups.It is mainly used in soil improvement,water pollutant adsorption,carbon sequestration and emission reduction,and energy storage materials,etc.Furthermore,raw materials,pyrolysis temperature and pyrolysis time will also affect its characteristics and applications.It is expected that this study may provide insight into the future research interests regarding biochar preparation.展开更多
基金supported by the Natural Science Foundation of Shanxi Province(Grant No.20210302124437)the Graduate Student Research and Innovation Project of Shanxi Province(Grant No.2023KY551).
文摘In this paper,the Taixin Integrated Economic Zone in Shanxi Province is taken as the research object,and the coupling coordination degree model and bivariate spatial autocorrelation model are used to judge the coupling coordination and spatial-temporal correlation between urbanization and ecosystem service,and the hotspot analysis is used to judge the spatial-temporal trend of urbanization and ecosystem service.The results show that:(1)The urbanization level from 2000 to 2020 continued to rise,the areas with relatively high urbanization were concentrated in the central part of the study area,and the relatively high terrain areas on both sides of the study area,the urbanization was relatively slow,and the hotspot areas with highly significant and significant urbanization level from 2000 to 2020 were distributed as bands in the central part of the study area and the area was rising,and there was no Cold spot area distribution;between 2000 and 2020,the ecosystem service value in the study area increased by 2.6800×10^(8) yuan.Over these two decades,it exhibited a development trend that first rose and then declined.The woodland and grassland agglomeration areas were located on the two sides of the study area,forming highly significant and significant hotspots.Conversely,the central and northeastern parts of the study area were characterized by concentrated man-made land surfaces and croplands,resulting in the formation of highly significant and significant cold spots.(2)In the central part of the study area where man-made land surface and cultivated land are concentrated,the coupling coordination between urbanization and ecosystem service is in the intermediate dislocation and mild dislocation interval;the woodland and grassland concentration areas on both sides of the study area are ecologically fragile,and the coupling coordination between the two is in the level of less than intermediate dislocation.(3)From 2000 to 2020,urbanization and the value of ecosystem services were both negatively correlated,although the correlation coefficient was low.In the central and northeastern parts,urbanization and ecosystem service exhibited patterns of high-low,high-high,and low-low clustering.Conversely,on both sides of the study area,most of the clusters showed a low-high pattern.
基金supported by MOE(Ministry of Education of China)the research projects of Humanities and Social Sciences(No.13YJCZH239)Project of innovation and entrepreneurship for undergraduates in Shanxi Medical University(No.20160311)
文摘Objective： To describe the revolution and research status of Advances in Psychological Science. Methods： A total of 3060 articles published in Advances in Psychological Science from 1983 to 2014 were analyzed with the information visualization method using Citespace software from the aspects of pub- lications, cited frequency and downloads, funding, organizations, authors and keywords. Results： The results showed that the amount of literature published annually had an upward tendency, and 49.4% of the papers were supported by national or provincial projects. Institutions such as the Chinese Academy of Sciences （CAS） and the normal universities were rated in the forefront of the sci- entific research output. Xiting Huang, Hong Li and Yuejia Luo were at the top of the list of prolific authors. Conclusions： A new pattern of cooperative development of the theory and application in the field of psychological research is forming.
基金supported by the National Natural Science Foundation of China[grant numbers 42101449,42090012 and 61825103]the Natural Science Foundation of Hubei Province,China[grant numbers 2022CFB773 and 2020CFA001]+2 种基金the Key Research and Development Program of Hubei Province,China[grant number 2022BAA048]the Chutian Scholar Program of Hubei Provincethe Yellow Crane Talent Scheme.
文摘Road traffic crashes are becoming thorny issues being faced worldwide.Traffic crashes are spatiotemporal events and the research on the spatiotemporal patterns and variation trends of traffic crashes has been carried out.However,the impact of built environment on traffic crash spatiotemporal trends has not received much attention.Moreover,the spatial non-stationarity between the variation trends of traffic crashes and their influencing factors is usually neglected.To make up for the lack of analysis of built environment factors influencing spatiotemporal hotspot trends in traffic crashes,this paper proposed a method of“ST-GWLR”for analyzing the influence of built environment factors on spatiotemporal hotspot trends of traffic crashes by combining the spatiotemporal hotspot trend analysis and Geographically Weighted Logistic Regression(GWLR)modeling methods.Firstly,the traffic crash spatiotemporal hotspot trends were explored using the space-time cube model,hotspot analysis,and Mann-Kendall trend test.Then,the GWLR was introduced to capture the spatial non-stationarity neglected by the classic Global Logistic Regression(GLR)model,to improve the accuracy of the model estimation.GWLR model is used for the first time to analyze the significant local correlation between the traffic crash spatiotemporal hotspot trends and the built environment factors,to accurately and effectively identify the built environment factors that have significant influences on the hotspot trends of traffic crashes.The performance of the GWLR models and GLR models was examined and compared sufficiently.The results showed that the proposed ST-GWLR,which captured spatial non-stationarity,performed better than the classic GLR combined with spatiotemporal analysis,and improved the prediction accuracy of the models by 14.9%,13.9%,and 15.1%,respectively.There were significant local correlations between intensifying hotspots and persistent hotspots of traffic crashes and the built environment factors.The findings of this paper have positive implications for traffic safety management and urban built environment planning.
基金Project supported by the National Natural Science Foundation of China(31960327,31560226)Natural Science Foundation of Jiangxi Province(20202BABL205004)。
文摘[Objective]In order to reflect the relationship between literatures quickly and efficiently and reveal the evolutionary path and hotspot,and predict the future trend of Lycoris researches.[Methods]In 19902019,CiteSpace software was used for visual graphic analysis authors,institutes and key words related to Lycoris research based on data sources of WOS and CNKI.[Results](1)Domestic researchers have formed a core group of authors in East China,but the cooperation between the different teams is relatively dispersed.(2)From the perspective of international cooperation level,the cocontribution in China is the largest.Among them,the Chinese Academy of Sciences published has the largest number of papers,and higher research level.(3)The research on Lycoris has experienced three stages:slow accumulation period,rapid growth period and stable growth period.And its research direction develops along the route of“interspecific relationship within genuspropagation and cultivationpharmacology and pharmacodynamicscytology and molecular biologycross breeding”.[Conclusion]The research of Lycoris mainly distributed in Asian countries such as China and Japan.On the whole,its research direction is developing from macro to micro.
基金The National Natural Science Foundation of China(No. 52072012)。
文摘To reduce the risk of traffic accidents significantly caused by the speeding behavior of electric bicycles,this study focuses on the Beijing Yizhuang Economic and Tech-nological Development Zone.This work relies on high-precision shared electric bicycle Global Positioning System trajectory data,integrating a spatiotemporal analysis model and geographic information system(GIS)technol-ogy to explore the spatial and temporal variability law and formation mechanism of speeding behavior.Through data preprocessing,speeding events are identified,and weekday features are extracted.Four periods are identified:morning peak,midday minipeak,evening peak,and nighttime flat peak.Using the GIS platform,global spatial autocorrela-tion and local clustering analysis are conducted to identify the spatial clustering characteristics of speeding behaviors and hotspot areas.The coldspot and hotspot patterns of speeding events and the dynamic trajectories of their evolu-tion are analyzed using spatiotemporal cube technology.The results show that speeding behaviors are strongly corre-lated with the commuting peak in time and spatially concen-trated in the intersections of urban main roads,the periphery of commercial complexes,and industrial parks,with a dif-fusion tendency.The results of this study provide novel in-sights into the research and analysis of the spatial and tempo-ral characteristics of speeding risk behaviors of electric bi-cycles and effective technical support for nonmotorized traf-fic safety management.
文摘In the 21st century,climate change has exacerbated global instability,leading to a rise in landslide occurrences.In Bangladesh,mountainous areas such as Bandarban experience significant landslides during the monsoon season.This study seeks to evaluate landslide susceptibility in Bandarban and identify hotspots for optimal landslide hazard mitigation.This study examined landslide susceptibility using the analytical hierarchy process(AHP)and spatial weighted overlay(SWO).Ten conditioning factors were considered,with AHP based on responses from 100 key respondents.Using field surveys and high-resolution satellite images,280 landslide occurrence samples were collected to rank the subfactors.Using AHP-derived weights of factors and subfactors,the SWO approach was used to create the landslide susceptibility map(LSM).The Getis-Ord(Gi*)spatial statistics was then used to generate landslide susceptibility hotspots.The result showed that human influence weight 17.02%,making it the most crucial factor in landslide susceptibility.AHP-derived weights were reliable because their consistency ratio was<0.1.According to the study,59.86% of the area is moderately susceptible,20.06%is high,and 4.31%is very high.The validation of LSM by ROC curve found excellent performance(AUC=0.93)of the approaches.Specifically,63.8%of very high susceptibility areas and 33.26%of high susceptibility areas were found within the hotspot zones with 99%confidence.The research showed the combined use of field samples and remote sensing-based spatial variables improved the accuracy of LSM.These findings can be useful for ensuring proper land use planning and implementation of landslide hazard mitigation measures.
基金the University Grants Commission,New Delhi,India,for providing financial support in the form of the Junior Research Fellowship。
文摘Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land cover(LULC)changes on LST and determined the intensity of urban heat island(UHI)in New Town Kolkata(a smart city),eastern India,from 1991 to 2021 at 10-a intervals using various series of Landsat multi-spectral and thermal bands.This study used the maximum likelihood algorithm for image classification and other methods like the correlation analysis and hotspot analysis(Getis–Ord Gi^(*) method)to examine the impact of LULC changes on urban thermal environment.This study noticed that the area percentage of built-up land increased rapidly from 21.91%to 45.63%during 1991–2021,with a maximum positive change in built-up land and a maximum negative change in sparse vegetation.The mean temperature significantly increased during the study period(1991–2021),from 16.31℃to 22.48℃in winter,29.18℃to 34.61℃in summer,and 19.18℃to 27.11℃in autumn.The result showed that impervious surfaces contribute to higher LST,whereas vegetation helps decrease it.Poor ecological status has been found in built-up land,and excellent ecological status has been found in vegetation and water body.The hot spot and cold spot areas shifted their locations every decade due to random LULC changes.Even after New Town Kolkata became a smart city,high LST has been observed.Overall,this study indicated that urbanization and changes in LULC patterns can influence the urban thermal environment,and appropriate planning is needed to reduce LST.This study can help policy-makers create sustainable smart cities.
基金National Natural Science Foundation of China(No.40501013)Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20122136110003)
文摘As a prerequisite for groundwater protection and contamination control, evaluation of groundwater con- tamination risk was the extension of groundwater vulnerability assessment. Based on disaster theory and using shallow groundwater of the lower reaches of Liaohe River Plain as the study area, we built an evaluation index system and a contamination index model for groundwater contamination risks from the perspectives of intrinsic vulnerability, external stresses, and functional value. We used data acquisition technology （remote sensing） and spatial analysis technology （GIS） to calculate the value of groundwater contamination risks. The spatial distribution of hotspots was obtained by calculating G index. Results show that groundwater contamination is above a mid-level risk in most of the study area. Areas with extreme high risk account for 37.86%, areas with high risk 32.47%, areas with moderate risk 12.07%, areas with light risk 3.17%, and areas with slight risk 14.43%. Hotspots areas are mainly located in central Shenyang City, northwest of Xinmin City, Beizhen City and Liaozhong County. Coldspots are mainly in Panjin City, Yingkou City, Dashiqiao City, Dawa County and Panshan County. The results reflect the spatial distribution and mechanism of groundwater contamination risk in the study area and provide relative references for land use planning and groundwater resource protection in the lower reaches of the Liaohe River Plain.
基金the National Natural Science Foundation of China(12032007,31971242)Chongqing Research Program of Basic research and Frontier Technology(cstc2019jcyjzdxmX0028,cstc2020jscx-msxmX0132)。
文摘Exosomes are membrane vesicles that exist in pathological or normal cells and are considered to be specifically secreted,contain complex RNAs and proteins,participate in intercellular communication functions,and have functions in organismal immune response,antigen presentation,cell migration,cell differentiation,and tumor invasion.In recent years,with the explosion of the development of minimally invasive diagnostics,the research of exosomes has been rapidly developed,and the number of articles published in this field has increased dramatically,and many articles summarize the published papers in a review-type analysis.In this paper,we use bibliometric analysis combined with theoretical analysis and pathfinding network scaling to visualize data and objectively count the development process,current research,and development trend of the corresponding field by analyzing the literature of the specified field.This paper presents the data visualization by analyzing the literature of the specified field to objectively count the development process,current research and development trend of the corresponding field.This paper presents a retrospective analysis and review of the articles on exosomes in the last 20 years(2001–2021)based on the bibliometric analysis method of CiteSpace software,while presenting the problems of current research and discussing the challenges encountered in the future,hoping to provide new ideas for the development of research in this field.
基金This paper is funded by National Key Research and Development Program of China(No.2018YFC1900904)Postgraduate Research Fund of Guizhou Province(No.YJSCXJH(2019)055).
文摘Biochar is the carbon-rich product obtained from the thermochemical conversion of biomass under oxygen-limited condi-tions.Preparation methods contribute to biochar properties,which are widely concerned in the agronomic and environmental benefits of agro-ecosystems.This research aims to use bibliometrics methods to comprehensively and objectively analyze the research trends in the global biochar production field from 2006 to 2019 based on the Web of Science Core Collection database.The results showed that 1434 papers related to biochar preparation were published,which gradually increased each year.The research topics were diversified,which were mainly divided into“Environmental Sciences and Ecology,”“Engineering”and“Agriculture”.Moreover,Bioresource Technology was the most published journal contained biochar preparation.Authors from China had the most publications,followed by the US,Australia and the UK.Meanwhile,Yong Sik Ok from Korea University contributed most of the publications and had the highest H-index.Keywords analysis indicated that biochar preparation by pyrolysis was a current hotspot,of which microwave and hydrothermal were a future research trend.Besides,gasification would be used to develop new biomass energy.Biochar has the characteristics of high pH,high specific surface area,high carbon content,and rich functional groups.It is mainly used in soil improvement,water pollutant adsorption,carbon sequestration and emission reduction,and energy storage materials,etc.Furthermore,raw materials,pyrolysis temperature and pyrolysis time will also affect its characteristics and applications.It is expected that this study may provide insight into the future research interests regarding biochar preparation.
