Picea Mill.species are important components of boreal and subalpine forests.They have a wide geographical range in the Northern Hemisphere,extending from the Eurasian continent to North America.In this study,publicati...Picea Mill.species are important components of boreal and subalpine forests.They have a wide geographical range in the Northern Hemisphere,extending from the Eurasian continent to North America.In this study,publications on Picea species from 2002 to 2016 were identified via the Web of Science(WoS)and the China National Knowledge Infrastructure(CNKI)databases,and subjected to relationship network visualization using CiteSpace software.This study represents the first such analysis of Picea and provides a reference for bibliometrics in forest tree species research.The results show that the total number of publications on Picea archived in WoS was20,958 and that the number of papers published annually has increased over time,peaking at 1725 in 2013.The studies were mainly conducted in North America,Europe and Asia;among them,Canada published the most papers and showed the strongest betweenness centrality(0.11).Among research institutions,the Swedish University of Agricultural Sciences in Uppsala had the highest publication record.The research contributions of the Chinese Academy of Sciences,the Chinese Academy of Forestry,and Beijing Forestry University have improved rapidly in recent years,greatly enhancing the international impact of Chinese research in this field.The research contents were grouped into five categories:forest ecosystems,pest resistance,extraction and functional analyses of active ingredients from various plant organs,nursery and afforestation techniques,and timber quality research.In China,the number of papers from the CNKI database was4532,increasing at an even pace.The research topics on Picea included forest ecosystems,seedling and afforestation techniques,basic studies on individual species and populations,and pests and diseases.Within and outside China,hotspots in Picea research included the relationships between Picea and environmental factors,and the genomic sequences of Picea.展开更多
In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure(CNKI)...In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure(CNKI), which covered the time span from 1984 to present and included more than 2.6 million master and doctoral dissertations from hundreds of institutions of China's Mainland. The bibliometric analysis summarized output, geographical, and institutional patterns, as well as research directions and hotspots in groundwater studies in China in the period of 1984-2014. A total of 1 396 groundwater-related dissertations including 1 161 master dissertations and 235 doctoral dissertations, contributed by 128 institutions distributed in 53 cities nationwide, were searched out in the database. It can be seen obviously that, the groundwater science teaching and research in China has experienced a notable growth in the past three decades especially during 2000-2014. Groundwater modeling, resource, and exploitation were the top three major subject categories; China University of Geosciences(Beijing), Jilin University and Chang’an University were the top three productive institutions together accounting for more than one third of the total dissertations and 50% of the doctoral dissertations, which further prompted the cities(Beijing, Changchun, and Xi’an) to become the top three productive cities. The dissertations generally covered all the international research topics, which indicated that hydrogeologists in China have tracked the international frontier closely during the past decades. The keywords analysis revealed that,(1) numerical modeling was still the hottest topic and PHREEQC, MODFLOW, GMS, and FEFLOW were the four most used softwares;(2) the topics related with groundwater pollution and quality developed steadily and rapidly;(3) environmental isotopes and GIS were frequently used tools for hydrogeological condition analysis, and spatial data processing respectively; and(4) the unsaturated zone as an integral part of aquifers attracted more and more attentions from hydrogeologists focus on saturated zone.展开更多
To help the government better understand and manage public sentiments,and help the public establish the values of rational participation in online discussions related to COVID-19,it is necessary to explore the themes ...To help the government better understand and manage public sentiments,and help the public establish the values of rational participation in online discussions related to COVID-19,it is necessary to explore the themes and emotions of different subjects discussing the pandemic on social media platforms.The study takes a comprehensive view by combining social media and scholarly outputs data.In particular,WeChat articles are investigated to reveal the public concern and public sentiment towards COVID-19,and WeChat mentions to scholarly papers are identified to show the interaction between the public and researchers.Text analysis is conducted to construct co-occurrence networks and reveal the distribution of themes.VOSviewer is applied to network visualization.Statistical and comparative analysis showed that discussion about COVID-19 keeps hot on WeChat.WeChat offical accounts from the information industry dominate,suggesting a free and flexible discussing environment.Topics on WeChat overlap with that of scholarly papers but have a much broader scope.WeChat mentions to scholarly papers has bridged the public with the research and has a high coverage of 61.7%.Public sentiment in WeChat is positive,demonstrating good confidence in defeating the pandemic.These findings are helpful in understanding the social attitude towards and comprehensive perception of COVID-19 in China.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.31660212).
文摘Picea Mill.species are important components of boreal and subalpine forests.They have a wide geographical range in the Northern Hemisphere,extending from the Eurasian continent to North America.In this study,publications on Picea species from 2002 to 2016 were identified via the Web of Science(WoS)and the China National Knowledge Infrastructure(CNKI)databases,and subjected to relationship network visualization using CiteSpace software.This study represents the first such analysis of Picea and provides a reference for bibliometrics in forest tree species research.The results show that the total number of publications on Picea archived in WoS was20,958 and that the number of papers published annually has increased over time,peaking at 1725 in 2013.The studies were mainly conducted in North America,Europe and Asia;among them,Canada published the most papers and showed the strongest betweenness centrality(0.11).Among research institutions,the Swedish University of Agricultural Sciences in Uppsala had the highest publication record.The research contributions of the Chinese Academy of Sciences,the Chinese Academy of Forestry,and Beijing Forestry University have improved rapidly in recent years,greatly enhancing the international impact of Chinese research in this field.The research contents were grouped into five categories:forest ecosystems,pest resistance,extraction and functional analyses of active ingredients from various plant organs,nursery and afforestation techniques,and timber quality research.In China,the number of papers from the CNKI database was4532,increasing at an even pace.The research topics on Picea included forest ecosystems,seedling and afforestation techniques,basic studies on individual species and populations,and pests and diseases.Within and outside China,hotspots in Picea research included the relationships between Picea and environmental factors,and the genomic sequences of Picea.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (2014ZX07201-010)the National Natural Science Foundation of China (41302179)the Fundamental Research Funds for the Central Universities (2013YB64)
文摘In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure(CNKI), which covered the time span from 1984 to present and included more than 2.6 million master and doctoral dissertations from hundreds of institutions of China's Mainland. The bibliometric analysis summarized output, geographical, and institutional patterns, as well as research directions and hotspots in groundwater studies in China in the period of 1984-2014. A total of 1 396 groundwater-related dissertations including 1 161 master dissertations and 235 doctoral dissertations, contributed by 128 institutions distributed in 53 cities nationwide, were searched out in the database. It can be seen obviously that, the groundwater science teaching and research in China has experienced a notable growth in the past three decades especially during 2000-2014. Groundwater modeling, resource, and exploitation were the top three major subject categories; China University of Geosciences(Beijing), Jilin University and Chang’an University were the top three productive institutions together accounting for more than one third of the total dissertations and 50% of the doctoral dissertations, which further prompted the cities(Beijing, Changchun, and Xi’an) to become the top three productive cities. The dissertations generally covered all the international research topics, which indicated that hydrogeologists in China have tracked the international frontier closely during the past decades. The keywords analysis revealed that,(1) numerical modeling was still the hottest topic and PHREEQC, MODFLOW, GMS, and FEFLOW were the four most used softwares;(2) the topics related with groundwater pollution and quality developed steadily and rapidly;(3) environmental isotopes and GIS were frequently used tools for hydrogeological condition analysis, and spatial data processing respectively; and(4) the unsaturated zone as an integral part of aquifers attracted more and more attentions from hydrogeologists focus on saturated zone.
基金funded by the National Natural Science Foundation of China(72274227)Humanity and Social Science Foundation of the Ministry of Education of China(22YJA870016).
文摘To help the government better understand and manage public sentiments,and help the public establish the values of rational participation in online discussions related to COVID-19,it is necessary to explore the themes and emotions of different subjects discussing the pandemic on social media platforms.The study takes a comprehensive view by combining social media and scholarly outputs data.In particular,WeChat articles are investigated to reveal the public concern and public sentiment towards COVID-19,and WeChat mentions to scholarly papers are identified to show the interaction between the public and researchers.Text analysis is conducted to construct co-occurrence networks and reveal the distribution of themes.VOSviewer is applied to network visualization.Statistical and comparative analysis showed that discussion about COVID-19 keeps hot on WeChat.WeChat offical accounts from the information industry dominate,suggesting a free and flexible discussing environment.Topics on WeChat overlap with that of scholarly papers but have a much broader scope.WeChat mentions to scholarly papers has bridged the public with the research and has a high coverage of 61.7%.Public sentiment in WeChat is positive,demonstrating good confidence in defeating the pandemic.These findings are helpful in understanding the social attitude towards and comprehensive perception of COVID-19 in China.