Grasslands,one of the major terrestrial ecosystems,are essential for the maintenance of ecological and production functions;however,they are undergoing extensive degradation.The development and cutting-edge exploratio...Grasslands,one of the major terrestrial ecosystems,are essential for the maintenance of ecological and production functions;however,they are undergoing extensive degradation.The development and cutting-edge explorations in grassland science are critical to addressing challenges such as climate change and the increasing influence of human activities.To identify research trends in grassland science,latent Dirichlet allocation(LDA)topic modelling was used to conduct an automated content analysis on 123,829 papers available on Web of Science Core Collection from 1900 to 2020.Results from this analysis showed that grassland research has become increasing multidisciplinary,accompanied by a pronounced reduction in the relative frequency of traditional production-oriented research and an increase in the themes focusing on ecological functions and modern technologies.Changes in research activities have been uneven globally,with a significant increase in the number of publications in China and Brazil,which probably reflects an increased support from various governmental agencies in these countries.Additionally,in 2019,China surpassed the United States in terms of the total number of publications.Further,this study identified important topics and emerging challenges in grassland research,such as biodiversity conservation,climate changes,and genetic considerations.Comprehensive improvement of education,research,global cooperation,and funding strategies will be necessary to promote grassland science research on frontier themes and to effectively address the social and environmental challenges in the new era.展开更多
Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends a...Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.展开更多
Construction of theme park has been launched since the early 1990s in Chengdu City,but ended up as a losing proposition after its short-term prosperity because of similar scale and similarity with those in other citie...Construction of theme park has been launched since the early 1990s in Chengdu City,but ended up as a losing proposition after its short-term prosperity because of similar scale and similarity with those in other cities.As more international well-known theme parks entering the market,theme parks in Chengdu have been faced with the transition,and novel concepts are also introduced into the operation of these parks.To adapt to the market,it is imperative to make marketing strategies and combine marketing elements.Through analyzing current development of local theme parks and introducing successful marketing modes of domestic and overseas theme parks,a favorable marketing mode for theme parks in Chengdu was defined on the basis of fully exploring Ba-Shu culture(Ba and Shu are two ancient kingdoms in the history of Sichuan).By defining a favorable theme,focusing more on visitors'experience,devoting more in developing new products,adopting flexible price strategies,and integrating advertisement marketing,internet marketing,and other marketing methods,outstanding brands will be formed,and tourism cultures with distinguished features of Chengdu will be created.展开更多
基于CiteSpace知识图谱分析方法,系统梳理了发表于Web of Science和中国知网数据库中的703篇外文文献与1036篇中文文献,围绕关键词词频、聚类与突现特征,系统呈现了要素市场扭曲的研究概况。在此基础上,依据生产要素的基本分类,从资本...基于CiteSpace知识图谱分析方法,系统梳理了发表于Web of Science和中国知网数据库中的703篇外文文献与1036篇中文文献,围绕关键词词频、聚类与突现特征,系统呈现了要素市场扭曲的研究概况。在此基础上,依据生产要素的基本分类,从资本、劳动力、土地以及数据四个层面归纳并评述了当前研究的主流。最后,结合现有研究的不足与新时代背景下的现实需求,提出未来研究的五个重点方向,包括:聚焦中国情境下的要素市场扭曲、深化数据要素市场研究、分析不同要素市场扭曲的相互作用、开展跨学科交叉研究、探讨新兴技术驱动下的要素市场扭曲,旨在深化对该领域的全面认识,并为后续相关研究提供理论参考与思路借鉴。展开更多
文摘Grasslands,one of the major terrestrial ecosystems,are essential for the maintenance of ecological and production functions;however,they are undergoing extensive degradation.The development and cutting-edge explorations in grassland science are critical to addressing challenges such as climate change and the increasing influence of human activities.To identify research trends in grassland science,latent Dirichlet allocation(LDA)topic modelling was used to conduct an automated content analysis on 123,829 papers available on Web of Science Core Collection from 1900 to 2020.Results from this analysis showed that grassland research has become increasing multidisciplinary,accompanied by a pronounced reduction in the relative frequency of traditional production-oriented research and an increase in the themes focusing on ecological functions and modern technologies.Changes in research activities have been uneven globally,with a significant increase in the number of publications in China and Brazil,which probably reflects an increased support from various governmental agencies in these countries.Additionally,in 2019,China surpassed the United States in terms of the total number of publications.Further,this study identified important topics and emerging challenges in grassland research,such as biodiversity conservation,climate changes,and genetic considerations.Comprehensive improvement of education,research,global cooperation,and funding strategies will be necessary to promote grassland science research on frontier themes and to effectively address the social and environmental challenges in the new era.
基金supported by the National Natural Science Foundation of China,No.81471308(to JL)the Stem Cell Clinical Research Project in China,No.CMR-20161129-1003(to JL)the Innovation Technology Funding of Dalian in China,No.2018J11CY025(to JL)
文摘Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells.
文摘Construction of theme park has been launched since the early 1990s in Chengdu City,but ended up as a losing proposition after its short-term prosperity because of similar scale and similarity with those in other cities.As more international well-known theme parks entering the market,theme parks in Chengdu have been faced with the transition,and novel concepts are also introduced into the operation of these parks.To adapt to the market,it is imperative to make marketing strategies and combine marketing elements.Through analyzing current development of local theme parks and introducing successful marketing modes of domestic and overseas theme parks,a favorable marketing mode for theme parks in Chengdu was defined on the basis of fully exploring Ba-Shu culture(Ba and Shu are two ancient kingdoms in the history of Sichuan).By defining a favorable theme,focusing more on visitors'experience,devoting more in developing new products,adopting flexible price strategies,and integrating advertisement marketing,internet marketing,and other marketing methods,outstanding brands will be formed,and tourism cultures with distinguished features of Chengdu will be created.
文摘基于CiteSpace知识图谱分析方法,系统梳理了发表于Web of Science和中国知网数据库中的703篇外文文献与1036篇中文文献,围绕关键词词频、聚类与突现特征,系统呈现了要素市场扭曲的研究概况。在此基础上,依据生产要素的基本分类,从资本、劳动力、土地以及数据四个层面归纳并评述了当前研究的主流。最后,结合现有研究的不足与新时代背景下的现实需求,提出未来研究的五个重点方向,包括:聚焦中国情境下的要素市场扭曲、深化数据要素市场研究、分析不同要素市场扭曲的相互作用、开展跨学科交叉研究、探讨新兴技术驱动下的要素市场扭曲,旨在深化对该领域的全面认识,并为后续相关研究提供理论参考与思路借鉴。
