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1.
The consolidation of the scientific publishing industry has been the topic of much debate within and outside the scientific community, especially in relation to major publishers’ high profit margins. However, the share of scientific output published in the journals of these major publishers, as well as its evolution over time and across various disciplines, has not yet been analyzed. This paper provides such analysis, based on 45 million documents indexed in the Web of Science over the period 1973-2013. It shows that in both natural and medical sciences (NMS) and social sciences and humanities (SSH), Reed-Elsevier, Wiley-Blackwell, Springer, and Taylor & Francis increased their share of the published output, especially since the advent of the digital era (mid-1990s). Combined, the top five most prolific publishers account for more than 50% of all papers published in 2013. Disciplines of the social sciences have the highest level of concentration (70% of papers from the top five publishers), while the humanities have remained relatively independent (20% from top five publishers). NMS disciplines are in between, mainly because of the strength of their scientific societies, such as the ACS in chemistry or APS in physics. The paper also examines the migration of journals between small and big publishing houses and explores the effect of publisher change on citation impact. It concludes with a discussion on the economics of scholarly publishing.  相似文献   

2.
中国森林生物多样性监测网络(CForBio)作为我国生物多样性科学综合研究平台, 其发展过程和研究成果对促进我国生物多样性研究具有重要意义, 掌握其研究态势与热点变化可为CForBio的长远发展以及其他生态监测研究提供参考。本文对2007-2017年间CNKI数据库和Web of Science核心合集数据库中CForBio发表的论文进行了较为全面的文献计量分析。结果表明: 2007年以来, CForBio发表论文的数量整体上呈快速上升趋势, 从2007年的3篇增长到2017年的55篇, 其中SCI收录论文的增长较为明显(从2007年的1篇增长到2017年的34篇)。金光泽(70篇)、马克平(68篇)、郝占庆(68篇)等学者发表论文数量较多, 中国科学院的植物研究所(104篇)、沈阳应用生态研究所(67篇)、华南植物园(59篇)等是CForBio中相对活跃的研究机构, 但各样地负责机构和学者间的合作仍较少, 跨机构间的协同研究还有待提高。CForBio的研究热点主要体现在树木空间分布格局、植物功能性状、树木密度制约、群落系统发育等方面, 为揭示我国不同气候带森林群落构建机制提供了大量的理论依据。未来CForBio的研究应加强国内外机构间的合作创新并建立数据共享途径, 注重近地面遥感、多源数据融合等新技术的应用, 在生物多样性格局的多尺度与多维度解析、植物-土壤反馈机制、树木冠层和根系的结构与功能等方向持续开展深入研究。  相似文献   

3.
严欢欢  肖娟  杨永清 《广西植物》2017,37(5):661-674
雌雄异株植物是研究植物性别的理想材料,同时作为生态系统的重要组成部分,对生物多样性的维持与保护起着重要作用。该文从文献计量学角度综述了雌雄异株植物相关研究的进展。通过检索Web of Science(WOS)平台的SCI-E数据库和CNKI数据库的有关雌雄异株研究的文献数据,从文献年代分布、期刊分布、研究国家与机构、核心作者和高引论文等方面进行了分析,并借助CitespaceⅢ信息可视化软件绘制雌雄异株植物研究的科学知识图谱,总结了雌雄异株研究的热点和前沿。结果表明:WOS数据库中,雌雄异株植物研究呈现快速上升趋势,就发文总量来看,发文前五的国家为美国、日本、加拿大、英格兰和中国。其中,美国发文量占比为31.03%;中国科学院为发文量最多的机构,发文占比3.36%,其次为牛津大学(2.613%),多伦多大学位列第三(2.427%);中国,巴西和印度三国,西班牙马萨里克大学和北京林业大学两个研究机构近5年来在该领域发文增量较快。论文主要集中在植物科学、环境科学与生态学和遗传学等学科。载文量前十位的期刊累计载文占比高达24.13%,发文量最多的期刊为American Journal of Botany,占总发文量的6.07%,其次为Evolution(2.80%),Annals of Botany(2.52%)排名第三。发文最多的作者为捷克科学院的VYSKOT B,发文占总数的2.57%,高引论文大多出自美国学者之手。从CNKI数据库看,西华师范大学、北京林业大学和河南师范大学发文数量位列前三,发文量最高的期刊为《生命世界》,占总发文量的3.00%。综合Web of Science和CNKI两大数据库的文献来看,青杨和番木瓜作为研究雌雄异株植物的模式植物,近年发文较多。当前的研究热点主要集中在雌雄性别决定,繁殖代价,雌雄个体对环境因子的响应差异等方面。  相似文献   

4.
曹梦  勾宇轩  黄元仿 《广西植物》2020,40(4):592-600
对金花茶研究领域的文献信息进行知识图谱可视化分析,可以为研究者准确把握该领域的研究进展提供理论参考。该文利用引文分析软件CiteSpace对1979年—2018年金花茶的相关研究成果进行了计量学和可视化分析,绘制知识图谱,揭示金花茶研究的发展和知识结构。结果表明:(1)金花茶的研究逐渐被重视,年均研究文献逐渐增多;载文期刊的所在地主要为广西。(2)虽已形成核心作者群,但核心作者团队之间合作并不紧密;研究机构集中在广西,已形成"研究机构-高校-企业"的合作方式。(3)研究主要经历了三个阶段,即起步探索期(1979年—1985年)、平稳发展期(1986年—2006年)和快速增长期(2007年—2018年)。(4)金花茶化学成分、繁殖技术以及产品研发的研究正在发展为新前沿。金花茶研究中存在一些问题亟需解决,建议加强对金花茶研究的重视,围绕现实需求深入开展金花茶研究,以实现生态与经济协调发展。  相似文献   

5.
This study explores the collaborative nature and interdisciplinarity of the origin(s) of life (OoL) research community. Although OoL research is one of the oldest topics in philosophy, religion, and science; to date there has been no review of the field utilizing bibliometric measures. A dataset of 5647 publications that are tagged as OoL, astrobiology, exobiology, and prebiotic chemistry is analyzed. The most prolific authors (Raulin, Ehrenfreund, McKay, Cleaves, Cockell, Lazcano, etc.), most cited scholars and their articles (Miller 1953, Gilbert 1986, Chyba & Sagan 1992, W?chtersh?user 1988, etc.), and popular journals (Origins of Life and Evolution of Biospheres and Astrobiology) for OoL research are identified. Moreover, interdisciplinary research conducted through research networks, institutions (NASA, Caltech, University of Arizona, University of Washington, CNRS, etc.), and keywords & concepts (astrobiology, life, Mars, amino acid, prebiotic chemistry, evolution, RNA) are explored.  相似文献   

6.
This study aims to assess the nanotribology research output at global level using scientometric tools. The SCOPUS database was used to retrieve records related to the nanotribology research for the period 1996–2010. Publications were counted on a fractional basis. The level of collaboration and its citation impact were examined. The performance of the most productive countries, institutes and most preferred journals is assessed. Various visualization tools such as the Sci2 tool and Ucinet were employed. The USA ranked top in terms of number of publications, citations per paper and h-index, while Switzerland published a higher percentage of international collaborative papers. The most productive institution was Tsinghua University followed by Ohio State University and Lanzhou Institute of Chemical Physics, CAS. The most preferred journals were Tribology Letters, Wear and Journal of Japanese Society of Tribologists. The result of author keywords analysis reveals that Molecular Dynamics, MEMS, Hard Disk and Diamond like Carbon are major research topics.  相似文献   

7.
We briefly summarize the history of the rise of comparative physiology in China, the research work focused on by domestic and international counterparts in the field of comparative physiology of China, and international academic exchange and collaboration during this period. We also introduce some of the interesting model systems used in past and current research. This paper is based on documents in historical materials such as the proceedings of the 1st (August 1988) to 6th (October, 2007) Comparative Physiology Academic Session of the Chinese Association for Physiological Sciences, collected physiological works in commemoration academic papers of the 70th (1926-1999) and 80th anniversary of the Chinese Association for Physiological Sciences (1926-2006), CBP and the Physiology History of China, and the authors' own research experience.  相似文献   

8.
The purpose of this study was to carry out a bibliometric analysis of the articles published in Chile during 1987-2006 that were categorized into the Plant Science discipline by ISI. The data was extracted from the Web of Science datábase, obtaining a total of 911 articles for analysis. Almost half of the articles were the outcome of an international collaboration, the United States being the country with more collaborative links with Chile within this discipline. A list was made with the 10 most-cited articles and 10 most frequently used journals. The analysis showed that almost 50% of the articles were concentrated in 10 different journals. The number of articles produced each year revealed a steady growth in scientific production since 1987. This is probably related to the progressive interaction between industry and public-research institutions.  相似文献   

9.
Using vital statistics, yearly changes in the twinning and triplet rates by zygosity were investigated in the Czech Republic and the Slovak Republic during the period 1972-1995. Monozygotic (MZ) twinning rates in both countries had remained nearly constant (about 3 per 1000 total births) during that period. With a few exceptions, the dizygotic (DZ) twinning rates remained constant from 1972 to 1994, and increased in 1995 for both countries. MZ twinning rates for both countries were the lowest in Europe. As for triplet rates, overall rates increased significantly year by year in the Czech Republic, but not in the Slovak Republic. The triplet rate was significantly higher in 1995 than in the period 1972-1982 for both countries. The MZ triplet rate remained constant during that period in the Czech Republic. The trizygotic (TZ) triplet rates increased 3-fold for the Czech Republic and 4-fold for the Slovak Republic in 1972-1976 and 1992-1995. In the later period, the TZ rate was 1.5-fold higher in the Czech Republic than in the Slovak Republic. The quadruplet rate increased 2.3-fold from 2.9 per million births in 1982-1986 to 6.7 in 1992-1995 in the Czech Republic. The corresponding values were 2.7, 2.20 and 5.9-fold in the Slovak Republic. Both the Czech and the Slovak Republics were not affected by fertility drugs and assisted reproductive techniques until recently.  相似文献   

10.
目的分析国际毛孢子菌病文献概貌,了解毛孢子菌病临床相关研究现状,为更好地开展毛孢子菌临床研究提供思路和依据。方法利用汤森路透TDA软件分析PubMed数据库收录的毛孢子菌病临床相关文献的时间、国家、期刊、作者和高频主题词分布,并获得作者合作网络图。结果临床毛孢子菌病相关文献始于1970年,经过1981~1992年的快速增长期后,近年来数量增长不明显。日本在临床毛孢子菌病研究领域具有领先优势,美国、印度、巴西、法国和中国内地发文量也较多。刊载毛孢子菌病临床研究文献最多的期刊是《日本胸部疾病杂志》(Nihon Kyobu Shikkan Gakkai Zasshi,Japa—nese Journal of Thoracic Diseases)和《临床微生物学杂志》(Journal of Clinical Microbiology)。发文量最多的作者分别是熊本大学医学部的Ando M、Araki S和琦玉医科大学的Sakata T。毛孢子菌病的高频主题词涉及毛孢子菌病的诊治、宿主免疫和毛孢子菌致病机制等。结论日本和美国仍是相关领域的研究大国,但近5a来,更多的中国科研团队加入到这一研究领域,提高了我国学者的学术影响力。侵袭性毛孢子菌病的诊治是临床毛孢子菌病研究的主要关注点。  相似文献   

11.
The community surveillance of respiratory virus infections performed during 1985-1987 in Sendai and 1988-1990 in Yamagata has identified a total of five herald waves of influenza virus infections: A/H3N2 virus infections in 1985 and 1989, A/H1N1 virus infections in 1986 and 1988, and type B virus infections in 1989. To investigate the antigenic and genetic relationships between the herald wave and epidemic strains, influenza A/H1N1 viruses isolated during the 1986 and 1988 herald waves were compared with those isolated during the 1986-1987 and 1988-1989 epidemic seasons, respectively, utilizing hemagglutination inhibition tests with anti-hemagglutinin monoclonal antibodies and oligonucleotide mapping of total viral RNAs. The results showed that multiple variants differing in antigenic and genetic properties were cocirculating during the 1986 herald wave as well as during each of the two epidemics (only one strain was isolated in the 1988 herald wave). It was also observed that viruses which had the antigenic and/or genetic characteristics closely similar to those of the viruses circulating in the 1986 and 1988 herald waves, were isolated during the winters of 1986-1987 and 1988-1989, respectively.  相似文献   

12.
The emerging role of immune activation and inflammation in the pathogenesis of human immunodeficiency virus (HIV) disease has stimulated the search for new approaches for managing HIV infection. Recent evidence suggests that an imbalance between matrix metalloproteinases (MMPs) and endogenous tissue inhibitors of MMPs (TIMPs) might contribute to HIV-associated pathology by inducing remodelling of the extracellular matrix. Here, we discuss the evidence and the potential mechanisms for altered MMP or TIMP function in HIV infection and disease. Furthermore, we outline the possible medical implications for the use of compounds that target MMP activity, and we propose that antiretroviral drugs, particularly HIV protease inhibitors (PIs), and compounds with anti-inflammatory properties, such as statins, natural omega-3 fatty acids and tetracyclines, which inhibit MMP function, might represent useful therapeutic approaches to mitigate potential MMP-related damage during HIV infection.  相似文献   

13.
It is now more than 20 years since both Council of Europe Convention ETS123 and EU Directive 86/609/EEC were introduced, to promote the implementation of the Three Rs in animal experimentation and to provide guidance on animal housing and care. It might therefore be expected that reports of the implementation of the Three Rs in animal research papers would have increased during this period. In order to test this hypothesis, a literature survey of animal-based research was conducted. A randomly-selected sample from 16 high-profile medical journals, of original research papers arising from European institutions that featured experiments which involved either mice or primates, were identified for the years 1986 and 2006 (Total sample = 250 papers). Each paper was scored out of 10 for the incidence of reporting on the implementation of Three Rs-related factors corresponding to Replacement (justification of non-use of non-animal methods), Reduction (statistical analysis of the number of animals needed) and Refinement (housing aspects, i.e. increased cage size, social housing, enrichment of cage environment and food; and procedural aspects, i.e. the use of anaesthesia, analgesia, humane endpoints, and training for procedures with positive reinforcement). There was no significant increase in overall reporting score over time, for either mouse or primate research. By 2006, mouse research papers scored an average of 0 out of a possible 10, and primate research papers scored an average of 1.5. This review provides systematic evidence that animal research is still not properly reported, and supports the call within the scientific community for action to be taken by journals to update their policies.  相似文献   

14.
The canopy transpiration of mountain mixed forest was investigated during summer 2006 at research plot Smrekovec in Tatra National Park in Slovakia after heavy windstorm in November 2004 on the area of 12,000 hectares. The research plot is situated in untouched forest at altitude 1249 m on the southern-east oriented slope. The forest is mixed with 80% of spruce trees and 20% of larch trees with rich under storey vegetation, 120 years old, 7th altitudinal vegetation stage. Whole tree sap flow based on up to dated stem tissue heat balance method was continuously measured in nine 120-years old larch and spruce trees. Stem basal area was used for tree-canopy up-scaling. Meteorological parameters were measured on the top of eddy stuff tower above investigated forest. Two virtual monocultures were assumed for characterizing of both species. The sap flow and tree transpiration were calculated for the whole measured period for both spruce and larch virtual forests.  相似文献   

15.
全球北极底栖生物研究文献计量分析   总被引:4,自引:1,他引:3  
刘爱原  林荣澄  郭玉清 《生态学报》2015,35(9):2789-2799
以Thomson Reuters的Web of Science信息平台提供的SCI-E数据库为数据源,检索到从1991年至2012年期间全球北极底栖生物研究论文2127篇,利用Note Express软件,分析22年间论文发表的年度、国家、机构、作者、期刊和学科等方面的分布特征,结果表明:1)全球北极底栖生物研究论文数量、篇均作者数和篇均参考文献数都在逐年增加;2)研究论文涉及58个国家或地区,位于前7位的国家依次是美国、德国、加拿大、挪威、俄罗斯、英国和丹麦;美国、加拿大、挪威和丹麦是该领域国际合作研究最主要的国家;3)论文涉及1364个机构,前20名的研究机构中,美国有6家,德国、加拿大和挪威各有3家,俄罗斯和丹麦各有2家,波兰有1家。俄罗斯、丹麦、波兰、德国和挪威超过60%的研究力量集中在位列前20位的相关机构中。俄罗斯科学院论文总量排列首位,德国阿尔弗雷德魏格纳极地与海洋研究中心和基尔大学论文的h指数最高为32;4)论文涉及最多的4个学科是海洋与淡水生物学、生态学、海洋学和多学科地球科学。Polar Biology和Marine Ecology Progress Series是发表该领域最核心的期刊。还对中国在该领域的研究现状进行了简要的分析。从文献计量学角度揭示了全球北极底栖生物研究现状,为提升我国该领域研究的国际竞争力提供科学参考。  相似文献   

16.
The increase in the size of the scientific community created an explosion in scientific production. We have analyzed the dynamics of biomedical scientific output during 1957–2007 by applying a bibliometric analysis of the PubMed database using different keywords representing specific biomedical topics. With the assumption that increased scientific interest will result in increased scientific output, we compared the output of specific topics to that of all scientific output. This analysis resulted in three broad categories of topics; those that follow the general trend of all scientific output, those that show highly variable output, and attractive topics which are new and grow explosively. The analysis of the citation impact of the scientific output resulted in a typical longtail distribution: the majority of journals and articles are of very low impact. This distribution has remained unchanged since 1957, although the interests of scientists must have shifted in this period. We therefore analyzed the distribution of articles in top journals and lower impact journals over time for the attractive topics. Novelty is rewarded by publication in top journals. Over time more articles are published in low impact journals progressively creating the longtail distribution, signifying acceptance of the topic by the community. There can be a gap of years between novelty and acceptance. Within topics temporary novelty is created with new subtopics. In conclusion, the longtail distribution is the foundation of the scientific output of the scientific community and can be used to examine different aspects of science practice.  相似文献   

17.
根据1976、1987和2001年3次大熊猫(Ailuropoda melanoleuca)调查资料及2006~2007年大熊猫监测数据,利用ArcView GIS软件系统地比较了1976~2007年之间秦岭大熊猫栖息地的变化。秦岭大熊猫栖息地由20世纪70年代的217 100 hm2退缩到90年代前的167 000 hm2,大熊猫栖息地缩减和片断化较为严重;90年代后有所好转,面积增加到347 499 hm2,并在格局上整体存在向北向西扩散的趋势。秦岭大熊猫栖息地变化的原因主要与森林采伐及1998年实施的天然林禁伐有关,而栖息地斑块化主要与公路建设、人为活动等有关。  相似文献   

18.
Bacterial cultures of marine mammal samples often yield multiple genera and species, and it can be difficult to determine if a cultured bacterium is a primary pathogen or an incidental finding. To determine the relative risk of bacterial isolates among Atlantic bottlenose dolphins Tursiops truncatus at the United States Navy Marine Mammal Program (MMP), retrospective data on isolates cultured during June 1987 through June 2007 were organized into a novel, 5-tier risk categorization system limited to sole bacteria cultured from internal organ or fluid samples. Of 2586 bacterial isolates cultured, only 34 (1.3%) and 25 (1.0%) were sole isolates attributed to morbidity and mortality, respectively, and only 19 (0.7%) isolates were associated with mortalities without evidence of fungal or viral co-infections. Highest risk bacterial isolates were most likely to be identified in pleural fluid (33.3% of pleural fluid samples with bacterial isolates had only one genus), followed by renal (23.1%) and splenic (11.1%) tissue. Sole Staphylococcus aureus isolates were identified as the highest risk bacterial pathogens in the MMP dolphin population, accounting for 0.4 % of total bacterial isolates over a 20 yr period. In summary, isolation of sole bacterial isolates definitively associated with morbidity and mortality in marine mammals was uncommon in the MMP population. Our proposed risk categorization system may be useful in determining high risk pathogens among other marine mammal populations.  相似文献   

19.
Noroviruses are the principal cause of epidemic gastroenteritis worldwide. Multiple reports have concluded that the major capsid proteins of GII.4 strains, which cause 80% of norovirus infections worldwide, are evolving rapidly, resulting in new epidemic strains. Surrogate neutralization assays using sera from outbreaks and from immunized mice suggest that, as with influenza virus, antigenic variation maintains GII.4 persistence in the face of human population herd immunity. To test this hypothesis, mice were hyperimmunized with virus-like particles (VLPs) representing an early (GII.4-1987) and a contemporary (GII.4-2006) GII.4 strain. Anti-GII.4-1987 IgG monoclonal antibodies (MAbs) strongly reacted with GII.4 VLPs derived between only 1987 and 2002. Ligand binding blockade was more efficient with GII.4-1987 and GII.4-1997 VLPs than with GII.4-2002. Anti-GII.4-2006 IgG MAbs recognized either a broad panel of GII.4 VLPs (1987 to 2006) or a subset of contemporary (2004 to 2006) VLPs. Most 2006 antibodies did not recognize or only poorly recognized GII.4 VLPs of 2007 or 2008, documenting rapid antigenic evolution of GII.4 capsids. Generally, 2006 MAbs blocked homotypic VLP-ligand binding but were unable to block VLPs representing strains primarily circulating during or earlier than 2002. These analyses demonstrate that both subtle and significant evolutionary change has occurred within antibody epitopes between epidemic strains, providing direct evidence that the GII.4 noroviruses are undergoing antigenic variation, likely in response to herd immunity. As with influenza virus, HIV, and hepatitis C virus, norovirus antigenic variation will significantly influence the design of efficacious vaccines and immunotherapeutics against these important human pathogens.  相似文献   

20.
基于Web of Science数据库的检索结果,利用Histcite、Bibexcel和Netdraw对国际植被物候研究文献进行计量分析。结果表明:1 060篇相关文献刊载于288种期刊,平均载文3.68篇; 共分33个研究方向; 3 380位作者(第一作者904位)、69个国家或地区、1 172个组织参与; 国际合作发文310篇,占比29.25%; 其中中美合作居第一(19次)。分析还表明:2002~2007年是该领域重要发展期; 国际植被物候研究热点主要集中在基于气候(climate)-物候的田间局地观测和基于遥感(remote sensing)的大尺度物候研究。  相似文献   

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