共查询到19条相似文献，搜索用时 156 毫秒
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文献半衰期与普赖斯指数之间的关系研究 总被引：2，自引：0，他引：2
文献半衰期和普赖斯指数是用来测度文献老化速度的两个重要指标。文章从文献老化B—K方程出发,首次给出文献半衰期与普赖斯指数之间的关系式。用该关系式拟合了超导专业期刊的引文数据。计算结果表明：B—K方程的半衰期计算公式和莫蒂列夫修正式的半衰期计算公式对某些文献半衰期小于3年的学科（专业）是不适用的;新的计算引文半衰期公式所得到的结果与内插法得到的结果非常接近;并且该公式给出的半衰期范围围要比B—K方程的半衰期和莫蒂列夫修正式的半衰期要大得多。因此,新的计算引文半衰期公式更具普适性。 相似文献
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计算机科学文献的老化速度 总被引：4，自引：0，他引：4
本文以计算机技术学科类具有代表性的10种期刊2001年发表的全部论文为统计对象,收集其引用文献进行该学科的文献老化研究。对该学科引文的时序分布、当年指标、最大引文年限、引文半衰期、普赖斯指数等文献老化量度指标进行统计分析。结果表明:该学科的中、外文文献最大引文年限分别为第3和第4年,引文半衰期为5.5年,普赖斯指数为45.8%,并提出分别以该学科中、外文文献发表后的11年和16年作为文献保存年限参考值,建议把该学科近5年内发表和出版的文献作为文献订购的时限。 相似文献
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国内人文社会科学文献老化规律对比研究——基于Web新形势下的研究 总被引：3，自引：1，他引：2
以CSSCI 2006—2008年间收录的所有专业期刊的共280,280篇来源文献的2,217,047条引文数据为样本,对比分析人文社会科学7大学科门类的老化规律;以引文分析共时法揭示了人文社会科学的整体老化现象。结果显示,历史学的老化并不严格遵循负指数函数;人文学科比社会学科文献老化慢很多;历史学和哲学对档案性文献的依赖性最强;人文社会科学各学科的普赖斯指数(P)*半衰期(H)=常数C,C在2.6左右波动;人文社会科学目前阶段的最大引文年限为3年。图3。表5。参考文献28。 相似文献
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采用引文分析方法,对《编辑学报》7年内刊载论文的引用文献年代、语种等进行了统计分析,计算了其普赖斯指数和半衰期,在此基础上进行了分析和讨论。 相似文献
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对2012~2014年入选F5000的农业科学类论文的引文总数、中文引文数、外文引文数、近5年引文数、引文类别和发表年份进行核查,对其篇均引文数及普赖斯指数等引文计量指标进行统计分析.结果表明:829篇农业科学论文的引文率为99.88﹪,篇均引文、中文引文、外文引文和近5年引文数分别为27.70、15.68、12.02和11.40条/篇;11~30条引文的论文共有556篇,占论文总数的67.07﹪;11~30条引文的论文中更易出现高被引论文.各年F5000农业科学论文的篇均引文数、中文引文数、外文引文数及近5年引文数均呈波动性上升趋势,但普赖斯指数呈下降趋势,引文半衰期呈增大趋势. 相似文献
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基于CSSCI不同类型文献的发展趋势定量研究 总被引：1，自引：0，他引：1
本文研究对象为中国社会科学引文索引(cssci)数据库,选取其中的1999年—2005年各种类别文献为统计对象,分别对期刊论文,图书,报纸,会议文献,学位论文,信件,汇编,报告,标准,法规,电子文献,其他等类文献进行统计分析。分析了以上12种不同类别文献,这7年间的被引变化趋势,发展动态。定量的验证了cssci中的期刊论文、图书半衰期与普赖斯指数的反比关系,为图书馆的不同类型的纸质文献和数字文献的购买,存取,剔除提供了参考价值。 相似文献
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从网络引文的可追溯性角度研究网络信息资源的老化规律.具体分析CSSCI(1998～2009年)的183 986条P(Print)-W(Web)网络引文,发现各年网络引文量呈逻辑增长,篇均引文量也呈逐年增长趋势,其中近一半(48%)的P-W引文不可追溯.在不可追溯的引文类型中,404所占比例最大;通过引入传统文献老化规律模型--负指数增长曲线分析,P-W网络引文的平均可追溯半衰期为7 13年.P-W网络引文可追溯性与其URL域名类型、URL网页类型、URL层数和年代等的关系方面,P-W引文不可追溯分布具有一定的规律性;URL层数与URL字符数之间具有显著线性相关关系. 相似文献
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抽取2005—2006年中山大学公共卫生学院硕士研究生的学位论文共202篇,以其中的148篇MPH学位论文为研究组,54篇公共卫生全日制研究生学位论文为对照组,比较分析了两组学位论文引文规律及信息需求的差异。结果表明,MPH组的引文量及外文文献的引用率均低于全日制组,且引文率及外文文献引用率存在学科间差异;两组引文类型基本一致,但各类引文所占比例不同,普赖斯指数和半衰期也存在差异。建议通过多种方式提高MPH研究生的信息检索技巧、文献吸收能力。 相似文献
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文献半衰期的类型及其应用 总被引：25，自引：1，他引：24
目前学术界关于文献老化的定量研究较多是停留在以某学科文献为对象的半衰期研究上，尚未能对文献半衰期的概念进行分解和推广，因而使得其应用性受到一定的限制。事实上，从引证的角度来看，文献半衰期可分为文献被引半衰期和文献引用半衰期两大类；而从文献的主体范围的角度来看，文献半衰期又可以分为学科文献半衰期、期刊半衰期、著者文献半衰期、部门文献半衰期、国别文献半衰期等。本文试就文献半衰期的各种类型及其应用等若干问题进行初步的论述 相似文献
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目的：评估中国科学引文数据库（CSCD）收录的7种儿科类期刊质量。方法：通过“中国科技期刊引证指标数据库”获得7种儿科类期刊2013年的篇均参考文献、被引半衰期、H 指数、引用半衰期、自引率、影响因子、即年指数、自被引率等数据,并将指标按其与期刊质量的正、负相关关系分为两组,分别绘制蛛网图,然后结合7种儿科类期刊的发文情况进行质量评估。结果：以篇均参考文献、影响因子、H 指数、即年指数为一组进行蛛网图法评估,排在前3位的期刊是《中华儿科杂志》《中华实用儿科临床杂志》、《中国循证儿科杂志》;以引用半衰期、自引率、被引半衰期、自被引率为一组进行蛛网图法评估,排在前3位的期刊是《中国循证儿科杂志》、《中华儿科杂志》、《临床儿科杂志》。结论：7种儿科类期刊整体质量较高,《中国循证儿科杂志》、《中华儿科杂志》综合评价最好,其他各刊还有提升空间。 相似文献
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Eugene Garfield 《Journal of Informetrics》2009,3(3):173-179
While ISSI was founded in 1993, Scientometrics and Bibliometrics are now at least half a century old. Indeed, the field can be traced to early quantitative studies in the early 20th century. In the 1930s, it evolved to the “science of science.” The publication of J.D. Bernal's Social Function of Science in 1939 was a key transition point but the field lay dormant until after World War II, when D.J.D. Price's books Science Since Babylon and Little Science, Big Science were published in 1961 and 1963. His role as the “Father of Scientometrics” is clearly evident by using the HistCite software to visualize his impact as well as the subsequent impact of the journal Scientometrics on the growth of the field. Scientometrics owes its name to V.V. Nalimov, the author of Naukometriya, and to Tibor Braun who adapted the neologism for the journal. The primordial paper on citation indexing by Garfield which appeared in Science 1955 became a bridge between Bernal and Price. The timeline for the evolution of Scientometrics is demonstrated by a HistCite tabulation of the ranked citation index of the 100,000 references cited in the 3000 papers citing Price. 相似文献
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期刊学术影响力、期刊对稿件的录用标准和期刊载文的学术影响力三者之间存在同向加强的机制,来自较高影响力期刊的引用具有较高的评价意义。作者的择刊引用和择刊发表使得较低学术影响力的期刊较少被较高影响力期刊引用。因而,可以通过同时考察构成期刊引证形象的施引期刊的学术影响力及其施引频次来评价被引期刊的学术影响力。以综合性期刊Nature和Science 2010年的引证形象为例,将期刊影响因子作为学术影响力的初评结果,提出了以施引频次对施引期刊影响因子加权的计算方法,以期通过量化的引证形象实现对期刊的评价。 相似文献
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《Journal of Informetrics》2020,14(3):101048
The purpose of this research is to illustrate the use of the gamma distribution to model the ages of references in published research, and to demonstrate that the two gamma distribution parameters characterise a field of research in a manner that is complementary to and more nuanced than the Price Index or mean age of references.Minimum Distance Estimation is shown to produce robust estimates of the gamma distribution parameters because of the insensitivity of the Kolmogorov–Smirnov test in the tails of the distribution.Using a sample of 816 articles from 26 different journals across six subject areas, it is shown that the gamma distribution is at least as good as a lognormal distribution to model the ages of references in research articles.The two gamma distribution parameters indicate the rate of publication of new knowledge within the respective discipline and the citing behaviour in terms of the recency of references. Interpretation of these gamma distribution parameters enables a more nuanced and granular interpretation of the distinctiveness of disciplines, sub-disciplines, formats of publication and the distribution of references within articles than possible using the Price Index, half-life or mean age of references. 相似文献
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《Journal of Informetrics》2014,8(1):197-211
Author co-citation analysis (ACA) has long been used as an effective method for identifying the intellectual structure of a research domain, but it relies on simple co-citation counting, which does not take the citation content into consideration. The present study proposes a new method for measuring the similarity between co-cited authors by considering author's citation content. We collected the full-text journal articles in the information science domain and extracted the citing sentences to calculate their similarity distances. We compared our method with traditional ACA and found out that our approach, while displaying a similar intellectual structure for the information science domain as the other baseline methods, also provides more details about the sub-disciplines in the domain than with traditional ACA. 相似文献
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In citation network analysis, complex behavior is reduced to a simple edge, namely, node A cites node B. The implicit assumption is that A is giving credit to, or acknowledging, B. It is also the case that the contributions of all citations are treated equally, even though some citations appear multiply in a text and others appear only once. In this study, we apply text-mining algorithms to a relatively large dataset (866 information science articles containing 32,496 bibliographic references) to demonstrate the differential contributions made by references. We (1) look at the placement of citations across the different sections of a journal article, and (2) identify highly cited works using two different counting methods (CountOne and CountX). We find that (1) the most highly cited works appear in the Introduction and Literature Review sections of citing papers, and (2) the citation rankings produced by CountOne and CountX differ. That is to say, counting the number of times a bibliographic reference is cited in a paper rather than treating all references the same no matter how many times they are invoked in the citing article reveals the differential contributions made by the cited works to the citing paper. 相似文献
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本文对新近提出的学术迹和影响矩指标应用于单篇论著的评价效果进行比较研究,以JASIST 2005—2014年间发表的25篇高被引论文和ASTROPHYSICAL JOURNAL 2011—2014年间发表的24篇高被引论文为两个样本集,研究学术迹和影响矩相对于总被引数和h指数等学术评价指标的异同,发现各指标排序既具有一定相关性,也呈现出一定独立性,说明这些指标均有独立存在价值,而学术迹和影响矩能提供更全面的测度信息。图3。表6。参考文献25。附录2。 相似文献
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《Journal of Informetrics》2020,14(4):101072
This work analyzes the variation over time of the effect of geographic distance on knowledge flows. The flows are measured through the citations exchanged between scientific publications, including and excluding self-citations. To calculate geographic distances between citing and cited publication, each publication is associated with a “prevailing” territory, according to the authors’ affiliations. We then apply a gravity model to account for the research size of the territories, in terms of cognitive proximity of citing-cited publications. The field of observation is the 2010–2017 world publications citing the 2010–2012 Italian publications, as indexed in the Web of Science. The results show that in domestic knowledge flows, geographic proximity remains an influential factor through time, although with differences among disciplines and trends of attenuating effects. Finally, we replicate the analyses of knowledge flows but with the exclusion of self-citations: in this manner the effect of geographic proximity seems reduced, particularly at the national scale, but the differences (with vs without self-citations) lessen through time. As shown in previous works, the effect of distance on continental flows is modest (imperceptible for intercontinental flows), yet here too time has some influence, including concerning exclusion of self-citations. 相似文献