首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   79篇
  免费   0篇
化学工业   1篇
机械仪表   1篇
轻工业   8篇
一般工业技术   68篇
冶金工业   1篇
  2022年   3篇
  2021年   2篇
  2020年   6篇
  2019年   8篇
  2018年   9篇
  2017年   7篇
  2016年   8篇
  2014年   4篇
  2013年   2篇
  2012年   7篇
  2011年   3篇
  2010年   4篇
  2009年   1篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  1996年   1篇
  1967年   1篇
  1962年   2篇
  1958年   1篇
  1956年   4篇
排序方式: 共有79条查询结果,搜索用时 31 毫秒
1.
Summary We investigated committee peer review for awarding long-term fellowships to post-doctoral researchers as practiced by the Boehringer Ingelheim Fonds (B.I.F.) - a foundation for the promotion of basic research in biomedicine. Assessing the validity of selection decisions requires a generally accepted criterion for research impact. A widely used approach is to use citation counts as a proxy for the impact of scientific research. Therefore, a citation analysis for articles published previous to the applicants' approval or rejection for a B.I.F. fellowship was conducted. Based on our model estimation (negative binomial regression model), journal articles that had been published by applicants approved for a fellowship award (n = 64) prior to applying for the B.I.F. fellowship award can be expected to have 37% (straight counts of citations) and 49% (complete counts of citations) more citations than articles that had been published by rejected applicants (n = 333). Furthermore, comparison with international scientific reference values revealed (a) that articles published by successful and non-successful applicants are cited considerably more often than the “average” publication and (b) that excellent research performance can be expected more of successful than non-successful applicants. The findings confirm that the foundation is not only achieving its goal of selecting the best junior scientists for fellowship awards, but also successfully attracting highly talented young scientists to apply for B.I.F. fellowships.  相似文献   
2.
Bornmann  Lutz 《Scientometrics》2018,117(1):637-640

Dimensions is a research data infrastructure and tool, including grants, publications, citations, clinical trials, and patents in one place. An interesting feature of Dimensions is its field classification scheme, which is not based on journal classification systems, as in the Web of Science or Scopus, but on machine learning. Each publication is assigned to at least one field. Using the set of my own publications, I investigated whether they were reliably and validly assigned to fields. The results put in question the reliability and validity of the scheme. Large scale studies seem necessary to investigate the scheme in more detail.

  相似文献   
3.
4.
5.
    
Zusammenfassung Umfangreiche akute, subakute und chronische Versuche über die Toxieität der Weichmacher Benzyloctyladipinat, Dibutylphthalat, Mesamoll, Dicyclohexylphthalat und Polymerweichmacher PW 63/51 ergaben, daß alle geprüften Substanzen wenig giftig sind. Es spricht aber manches dafür, daß Mesamoll und PW 63/51 eine besonders günstige Beurteilung hinsichtlich der Unbedenklichkeit ihrer Verwendung auch in Folien, die zur Verpackung von Lebensmitteln gebraucht werden sollen, verdienen. Vor dem Einsatz von Dibutylphthalat zu dem genannten Zweck werden weitere Versuche für nötig gehalten.  相似文献   
6.
Bornmann  Lutz  Marewski  Julian N. 《Scientometrics》2019,120(2):419-459
Scientometrics - While bibliometrics are widely used for research evaluation purposes, a common theoretical framework for conceptually understanding, empirically studying, and effectively teaching...  相似文献   
7.
Scientometrics - Using 3-year moving averages of the complete Journal Citation Reports 1994–2016 of the Science Citation Index and the Social Sciences Citation Index (combined), we analyze...  相似文献   
8.
We have constructed a new ultrahigh vacuum apparatus with a triode configuration for the systematic investigation of photo-induced field emission (PFE) from metallic or semiconducting cathodes. These are exposed to electric fields up to 400 MV∕m and laser irradiation by means of hole or mesh gates. Cathodes and gates are in situ exchangeable and adjustable with high precision to ensure a homogeneous extraction of electrons which are partially transmitted to the fixed electron spectrometer. Its hemispherical sector analyzer provides an energy resolution limit of 8 meV. The commissioning of the measurement system has been performed with a tungsten needle. Its temperature showed up in the high-energy tail of the electron spectrum, while its work function was derived from the spectral low-energy part combined with the integral current-voltage curve. First PFE measurements on B-doped Si-tip arrays yielded a small field emission current increase under green laser illumination. A shift and splitting of the energy spectra was observed which revealed different emission regimes as well as the photosensitivity of the cathode due to carrier excitation into the conduction band. For the full exploitation of the PFE system, a tunable laser over a wide eV-range is required.  相似文献   
9.
In this short communication, we provide an overview of a relatively newly provided source of altmetrics data which could possibly be used for societal impact measurements in scientometrics. Recently, Altmetric—a start-up providing publication level metrics—started to make data for publications available which have been mentioned in policy-related documents. Using data from Altmetric, we study how many papers indexed in the Web of Science (WoS) are mentioned in policy-related documents. We find that less than 0.5% of the papers published in different subject categories are mentioned at least once in policy-related documents. Based on our results, we recommend that the analysis of (WoS) publications with at least one policy-related mention is repeated regularly (annually) in order to check the usefulness of the data. Mentions in policy-related documents should not be used for impact measurement until new policy-related sites are tracked.  相似文献   
10.
Iqbal  Sehrish  Hassan  Saeed-Ul  Aljohani  Naif Radi  Alelyani  Salem  Nawaz  Raheel  Bornmann  Lutz 《Scientometrics》2021,126(8):6551-6599
Scientometrics - In-text citation analysis is one of the most frequently used methods in research evaluation. We are seeing significant growth in citation analysis through bibliometric metadata,...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号