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   1705篇
  免费   39篇
教育   1321篇
科学研究   91篇
各国文化   23篇
体育   108篇
文化理论   24篇
信息传播   177篇
  2023年   20篇
  2022年   32篇
  2021年   30篇
  2020年   58篇
  2019年   98篇
  2018年   126篇
  2017年   115篇
  2016年   99篇
  2015年   74篇
  2014年   95篇
  2013年   314篇
  2012年   81篇
  2011年   59篇
  2010年   76篇
  2009年   36篇
  2008年   58篇
  2007年   44篇
  2006年   22篇
  2005年   28篇
  2004年   34篇
  2003年   23篇
  2002年   34篇
  2001年   13篇
  2000年   25篇
  1999年   13篇
  1998年   15篇
  1997年   8篇
  1996年   14篇
  1995年   7篇
  1994年   10篇
  1993年   9篇
  1992年   7篇
  1991年   12篇
  1990年   9篇
  1989年   8篇
  1988年   9篇
  1987年   3篇
  1986年   6篇
  1985年   2篇
  1982年   2篇
  1981年   1篇
  1980年   5篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1972年   1篇
  1967年   1篇
排序方式: 共有1744条查询结果,搜索用时 15 毫秒
61.
ABSTRACT

Recently, there has been much controversy over the International Association of Athletics Federation (IAAF) regulations regarding eligibility to compete and natural testosterone levels in female athletes. Much interest lies in the analysis of Caster Semenya's extraordinary performance. The objective of this work were, a) Complete an analysis of Caster Semenya's results during the 800m finals and b) search for existing similar performances by other female athletes. We analysed the results of the finals of all IAAF World Championships and Olympic Games from 1984–2016, including the 800m results of the Diamond Leagues 2016–2018. Exponential curves were fit to the data to characterise and predict performance for each event. Caster Semenya's finishing times before her ineligibility to compete and after the suspension of the IAAF hyperandrogenism regulation were found to be 1.24% and 1.49%, respectively, faster than the characteristic performance of the elite-standard in the women’s 800m final. Other female athletes, with finishing times faster than the ones predicted by the characteristic curves were also discovered. The percentage difference in performance between Caster Semenya and the other participants did not reach 3% in the 800m event. No conclusions can be drawn regarding extraordinary results ever performed during the 100m, 200m or 400m finals.  相似文献   
62.
Aim was to identify critical load (CL) in young and elderly apparently healthy male cohorts. To contrast the metabolic, cardiovascular and perceptual responses on CL according to age. We evaluated 12 young (23 ± 3 years) and 10 elderly (70 ± 2 years) apparently healthy active males, who underwent: (1) 1 repetition maximum (1RM) test on a 45° Leg Press; (2) on different days, three high-intensity resistance exercise constant load tests (60%, 75% and 90% 1RM) until fatigue (Tlim). Absolute values of both the CL asymptote and curvature constant (kg) were significantly lower in elderly subjects (P < 0.05). In contrast, elderly subjects demonstrated a significantly higher number of repetitions at CL when compared with young subjects (P < 0.05). As expected, oxygen uptake (VO2) and heart rate (HR) during maximal aerobic exercise testing were significantly reduced in older subjects. However, percent-predicted aerobic capacity were higher in older subjects (P < 0.05). In addition, blood lactate ([La?]) corrected to Tlim and rating of perceived exertion values were greater in younger subjects at all intensities (P < 0.05). These findings, despite reduced force production in older subjects, endurance-related parameters are well preserved according to age-adjusted percent-predicted values in apparently healthy males.  相似文献   
63.
A motor skills assessment could be helpful in talent development by estimating essential perceptuo-motor skills of young players, which are considered requisite to develop excellent technical and tactical qualities. The Netherlands Table Tennis Association uses a motor skills assessment in their talent development programme consisting of eight items measuring perceptuo-motor skills specific to table tennis under varying conditions. This study aimed to investigate this assessment regarding its reproducibility, internal consistency, underlying dimensions and concurrent validity in 113 young table tennis players (6–10 years). Intraclass correlation coefficients of six test items met the criteria of 0.7 with coefficients of variation between 3% and 8%. Cronbach’s alpha valued 0.853 for internal consistency. The principal components analysis distinguished two conceptually meaningful factors: “ball control” and “gross motor function.” Concurrent validity analyses demonstrated moderate associations between the motor skills assessment’s results and national ranking; boys r = ?0.53 (< 0.001) and girls r = ?0.45 (= 0.015). In conclusion, this evaluation demonstrated six test items with acceptable reproducibility, good internal consistency and good prospects for validity. Two test items need revision to upgrade reproducibility. Since the motor skills assessment seems to be a reproducible, objective part of a talent development programme, more longitudinal studies are required to investigate its predictive validity.  相似文献   
64.
Academic writing can seem a daunting prospect although with the right support and information it can be more achievable than you think. In this first set of editorial comments of 2016, editors from all sections of the Health Information and Libraries Journal outline the origins of the individual section of the journal which they oversee and highlight some of the things you might want to consider when thinking of submitting your writing for publication.  相似文献   
65.
Big data, like MOOCs, altmetrics and open access, is a term that has been commonplace in the library community for some time yet, despite its prevalence, many in the library and information sector remain unsure of the relationship between big data and their roles. This editorial explores what big data could mean for the day‐to‐day practice of health library and information workers, presenting examples of big data in action, considering the ethics of accessing big data sets and the potential for new roles for library and information workers.  相似文献   
66.
Public libraries across the country design and deliver programs for military veterans and their families, often collaborating with other organizations and agencies. The examples were assembled from both general and specialized interviews with librarians, and literature and Internet searches, with summaries of programs assembled and written by multiple researchers. The specific limitations on the listing in this article are clearly outlined in the first section. Overall, however, the article provides a good introductory overview of what’s going on in veteran’s programs and services in America’s public libraries in over seventy libraries in forty states. We hope this list of what public libraries have organized or are doing will supply other public librarians with ideas on how to provide new services or enhance their existing ones.  相似文献   
67.
ABSTRACT

Librarians at Linköping University help researchers keep abreast of developments in their fields and to increase the visibility of their work. Strategic, professional use of social media ought to be an essential part of a researcher's communication strategy. This article investigates the level of awareness of the professional use of social media among LiU researchers. The investigation showed that use of social media was not significant; however, a small number saw potential. The purpose of this article is threefold. The first purpose was to evaluate the potential of using social media as a tool for communicating research outside LiU. Second, the article presents a study in which views of LiU researchers on social media were ascertained via seminar discussions, informal feedback, and interviews. The study has a case study approach involving eight researchers. Third, the article covers how LiU Library created a web-based information package to support researchers in social media use.  相似文献   
68.
Web-scale discovery services (WSDs) are a widespread phenomenon sweeping university libraries across the world. In this article the authors discuss this trend and their experience working on a test server with the open source discovery layer VuFind. Developed by Demian Katz of Villanova University, VuFind’s potential to index not only the library’s catalog but also proprietary databases through the integration of application program interfaces (APIs) offers public libraries the opportunity to develop a seamless website-to-catalog experience, thereby building a true virtual branch for their patrons.  相似文献   
69.
The oil painting “La Medusa” executed by Caravaggio at the end of the XVI century on a wooden shield, was investigated by integrated physical–chemical and analytical methodologies in order to obtain scientific data capable of elucidating the state of conservation and the painting technique. Optical (OM) and electronic (SEM-EDS) microscopy, micro-FT-IR spectroscopy, gas chromatography–mass spectrometry (GC–MS) and pyrolysis GC–MS were applied on two microfragments and some organic samples obtained by solvent extraction using the swab cleaning technique. The obtained results indicated that Caravaggio probably reused an old shield as a previous gypsum preparation layer has been detected under the original painting layers. He used white lead, natural earths, verdigris and lead–tin yellow type I mixed with drying oils to paint. The considerable amount of amorphous particles of copper chlorides found in the green pigment verdigris suggests that it could have been produced according to the ancient recipe of verde salsum described by Theophilus. Mordant gilding has been identified on the upper part of the shield that can be related to an abandoned experiment to give the painting a mirror-like reflecting effect. Three different varnishes layers have been detected above the painted surface. The original and restoration varnishes have been identified and they contain a mixture of drying oil, mastic and turpentine and some beeswax. Cleaning tests, performed with different organic solvents, suggest the use of isopropyl alcohol as cleaning agent because it is less efficient in comparison to others solvents; thus it ensures a careful and controlled removal of the varnishes.  相似文献   
70.
This paper introduces a framework and methodology for establishing indicators and metrics in order to assess the quality and performance of one-stop e-Government service offerings. The set of quality and performance indicators and metrics proposed has been derived in an outcomes assessment approach, based on the perspectives of e-Government service providers and end-users and following a goal-question-metric line of work that departs from some key quality and performance benefits. A methodology that employs the proposed framework to set improvement targets according to alternative scenarios is presented, and a strategy is elaborated for analyzing root causes of potential quality and performance shortcomings and undertaking appropriate countermeasures. Some results of application in a real case study, in the context of an EU-funded R&D project, are also provided. Finally, recommendations are given about usefulness of the proposed approach for e-Government service providers, as well as policy and decision-makers, and directions of future work are discussed in order to enhance the conceptual coverage of this approach, while at the same time not compromising its simplicity of application and generality of purpose.  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