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   16126篇
  免费   228篇
  国内免费   120篇
教育   11037篇
科学研究   2137篇
各国文化   118篇
体育   1405篇
综合类   11篇
文化理论   138篇
信息传播   1628篇
  2021年   120篇
  2020年   227篇
  2019年   334篇
  2018年   456篇
  2017年   401篇
  2016年   405篇
  2015年   256篇
  2014年   331篇
  2013年   2778篇
  2012年   316篇
  2011年   355篇
  2010年   254篇
  2009年   256篇
  2008年   259篇
  2007年   294篇
  2006年   284篇
  2005年   277篇
  2004年   263篇
  2003年   255篇
  2002年   244篇
  2001年   262篇
  2000年   277篇
  1999年   283篇
  1998年   146篇
  1997年   155篇
  1996年   188篇
  1995年   177篇
  1994年   137篇
  1993年   149篇
  1992年   225篇
  1991年   229篇
  1990年   234篇
  1989年   260篇
  1988年   212篇
  1987年   233篇
  1986年   224篇
  1985年   254篇
  1984年   228篇
  1983年   213篇
  1982年   184篇
  1981年   176篇
  1980年   162篇
  1979年   247篇
  1978年   197篇
  1977年   191篇
  1976年   157篇
  1975年   135篇
  1974年   153篇
  1973年   137篇
  1971年   119篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
71.
This study sought to determine if exposure to two communication-oriented activities, videotapes and public service announcements, accounts for changes in substance use among adolescents participating in the Drug Resistance Strategies Project's keepin' it REAL adolescent substance use prevention curriculum. Middle-school students (4,734, 72% Latino) responded to questionnaires related to these analyses. An analysis of covariance (ANCOVA) model was fit separately to six substance use outcomes. The results suggested that intervention students who saw four or five videos engaged in less substance use in the past month than did students who saw fewer videos. Having seen the PSAs one or more times did not predict the reported change in substance use.  相似文献   
72.
The University of Colorado at Boulder Libraries used participatory management to reduce a special collections backlog. Without an increase in budget or staffing, technical and public services departments designed a pilot project to redeploy internal human resources in a collaborative manner. The process of backlog management is discussed.  相似文献   
73.
74.
75.
OBJECTIVES: The objective is to highlight the important role that librarians have in teaching within a successful medical informatics program. Librarians regularly utilize skills that, although not technology dependent, are essential to conducting computer-based research. The Metropolis analogy is used to introduce the part librarians play as informatics partners. Science fiction is a modern mythology that, beyond a technical exterior, has lasting value in its ability to reflect the human condition. The teaching of medical informatics, an intersection of technology and knowledge, is also most relevant when it transcends the operation of databases and systems. Librarians can teach students to understand, research, and utilize information beyond specific technologies. METHODS: A survey of twenty-six informatics programs was conducted during 2002, with specific emphasis on the role of the library service. RESULTS: The survey demonstrated that librarians currently do have a central role in informatics instruction, and that library-focused skills form a significant part of the curriculum in many of those programs. In addition, librarians have creative opportunities to enhance their involvement in informatics training. As a sample program in the study, the development of the informatics course at the Massachusetts College of Pharmacy and Health Sciences is included. CONCLUSIONS: Medical informatics training is a wonderful opportunity for librarians to collaborate with professionals from the sciences and other information disciplines. Librarians' unique combination of human research and technology skills provides a valuable contribution to any program.  相似文献   
76.
keystone公司长期停滞的ERP项目终于宣告成功, 系统将 130 个厂房,全美国2000 多员工连接在一起。回首keystone 信息化历程,其经验教训值得我们深思。  相似文献   
77.
Bast fibres have been commonly used as a textile material in Northern Europe since Neolithic times. However, the process of identifying the different species has been problematic, and many important questions related to their cultural history are still unanswered. For example, a modified Herzog test and the presence of calcium oxalate crystals have both been used in identification. In order to generate more reliable results, further research and advancement in multi-methodological methods is required. This paper introduces a combination of methods which can be used to identify and distinguish flax (Linum usitatissimum), hemp (Cannabis sativa), and stinging nettle (Urtica dioica). The research material consisted of reference fibres and 25 fibre samples obtained from 12 textiles assumed to be made of nettle. The textiles were from the Finno-Ugric and Historical Collections of The National Museum of Finland. The fibre samples were studied by observing the surface characteristics and cross sections with transmitted light microscopy, and by using a modified Herzog test with polarized light, in order to identify the distinguishable features in their morphological structures. The study showed that five out of 25 samples were cotton, 16 nettle, one flax, and one hemp. Findings from two samples were inconsistent. The results show that it is possible to distinguish common north European bast fibres from each other by using a combination of microscopic methods. Furthermore, by utilizing these combined methods, new and more reliable information could be obtained from historical ethnographic textiles, which creates new vistas for the interpretation of their cultural history.  相似文献   
78.
This paper analyses the publication patterns of researchers in the field of applied sciences at Universities of Technology in South Africa. Aspects investigated include publications in SCOPUS-listed journals; number of citations and countries of publication. Collaborative research patterns at national and international levels were also investigated. A bibliometric analysis approach was followed using SCOPUS as the main source of data and analysing the articles published in selected applied science disciplines. Results show that researchers in the field of applied sciences in universities of technology have increased their number of publications over the past 10?years and are also working in conjunction with other researchers both nationally and internationally. The analysis is an important addition to the field in South Africa which helps in measuring how institutions are positively responding to government incentives in research. The results are also important to information professionals who are increasingly playing an important role in research impact assessments.  相似文献   
79.
In 2008 Meier and Conkling first tested Google Scholar's coverage of the engineering literature against citations gathered from the Compendex database. Since that time, other studies have used the same methodology and found improvement in Google Scholar's coverage. This study uses engineering dissertations from Proquest Dissertations & Theses to create a data set of citations for the comparison of fee-based databases, Compendex and Scopus, against Google Scholar. From 1950 to 2017 Google Scholar outperformed both Compendex and Scopus in discoverability of citations in nine engineering subjects. These results have implications for collection management and information literacy program planning for librarians.  相似文献   
80.
The purpose of this study was to examine the outcomes of information literacy instruction for the Design first year students at the Temasek Polytechnic Library. Also of interest was whether or not the librarian was being seen as easily approachable, and if the students were deeming the lessons to be worthwhile. A participant action research approach was used, with the data being collected from multiple choice tests delivered via the institutional learning management system, group exercises, and a diagnostic assessment that was delivered before the workshops. It was found that the students did see the librarian as someone who was eminently approachable, and the majority of them found the lessons to be of value. It was concluded that the use of a diagnostic tool can be very useful in highlighting the gaps in students' knowledge, and that it would be beneficial to use it for all information literacy instruction at TP. Suggested future research could include a study of how much the students retain of IL skills into their third year of study.  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