全文获取类型
收费全文 | 25806篇 |
免费 | 451篇 |
国内免费 | 254篇 |
专业分类
教育 | 17408篇 |
科学研究 | 3098篇 |
各国文化 | 240篇 |
体育 | 1773篇 |
综合类 | 512篇 |
文化理论 | 102篇 |
信息传播 | 3378篇 |
出版年
2022年 | 202篇 |
2021年 | 444篇 |
2020年 | 428篇 |
2019年 | 450篇 |
2018年 | 591篇 |
2017年 | 635篇 |
2016年 | 577篇 |
2015年 | 610篇 |
2014年 | 918篇 |
2013年 | 3889篇 |
2012年 | 1128篇 |
2011年 | 1202篇 |
2010年 | 1082篇 |
2009年 | 1039篇 |
2008年 | 1071篇 |
2007年 | 1112篇 |
2006年 | 1128篇 |
2005年 | 937篇 |
2004年 | 565篇 |
2003年 | 575篇 |
2002年 | 514篇 |
2001年 | 606篇 |
2000年 | 455篇 |
1999年 | 398篇 |
1998年 | 242篇 |
1997年 | 215篇 |
1996年 | 237篇 |
1995年 | 186篇 |
1994年 | 177篇 |
1993年 | 158篇 |
1992年 | 240篇 |
1991年 | 214篇 |
1990年 | 242篇 |
1989年 | 219篇 |
1988年 | 177篇 |
1987年 | 185篇 |
1986年 | 191篇 |
1985年 | 177篇 |
1984年 | 183篇 |
1983年 | 169篇 |
1982年 | 136篇 |
1981年 | 136篇 |
1980年 | 132篇 |
1979年 | 190篇 |
1978年 | 160篇 |
1977年 | 112篇 |
1976年 | 119篇 |
1975年 | 111篇 |
1973年 | 104篇 |
1971年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
L Darling 《Bulletin of the Medical Library Association》1966,54(4):311-315
This paper supplements information given in earlier papers on the UCLA MEDLARS Search Station. Four major machine problem areas in the operation of a decentralized station are identified: adjustments required to run a large information retrieval type program in an academic computing facility serving many users; handicap in running time for COBOL programs; advent of the third generation of computers with attendant preparation; and need for constant current communication among all members of a decentralized network system. Statistics are given for the initial operating period, January-May 1966: 119 search requests received, 109 formulated, and 60 fully processed. Parallel searches with other MEDLARS installations, comparisons of MEDLARS and manual Index Medicus searches, and other search activities are reported. 相似文献
42.
L S Mullins 《Bulletin of the Medical Library Association》1966,54(3):230-242
Adequate research in the peripheral field of medical geography requires familiarity with the literature of medicine, geography, and other environmentally oriented fields. The pertinent literature of the two primary disciplines, as well as that of anthropology, nutrition, and human bioclimatology, is surveyed from a bibliographical point of view. A brief review of historical sources is presented, followed by a discussion of the contemporary organizations, both international and national, active in the field. Emphasis is placed on the publishing programs and projects, maps, atlases, symposia, reports, and other literature sponsored or stimulated by these organizations. Regional bibliographical surveys for East Africa, India, and the Soviet Union are also noted. Pertinent aspects of bibliographies, indexes, abstracts, library card catalogs and accession lists, and other resources are listed, with emphasis on the various subject headings and other approaches to them. Throughout, the sources of information are approached from a multidisciplinary and interdisciplinary viewpoint. 相似文献
43.
44.
45.
Tseng SC Arcand JL Brugger JM Finn M Olson AJ Somers S 《Library resources & technical services》1990,34(2):139-157
Serials, one of the more complicated areas of library technical endeavors, has lacked the benefit of standards for a long time. Even now, with standards beginning to be available, the majority of institutions are not working within standard serials formats. A survey to determine the use of serials standards in libraries was conducted in 1988 by the American Library Association, Resources and Technical Services Division, Serials Section, Committee to Study Serials Standards. In the spring of 1988 a survey was sent to a group encompassing the Association of Research Libraries members, CONSER participants, United States Newspaper Program participants, Microform Project libraries, and some vendors and librarians who attended the Committee meetings on a regular basis. The survey questionnaire assessed the current level of serials standards awareness of librarians and vendors. Topics included the type of serials systems used, standards relevant to serials control and union listing and whether or not they are implemented, types and levels of training staff received in the application of standards, benefits of the standards, and areas where standards are most needed. 相似文献
46.
47.
48.
49.
澳大利亚政府十分重视鼓励国民阅读和发展健康的图书业,这一点在其政策与法律上都有鲜明的体现.例如,该国艺术与体育部委托澳大利亚艺术委员会(Australia Council for the Ans)运作"Books Alive"项目,通过这一项目让澳大利亚本土作家的作品能够为广大读者所了解. 相似文献
50.
专利是知识产权的重要组成部分,通过专利引文分析获取有价值的信息具有重要的意义。但是在科技日益发达的的今天,专利信息如海潮般涌向我们,如何从纷繁复杂的专利信息中收集对用户有用的信息,才是我们所关注的。文章主要围绕数据挖掘技术在专利引文分析中的应用以及意义展开了讨论。 相似文献