全文获取类型
收费全文 | 14724篇 |
免费 | 214篇 |
国内免费 | 12篇 |
专业分类
教育 | 10318篇 |
科学研究 | 1745篇 |
各国文化 | 122篇 |
体育 | 1044篇 |
综合类 | 17篇 |
文化理论 | 171篇 |
信息传播 | 1533篇 |
出版年
2021年 | 139篇 |
2020年 | 215篇 |
2019年 | 291篇 |
2018年 | 417篇 |
2017年 | 440篇 |
2016年 | 397篇 |
2015年 | 262篇 |
2014年 | 387篇 |
2013年 | 2490篇 |
2012年 | 342篇 |
2011年 | 330篇 |
2010年 | 318篇 |
2009年 | 286篇 |
2008年 | 304篇 |
2007年 | 315篇 |
2006年 | 301篇 |
2005年 | 257篇 |
2004年 | 286篇 |
2003年 | 246篇 |
2002年 | 259篇 |
2001年 | 326篇 |
2000年 | 348篇 |
1999年 | 266篇 |
1998年 | 150篇 |
1997年 | 197篇 |
1996年 | 191篇 |
1995年 | 133篇 |
1994年 | 148篇 |
1993年 | 135篇 |
1992年 | 217篇 |
1991年 | 203篇 |
1990年 | 229篇 |
1989年 | 234篇 |
1988年 | 199篇 |
1987年 | 217篇 |
1986年 | 189篇 |
1985年 | 233篇 |
1984年 | 175篇 |
1983年 | 159篇 |
1982年 | 144篇 |
1981年 | 141篇 |
1980年 | 136篇 |
1979年 | 201篇 |
1978年 | 159篇 |
1977年 | 130篇 |
1976年 | 106篇 |
1975年 | 103篇 |
1974年 | 111篇 |
1973年 | 110篇 |
1971年 | 100篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
Markus Keidl Alfons Kemper Donald Kossmann und Alexander Kreutz 《Informatik - Forschung und Entwicklung》2002,17(3):123-134
Zusammenfassung. Wir pr?sentieren in dieser Arbeit das ObjectGlobe-System, ein offenes und verteiltes Anfragebearbeitungssystem auf Internet-Datenquellen.
ObjectGlobe erweitert die begrenzten F?higkeiten des Internets bezüglich Anfragebearbeitung, indem es einen offenen Marktplatz
schafft, in dem eine Vielzahl von Anbietern Rechenzeit, Daten und Anfrageoperatoren bereitstellen. Den Schwerpunkt dieses
Beitrags bildet die im Rahmen des ObjectGlobe-Projekts entwickelte Metadatenverwaltung MDV, ein verteiltes Metadaten-Management-System.
Es besitzt eine 3-schichtige Architektur und unterstützt Caching und Replikation in der Mittelschicht, so dass Anfragen lokal
ausgewertet werden k?nnen. Benutzer spezifizieren die Informationen, die sie ben?tigen und die repliziert werden, mit Hilfe
einer besonderen Regelsprache. Um Replikate aktuell zu halten und die Replikation von neuen und relevanten Informationen anzusto?en,
verwendet das MDV-System einen neuartigen Publish & Subscribe-Algorithmus. Wir beschreiben diesen Algorithmus im Detail und
zeigen, wie er mit Hilfe eines normalen relationalen Datenbanksystems implementiert werden kann.
Eingegangen am 19. November 2001 / Angenommen am 30. Juli 2002 相似文献
34.
The roles of academic health sciences librarians are continually evolving as librarians initiate new programs and services in response to developments in computer technology and user demands. However, statistics currently collected by libraries do not accurately reflect or measure these new roles. It is essential for librarians to document, measure, and evaluate these new activities to continue to meet the needs of users and to ensure the viability of their professional role. To determine what new measures should be compiled, the authors examined current statistics, user demands, professional literature, and current activities of librarians as reported in abstracts of poster sessions at Medical Library Association annual meetings. Three new categories of services to be measured are proposed. The first, consultation, groups activities such as quality filtering and individual point-of-need instruction. The second, outreach, includes activities such as working as liaisons, participating in grand rounds or morning report, and providing continuing education. The third area, Web authoring, encompasses activities such as designing Web pages, creating online tutorials, and developing new products. Adding these three measures to those already being collected will provide a more accurate and complete depiction of the services offered by academic health sciences librarians. 相似文献
35.
This study examined the argument patterns that result when Israeli-Jews and Palestinians confront each other during group dialogues. We tested predictions derived from two theories. The first was a theory of cultural communication which predicted that Israeli-Jews and Palestinians would argue in a manner consistent with their respective cultural communication codes known as dugri and musayra respectively. Thus, the Israeli-Jews were expected to be assertive and the Palestinians more accommodating. The second theory was rooted in majority/minority power relations and predicted the opposite. The data were generated from reconciliation-based dialogue groups of Israeli-Jews and Palestinians. Communicative acts were coded according to the Conversational Argument Coding Scheme. Analysis of covariance was used to determine which patterns of argument distinguished the groups, and to identify variance attributable to lag sequences and individuals. The results were supportive of predictions from majority/minority power relations. 相似文献
36.
The many challenges faced by health sciences libraries of all types and sizes often require innovative solutions. When an innovative solution involves calculated risk taking, the approach is called intrapreneurial. At the University of Miami School of Medicine, an intrapreneurial approach solved the fiscal problems of the biomedical communications unit. The Louis Calder Memorial Library inherited these problems when the Department of the Library and Biomedical Communications was created in the early 1980s. In this paper, two intrapreneurial programs are described, and the benefit and suitability of this management style to information services are demonstrated. 相似文献
37.
38.
S. Ramasesha 《Resonance》2009,14(8):782-798
Efficient lighting and display have become important concerns in the energy-starved modern world. This has led to new paradigms
in lighting and display technologies. Organic molecules provide a new class of active materials for such technologies. This
article gives the basic science behind the design of such molecular materials used in displays and lighting. 相似文献
39.
Nicole S. Ofiesh Charles Hughes Sally S. Scott 《Learning disabilities research & practice》2004,19(1):57-70
The most frequently requested accommodation among students with learning disabilities (LD) in postsecondary settings is extended test time. The frequency with which this accommodation is requested and granted compels disability service providers to become knowledgeable about the factors that influence the need for, and appropriateness of, the accommodation. Moreover, the synthesis of these factors becomes the basis for determining if the accommodation is reasonable under federal law. The purpose of this article is to present a step‐by‐step model to be used as a decision‐making process when considering the accommodation of extended test time for postsecondary students with LD. The model is designed to assist disability service providers in the analysis and synthesis of information collected from (1) the student's diagnostic evaluation, (2) the course or classroom test to be accommodated, and (3) student interviews. A list of diagnostic tests from the four most frequently administered test batteries used with adults is provided, along with a concise explanation of how characteristics of LD impact reading, writing, and math, and relate to the need for extended time. This information can be used to determine if extended test time is a reasonable accommodation and to estimate how much additional time to provide. 相似文献
40.