全文获取类型
收费全文 | 4769篇 |
免费 | 61篇 |
国内免费 | 10篇 |
专业分类
教育 | 3586篇 |
科学研究 | 247篇 |
各国文化 | 43篇 |
体育 | 423篇 |
综合类 | 3篇 |
文化理论 | 64篇 |
信息传播 | 474篇 |
出版年
2022年 | 26篇 |
2021年 | 45篇 |
2020年 | 60篇 |
2019年 | 115篇 |
2018年 | 150篇 |
2017年 | 157篇 |
2016年 | 154篇 |
2015年 | 104篇 |
2014年 | 119篇 |
2013年 | 974篇 |
2012年 | 141篇 |
2011年 | 129篇 |
2010年 | 153篇 |
2009年 | 138篇 |
2008年 | 153篇 |
2007年 | 153篇 |
2006年 | 111篇 |
2005年 | 102篇 |
2004年 | 107篇 |
2003年 | 85篇 |
2002年 | 99篇 |
2001年 | 69篇 |
2000年 | 111篇 |
1999年 | 78篇 |
1998年 | 75篇 |
1997年 | 69篇 |
1996年 | 76篇 |
1995年 | 59篇 |
1994年 | 69篇 |
1993年 | 64篇 |
1992年 | 53篇 |
1991年 | 73篇 |
1990年 | 58篇 |
1989年 | 48篇 |
1988年 | 41篇 |
1987年 | 47篇 |
1986年 | 47篇 |
1985年 | 49篇 |
1984年 | 52篇 |
1983年 | 41篇 |
1982年 | 33篇 |
1981年 | 36篇 |
1980年 | 32篇 |
1979年 | 25篇 |
1978年 | 33篇 |
1977年 | 39篇 |
1976年 | 27篇 |
1975年 | 25篇 |
1974年 | 23篇 |
1972年 | 16篇 |
排序方式: 共有4840条查询结果,搜索用时 46 毫秒
11.
12.
The Dynamics of Opinion Formation in Local Popular Referendums: Why the Dutch Always Say No 总被引:1,自引:0,他引:1
There is growing research on voting behavior in referendums.However, the dynamics of opinion formation in popular referendums,referendums initiated by the electorate to approve or rejectdecisions made by representative bodies, has not yet been studied.This is especially unfortunate as voting decisions in popularreferendums differ from those in other referendums in interestingways. Opinion formation can be a very dynamic process in popularreferendums, making the referendum campaign crucial. This paperstudies the dynamics of opinion formation in popular referendumsand relates them to particular characteristics of the campaignsand the issues at hand. Based on the literature, we consideredthe effects of the intensity of the yes and no campaigns, familiaritywith the issue, and partisan cues. Our study uses content analysisdata and data from public opinion surveys dealing with variouspopular referendums held in the Netherlands. The study revealedseveral factors that contributed to the volatility of opinionsin the referendum campaigns: the issue (new and did not fittraditional political schemes), lack of support from societaland community organizations for the position of the local authorities,and low profile campaigns on the part of local authorities.While some of these factors are general and may play a rolein referendums everywhere, some can be considered typicallyDutch, related to the characteristics of popular referendumsin the Netherlands and the countrys political system. 相似文献
13.
Peter Banks 《Learned Publishing》2004,17(2):135-142
The benefits claimed for open access publishing in the medical area are subjected to evaluation and question. It is represented that these benefits are, in many cases, illusory or doubtful. 相似文献
14.
Nigel Lees 《Learned Publishing》2004,17(3):189-194
An account is given of the effects of the EU Copyright Directive on the working of the library of a learned society and the changes in practices required to conform with it. 相似文献
15.
ABSTRACTControl of relative humidity (RH) for collections care is challenging in U.K. historic houses because they are often highly ventilated with poor heat retention, a porous building fabric and naturally tend to high (60–80%) RH if unheated. The significance of the building means that large-scale modifications and installation of air handling systems may be unfeasible and undesirable for the conservation of the building. In the late 1980s the National Trust, for English, Wales and Northern Ireland, investigated conservation heating as an RH control method that works with the natural environment of historic buildings, mimicking historic heating and requiring only modification of existing heating services or a light touch installation of new heating systems. The National Trust adopted conservation heating as its preferred method for environmental control in historic buildings from the 1990s. This method was presented at the IIC 1994 Ottawa congress on preventive conservation. Conservation heating has since been adopted by many historic house management organisations, particularly across north-west Europe, where it is well suited to the climate. This paper reviews conservation heating developments implemented by the National Trust since 1994, in response to a changing external context, new knowledge and developments in operational practice. 相似文献
16.
The purpose of this study is to find a theoretically grounded, practically applicable and useful granularity level of an algorithmically constructed publication-level classification of research publications (ACPLC). The level addressed is the level of research topics. The methodology we propose uses synthesis papers and their reference articles to construct a baseline classification. A dataset of about 31 million publications, and their mutual citations relations, is used to obtain several ACPLCs of different granularity. Each ACPLC is compared to the baseline classification and the best performing ACPLC is identified. The results of two case studies show that the topics of the cases are closely associated with different classes of the identified ACPLC, and that these classes tend to treat only one topic. Further, the class size variation is moderate, and only a small proportion of the publications belong to very small classes. For these reasons, we conclude that the proposed methodology is suitable to determine the topic granularity level of an ACPLC and that the ACPLC identified by this methodology is useful for bibliometric analyses. 相似文献
17.
Many studies demonstrate differences in the coverage of citing publications in Google Scholar (GS) and Web of Science (WoS). Here, we examine to what extent citation data from the two databases reflect the scholarly impact of women and men differently. Our conjecture is that WoS carries an indirect gender bias in its selection criteria for citation sources that GS avoids due to criteria that are more inclusive. Using a sample of 1250 U.S. researchers in Sociology, Political Science, Economics, Cardiology and Chemistry, we examine gender differences in the average citation coverage of the two databases. We also calculate database-specific h-indices for all authors in the sample. In repeated simulations of hiring scenarios, we use these indices to examine whether women's appointment rates increase if hiring decisions rely on data from GS in lieu of WoS. We find no systematic gender differences in the citation coverage of the two databases. Further, our results indicate marginal to non-existing effects of database selection on women's success-rates in the simulations. In line with the existing literature, we find the citation coverage in WoS to be largest in Cardiology and Chemistry and smallest in Political Science and Sociology. The concordance between author-based h-indices measured by GS and WoS is largest for Chemistry followed by Cardiology, Political Science, Sociology and Economics. 相似文献
18.
19.
20.
Within the school of thought known as Critical Thinking, identifying or finding missing assumptions is viewed as one of the principal thinking skills. Within the new subject in schools and colleges, usually called Critical Thinking, the skill of finding missing assumptions is similarly prominent, as it is in that subject's public examinations. In this article we examine how school‐ and college‐focused texts explain and teach ‘this very important skill’. The same texts also deal with the nature of assumptions, validity and the role of stated reasons in arguments, and the way these matters are tackled will also be examined in our inquiry. In addition we explore what respected contributors to the critical thinking movement have had to say about some of these issues. 相似文献