全文获取类型
收费全文 | 18690篇 |
免费 | 158篇 |
国内免费 | 22篇 |
专业分类
教育 | 12540篇 |
科学研究 | 2999篇 |
各国文化 | 177篇 |
体育 | 1251篇 |
综合类 | 13篇 |
文化理论 | 177篇 |
信息传播 | 1713篇 |
出版年
2021年 | 148篇 |
2020年 | 194篇 |
2019年 | 323篇 |
2018年 | 451篇 |
2017年 | 482篇 |
2016年 | 507篇 |
2015年 | 352篇 |
2014年 | 352篇 |
2013年 | 3136篇 |
2012年 | 448篇 |
2011年 | 466篇 |
2010年 | 355篇 |
2009年 | 293篇 |
2008年 | 346篇 |
2007年 | 322篇 |
2006年 | 268篇 |
2005年 | 908篇 |
2004年 | 740篇 |
2003年 | 517篇 |
2002年 | 352篇 |
2001年 | 294篇 |
2000年 | 273篇 |
1999年 | 244篇 |
1998年 | 129篇 |
1997年 | 145篇 |
1996年 | 168篇 |
1995年 | 130篇 |
1994年 | 148篇 |
1993年 | 136篇 |
1992年 | 184篇 |
1991年 | 210篇 |
1990年 | 197篇 |
1989年 | 215篇 |
1988年 | 154篇 |
1987年 | 176篇 |
1986年 | 203篇 |
1985年 | 210篇 |
1984年 | 184篇 |
1983年 | 189篇 |
1982年 | 160篇 |
1981年 | 142篇 |
1980年 | 136篇 |
1979年 | 189篇 |
1978年 | 177篇 |
1977年 | 152篇 |
1976年 | 135篇 |
1975年 | 112篇 |
1974年 | 134篇 |
1973年 | 122篇 |
1971年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
H.E. Suess 《Endeavour》1980,4(3):113-117
Radiocarbon dating is, and remains, one of the most powerful methods of dating archaeological artefacts. Initially, it was assumed that the carbon-14 content of atmospheric carbon dioxide had remained constant, but latterly it has been shown that this assumption is not valid. It has now proved possible, mainly by correlation with tree-growth rings, to measure historic fluctuations in carbon-14 content and to make the necessary corrections—of up to one thousand years—to the conventionally calculated dates. 相似文献
993.
994.
995.
The current pattern of bibliographic control in audio-visual distributors' catalogs is described. Eight bibliographic control elements are defined, and the criteria for evaluating the occurrence of these elements in sixty-four sample catalogs are specified. When the distributors are grouped according to category, such as educational or commercial, the pattern of bibliographic control has three distinct clusters of elements. When the distributors are grouped by the number of titles handled, there is no clear pattern. The implications of these patterns are discussed in terms of practical library reference services. A solution to the problem of bibliographic control of health science audiovisual materials is proposed. 相似文献
996.
997.
998.
999.
This paper proposes a new interpretation of John Stuart Mill's notion of utility, which is used to provide a utilitarian justification for an eclectic, rather than a vocational, education. Vocational education is strongly promoted in recent policy documents, which makes it important to raise the question of justification. Many existing interpretations of Mill's utilitarianism argue for a hierarchy of pleasures. Although this enables one to justify an eclectic education, it is an interpretation that could be dismissed as ‘un‐utilitarian’. This paper proposes an alternative interpretation of Mill's notion of utility as a hierarchy of preferences. Our interpretation not only provides grounds for justifying an eclectic or critical education, it is also consistent with utilitarianism as an ethical theory. The paper also shows how the resultant curricula will better support democracy and participation in civil society. 相似文献
1000.