全文获取类型
收费全文 | 44272篇 |
免费 | 1727篇 |
国内免费 | 31篇 |
专业分类
46030篇 |
出版年
2020年 | 490篇 |
2019年 | 649篇 |
2018年 | 886篇 |
2017年 | 929篇 |
2016年 | 929篇 |
2015年 | 676篇 |
2014年 | 796篇 |
2013年 | 3843篇 |
2012年 | 1396篇 |
2011年 | 1552篇 |
2010年 | 982篇 |
2009年 | 1016篇 |
2008年 | 1388篇 |
2007年 | 1319篇 |
2006年 | 1272篇 |
2005年 | 1110篇 |
2004年 | 1031篇 |
2003年 | 1090篇 |
2002年 | 1031篇 |
2001年 | 1425篇 |
2000年 | 1375篇 |
1999年 | 1046篇 |
1998年 | 543篇 |
1997年 | 488篇 |
1996年 | 470篇 |
1995年 | 452篇 |
1994年 | 443篇 |
1993年 | 437篇 |
1992年 | 849篇 |
1991年 | 837篇 |
1990年 | 781篇 |
1989年 | 719篇 |
1988年 | 665篇 |
1987年 | 683篇 |
1986年 | 663篇 |
1985年 | 760篇 |
1984年 | 622篇 |
1983年 | 499篇 |
1982年 | 416篇 |
1981年 | 425篇 |
1979年 | 559篇 |
1978年 | 452篇 |
1977年 | 421篇 |
1976年 | 404篇 |
1975年 | 504篇 |
1974年 | 522篇 |
1973年 | 553篇 |
1972年 | 442篇 |
1968年 | 404篇 |
1966年 | 411篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
D M Fragaszy S R Mitchell 《Journal of comparative psychology (Washington, D.C. : 1983)》1990,104(3):275-282
Patterns of manual preference and the extent to which preference provided a benefit in performance (movement time) were evaluated in 7 young adult capuchin monkeys (Cebus apella). Directions of preference were inconsistent within individual animals across home-cage activities, unimanual, and bimanual experimental tasks. Preferences were more strongly expressed in the experimental tasks than in the home cage. A left bias in the population for prehension, predicted by recent theories, was not evident in any setting. Movement time was moderately negatively correlated with degree of preference within experimental tasks. The benefit to performance conferred by lateral preference was not dependent on whether the right or left hand was preferred. Lateralization of prehension appears to be a flexible process in these monkeys, which can result in quickly realized benefits in some conditions. 相似文献
993.
994.
M.A.S. Abdel Haleem 《Islam & Christian-Muslim Relations》1990,1(2):171-191
The story of Joseph in the Qur'an has been approached by many non‐Muslim writers1 who were content to list which details of the biblical story have been missed out from the biblical story and which points have been added, maintaining that these had their origins in biblical or other Jewish sources. Our treatment here concentrates on the texts of the story in the Qur'an and the Old Testament, attempting to identify the differing functions and preoccupations of the two accounts in their respective contexts, to show how this difference affects the choice of material and the treatment given to it. This article concludes that the two versions should be approached by readers, Muslims and non‐Muslims, with this difference in mind in order to appreciate the message and the qualities of each. 相似文献
995.
996.
K. Blokker S. Bruin J. Bryden I. Houseman C. Okkerse C. Van der Meer A. P. Verkaik 《Knowledge, Technology, and Policy》1990,3(3):76-83
In this article the perspective shifts to the “upstream” end of the agricultural knowledge and information system (AKIS).
Because knowledge policy and strategic decision-making are not the prerogative of the public sector, organizations such as
cooperative unions and multinational companies are included. After considering the influence of the changing environment on
the nature of the AKIS, the role of knowledge management and policy in the emerging knowledge and information market is examined.
Special attention is given to public and private R&D. The article then looks where information technology (IT) fits in and
what considerations determine strategic investment in IT projects and sustained services. Some of the European experiences
with this strategic investment are evaluated. 相似文献
997.
What we usually think of as higher order skills in argumentation can be profitably viewed as systematic structures for organizing and representing information. Standard terms like line of argument, synthesis, analysis and draft can be viewed as ways of constructing, storing, and accessing data in a social context — data structures for social communication. What makes argument difficult are the multiple structures that arguers have to construct and negotiate when reading and composing. In this paper, we describe the WARRANT project, a project designed to identify data structures of written argument and to design and implement computer tools to aid in the reading and design of argument. 相似文献
998.
Hardware and software modifications are presented that allow for collection and recognition by a Commodore computer of spoken responses. Responses are timed with millisecond accuracy and automatically analyzed and scored. Accuracy data for this device from several experiments are presented. Potential applications and suggestions for improving recognition accuracy are also discussed. 相似文献
999.
1000.