首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21054篇
  免费   28篇
  2020年   9篇
  2019年   10篇
  2018年   3493篇
  2017年   2827篇
  2016年   2255篇
  2015年   201篇
  2014年   84篇
  2013年   182篇
  2012年   577篇
  2011年   2390篇
  2010年   2528篇
  2009年   1482篇
  2008年   1716篇
  2007年   2181篇
  2006年   42篇
  2005年   220篇
  2004年   175篇
  2003年   120篇
  2002年   76篇
  2001年   52篇
  2000年   61篇
  1999年   27篇
  1998年   29篇
  1997年   27篇
  1996年   17篇
  1995年   9篇
  1994年   15篇
  1993年   13篇
  1992年   10篇
  1991年   9篇
  1990年   16篇
  1989年   11篇
  1987年   8篇
  1986年   9篇
  1985年   12篇
  1984年   6篇
  1983年   11篇
  1982年   6篇
  1980年   6篇
  1979年   9篇
  1978年   10篇
  1977年   11篇
  1976年   6篇
  1973年   9篇
  1972年   7篇
  1971年   7篇
  1970年   6篇
  1969年   9篇
  1968年   10篇
  1950年   11篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
41.
42.
The termmultimedia refers to the combined use of different media of communication, and originally belonged primarily to the fields of entertainment and education. Advances in computer, audio, and video technology have now brought multimedia possibilities to the individual. Further, they give the user control over what happens. Suchinteractive multimedia systems offer the user personal access to large amounts of information, including pictures, graphics, video, text, and audio. The potential range of applications is very broad, from simple interactions where the user will merely make occasional choices and then sit back and view sections of program material, to more purposeful interactions where the application can help the user to achieve a goal. This article describes research onknowledge-based interactive multimedia systems. Targeted on the new Compact Disc Interactive format, we have protyped an advisor which will help the user to tackle a typical domestic task. The necessary decision-making process can be enlivened by multimedia interaction, and placed on solid ground by the inclusion of expert advice.  相似文献   
43.
This paper describes a possible near-death experience (NDE) among the Mapuche people of Chile. The individual reporting the experience was in a cataleptic-like state for two days, the experience itself occurring at the end of this period. Some common features of NDEs, such as encounters with deceased people and being sent back, are present, together with clear evidence that past and present cultural environment shape in part the content of mental experiences.This work was funded in part by the University of Chile (DTI Project Q-3064).The author thanks Editorial Andrés Bello for permissionto translate the near death account into English.  相似文献   
44.
45.
46.
The essay examines the argument advanced by E.D. Hirsch, Jr., for instituting ‘cultural literacy’ as a fundamental priority of schools. A number of confusions and equivocations in Hirsch's reasoning are identified, and the propensity of his project to indoctrinate is exposed. Among the features of Hirsch's argument shown to be troubling are his shifting construal of ‘language’, his inconsistency about the requirements of cultural literacy, and his uncritical relation to traditional images of the American past and present. The upshot is to raise the question why Hirsch's project has elicited wide support and praise.  相似文献   
47.
The cellular expression of S-100β protein is upregulated in Alzheimer's disease and in Down's syndrome, and this protein has been implicated in memory-related processes in laboratory animals. However, the possibility that the α subunit of S-100 is also involved in memory has not yet been examined. In the present study, day-old black Australorp white Leghorn cockerel chicks (Gallus domesticus) received injections of monoclonal antisera to S-100α (1:50) or S-100β (1:500) into each hemisphere immediately after training on a one-trial passive avoidance task. The chicks displayed significantly lower retention levels than control birds that had been injected with antisera to carbonic anhydrase, or with saline (p< .01). S-100α antisera had an amnestic effect when injected between 0 and 20 min after training, with memory deficits occurring from 30 min postlearning, at the point of transition between the A and the B phases of the Gibbs-Ng intermediate memory stage. By contrast, the S-100β antisera needed to be injected either 5 min before or immediately after training and produced amnesia 10 min earlier, at the start of the A phase of the intermediate memory stage. We conclude that the two subunits of the S-100 protein are required at different points in the sequence of events leading to the consolidation of passive avoidance memory.  相似文献   
48.
Given a 1-ary sentence operator , we describe L - another 1-ary operator - as as a left inverse of in a given logic if in that logic every formula is provably equivalent to L. Similarly R is a right inverse of if is always provably equivalent to R. We investigate the behaviour of left and right inverses for taken as the operator of various normal modal logics, paying particular attention to the conditions under which these logics are conservatively extended by the addition of such inverses, as well as to the question of when, in such extensions, the inverses behave as normal modal operators in their own right.  相似文献   
49.
50.
How can we explain that an assertion on something perceived can be understood in the same manner by somebody who cannot perceive that scene? This problem bases the interest in computational linguistics in how listener modeling could possibly be harmonized with reference semantics. Mental images substituting real perception appear as a way out. The architecture of the listener model has to be adapted to the creation and use of such pictorial data structures. Furthermore, the relation between the latter and a verbal (i. e., propositional) representation must be understood. The resulting architecture of a listener model with reference semantics can be employed to solve communicational problems from three general classes in a better way, as is demonstrated by an example implementation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号