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   24128篇
  免费   969篇
  国内免费   11篇
  2020年   230篇
  2019年   298篇
  2018年   427篇
  2017年   447篇
  2016年   480篇
  2015年   377篇
  2014年   391篇
  2013年   2030篇
  2012年   709篇
  2011年   741篇
  2010年   442篇
  2009年   423篇
  2008年   564篇
  2007年   625篇
  2006年   548篇
  2005年   511篇
  2004年   481篇
  2003年   481篇
  2002年   509篇
  2001年   784篇
  2000年   745篇
  1999年   570篇
  1998年   241篇
  1996年   256篇
  1995年   232篇
  1992年   471篇
  1991年   479篇
  1990年   461篇
  1989年   428篇
  1988年   454篇
  1987年   410篇
  1986年   411篇
  1985年   432篇
  1984年   328篇
  1983年   310篇
  1982年   237篇
  1981年   236篇
  1979年   376篇
  1978年   286篇
  1977年   241篇
  1975年   296篇
  1974年   376篇
  1973年   383篇
  1972年   298篇
  1971年   291篇
  1970年   290篇
  1969年   259篇
  1968年   359篇
  1967年   320篇
  1966年   291篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
Changeover behavior and preference in concurrent schedules   总被引:2,自引:2,他引:0       下载免费PDF全文
Pigeons were trained on a multiple schedule of reinforcement in which separate concurrent schedules occurred in each of two components. Key pecking was reinforced with milo. During one component, a variable-interval 40-s schedule was concurrent with a variable-interval 20-s schedule; during the other component, a variable-interval 40-s schedule was concurrent with a variable-interval 80-s schedule. During probe tests, the stimuli correlated with the two variable-interval 40-s schedules were presented simultaneously to assess preference, measured by the relative response rates to the two stimuli. In Experiment 1, the concurrently available variable-interval 20-s schedule operated normally; that is, reinforcer availability was not signaled. Following this baseline training, relative response rate during the probes favored the variable-interval 40-s alternative that had been paired with the lower valued schedule (i.e., with the variable-interval 80-s schedule). In Experiment 2, a signal for reinforcer availability was added to the high-value alternative (i.e., to the variable-interval 20-s schedule), thus reducing the rate of key pecking maintained by that schedule but leaving the reinforcement rate unchanged. Following that baseline training, relative response rates during probes favored the variable-interval 40-s alternative that had been paired with the higher valued schedule. The reversal in the pattern of preference implies that the pattern of changeover behavior established during training, and not reinforcement rate, determined the preference patterns obtained on the probe tests.  相似文献   
912.
913.
The paper discusses regularisation of dualities. A given duality between (concrete) categories, e.g. a variety of algebras and a category of representation spaces, is lifted to a duality between the respective categories of semilattice representations in the category of algebras and the category of spaces. In particular, this gives duality for the regularisation of an irregular variety that has a duality. If the type of the variety includes constants, then the regularisation depends critically on the location or absence of constants within the defining identities. The role of schizophrenic objects is discussed, and a number of applications are given. Among these applications are different forms of regularisation of Priestley, Stone and Pontryagin dualities.  相似文献   
914.
In responding to and examining Mary Anne Raywid's (1989) adoption of community building as an aim for schools, I survey a number of types of communities, including recreational, intentional and language communities. In considering all these communities, I try to show both the power of communities in our personal lives and some idea of why we might be of two minds about promoting community as an ideal in the modern world and in schools in particular.  相似文献   
915.
Similarity is a central component of many cognitive processes. Current research suggests that similarity is well characterized as a comparison of structured representations. This process yields commonalities, differences related to the commonalities (alignable differences), and differences not related to the commonalities (nonalignable differences). In the first study, further evidence for this tripartite distinction is provided in a commonality and difference listing study involving pairs of pictures. This study indicates that alignable differences rather than nonalignable differences are central to the comparison process by virtue of their connection to the commonalities. The second study further demonstrates that alignable differences count more against the similarity of a pair than do nonalignable differences. We end by discussing implications of the distinction between alignable and nonalignable differences for other cognitive processes involving comparisons.  相似文献   
916.
On Alan Turing's anticipation of connectionism   总被引:2,自引:0,他引:2  
It is not widely realised that Turing was probably the first person to consider building computing machines out of simple, neuron-like elements connected together into networks in a largely random manner. Turing called his networks unorganised machines. By the application of what he described as appropriate interference, mimicking education an unorganised machine can be trained to perform any task that a Turing machine can carry out, provided the number of neurons is sufficient. Turing proposed simulating both the behaviour of the network and the training process by means of a computer program. We outline Turing's connectionist project of 1948.In Memory of Robin Gandy  相似文献   
917.
You'll Never Believe This: Irony and Hyperbole in Expressing Surprise   总被引:2,自引:0,他引:2  
Three experiments compared how people comprehend irony and hyperbole as expressing surprise. Experiment 1 demonstrated that, when irony and hyperbole are used together, they express more surprise than if either is used alone. There was no difference between the degree of surprise expressed by hyperbole and irony, although both expressed more surprise than literal commentary. Experiment 2 revealed that, when a speaker has exaggerated about some unexpected event, as much surprise is expressed by very slight, realistically possible hyperbole as by outlandish, impossible hyperbole. In a third experiment the range of possible levels of hyperbole tested in Experiment 2 was shown to cause differences in how easy it was to determine that a speaker was surprised at some turn of events. The results are discussed in terms of theories of irony and hyperbole comprehension.  相似文献   
918.
Although I became a parapsychologist in part to help me understand the near-death experience (NDE) I had in 1952 as an undergraduate, it was not until 1990 that I began to integrate my NDE into my life. Doing so alerted me to the role the larger cultural context plays in regard to NDEs and other exceptional human experiences (EHEs). I propose not only that we need to draw on cultural resources to amplify the meaning of our exceptional human experiences, but that EHEs themselves carry the seeds of cultural change.  相似文献   
919.
A review indicates that (a) comparatively little is known about the common phenomenon of lifelong mild bad feelings, and (b) psychotherapy has generally overlooked an effective focus on this enigmatic feeling state. As an invitation for clinicians to provide more attention to this feeling state, a proposal is suggested toward one way of freeing a patient of lifelong mild bad feelings in the course of a session.  相似文献   
920.

To what extent do differences in biologicalsexand psychological gender identity influence affectivereactions to different genres of film? In order toaddress this question, this investigation examined the impact of sex and gender roleself-perceptions on viewers' responses to neutral,melodramatic, and violent film segments. Working with apredominantly Caucasian population (93% Caucasian) at asoutheastern university, the results emphasize theimportance of sex and gender role self-perceptions onviewers' affective responses to media entertainment. Theimplications of these findings are discussed.

  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