全文获取类型
收费全文 | 10934篇 |
免费 | 521篇 |
国内免费 | 3篇 |
出版年
2020年 | 139篇 |
2019年 | 148篇 |
2018年 | 258篇 |
2017年 | 231篇 |
2016年 | 239篇 |
2015年 | 174篇 |
2014年 | 200篇 |
2013年 | 805篇 |
2012年 | 333篇 |
2011年 | 368篇 |
2010年 | 224篇 |
2009年 | 185篇 |
2008年 | 293篇 |
2007年 | 277篇 |
2006年 | 259篇 |
2005年 | 212篇 |
2004年 | 203篇 |
2003年 | 181篇 |
2002年 | 193篇 |
2001年 | 413篇 |
2000年 | 386篇 |
1999年 | 266篇 |
1998年 | 105篇 |
1996年 | 92篇 |
1995年 | 92篇 |
1992年 | 208篇 |
1991年 | 215篇 |
1990年 | 202篇 |
1989年 | 201篇 |
1988年 | 205篇 |
1987年 | 183篇 |
1986年 | 172篇 |
1985年 | 172篇 |
1984年 | 158篇 |
1983年 | 114篇 |
1982年 | 114篇 |
1979年 | 149篇 |
1978年 | 94篇 |
1977年 | 95篇 |
1976年 | 91篇 |
1975年 | 138篇 |
1974年 | 157篇 |
1973年 | 181篇 |
1972年 | 155篇 |
1971年 | 141篇 |
1970年 | 124篇 |
1969年 | 133篇 |
1968年 | 176篇 |
1967年 | 132篇 |
1966年 | 141篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
321.
322.
323.
324.
325.
326.
If rats are overtrained on a visual discrimination they generally learn the reversal of the discrimination faster than non-overtrained rats. In position discriminations, however, this effect does not generally hold—indeed several investigators have found overtraining to retard position reversal. One of the important differences between the two types of problem seems to be the presence of irrelevant cues in visual discriminations, and their absence in position discriminations. It is suggested that a second important feature of position discriminations is that overtraining usually causes control of the maze running habit to be transferred from external to proprioceptive stimuli, and that successful reversal cannot normally occur until external control is re-established. In two experiments a study by Krechevsky and Honzik (1932) is repeated with certain modifications, with results that support this hypothesis; and a third experiment provides direct evidence of transfer to proprioceptive control in a T-maze. It is shown that this analysis will explain the apparently conflicting results of all recent position reversal experiments. 相似文献
327.
Previous training studies of fluid intellectual abilities have involved training on either figural relations or induction tasks. In the present study, young, middle-aged, and elderly adults were given training on another measure of fluid ability--Raven's Progressive Matrices. The training involved a strategy-modeling technique that lasted no more than a few minutes. The results indicated that (a) performance on the Raven decreased with increasing age, (b) training significantly improved performance, and (c) the effect of training did not differ as a function of the age or sex of the subjects. Thus, the results indicate that performance on the Raven can be significantly improved in a single, brief training session. 相似文献
328.
Systematic 24-hr behavioral observations of sleep and wakefulness in a skilled-care nursing facility
Sleep patterns of aged, infirm, demented, chronically institutionalized residents of a skilled-care nursing facility were studied. The purpose of this naturalistic study was to describe sleep and wakefulness (S/W) within the limits afforded by brief behavioral observations and to examine homeostasis and diurnal rhythmicity of S/W as a function of psychoactive drug intake. Observers noted S/W every 15 min, 24 hr a day for 10 days in 24 Ss. Results indicated substantial individual variation in daytime hours. Daily and weekly variation within Ss was minimal. Sleep was least likely near sunset. Ss on psychoactive drugs showed dampened diurnal variation in S/W rhythms. In Ss not on such drugs, there was a suggestion of homeostasis of S/W between sleep during the morning and evening hours. Results are discussed methodologically (viability of approach), theoretically (age-related change in sleep), and practically (potential treatments). 相似文献
329.
Teaching the Use of Cost-Benefit Reasoning in Everyday Life 总被引:1,自引:0,他引:1
330.
Kimary N. Shahin 《Argumentation》1990,4(3):347-361
Problems with regard to the analysis of argumentative partly discourse arise from definitorial disconformity. In this article, Informal argument is taken as the primary definition to study the basic structure of argument from a fragment of an Agatha Christie novel. Bilmes' account of the notions of Formulation (F) and Decision (D+/D-) are adapted to describe the relations of opposition which are displayed in informal argument. The minimal structure of argument is represented by the formula F/D-/D-, in which F is a speaker's personal composition of a fact, the first D- is the disconfirming uptake of it by another speaker and the second D- is the completing disconfirming uptake by the initial speaker. Some of the speaker's possibilities to initiate an argument by expressing a Formulation are explored, as well as the social and cultural norms which play a role in argument-initiation and the concepts of win and loss. 相似文献