全文获取类型
收费全文 | 4327篇 |
免费 | 188篇 |
国内免费 | 35篇 |
专业分类
4550篇 |
出版年
2022年 | 31篇 |
2021年 | 50篇 |
2020年 | 72篇 |
2019年 | 97篇 |
2018年 | 129篇 |
2017年 | 143篇 |
2016年 | 130篇 |
2015年 | 100篇 |
2014年 | 152篇 |
2013年 | 539篇 |
2012年 | 234篇 |
2011年 | 231篇 |
2010年 | 125篇 |
2009年 | 137篇 |
2008年 | 168篇 |
2007年 | 195篇 |
2006年 | 178篇 |
2005年 | 129篇 |
2004年 | 145篇 |
2003年 | 133篇 |
2002年 | 100篇 |
2001年 | 62篇 |
2000年 | 59篇 |
1999年 | 71篇 |
1998年 | 54篇 |
1997年 | 41篇 |
1996年 | 36篇 |
1995年 | 37篇 |
1994年 | 38篇 |
1993年 | 43篇 |
1992年 | 37篇 |
1991年 | 29篇 |
1990年 | 40篇 |
1988年 | 35篇 |
1987年 | 29篇 |
1986年 | 42篇 |
1985年 | 42篇 |
1984年 | 40篇 |
1983年 | 40篇 |
1982年 | 36篇 |
1981年 | 34篇 |
1980年 | 37篇 |
1979年 | 32篇 |
1978年 | 39篇 |
1977年 | 26篇 |
1976年 | 36篇 |
1975年 | 39篇 |
1974年 | 38篇 |
1973年 | 28篇 |
1972年 | 25篇 |
排序方式: 共有4550条查询结果,搜索用时 0 毫秒
81.
本工作采用食物性运动,条件反射方法和慢性微电极记录技术。条件反射实验在9只兔上进行,海马自发放电的实验在22只兔上进行。在9次实验中,30μg的东莨菪碱注入一侧脑室后,条件反射均受到抑制,而吃食则不受影响。注射剂量为45μg时,注射后3—5分,条件反射完全消失,而吃食行为在了次实验中不受影响,在2次实验中稍有减弱,注射后20分钟左右条件反射开始恢复;侧脑室注射40μg的东莨菪碱后,海马神经元的自发活动无明显改变。文中并对抗胆碱药作用于海马抑制条件反射的可能方式进行了讨论。 相似文献
82.
Martin R. Adams 《Journal of Fluency Disorders》1978,3(4):265-271
This article presents a further analysis of stuttering as a phonetic transition defect. Three types of phonetic transitions are identified. Two of these occur within words and represent sites where stutterings are readily detectable. The third transition involves movement from the end of one word to the beginning of the next. Spectrographic evidence is provided to show that stuttering also occurs at points of transition of this type. The same data are interpreted relative to their implications for stuttering theory, research, and therapy. 相似文献
83.
Human subjects learned a key-pressing response in order to avoid or escape shock. The reinforcement contingencies were then changed to punishment or to regular nonpunished extinction. The locus of shock onset and offset was systematically varied during the punishment phase. More subjects reported awarencess of the change in the nonpunished extinction group. By inference, the punished groups responded more, and thus the results appear analogous to animal studies on vicious circle, self-punitive responding. Discriminability of change from acquisition to extinction appeared to affect detection of the change. 相似文献
84.
85.
Maryanne Martin 《Quarterly journal of experimental psychology (2006)》1978,30(2):187-200
In the first of two experiments investigating focussed attention, sets of four pairs of digits were dichotically presented to subjects who were instructed to attend to digits arriving in either the left or the right ear. Following presentation, two different report orders were used: attended followed by unattended, and unattended followed by attended. It was found that unattended items did not suffer from being recalled second rather than first. The serial position curve for unattended items was U-shaped. These results were interpreted as evidence that unattended items are not retained in a limited-capacity auditory buffer with a fast rate of loss. The experiment was repeated using visually presented pairs of letters. A similar pattern of results was obtained, consistent with the hypothesis that unattended items are recalled from a store with a large capacity and a very slow rate of loss. 相似文献
86.
The relationship between the Fourier spectra of visual textures (represented by four hypothetical visual channels sensitive to spatial frequencies) and the perceptual appearance of the textures was investigated. Thirty textures were synthesized by combining various spatial frequencies of different amplitudes. Twenty subjects grouped the textures into 2, 3, 4, and 5 groups based on the similarity of their appearance. The groupings were analyzed by means of linear discriminant analysis using the activity of the four channels as predictor variables. The groupings were also examined by multidimensional scaling, and the resulting stimulus configuration was canonically correlated with the channel activity. The results of both analyses indicate a strong relationship between the perceptual appearance of the textures and their Fourier spectra. These findings suport a multiple-channel spatial-frequency model of perception. 相似文献
87.
Julesz (1975) proposed a theory of texture discrimination, based on an order statistics principle, which states that no two textures can be perceptually discriminated if they have identical second-order statistics. The experiments reported here demonstrate that this principle is not adequate to predict visual texture discriminability. Both letter and dot micropatterns were used to create texture pairs that either differed or were identical with respect to secondorder statistics. The subject’s task was to decide which quadrant of an array contained a disparate texture. In Experiments 1, 2, and 3, when controlling for spatial overlap, texture pairs having identical second-order statistics were discriminated more quickly than similar texture pairs having different second-order statistics, in contradiction to the principle. Although a significant effect in the direction predicted by the order statistics principle was found in Experiment 4 for texture pairs created from the dot micropatterns, other factors, such as spatial overlap, border differences, and goodness of pattern, must also be considered in predicting texture discriminability. 相似文献
88.
Maryanne Martin 《Acta psychologica》1980,44(2):99-115
Theoretical controversy surrounds the issue of whether central processing capacity is unitary and general or whether different types of processing capacity may be distinguished. Three bisensory experiments investigated the selection of words by physical and semantic attributes. It was found that recall was superior following bimodal (auditory and visual) rather than unimodal (auditory or visual) presentation. Furthermore, the difference between bimodal and unimodal recall was greater when the words were physically selected than when they were semantically selected. The results provide evidence that the availability of different types of processing capacity is dependent upon the mode of presentation of material and its required type of analysis. 相似文献
89.
90.