全文获取类型
收费全文 | 25911篇 |
免费 | 183篇 |
国内免费 | 5篇 |
专业分类
26099篇 |
出版年
2020年 | 85篇 |
2019年 | 80篇 |
2018年 | 3631篇 |
2017年 | 2957篇 |
2016年 | 2378篇 |
2015年 | 275篇 |
2014年 | 179篇 |
2013年 | 558篇 |
2012年 | 771篇 |
2011年 | 2589篇 |
2010年 | 2635篇 |
2009年 | 1620篇 |
2008年 | 1867篇 |
2007年 | 2353篇 |
2006年 | 167篇 |
2005年 | 357篇 |
2004年 | 299篇 |
2003年 | 220篇 |
2002年 | 169篇 |
2001年 | 187篇 |
2000年 | 163篇 |
1999年 | 117篇 |
1998年 | 81篇 |
1997年 | 70篇 |
1996年 | 69篇 |
1994年 | 56篇 |
1993年 | 65篇 |
1992年 | 81篇 |
1991年 | 83篇 |
1990年 | 78篇 |
1989年 | 70篇 |
1988年 | 71篇 |
1987年 | 72篇 |
1986年 | 60篇 |
1985年 | 71篇 |
1984年 | 69篇 |
1983年 | 64篇 |
1982年 | 64篇 |
1981年 | 51篇 |
1979年 | 67篇 |
1978年 | 75篇 |
1977年 | 62篇 |
1976年 | 51篇 |
1975年 | 76篇 |
1974年 | 71篇 |
1973年 | 60篇 |
1972年 | 56篇 |
1971年 | 54篇 |
1968年 | 53篇 |
1967年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
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
192.
S. A. Corson E. O’L. Corson R. E. Becker B. E. Ginsburg A. Trattner R. L. Connor L. A. Lucas J. Panksepp J. P. Scott 《Integrative psychological & behavioral science》1980,15(1):5-11
A model of childhood hyperkinesis, using the Telomian-beagle hybrid dog, is described, demonstrating the interactions of genetics and separation in the development of this syndrome and in the favorable responses of some of these dogs to amphetamine. This work represents the collaboration of three laboratories, utilizing chiefly methods of inhibitory training. Inducing separation distress enhanced the resistance to inhibitory training and the favorable responses to amphetamine. 相似文献
193.
The present experiment investigated semantic information extraction in parafoveal word perception. An ambiguous word (bank) was presented in foveal vision, and simultaneously a disambiguating word (water, money) was presented in the parafovea. Subjects were required to make a forced choice between two phrases, and the task was constructed so that a correct choice could be made if semantic information about both the foveal and parafoveal word had been obtained. However, the results indicated that the forced-choice results could be explained by two factors: identification of the parafoveal word and correct guessing. Hence, it was concluded that those models of reading which rely on unconscious semantic preprocessing of parafoveal words were not supported. 相似文献
194.
A questionnaire completed by 1282 male life insurance agency managers from 50 companies was used to develop (via factor analysis) six behavorial functions of agency managers. The relationship between the frequency of activity in each function and five variables–number of agents, number of supervisors, tenure, type of agency and origin of agency–was examined using zero order and multiple correlation procedures. The two measures of size, number of agents and number of supervisors, were the most consistent correlates of behavior. The degree of shared variance among management functions and the five variables, though significant statistically, did not exceed 9%. Reasons cited for these results included: (1) policies and practices particular to individual companies; (2) the discretion managers have in choosing task activities; (3) the limited number of variables examined as correlates of managerial functions; and, (4) individual differences among agency managers. It was concluded, for practical reasons, that management research should include efforts to develop taxonomies that cut across technological categories of managers as well as defining the specific behavior functions of managers in particular technological categories. Such specific taxonomies are required for effective human resource management practices at managerial levels in organizations. 相似文献
195.
Richard J Harris David M Messick Keith P Sentis 《Journal of experimental social psychology》1981,17(2):210-225
Messick and Sentis found greater support for weak proportionality in subjects' outcome allocations (suggesting that subjects wish to maintain a constant ratio between outcomes across situations when inputs are held constant) than for constant differences between outcomes. They claimed that their data thus provided stronger support for Adams' ratio definition of equity than for Harris' linear formula. A dialogue between the two sets of authors establishes that (1) so far as their specification of fair outcomes is concerned, Adams' formula is a special case of the linear formula; (2) weak proportionality does not necessarily follow from Adams' formula and can be derived from the linear formula; (3) Adams' formula applied to subjective (rather than experimenter-defined) inputs nevertheless provides a more natural base from which to derive weak proportionality than does the linear formula in its general form; (4) excellent fits to several sets of data, including much better fit to Messick and Sentis' data than that provided by weak proportionality, are obtained if we assume that subjects use allocations which are a weighted average of those implied by Adams' formula, the Equality principle, and Komorita and Kravitz' Equal Excess Norm; and (5) a fit to Messick and Sentis' data that is almost as good as that provided by the weighted solutions model is obtained by assuming that subjects apply Adams' formula to subjective inputs and subjective outcomes that are different from the corresponding experimenter-defined values. It is agreed that the delineation of the relationships among observable properties of outcome distributions, alternative equity formulae, and different psychological processes is as important as it can be devious. 相似文献
196.
Lynn L. Peterson Kent O. Dana Joan S. Reisch Thomas Hibberd Maurice Korman Paul I. Munves Alvin J. North Thomas A. Van Hoose Frank Trimboli 《Behavior research methods》1981,13(4):485-498
An information processing system for a psychiatric emergency room is described. Several studies are presented that show the utility of the system. In the first study, variables involved in diagnosis are explicated. The second study attempts to determine the characteristics that distinguish recidivists from nonrecidivists at an emergency room. The third study attempts to find patient variables related to success in short-term treatment programs. The final study is aimed at discovering whether there are psychopathological effects related to the use of inhalants. Together, these studies show the potential of a mental health information system for learning more about the nature of mental disorders and their treatment. 相似文献
197.
198.
D. O. Bowker 《Attention, perception & psychophysics》1981,29(6):568-577
Using an adjustment procedure, human observers matched the apparent spatial frequencies of sinusoidal gratings presented in different orientations (0, 45, 90, and 135 deg). Matches were made between all possible pairwise orientation combinations. Significant match deviations indicated that the apparent frequency of a grating depends on its orientation. The most consistent deviations were found between horizontal and vertical gratings, with horizontal gratings appearing to be of a lower spatial frequency than vertical gratings. These effects were relatively independent of stimulus contrast and persisted when the optics of the eye were bypassed with laser interferometry. A neurophysiological explanation of these effects is proposed. 相似文献
199.
Alexander Pollatsek Shmuel Bolozky Arnold D. Well Keith Rayner 《Brain and language》1981,14(1):174-180
Native Israeli readers read Hebrew and English text as their eye movements were monitored. A window of text moved in synchrony with their eye movements and the window was either symmetrical about the fixation point or offset to the left or right. When subjects were reading Hebrew, the perceptual span was asymmetric to the left and when they were reading English it was asymmetric to the right. The results point out the importance of attentional factors in reading. 相似文献
200.