全文获取类型
收费全文 | 24996篇 |
免费 | 906篇 |
国内免费 | 9篇 |
专业分类
25911篇 |
出版年
2018年 | 325篇 |
2017年 | 350篇 |
2016年 | 360篇 |
2015年 | 259篇 |
2014年 | 332篇 |
2013年 | 1747篇 |
2012年 | 586篇 |
2011年 | 643篇 |
2010年 | 444篇 |
2009年 | 400篇 |
2008年 | 634篇 |
2007年 | 562篇 |
2006年 | 539篇 |
2005年 | 459篇 |
2004年 | 463篇 |
2003年 | 462篇 |
2002年 | 477篇 |
2001年 | 637篇 |
2000年 | 643篇 |
1999年 | 503篇 |
1998年 | 259篇 |
1997年 | 284篇 |
1996年 | 282篇 |
1995年 | 260篇 |
1992年 | 495篇 |
1991年 | 466篇 |
1990年 | 453篇 |
1989年 | 426篇 |
1988年 | 442篇 |
1987年 | 418篇 |
1986年 | 459篇 |
1985年 | 435篇 |
1984年 | 384篇 |
1983年 | 336篇 |
1982年 | 260篇 |
1981年 | 276篇 |
1979年 | 407篇 |
1978年 | 335篇 |
1977年 | 293篇 |
1976年 | 300篇 |
1975年 | 341篇 |
1974年 | 436篇 |
1973年 | 468篇 |
1972年 | 348篇 |
1971年 | 372篇 |
1970年 | 340篇 |
1969年 | 367篇 |
1968年 | 436篇 |
1967年 | 401篇 |
1966年 | 420篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
142.
S Streufert R M Pogash J Roache D Gingrich R Landis W Severs L Lonardi A Kantner 《The Journal of applied psychology》1992,77(4):515-524
Adult men (N = 44) participated for 2 days (alcohol vs. placebo treatment) in a double-blind, crossover experiment. Performance on the Digit Symbol Substitution Task (DSST) and a visuomotor (VM) task was measured 4 times each day. On the alcohol-treatment day, data were obtained once during ascending breath alcohol levels (BALs), once during maximal BALs (0.05 or 0.10), and twice during descending BALs. Data were collected at the same time points on the placebo-treatment day. Limited evidence for acute tolerance was obtained with the DSST, but error rates on the VM task were higher during maximal and descending BALs. Error rates remained near placebo values, and participants displayed slightly greater caution, while BALs were ascending. Strategy scores on the VM task exceeded placebo scores during maximal intoxication. Data interpretation is focused on individuals in higher level (e.g., professional) positions. 相似文献
143.
144.
A variant of Ponzo's pattern was devised by drawing converging oblique lines at the ends of each of two horizontal lines that were located directly one above the other. Pairs of converging or diverging fins (either between or outside the horizontal shafts) were systematically removed. The results showed that, as predicted by integrative field theory, oblique lines between the shafts produced more distortion than did oblique lines outside the shafts. Also, it was shown that the attentive field construct in integrative field theory was crucial for predicting patterns of means and variances in this experiment. The modified Ponzo effect was shown to have much in common with the classical Müller-Lyer illusion. The subtle differences between the two were explained by proposing that the size of the optimum attentive field was larger in the Ponzo tasks than in the Müller-Lyer tasks because expansion fins are found on both shafts in the Ponzo-like figure. 相似文献
145.
D W Grantham 《Perception & psychophysics》1992,52(2):144-150
Thresholds for auditory motion detectability were measured in a darkened anechoic chamber while subjects were adapted to horizontally moving sound sources of various velocities. All stimuli were 500-Hz lowpass noises presented at a level of 55 dBA. The threshold measure employed was the minimum audible movement angle (MAMA)--that is, the minimum angle a horizontally moving sound must traverse to be just discriminable from a stationary sound. In an adaptive, two-interval forced-choice procedure, trials occurred every 2-5 sec (Experiment 1) or every 10-12 sec (Experiment 2). Intertrial time was "filled" with exposure to the adaptor--a stimulus that repeatedly traversed the subject's front hemifield at ear level (distance: 1.7 m) at a constant velocity (-150 degrees/sec to +150 degrees/sec) during a run. Average MAMAs in the control condition, in which the adaptor was stationary (0 degrees/sec,) were 2.4 degrees (Experiment 1) and 3.0 degrees (Experiment 2). Three out of 4 subjects in each experiment showed significantly elevated MAMAs (by up to 60%), with some adaptors relative to the control condition. However, there were large intersubject differences in the shape of the MAMA versus adaptor velocity functions. This loss of sensitivity to motion that most subjects show after exposure to moving signals is probably one component underlying the auditory motion aftereffect (Grantham, 1989), in which judgments of the direction of moving sounds are biased in the direction opposite to that of a previously presented adaptor. 相似文献
146.
The scale illusion (Deutsch, 1975) shows the importance of frequency range in the perceptual organization of a sequence of notes. This paper includes three experiments on the scale illusion. Experiments 1 and 2 demonstrated that if the structure of the pattern of notes used in the original scale illusion study is altered slightly, by adding or subtracting a pair of notes from the ends of the sequence, there is a significant decrease in the rate of frequency-based responses, suggesting a weaker illusion. Experiment 3 investigated two features of the note patterns that may have led to this change. Specifically, it asked whether the decrease in the strength of the illusion is due to (1) the nature of the notes at the extremes of the frequency range and/or (2) the nature of the notes at the crossing point of the two scales. While both sources were found to affect the strength of the scale illusion, the former had a greater influence. 相似文献
147.
A previous report on the effect of the day of the full moon on the acting-out behavior of 20 developmentally delayed, institutionalized women showed that on the day of the full moon there were significantly more misbehaviors than on any other day during the lunar period. The records were re-evaluated to assess the frequency of acting-out behaviors on weekends and holidays as contrasted with the balance of the month. This re-evaluation indicated there was no significant difference between the weekends and holidays and the balance of the month (t = 1.14). The results were taken as support of the previous findings that on the day of the full moon there were significantly more misbehaviors than on any other day of the lunar period. 相似文献
148.
Psychophysical studies with infants or with patients often are unable to use pilot data, training, or large numbers of trials. To evaluate threshold estimates under these conditions, computer simulations of experiments with small numbers of trials were performed by using psychometric functions based on a model of two types of noise: stimulus-related noise (affecting slope) and extraneous noise (affecting upper asymptote). Threshold estimates were biased and imprecise when extraneous noise was high, as were the estimates of extraneous noise. Strategies were developed for rejecting data sets as too noisy for unbiased and precise threshold estimation; these strategies were most successful when extraneous noise was low for most of the data sets. An analysis of 1,026 data sets from visual function tests of infants and toddlers showed that extraneous noise is often considerable, that experimental paradigms can be developed that minimize extraneous noise, and that data analysis that does not consider the effects of extraneous noise may underestimate test-retest reliability and overestimate interocular differences. 相似文献
149.
W Prinzmetal 《Perception & psychophysics》1992,51(5):473-484
Six experiments examined the possibility of obtaining a word-superiority effect (WSE) without the use of brief stimulus exposures or a poststimulus mask. In each experiment, subjects were presented a stimulus string and two alternative strings that differed by a single letter (Reicher, 1969). The alternatives and stimulus remained in view until subjects responded, and subjects were under no pressure to respond quickly. In Experiments 1-3, the stimuli were presented in very small type so that they were difficult to see. Subjects were significantly more accurate with words than with nonwords, letters embedded among digits, or letters embedded among number signs (#s). In Experiments 4 and 5, the stimuli were embedded in a simultaneously present pattern mask. Subjects were significantly more accurate with words than with single letters by themselves. In the final experiment, the stimuli were presented in a mask with specific spatial frequency characteristics, and performance was significantly better with words than with nonwords. The WSE is a more general phenomenon than previously supposed; it is not limited to a tachistoscopic exposure. 相似文献
150.
A soft contact-lens system for achieving unilateral visual stimulation in a free vision format is described. Initial testing with light transmittance and visual perimetry indicated that the lenses created artificial visual-field deficits. The efficacy of the lenses as a technique for lateralizing visual input was evaluated by examining within-subject differences in performance on two visuospatial tasks. Speed and accuracy of performance were greater with visual input directed to the right hemisphere. These data support the lens design as a useful alternative to tachistoscopic procedures and previous lens systems. 相似文献