全文获取类型
收费全文 | 53762篇 |
免费 | 2065篇 |
国内免费 | 34篇 |
出版年
2020年 | 544篇 |
2019年 | 635篇 |
2018年 | 845篇 |
2017年 | 865篇 |
2016年 | 985篇 |
2015年 | 690篇 |
2014年 | 813篇 |
2013年 | 4054篇 |
2012年 | 1542篇 |
2011年 | 1570篇 |
2010年 | 948篇 |
2009年 | 1021篇 |
2008年 | 1378篇 |
2007年 | 1330篇 |
2006年 | 1193篇 |
2005年 | 1074篇 |
2004年 | 1031篇 |
2003年 | 982篇 |
2002年 | 1027篇 |
2001年 | 1611篇 |
2000年 | 1597篇 |
1999年 | 1165篇 |
1998年 | 543篇 |
1997年 | 508篇 |
1992年 | 1027篇 |
1991年 | 979篇 |
1990年 | 955篇 |
1989年 | 935篇 |
1988年 | 891篇 |
1987年 | 846篇 |
1986年 | 879篇 |
1985年 | 957篇 |
1984年 | 792篇 |
1983年 | 731篇 |
1982年 | 546篇 |
1981年 | 548篇 |
1979年 | 855篇 |
1978年 | 618篇 |
1977年 | 560篇 |
1976年 | 566篇 |
1975年 | 729篇 |
1974年 | 848篇 |
1973年 | 896篇 |
1972年 | 759篇 |
1971年 | 713篇 |
1970年 | 650篇 |
1969年 | 695篇 |
1968年 | 849篇 |
1967年 | 782篇 |
1966年 | 746篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
In two experiments, we investigated the factors that influence the perceived similarity of speech sounds at two developmental levels. Kindergartners and second graders were asked to classify nonsense words, which were related by syllable and phoneme correspondences. The results support the existence of a developmental trend toward increased attention to individual phonemic segments. Moreover, one significant factor in determining the perceived similarity of speech sounds appears to be the position of the component correspondences; attention to the beginning of utterances may have developmental priority. An unexpected finding was that the linguistic status of the unit involved in a correspondence (whether it was a syllable or a phoneme) did not seem particularly important. Apparently, the factors which contribute to the perceived similarity of speech sounds in the classification task are not identical to those which underlie performance in explicit segmentation and manipulation tasks, since in the latter sort of task, syllables are more accessible than phonemes for young children. The present task may tap a level of processing that is closer to the one entailed in word recognition and lexical access. 相似文献
942.
Predicting which words get recalled: Measures of free recall,availability, goodness,emotionality, and pronunciability for 925 nouns 总被引:3,自引:0,他引:3
To investigate the properties that make a word easy to recall, we added to existing norms for 925 nouns measures of availability, goodness, emotionality, pronunciability, and probability of recall in multiple-trial free recall. Availability, imagery, and emotionality were found to be the best predictors of which words were recalled. This result, which is stable across recall data collected in three separate laboratories, argues for the importance of availability as a predictor of recall and questions the role of the correlated variables of word frequency and meaningfulness. Consistent with earlier work on a smaller sample of words, six factors describe the numerous properties of words studied by psychologists. The six factors are composed of variables based on orthography, imagery and meaning, word frequency, recall, emotionality, and goodness. 相似文献
943.
Punctuation in 20 radio homilies by four speakers accounted for 76% of pause time and 64% of pause number. Pause duration varied systematically according to punctuation type. Commas accounted for 82% of punctuated positionsnot used for pausing.RRelevance for theories of text unitization is discussed. Both typographical and temporal measures are compared with a similar corpus of German homilies. 相似文献
944.
Santosh C. Panda 《Synthese》1986,67(2):259-271
The axioms adopted by Packard (1981) and Heiner and Packard (1983) for plausibility ranking of sets of statements are critically examined. It is shown that the informational requirement of the Heiner-Packard (1983) framework is much stronger than Packard's (1981) framework and hence both axiomatic setups are examined separately. A characterization of the leximin rule is provided in Packard's framework and the nonintuitive implications of the Heiner-Packard (1983) axioms are discussed. It is also demonstrated that in both frameworks, minor variations of some of the axioms convert the characterization results into logical impossibilities.I am grateful to Prof. P. K. Pattanaik for many helpful suggestions. 相似文献
945.
946.
947.
Four experiments investigated the relation between the development of binocular vision and infant spatial perception. Experiments 1 and 2 compared monocular and binocular depth perception in 4- and 5-month-old infants. Infants in both age groups reached more consistently for the nearer of two objects under binocular viewing conditions than under monocular viewing conditions. Experiments 3 and 4 investigated whether the superiority of binocular depth perception in 4-month-olds is related to the development of sensitivity to binocular disparity. Under binocular viewing conditions in Experiment 3, infants identified as disparity-sensitive reached more consistently for the nearer object than did infants identified as disparity-insensitive. The two groups' performances did not differ under monocular viewing conditions. These results suggest that, binocularly, the disparity-sensitive infants perceived the objects' distances more accurately than did the disparity-insensitive infants. In Experiment 4, infants were habituated to an object, then presented with the same object and a novel object that differed only in size. Disparity-sensitive infants showed size constancy by recovering from habituation when viewing the novel object. Disparity-insensitive infants did not show clear evidence of size constancy. These findings suggest that the development of sensitivity to binocular disparity is accompanied by a substantial increase in the accuracy of infant spatial perception. 相似文献
948.
Temporal integration and vibrotactile backward masking 总被引:1,自引:0,他引:1
P M Evans J C Craig 《Journal of experimental psychology. Human perception and performance》1986,12(2):160-168
Subjects were presented with vibrotactile target patterns to their left index fingertips. The target patterns varied in the number of line segments that they contained and were presented in the presence or absence of a backward-masking stimulus. The stimulus onset asynchrony (SOA) between the target and masker was varied. In an identification task, subjects' errors indicated that the effect of the masker at brief SOAs was to increase the perceived number of line segments in the target. This effect diminished with increasing SOA, and at the longest SOAs subjects confused targets with patterns containing the same number of line segments but varying in how the line segments were related. In an estimation task, the effect of the masker was to increase the number of line segments estimated to be contained in the target pattern. The effect of the masker at brief SOAs is discussed in terms of an integration theory of vibrotactile backward masking. At longer SOAs, the results suggest that the masker may interfere with the extraction of relational information in the target pattern. 相似文献
949.
H Wallach F J Marshall 《Journal of experimental psychology. Human perception and performance》1986,12(3):338-342
The distortion of polar perspective depends on the depth of the tridimensional shape and on the observation distance. In four experiments using 54 undergraduates as subjects, we found that a compensation process which takes depth and observation distance into account corrects for such distortions. Compensation was demonstrated in experiments in which deceptive information on depth and on observation distance was provided. The result was distortions of the perceived shapes that would be expected if compensation were based on the deceptive information. 相似文献
950.
A homogeneous sample of normal adults living in a religious order in a study of age effects on reference as a cohesive device in discourse production and comprehension. Narrative and procedural discourse were examined across various levels of complexity and stimulus/response requirements. Results indicate that significant ambiguity of reference emerges in the younger elderly group (age 64-76) in comparison to the middle-aged group (age 27 to 55), and increases markedly in the older elderly group (age 77-92). Related impairments of comprehension and cognition were also observed. These findings are interpreted to be general features of linguistic variation with advancing age. Communicative consequences of ambiguous reference are discussed. 相似文献