全文获取类型
收费全文 | 21794篇 |
免费 | 852篇 |
国内免费 | 11篇 |
专业分类
22657篇 |
出版年
2019年 | 255篇 |
2018年 | 369篇 |
2017年 | 392篇 |
2016年 | 413篇 |
2015年 | 317篇 |
2014年 | 349篇 |
2013年 | 1737篇 |
2012年 | 621篇 |
2011年 | 640篇 |
2010年 | 386篇 |
2009年 | 362篇 |
2008年 | 490篇 |
2007年 | 547篇 |
2006年 | 463篇 |
2005年 | 441篇 |
2004年 | 416篇 |
2003年 | 407篇 |
2002年 | 436篇 |
2001年 | 742篇 |
2000年 | 710篇 |
1999年 | 539篇 |
1998年 | 216篇 |
1996年 | 219篇 |
1995年 | 198篇 |
1992年 | 448篇 |
1991年 | 440篇 |
1990年 | 425篇 |
1989年 | 400篇 |
1988年 | 418篇 |
1987年 | 375篇 |
1986年 | 389篇 |
1985年 | 386篇 |
1984年 | 306篇 |
1983年 | 274篇 |
1982年 | 204篇 |
1981年 | 207篇 |
1979年 | 349篇 |
1978年 | 253篇 |
1977年 | 213篇 |
1976年 | 198篇 |
1975年 | 279篇 |
1974年 | 354篇 |
1973年 | 366篇 |
1972年 | 289篇 |
1971年 | 282篇 |
1970年 | 281篇 |
1969年 | 251篇 |
1968年 | 349篇 |
1967年 | 307篇 |
1966年 | 284篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
271.
Orthogonal and oblique factor analyses were performed using the Wechsler Adult Intelligence Scale-Revised (WAIS-R) standardization sample (Wechsler, 1981). Using objective criteria, it was decided to retain two factors. Evidence for a strong general intelligence (g) factor was found from both the orthogonal and oblique rotations. Whereas the verbal IQ provided an acceptable estimate of the Verbal Comprehension factor, a purer measure was found in the form of a Verbal Comprehension Deviation Quotient containing only the Information, Vocabulary, Comprehension, and Similarities subtests. The performance IQ was found to be an inadequate measure of the Perceptual Organization factor. A Perceptual Organization Deviation Quotient, containing only the Block Design and Object Assembly subtests, was recommended as an effective alternative. Analysis of the variance components for each subtest at every age level revealed that a substantial proportion of subtests at a wide range of age levels evidence either high or intermediate levels of specific variance. These results are discussed in terms of interpreting individual subtest scores and patterns. Each of the study's major findings are compared with prior work done with the Wechsler Adult Intelligence Scale (WAIS) (Wechsler, 1955). 相似文献
272.
B F Skinner 《Journal of the experimental analysis of behavior》1984,41(2):217-221
273.
274.
275.
Three studies compared the efficacy of various treatments for public-speaking incompetence. These effects were evaluated for the target behavior as well as for generalization effects across situations (conversations), settings (different sizes and types of audiences) and time (6-month follow-up). The first study showed that Self-instructional Training, either alone or in combination with other procedures, produced little or no benefits. The second study demonstrated the superiority of a Skills Training program over flooding therapy, while the final study failed to detect any enhancement of treatment benefits for the addition of home-practice to the Skills Training. In the first two studies generalization occurred across the three dimensions (settings, situations and time), while in the final study it was shown that the program was effective for a clinical population as well as recruited volunteers. 相似文献
276.
Objects, parts, and categories 总被引:5,自引:0,他引:5
Concepts may be organized into taxonomies varying in inclusiveness or abstraction, such as furniture, table, card table or animal, bird, robin. For taxonomies of common objects and organisms, the basic level, the level of table and bird, has been determined to be most informative (Rosch, Mervis, Gray, Johnson, & Boyes-Braem, 1976). Psychology, linguistics, and anthropology have produced a variety of measures of perception, behavior, and communication that converge on the basic level. Here, we present data showing that the basic level differs qualitatively from other levels in taxonomies of objects and of living things and present an explanation for why so many measures converge at that level. We have found that part terms proliferate in subjects' listings of attributes characterizing category members at the basic level, but are rarely listed at a general level. At a more specific level, fewer parts are listed, though more are judged to be true. Basic level objects are distinguished from one another by parts, but members of subordinate categories share parts and differ from one another on other attributes. Informants agree on the parts of objects, and also on relative "goodness" of the various parts. Perceptual salience and functional significance both appear to contribute to perceived part goodness. Names of parts frequently enjoy a duality not evident in names of other attributes; they refer at once to a particular appearance and to a particular function. We propose that part configuration underlies the various empirical operations of perception, behavior, and communication that converge at the basic level. Part configuration underlies the perceptual measures because it determines the shapes of objects to a large degree. Parts underlie the behavioral tasks because most of our behaviors is indirect toward parts of objects. Labeling appears to follow the natural breaks of perception and behavior; consequently, part configuration also underlies communication measures. Because elements of more abstract taxonomies, such as scenes and events, can also be decomposed into parts, this analysis provides a bridge to organization in other domains of knowledge. Knowledge organization by parts (partonomy) is contrasted to organization by kinds (taxonomy). Taxonomies serve to organize numerous classes of entities and to allow inference from larger sets to sets included in them. Partonomies serve to separate entities into their structural components and to organize knowledge of function by components of structure. The informativeness of the basic level may originate from the availability of inference from structure to function at that level. 相似文献
277.
Vasopressin prolongs bradycardiac response during orientation 总被引:1,自引:0,他引:1
Adult male rats were implanted with transcutaneous ECG electrodes and habituated to a dark chamber with elevated background noise levels. ECG was recorded prior to, immediately after, and 3 min after sudden elimination of background noise. The orienting response to the stimulus offset was accompanied by transient bradycardia. Neither AVP (1 microgram/rat) nor oxytocin (1 microgram/rat) injected subcutaneously 1 hr prior to testing altered baseline heart rate or the immediate bradycardiac response to stimulus offset. However, AVP, and to a lesser extent oxytocin, prolonged the bradycardia induced by stimulus offset. The results show that neurohypophyseal peptide hormones enhance the cardiovascular component of orienting to stimulus change. 相似文献
278.
To compare the predictive value of "cognitive map" and "working memory" theories of hippocampal function, the performance of rats with dorsal hippocampal lesions was compared to that of control rats in a series of experiments. In Experiment I, experimental rats learned a spatial alternation task with normal ease, but in Experiment II, they were significantly impaired on an elevated 8-arm radial maze. In Experiment III, the performance of the same experimental and control rats was compared on two versions of a 16-arm enclosed radial maze. In the first version, carpet inserts served as cues to mark eight unbaited arms and each of the remaining arms contained one food pellet. While both experimental and control rats successfully avoided the set of cued arms, experimental rats reentered uncued baited arms more frequently than did control rats. In the second version no intramaze cues were provided, but the spatial distribution of baited and unbaited arms remained the same as that used in the first version. In this uncued version, experimental rats both entered unbaited arms and reentered baited arms more frequently than did control rats, i.e., they were impaired in both "reference" and "working" memory. These findings are compatible with the hypothesis that hippocampal lesions result in an impaired capacity to form cognitive maps but they are not compatible with the working memory hypothesis. Furthermore, twelve separate evaluators classed experimental rats as using fewer mapping and more orientation strategies than control rats in the 8-arm maze. 相似文献
279.
Barrie B. Alexander Suzanne B. Johnson Randy L. Carter 《Journal of abnormal child psychology》1984,12(2):199-207
The Family Adaptability and Cohesion Evaluation Scales (FACES), a measure of family functioning, contains three scales: cohesion, adaptability, and social desirability. These were slightly modified (FACES- R) on the basis of pilot data and were administered to 42 clinic families (families seeking or receiving psychological services) and 206 nonclinic families. Support for the scales was found in high coefficient alpha reliabilities and similarity of the sample means and standard deviations to those of the standardization sample. However, there was little agreement among family members' scale scores. Therapists' ratings of cohesion and adaptability did not correlate with scale scores among clinic families. There was no difference between clinic and nonclinic samples on the cohesion or adaptability scales, although the social desirability scale did discriminate between groups. Factor analysis suggested that cohesion, adaptability, and social desirability cannot be clearly differentiated using this measure.This work was supported by the American Association of University Women and by Grant R01HD13820 from the National Institute of Child Health and Human Development. 相似文献
280.