全文获取类型
收费全文 | 58320篇 |
免费 | 975篇 |
国内免费 | 5篇 |
专业分类
59300篇 |
出版年
2020年 | 622篇 |
2019年 | 731篇 |
2018年 | 999篇 |
2017年 | 1110篇 |
2016年 | 1127篇 |
2015年 | 770篇 |
2014年 | 960篇 |
2013年 | 4349篇 |
2012年 | 1785篇 |
2011年 | 1822篇 |
2010年 | 1178篇 |
2009年 | 1093篇 |
2008年 | 1597篇 |
2007年 | 1611篇 |
2006年 | 1432篇 |
2005年 | 1280篇 |
2004年 | 1215篇 |
2003年 | 1152篇 |
2002年 | 1188篇 |
2001年 | 1749篇 |
2000年 | 1726篇 |
1999年 | 1333篇 |
1998年 | 607篇 |
1997年 | 568篇 |
1993年 | 526篇 |
1992年 | 1102篇 |
1991年 | 989篇 |
1990年 | 1065篇 |
1989年 | 957篇 |
1988年 | 976篇 |
1987年 | 932篇 |
1986年 | 947篇 |
1985年 | 921篇 |
1984年 | 797篇 |
1983年 | 741篇 |
1982年 | 568篇 |
1981年 | 533篇 |
1979年 | 897篇 |
1978年 | 647篇 |
1977年 | 575篇 |
1975年 | 748篇 |
1974年 | 821篇 |
1973年 | 853篇 |
1972年 | 675篇 |
1971年 | 642篇 |
1970年 | 572篇 |
1969年 | 679篇 |
1968年 | 784篇 |
1967年 | 705篇 |
1966年 | 648篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
THE VALIDITY and FAIRNESS OF EMPLOYMENT and EDUCATIONAL TESTS FOR HISPANIC AMERICANS: A REVIEW and ANALYSIS 总被引:1,自引:0,他引:1
This study examined the questions of whether employment and educational tests demonstrate either differential validity or test unfairness to Hispanic Americans relative to the majority group. Relevant data from 19 published and unpublished studies formed the basis of the review and analysis. Results for employment tests, based on a very large amount of data, indicated that differential validity occurs no more frequently than would be expected on the basis of chance plus the operation of various statistical artifacts. The frequencies of slope and intercept differences between Hispanic and majority regressions were also within the chance range. A similar pattern of results obtained for the more limited amount of data available on educational tests. Taken together, the results provide strong evidence that tests are neither differentially valid for, nor unfair to, Hispanics. These findings are consistent with the results of previous studies of test validity and fairness for blacks. 相似文献
972.
One possibility suggested by the literature for maximizing the efficiency of behavior modification procedures concerns the relationship between target behaviors and their reinforcers. Therefore, in this experiment three severely autistic children were taught a total of six new target behaviors (in a multiple baseline design) employing two different response-reinforcer relationships: (1) those where the target behaviors were a direct part of the response chain required to procure a reinforcer (e.g., opening the lid of a container to obtain a food reward inside the container); and (2) those where the target behavior was an indirect part of the chain leading to the reinforcer (e.g., the therapist handing the child a food reward after the child had opened the lid of an empty container). In all cases, the results showed rapid acquisition only when the target behavior was a direct part of the chain leading to the reinforcer. The results are discussed in terms of several possible conceptualizations concerning efficient reinforcement contingencies, and in terms of their implications for teaching autistic children.This investigation was supported by U.S. Public Health Service Research Grants MH 28210 and MH 28231, and by U.S. Office of Education Research Grant G007802084 from the Bureau for the Education of the Handicapped. Portions of the results described in this article were discussed in a presentation at the 13th Annual AABT Convention in San Francisco, 1979. The authors are particularly grateful to Andrew Egel, Roberta Elman, Janis Costello, and Karen Britten, for their helpful comments, and to Jody Fisher and Gina Richman, for their assitance in the data collection. 相似文献
973.
The lexical representation of Serbo-Croatian nouns was investigated in a lexical decision task. Because Serbo-Croatian nouns are declined, a noun may appear in one of several grammatical cases distinguished by the inflectional morpheme affixed to the base form. The grammatical cases occur with different frequencies, although some are visually and phonetically identical. When the frequencies of identical forms are compounded, the ordering of frequencies is not the same for masculine and feminine genders. These two genders are distinguished further by the fact that the base form for masculine nouns is an actual grammatical case, the nominative singular, whereas the base form for feminine nouns is an abstraction in that it cannot stand alone as an independent word. Exploiting these characteristics of the Serbo-Croatian language, we contrasted three views of how a noun is represented: (1) the independent-entries hypothesis, which assumes an independent representation for each grammatical case, reflecting its frequency of occurrence; (2) the derivational hypothesis, which assumes that only the base morpheme is stored, with the individual cases derived from separately stored inflectional morphemes and rules for combination; and (3) the satellite-entries hypothesis, which assumes that all cases are individually represented, with the nominative singular functioning as the nucleus and the embodiment of the noun’s frequency and around which the other cases cluster uniformly. The evidence strongly favors the satellite-entries hypothesis. 相似文献
974.
Selective attention to visual and auditory stimuli and reflection-impulsivity were studied in normal and learning-disabled 8- and 12-year-old boys. Multivariate analyses, followed by univariate and paired-comparison tests, indicated that the normal children increased in selective attention efficiency with age to both visual and auditory stimuli. Learning-disabled children increased in selective attention efficiency with age to auditory, but not to visual, stimuli. Both groups increased with age in reflection as measured by Kagan's Matching Familiar Figures Test (MFF). The 8-year-old learning-disabled children were more impulsive than the 8-year-old normals on MFF error scores, but not on MFF latency scores. No difference occurred between the 12-year-old learning-disabled and normal children on either MFF error or MFF latency scores. Correlations between the selective attention scores and MFF error and latency scores were not significant.This research was supported in part by BEH grant G007507227. The authors are indebted to Eleanor McCandless for her assistance in securing the learning-disabled subjects and to James McLeskey and Michael Popkin for their assistance in collecting and analyzing data. 相似文献
975.
In three experiments a series of nonsense syllables ending in consonants was presented to adult subjects who had to discover or learn a rule classifying the syllables into two groups. The rule was based either on the voicing of the final consonants or on an arbitrary division of them. Subjects performed better with the voicing than with the arbitrary rule only when there was a straightforward relationship between the voicing rule and the plural formation rule in English or, more generally, when voicing assimilation with an added consonant was involved and attention was focused on the sound and articulation of the syllables. We conclude that the voicing distinction is not ordinarily accessible and that individuals easily learn and use phonological rules involving voicing assimilation because of articulatory constraints on the production of consonant clusters. 相似文献
976.
William L. Gekoski 《Journal of psycholinguistic research》1980,9(5):429-449
A distinction between compound and coordinate bilingualism has been employed to conceptualize linguistic organization in bilinguals. Compound bilinguals are those who acquired their languages in a joint context and therefore are presumed to store linguistic information interdependently. Coordinates include those who acquired their languages in separate contexts and therefore are presumed to maintain independent linguistic stores. To study the usefulness of this distinction, Spanish-English and English-Spanish, compound, and coordinate bilinguals were asked to give intra-and interlingual free and restricted word associations to equivalent English and Spanish stimuli for which the responses of monolingual speakers were not equivalent. As predicted, compound bilinguals gave significantly more equivalent responses and responded significantly faster than did coordinates. However, since these differences were only modest in size, they cannot be interpreted as supporting the usefulness of the compound-coordinate distinction. None of the predictions regarding the effect of proficiency on performance were supported. Differences as a function of native language, type of association task, and association conditions were obtained and are discussed.This research was supported by USPHS Grant HD 01368 to Dr. Klaus Riegel, University of Michigan, and was included as one portion of a doctoral dissertation submitted by the author to the Horace H. Rackham School of Graduate Studies at the University of Michigan. 相似文献
977.
978.
Right CVAs, mild left CVAs, and non-brain-damaged adults received the Token Test under three conditions: quiet, white noise, and speech babble. Left CVAs performed most poorly of all groups in all conditions experiencing difficulty with subtests III, IV, and V. Right CVAs were inferior to controls on each of these three subtests in the speech babble condition only. Thus, right CVA difficulty with both memory and syntactic tasks was demonstrated in speech babble. These results are explained by the hypothesis that both hemispheres are necessary to process auditory information under complex listening conditions. Total brain capacity of right CVA patients may be overloaded if either memory load or linguistic complexity is increased in the presence of certain types of listening competition. 相似文献
979.
The communication disorder in dialysis dementia is an integral feature of the syndrome. This report describes the communication disorder in a 67-year-old man over a period of 4 months from his admission to the hospital to his death. In the early stage of the syndrome, the most prominent feature was a speech problem, the characteristics of which may vary among cases. In the middle stage, it was difficult to distinguish among aphemia, aphasia, or a combination of dysarthria and confusional state. The severity of the problems in these stages was temporally related to the dialysis treatments. The final stage was characterized by constant mutism and was unrelated to the dialysis treatments. Death occurred 10 months after the communication problems emerged. Communication studies of dialysis dementia patients may offer a systematic method to monitor the course of the syndrome, its response to therapeutic trials, and a clinical model for the study of communication disorders in general. 相似文献
980.