全文获取类型
收费全文 | 32946篇 |
免费 | 1336篇 |
国内免费 | 11篇 |
出版年
2019年 | 433篇 |
2018年 | 561篇 |
2017年 | 590篇 |
2016年 | 589篇 |
2015年 | 418篇 |
2014年 | 532篇 |
2013年 | 2402篇 |
2012年 | 978篇 |
2011年 | 1046篇 |
2010年 | 614篇 |
2009年 | 610篇 |
2008年 | 903篇 |
2007年 | 887篇 |
2006年 | 837篇 |
2005年 | 753篇 |
2004年 | 738篇 |
2003年 | 665篇 |
2002年 | 696篇 |
2001年 | 1023篇 |
2000年 | 934篇 |
1999年 | 716篇 |
1998年 | 383篇 |
1997年 | 314篇 |
1996年 | 309篇 |
1992年 | 552篇 |
1991年 | 545篇 |
1990年 | 528篇 |
1989年 | 542篇 |
1988年 | 536篇 |
1987年 | 498篇 |
1986年 | 525篇 |
1985年 | 570篇 |
1984年 | 455篇 |
1983年 | 432篇 |
1982年 | 356篇 |
1981年 | 340篇 |
1979年 | 524篇 |
1978年 | 384篇 |
1977年 | 316篇 |
1976年 | 363篇 |
1975年 | 435篇 |
1974年 | 491篇 |
1973年 | 511篇 |
1972年 | 414篇 |
1971年 | 382篇 |
1970年 | 380篇 |
1969年 | 415篇 |
1968年 | 493篇 |
1967年 | 426篇 |
1966年 | 425篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
921.
Irwin Silverman Susan E. Dickens Marion Eals Judith Fine 《Infant and child development》1993,2(3):135-144
This study emanated from the long-standing question of whether a maternal bonding process similar to other mammalian species occurs in humans. The perceptions of adult adoptees and a matched sample of non-adoptees about their parents' behaviours towards them were compared on an original Parental Solicitude Scale. As hypothesized, birth children perceived their mothers as the more solicitous parent, but ratings of adoptive mothers showed a unilateral decline. Further, the differential ratings for birth and adoptive mothers occurred mostly for the factors labelled benignity vs abuse and tolerance vs control, rather than caretaking vs neglect, which was congruent to reported effects in prior studies of lack of mother-infant contact during the sensitive period for bonding. An alternative explanation of the data was also tested but not substantiated. 相似文献
922.
Can spatial frequency differences between local and global forms account for differences in the way different levels of structure are analyzed? We examined this question by having subjects identify local or global forms of hierarchical stimuli that had beencontrast balanced. Contrast balancing eliminates low spatial frequencies, so that both local and global forms must be identified on the basis of high spatial frequency information. Response times (RTs) to global (but not local) forms were slowed for contrast-balanced stimuli, suggesting that low spatial frequencies mediate the global RT advantage typically found. In contrast, interference between local and global forms was little affected by contrast balancing or by shifts of attention between local and global forms, suggesting that it does not result from inhibitory interactions between spatial frequency channels or from temporal precedence of low versus high spatial frequency information. Finally, shifts of attention between local and global forms were also little affected by contrast balancing, suggesting that they were not based on spatial frequency. 相似文献
923.
David C. Geary Pierre Cormier Judith P. Goggin Patricia Estrada Melanie C. E. Lunn 《International journal of psychology》1993,28(2):185-201
Two experiments compared rates of solving simple and complex addition and multiplication problems in groups of speakers of French or English in Experiment 1 (n = 35) and Spanish or English in Experiment 2 (n = 84). Subjects were divided into groups of English unilinguals, weak bilinguals, and strong bilinguals according to their performance on a naming task. In both experiments, simple problems consisted of two single-digit numbers. At least three single-digit numbers were used for complex problems in Experiment 1 and double-digit numbers in Experiment 2. Mean solution times, particularly for complex problems, were lowest for the monolingual group, followed in turn by the weak bilingual and strong bilingual groups, but these differences were not statistically reliable in either experiment. In Experiment 2, however, componential analyses of solution times indicated that strong bilingual subjects were slower at executing the carry operation when solving complex problems, relative to the two remaining groups. Results were interpreted in terms of the relationship between bilingualism and the representation and processing of numerical information. 相似文献
924.
925.
Lammers SE 《Christian century (Chicago, Ill. : 1902)》1993,110(25):845-846
926.
Genetic and Environmental Effects on Openness to Experience, Agreeableness, and Conscientiousness: An Adoption/Twin Study 总被引:4,自引:0,他引:4
C. S. Bergeman Heather M. Chlpuer Robert Plomin Nancy L. Pedersen G. E. McClearn John R. Nesselroade Paul T. Costa Jr. Robert R. McCrae 《Journal of personality》1993,61(2):159-179
ABSTRACT Previous research has indicated that extraversion and neuroticism are substantially affected both by genotype and environment. This study assesses genetic and environmental influences on the other three components of the five-factor model of personality: Openness to Experience, Agreeableness, and Conscientiousness. An abbreviated version of the NEO Personality Inventory (NEO-PI) was administered to 82 pairs of identical twins and 171 pairs of fraternal twins reared apart and 132 pairs of identical twins and 167 pairs of fraternal twins reared together. Estimates of genetic and environmental effects for Openness and Conscientiousness were similar to those found in other studies of personality: Genetic influence was substantial and there was little evidence of shared rearing environment. Results for Agreeableness were different: Genetic influence accounted for only 12% of the variance and shared rearing environment accounted for 21% of the variance. Few significant gender or age differences for genetic and environmental parameters were found in model-fitting analyses. 相似文献
927.
When subjects attempt to fake psychopathology on the MMPI, scores on subtle subscales tend to be lower than those of nonfaking subjects. Our study hypothesized that this paradox comes about because the subtle subscales have no predictive validity, but their face validity for psychopathology is the opposite of the keyed direction for psychopathology. Subjects who attempt to fake psychopathology do so on the basis of item content and thus achieve lower rather than higher scores. Three groups of 80 undergraduates took the MMPI under regular, faking-good, or faking-bad instructions. As expected, faking-bad subjects scored significantly lower than regular subjects on the 100 most subtle items, and this was due to their responses to those. 73 of the items whose face validity was misleading. The results are consistent with other work showing valid uses of subtle items in detecting deception. 相似文献
928.
Sharon E. Robinson Sari L. Roth Lynn L. Brown 《Journal of applied social psychology》1993,23(3):244-251
In an attempt to account for morale and job satisfaction among 314 nurses, this study investigated the influence of work-related and interpersonal variables. Morale on the unit was directly related to supervisor support, co-worker relationships, and work recognition. Personal morale was accounted for by recognition, physical environment, the job itself, and pay. Job satisfaction was predicted by personal morale, work commitment, job clarity, work pressure, and innovation. Suggestions for improving nurse morale and job satisfaction are made. 相似文献
929.
Substitutability is a construct borrowed from microeconomics that describes a continuum of possible interactions among the reinforcers in a given situation. Highly substitutable reinforcers, which occupy one end of the continuum, are readily traded for each other due to their functional similarity. Complementary reinforcers, at the other end of the continuum, tend to be consumed jointly in fairly rigid proportion, and therefore cannot be traded for one another except to achieve that proportion. At the center of the continuum are reinforcers that are independent with respect to each other; consumption of one has no influence on consumption of another. Psychological research and analyses in terms of substitutability employ standard operant conditioning paradigms in which humans and nonhumans choose between alternative reinforcers. The range of reinforcer interactions found in these studies is more readily accommodated and predicted when behavior-analytic models of choice consider issues of substitutability. New insights are gained into such areas as eating and drinking, electrical brain stimulation, temporal separation of choice alternatives, behavior therapy, drug use, and addictions. Moreover, the generalized matching law (Baum, 1974) gains greater explanatory power and comprehensiveness when measures of substitutability are included. 相似文献
930.
Delay-reduction theory states that the effectiveness of a stimulus as a conditioned reinforcer may be predicted most accurately by the reduction in time to primary reinforcement correlated with its onset. We review support for the theory and then discuss two new types of experiments that assess it. One compares models of choice in situations wherein the less preferred outcome is made more accessible; the other investigates whether frequency of conditioned reinforcement affects choice beyond the effect exerted by frequency of primary reinforcement. 相似文献