全文获取类型
收费全文 | 124023篇 |
免费 | 5062篇 |
国内免费 | 42篇 |
出版年
2020年 | 1311篇 |
2019年 | 1647篇 |
2018年 | 2257篇 |
2017年 | 2357篇 |
2016年 | 2443篇 |
2015年 | 1761篇 |
2014年 | 2119篇 |
2013年 | 10019篇 |
2012年 | 3882篇 |
2011年 | 4058篇 |
2010年 | 2501篇 |
2009年 | 2538篇 |
2008年 | 3584篇 |
2007年 | 3535篇 |
2006年 | 3285篇 |
2005年 | 2881篇 |
2004年 | 2783篇 |
2003年 | 2631篇 |
2002年 | 2696篇 |
2001年 | 3793篇 |
2000年 | 3597篇 |
1999年 | 2761篇 |
1998年 | 1446篇 |
1997年 | 1264篇 |
1996年 | 1292篇 |
1995年 | 1187篇 |
1992年 | 2311篇 |
1991年 | 2170篇 |
1990年 | 2191篇 |
1989年 | 2047篇 |
1988年 | 2009篇 |
1987年 | 1908篇 |
1986年 | 1949篇 |
1985年 | 2041篇 |
1984年 | 1737篇 |
1983年 | 1573篇 |
1982年 | 1203篇 |
1981年 | 1187篇 |
1979年 | 1856篇 |
1978年 | 1344篇 |
1975年 | 1507篇 |
1974年 | 1684篇 |
1973年 | 1789篇 |
1972年 | 1469篇 |
1971年 | 1387篇 |
1970年 | 1258篇 |
1969年 | 1313篇 |
1968年 | 1613篇 |
1967年 | 1454篇 |
1966年 | 1322篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
901.
From previous research, the ultrasonic vocalizations of male mice (Mus domesticus) to female mouse urine were hypothesized to be learned as a result of classical conditioning during adult heterosexual encounters. According to this interpretation, a previously neutral conditioned stimulus in female urine comes to elicit vocalizations as a result of its association with some other unknown unconditioned stimulus associated with adult females. However, the research from which this hypothesis was derived utilized urine collected from females housed in metabolic cages. Three experiments further examined the classical conditioning hypothesis using two types of female urine: (i) metabolic-cage-collected urine and (ii) freshly voided urine. Experiment 1 demonstrated that, in contrast to vocalizations to metabolic-cage-collected urine, adult heterosexual experience was not necessary for males to vocalize to freshly voided female urine. In addition, unlike metabolic-cage-collected urine (Experiment 3), freshly voided urine remained a potent stimulus for eliciting vocalizations during repeated testing (Experiments 2 and 3). Finally, freshly voided urine appeared to cause a previously neutral stimulus (cotton swab) to acquire ultrasound eliciting properties (Experiment 2). We suggest from these findings that two chemosignals that elicit vocalizations from males may exist in female mouse urine: (i) a potent, but volatile or easily degraded, unconditioned stimulus to which males vocalize without sexual experience and (ii) a nonvolatile, chemically stable conditioned stimulus. 相似文献
902.
The global threat of AIDS requires massive public educational campaigns that employ social and behavioral sciences such as psychology, sociology, and anthropology because sexual behavior possesses a social dimension. Research is concerned with what stimulates behavioral change, what are the prerequisites of learned behavior, and what enables personal control over the environment and future. Educational programs designing strategies for AIDS prevention require social and behavioral science content and input. Interdisciplinary provides general principles with psychological, social, and cultural aspects of human behavior. Without knowledge about psychological processes (thinking, perception, speech, aspects of personality, and interactive behavior) and social processes (economic conditions, social networks, and resources) which are implicated in health problems and also in AIDS, these educational programs cannot produce credible results. These programs and their subsequent implementation require their application in practice in a systemic and consistent fashion. Evaluations are also needed to make sure that the applied processes for behavioral change conform to methodological criteria that ensure their effectiveness. These types of studies are more complex than pure AIDS research which is aimed at finding a cure. 相似文献
903.
In a group of male and female subjects we studied the VEPs related to the solution of a lexical decision task presented in the Left and Right Hemispaces with respect to the Central position in order to explore the electrophysiological correlates of the performance asymmetries obtained when overt spatial attention is directed to the Left or Right Hemispace. When stimuli were presented in the Left Hemispace a significant asymmetry was observed between the two hemispheres of the negative activity around 280 msec in the occipital-parietal areas. Moreover a general increase in the Central and Frontal areas of both the hemispheres was observed. In this paper we discuss why these effects can be considered to be the cause of the costs on accuracy observed in the male subjects. The differences obtained with the female group are discussed in relation to the observed modification on the negative activity around 400 msec with stimuli in the Left Hemispace. These findings give some suggestions about the interaction of structural and attentional mechanisms in the brain during the solution of a lateralized cognitive task. 相似文献
904.
Patterns of coping with cancer. 总被引:12,自引:0,他引:12
We identified five patterns of coping in a sample of 603 cancer patients: "seeking or using social support," "focusing on the positive," "distancing," "cognitive escape-avoidance," and "behavioral escape-avoidance." Relationships of these coping patterns to sociodemographic characteristics, medical factors, stress appraisals, psychotherapeutic experience, and emotional distress were tested using correlational and regression techniques. Type of cancer, time since diagnosis, and whether a person was currently in treatment had few or no relationships to coping. The specific cancer-related problem (e.g., pain, fear of future) was also not associated with how individuals coped. Perceptions of its stressfulness, however, were related to significantly more coping through social support and more of both forms of escape-avoidance. Coping through social support, focusing on the positive, and distancing was associated with less emotional distress, whereas using cognitive and behavioral escape-avoidance was associated with more emotional distress. Implications of the results for understanding coping processes and intervention with cancer patients are discussed. 相似文献
905.
S Bentin M Moscovitch I Heth 《Journal of experimental psychology. Learning, memory, and cognition》1992,18(6):1270-1283
Event-related potentials (ERPs) recorded on the scalp were shown to be sensitive indicators of the strength of a memory trace on both implicit and explicit tests of memory. In explicit recognition tests, the amplitude of a positive potential identified as P300 was larger for "old" than for "new" words regardless of whether the subject categorized the items correctly. This effect, however, was statistically reliable only when the recognition memory (d') was relatively high. In contrast to ERPs, the reaction times in explicit recognition were sensitive to accuracy but not to repetition. In implicit tests, lexical decisions to repeated words were faster than to newly presented words. The magnitude of the repetition effect varied neither with elapsed time since the last repetition nor with the number of previous repetitions. In contrast, the P300 elicited by the same words were sensitive to both lag and recency of repetition, suggesting that they were influenced by the episodic memory strength of the items. 相似文献
906.
H Intraub R S Bender J A Mangels 《Journal of experimental psychology. Learning, memory, and cognition》1992,18(1):180-191
Ss tend to remember close-up photographs as having had extended boundaries (Intraub & Richardson, 1989). Three alternate explanations were tested: object completion, distortion toward a perceptual schema, and normalization toward a prototypic view. In three experiments, 55-130 undergraduates viewed 16 close-up, prototypic, or wide-angle views of objects for 15 s each. Immediately or 48 hr later, they rated test pictures on a 5-point scale as "same", "closer up", or "father away." Results ruled out object completion because boundary extension occurred when the picture contained no incomplete objects. Immediate tests supported the perceptual schema hypothesis because all unidirectional distortions involved boundary extension. Delayed tests were more suggestive of a memory schema effect because wide-angle pictures yielded boundary restriction. A two-component model of picture processing is proposed. 相似文献
907.
Remembering pictures: pleasure and arousal in memory. 总被引:17,自引:0,他引:17
M M Bradley M K Greenwald M C Petry P J Lang 《Journal of experimental psychology. Learning, memory, and cognition》1992,18(2):379-390
Incidental memory performance for pictures that varied along the affective dimensions of pleasantness and arousal was assessed. For both an immediate and delayed (1 year later) free-recall task, only the arousal dimension had a stable effect on memory performance: Pictures rated as highly arousing were remembered better than low-arousal stimuli. This effect was corroborated in a speeded recognition test, in which high-arousal materials encoded earlier in the experiment produced faster reaction times than their low-arousal counterparts. Pleasantness affected reaction time decisions only for pictures not encoded earlier. These results suggest that whereas both the dimensions of pleasantness and arousal are processed at initial encoding, long-term memory performance is mainly affected by arousal. 相似文献
908.
Anterior cerebral asymmetry and the nature of emotion. 总被引:14,自引:0,他引:14
R J Davidson 《Brain and cognition》1992,20(1):125-151
This article presents an overview of the author's recent electrophysiological studies of anterior cerebral asymmetries related to emotion and affective style. A theoretical account is provided of the role of the two hemispheres in emotional processing. This account assigns a major role in approach- and withdrawal-related behavior to the left and right frontal and anterior temporal regions of two hemispheres, respectively. Individual differences in approach- and withdrawal-related emotional reactivity and temperament are associated with stable differences in baseline measures of activation asymmetry in these anterior regions. Phasic state changes in emotion result in shifts in anterior activation asymmetry which are superimposed upon these stable baseline differences. Future directions for research in this area are discussed. 相似文献
909.
910.