全文获取类型
收费全文 | 2707篇 |
免费 | 102篇 |
出版年
2023年 | 16篇 |
2020年 | 36篇 |
2019年 | 42篇 |
2018年 | 56篇 |
2017年 | 69篇 |
2016年 | 67篇 |
2015年 | 65篇 |
2014年 | 53篇 |
2013年 | 252篇 |
2012年 | 99篇 |
2011年 | 104篇 |
2010年 | 68篇 |
2009年 | 71篇 |
2008年 | 98篇 |
2007年 | 94篇 |
2006年 | 96篇 |
2005年 | 75篇 |
2004年 | 82篇 |
2003年 | 93篇 |
2002年 | 99篇 |
2001年 | 40篇 |
2000年 | 36篇 |
1999年 | 50篇 |
1998年 | 51篇 |
1997年 | 53篇 |
1996年 | 33篇 |
1995年 | 39篇 |
1994年 | 48篇 |
1993年 | 47篇 |
1992年 | 56篇 |
1991年 | 36篇 |
1990年 | 45篇 |
1989年 | 31篇 |
1988年 | 33篇 |
1987年 | 35篇 |
1986年 | 31篇 |
1985年 | 29篇 |
1984年 | 37篇 |
1983年 | 34篇 |
1982年 | 26篇 |
1981年 | 33篇 |
1980年 | 32篇 |
1979年 | 41篇 |
1978年 | 34篇 |
1977年 | 23篇 |
1976年 | 37篇 |
1975年 | 19篇 |
1974年 | 21篇 |
1973年 | 21篇 |
1966年 | 15篇 |
排序方式: 共有2809条查询结果,搜索用时 15 毫秒
171.
Mohanty A Herrington JD Koven NS Fisher JE Wenzel EA Webb AG Heller W Banich MT Miller GA 《Journal of abnormal psychology》2005,114(1):16-27
Negatively valenced stimuli foster cognitive impairment in schizotypy and schizophrenia. To identify relevant brain mechanisms, the authors had 16 positive-schizotypy and 16 control participants perform an emotional Stroop task, judging the ink color of negative and neutral words during functional magnetic resonance imaging (fMRI) of regional brain activity. Schizotypy individuals showed increased right and decreased left activity in dorsolateral prefrontal cortex, indicating a deficit in maintenance of attentional set in the presence of negative emotional distractors. They also showed abnormal activity in ventral limbic areas, including decreased activity in nucleus accumbens and increased activity in hippocampus and amygdala, a circuit involved in the integration of cognitive and affective processes. These results indicate that aspects of emotion-cognition processes and the brain mechanisms that implement them are similar in schizotypy and schizophrenia. 相似文献
172.
Brief multiple-stimulus-without-replacement (MSWO) preference assessments were conducted with 3 adolescent boys with emotional-behavioral disorders in the context of their public school educational program. The reinforcing effects of stimuli identified as high, medium, and low preference were then evaluated using an alternating treatments design in which, following an initial baseline, stimuli were delivered contingent on on-task behavior. High-preference stimuli produced the highest percentages of on-task behavior for all 3 participants. 相似文献
173.
Sixty-two first and second grade students (28 boys, 34 girls) were exposed to one of three commercial videotapes in which either all-boys (traditional condition) or all-girls (nontraditional) were playing with a toy. Participants in the control condition were exposed to nontoy commercials. After exposure to one of the conditions participants performed a toy sort where they were asked if six toys, including the two manipulated toys, were for boys, girls, or both boys and girls. Participants in the nontraditional condition were more likely to report that the manipulated toys were for both boys and girls than were participants in the traditional condition, who were more likely to report that the manipulated toys were for boys. This effect was stronger for boys than for girls. 相似文献
174.
175.
Two experiments exploring the effects of social category membership on real-life helping behavior are reported. In Study 1, intergroup rivalries between soccer fans are used to examine the role of identity in emergency helping. An injured stranger wearing an in-group team shirt is more likely to be helped than when wearing a rival team shirt or an unbranded sports shirt. In Study 2, a more inclusive social categorization is made salient for potential helpers. Helping is extended to those who were previously identified as out-group members but not to those who do not display signs of group membership. Taken together, the studies show the importance of both shared identity between bystander and victim and the inclusiveness of salient identity for increasing the likelihood of emergency intervention. 相似文献
176.
We examine whether children with early unilateral brain injury show an IQ decline over the course of development. Fifteen brain injured children were administered an IQ test once before age 7 and again several years later. Post-7 IQ scores were significantly lower than pre-7 IQ scores. In addition, pre-7 IQ scores were lower for children with larger lesions, but children with smaller lesions and higher pre-7 IQ scores showed a greater IQ decline over time. These findings suggest that the cognitive outcomes of children with early lesions, particularly those with relatively small lesions, change over the course of development. 相似文献
177.
In their role as committed advocates, parents of children with Down syndrome have always sought alternative therapies, mainly to enhance cognitive function but also to improve their appearance. Nutritional supplements have been the most frequent type of complementary and alternative therapy used. Cell therapy, plastic surgery, hormonal therapy, and a host of other therapies such as massage therapy have been used. There is a lack of well-designed scientific studies on the use of alternative therapies in individuals with Down syndrome. Antioxidants hold theoretical promise for treatment of the cognitive, immune, malignancy, and premature aging problems associated with Down syndrome. Medications for treatment of Alzheimer's disease may also result in benefit for the population of individuals with Down syndrome. 相似文献
178.
Zimmerman IL Castilleja NF 《Mental retardation and developmental disabilities research reviews》2005,11(3):238-246
The PLS-4 (Preschool Language Scale, 4th edition) is a psychometrically sound instrument constructed to assess language skills in children from birth to 6 years 11 months. It is a useful diagnostic and research tool that can be used to identify current comprehension and expressive language skills and can measure changes in language skills over time. The test is individually administered and includes tasks that assess skills in the areas of preverbal behaviors, as well as linguistic skills in the areas of semantics, morphology, syntax, integrative language skills, and preliteracy skills. Extensive reliability and validity evidence are presented. The test has been used extensively in research examining language development of young children from different home environments, children with identified medical conditions, and children participating in a variety of habilitation and intervention programs. Both the previous edition (PLS-3) and the new PLS-4 English and Spanish editions are used extensively in clinical, medical, and research settings to examine developmental language patterns of infants, toddlers, and preschoolers. 相似文献
179.
Levine SR 《CNS spectrums》2005,10(7):567-578
Blood disorders have been implicated in approximately 5% to 10% of ischemic stroke, with an increased frequency in younger patients. Most disorders are associated with an increased thrombotic tendency and, therefore, an increased risk of ischemic stroke. Less commonly, a bleeding diathesis may predispose a patient to intracranial hemorrhage. While many conditions predisposing to thrombosis have been associated with stroke, there are relatively few prospective, epidemiological studies addressing hypercoagulable states and arterial stroke compared with the number of studies on the genetic thrombophilias, which are predominantly associated with venous thrombosis. When ordering tests of coagulation in stroke patients, one should keep in mind whether the results will influence therapy and/or patient outcome. It is generally not advocated to screen all stroke patients for a "hypercoagulable workup". Typically, patients to be screened for coagulation defects will have a prior history of one or more unexplained thromboembolic events. The yield for diagnosing a hypercoagulable state is typically greatest for young stroke patients or those with a family history of thrombosis and who have no other explanations for their stroke (cryptogenic stroke). The yield in typically low in unselected ischemic stroke patients and older patients. Treatment of a first stroke with a documented hypercoagulable state is typically long-term or indefinite duration warfarin, although there is a paucity of clinical trial data supporting this clinical approach. 相似文献
180.
Structure and stimulus familiarity: a study of memory in chess-players with functional magnetic resonance imaging 总被引:1,自引:0,他引:1
A grandmaster and an international chess master were compared with a group of novices in a memory task with chess and non-chess stimuli, varying the structure and familiarity of the stimuli, while functional magnetic resonance images were acquired. The pattern of brain activity in the masters was different from that of the novices. Masters showed no differences in brain activity when different degrees of structure and familiarity where compared; however, novices did show differences in brain activity in such contrasts. The most important differences were found in the contrast of stimulus familiarity with chess positions. In this contrast, there was an extended brain activity in bilateral frontal areas such as the anterior cingulate and the superior, middle, and inferior frontal gyri; furthermore, posterior areas, such as posterior cingulate and cerebellum, showed great bilateral activation. These results strengthen the hypothesis that when performing a domain-specific task, experts activate different brain systems from that of novices. The use of the experts-versus-novices paradigm in brain imaging contributes towards the search for brain systems involved in cognitive processes. 相似文献