首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3415篇
  免费   168篇
  国内免费   5篇
  2020年   47篇
  2019年   53篇
  2018年   100篇
  2017年   83篇
  2016年   80篇
  2015年   50篇
  2014年   82篇
  2013年   400篇
  2012年   154篇
  2011年   151篇
  2010年   91篇
  2009年   77篇
  2008年   156篇
  2007年   147篇
  2006年   126篇
  2005年   105篇
  2004年   102篇
  2003年   98篇
  2002年   98篇
  2001年   82篇
  2000年   75篇
  1999年   71篇
  1998年   57篇
  1997年   34篇
  1996年   51篇
  1995年   52篇
  1994年   44篇
  1993年   38篇
  1992年   58篇
  1991年   36篇
  1990年   36篇
  1989年   36篇
  1988年   33篇
  1987年   40篇
  1986年   34篇
  1985年   38篇
  1984年   30篇
  1983年   34篇
  1982年   33篇
  1981年   29篇
  1980年   25篇
  1979年   26篇
  1978年   43篇
  1977年   35篇
  1976年   23篇
  1975年   35篇
  1974年   29篇
  1972年   19篇
  1971年   19篇
  1968年   27篇
排序方式: 共有3588条查询结果,搜索用时 15 毫秒
861.
862.
863.
864.
OBJECTIVE: We developed and tested the psychometric properties of Spanish versions of the Trait and State Food Cravings Questionnaires (FCQ-T and FCQ-S respectively). METHOD: The instruments were translated and adapted to Spanish and administered to undergraduate students from a Southern university in Spain (N = 271). The data were analyzed using confirmatory factor analysis to compare the factor structure of the English and Spanish versions of both questionnaires. RESULTS: The factors structure of both questionnaires obtained excellent fit indices across their Spanish versions with the one exception that some factors of the FCQ-S were more highly intercorrelated among the Spanish sample than the American. DISCUSSION: This study supports the conceptualization of food cravings as universal multidimensional motivational states that can be reliably measured and supports the use of the Spanish versions of the FCQ.  相似文献   
865.
Two experiments demonstrated stimulus control and generalization of conditioned punishment with humans. In both studies, responses first were reinforced with points exchangeable for money on a variable-interval schedule in the presence of one line length (S(D)). Next, a second line length was introduced, and point loss followed every response in the presence of that line (S(D)p). In the final training condition, points were deducted at session end. Response rate was lower in the presence of the S(D)p despite equal rates of points for money in the presence of both stimuli. In generalization testing for Experiment 1, the two lines were included in a 10-line continuum; S(D)p fell in the middle and the trained SD was at one end. Lines were presented randomly, and point delivery and loss contingencies were as in training but with points available in the presence of all lines. For all subjects, response rates were lowest around S(D)p and increased towards the SD end of the continuum. Because testing included only one or two lines beyond S(D), this pattern did not rule out S(D) generalization. Thus, in Experiment 2, stimuli beyond S(D) were added to generalization tests. Response rates did not decrease as a function of distance from S(D), clarifying the demonstration of punishment generalization.  相似文献   
866.
As part of the behavioral treatment in the Multimodal Treatment Study of Children with ADHD (MTA), children participated in an intensive summer treatment program (STP). This study examined the differences between 57 children in the combined treatment (Comb) group, who were medicated, and 60 children in the behavioral treatment (Beh) group, who were unmedicated throughout the STP. Comb children were significantly better than Beh on 5 measures: rule following, good sportsmanship, peer negative nominations, and STP teacher posttreatment ratings of inattention/overactivity. Groups did not differ on any of the other 30 measures, and responded similarly to the STP over time. Comparisons to normative data revealed that Comb children were more likely to fall within the normative range on 6 measures. The differences between these results and the main MTA results, in which Comb was always superior to Beh, are discussed in terms of the relative intensity of combined treatments. The implications for future studies of pharmacological and behavioral treatment for ADHD are discussed.  相似文献   
867.
These experiments examined the contribution of noradrenergic neurons in the nucleus of the solitary tract (NTS) in mediating the memory-facilitating effects of epinephrine. In Experiment 1, saline or 0.05 or 0.1 mg/kg of epinephrine was given intraperitoneally (ip) to rats after the second day of training in a light-dark Y-maze discrimination task. On a 20-trial retention test given 2 and 7 days later, the 0.1 mg/kg epinephrine group made significantly more correct responses than controls and required fewer trials to reach criterion. In Experiment 2, phosphate-buffered saline or the noradrenergic antagonist dl-propranolol (0.3 or 1.0 microg/0.5 microl) was infused into the NTS prior to an ip injection of saline or 0.1 mg/kg of epinephrine. The memory-enhancing effects of epinephrine were attenuated by the infusion of 0.3 microg/0.5 microl of dl-propranolol into the NTS. These findings indicate an involvement of NTS noradrenergic neurons in mediating the effects of peripheral epinephrine on memory storage processes.  相似文献   
868.
False memories sometimes contain specific details, such as location or colour, about events that never occurred. Based on the source-monitoring framework, we investigated one process by which false memories acquire details: the reactivation and misattribution of feature information from memories of similar perceived events. In Experiments 1A and 1B, when imagined objects were falsely remembered as seen, participants often reported that the objects had appeared in locations where visually or conceptually similar objects, respectively, had actually appeared. Experiment 2 indicated that colour and shape features of seen objects were misattributed to false memories of imagined objects. Experiment 3 showed that perceived details were misattributed to false memories of objects that had not been explicitly imagined. False memories that imported perceived features, compared to those that presumably did not, were subjectively more like memories for perceived events. Thus, perception may be even more pernicious than imagination in contributing to false memories.  相似文献   
869.
A significant number of animal and human studies demonstrate that memories for new experiences are encoded more effectively under environmental or laboratory conditions which elevate peripheral concentrations of the hormone epinephrine and in turn, induce emotional arousal. Although this phenomenon has been replicated across several learning paradigms, understanding of how this arousal related hormone affects memory processing remains obscure because epinephrine does not freely enter into the central circulation to produce any direct effects on the brain. This study examined whether epinephrine's actions on the CNS may be mediated by the initial activation of peripheral vagal fibers that project to the brain. The vagus was selected as a candidate for this role since it is densely embedded with beta-adrenergic receptors and the peripheral endings of this nerve innervate a broad spectrum of sensory organs that are directly affected by epinephrine release. Electrophysiological recordings of cervical vagal activity was measured over 110 min in urethane-anesthetized Sprague-Dawley rats given saline, epinephrine (0.3 mg/kg), the peripherally acting beta-adrenergic antagonist sotalol (2.0 mg/kg), or a combination of sotalol followed 15 min later by an injection of epinephrine. Epinephrine produced a significant increase in vagal nerve firing 10 min post-injection (p < .05) relative to controls and neural impulses recorded from the vagus remained significantly elevated for the remaining 55 min collection period. The excitatory actions of epinephrine were not observed in groups given an identical dose of the hormone after peripheral beta-adrenergic receptor blockade with sotalol. These findings demonstrate that neural discharge in vagal afferent fibers is increased by elevations in peripheral concentrations of epinephrine and the significance of these findings in understanding how epinephrine modulates brain limbic structures to encode and store new information into memory is discussed.  相似文献   
870.
The current study examined the combined moderating effects of cognitive ability and social support on the relation between race-related stress and quality of life in a sample of Black Americans. Participants (N = 323) were administered the Wonderlic Personnel Test (WPT; E. F. Wonderlic Associates, Inc., 1983), the Multidimensional Social Support Scale (MDSS; Winefield, Winefield, & Tiggemann, 1992), the Index of Race-Related Stress-Brief (Utsey, 1999), and the WHOQOL-BREF (The WHO Group, 1998). The findings indicated that cognitive ability and social support, conjointly, moderated the relation between individual and cultural race-related stress and quality of life for Black Americans in the current sample. The paper concludes by discussing the study's findings, limitations, and by offering recommendations for future research related to this area of inquiry.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号