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   711篇
  免费   43篇
  754篇
  2024年   3篇
  2023年   3篇
  2022年   4篇
  2021年   4篇
  2020年   14篇
  2019年   23篇
  2018年   34篇
  2017年   31篇
  2016年   42篇
  2015年   17篇
  2014年   38篇
  2013年   78篇
  2012年   45篇
  2011年   46篇
  2010年   21篇
  2009年   27篇
  2008年   26篇
  2007年   32篇
  2006年   31篇
  2005年   28篇
  2004年   21篇
  2003年   27篇
  2002年   22篇
  2001年   12篇
  2000年   12篇
  1999年   9篇
  1998年   8篇
  1997年   7篇
  1996年   5篇
  1995年   6篇
  1994年   6篇
  1993年   4篇
  1992年   5篇
  1991年   11篇
  1990年   2篇
  1989年   3篇
  1988年   3篇
  1987年   3篇
  1986年   4篇
  1985年   3篇
  1983年   4篇
  1981年   4篇
  1980年   3篇
  1979年   2篇
  1978年   6篇
  1974年   2篇
  1973年   2篇
  1968年   2篇
  1967年   2篇
  1952年   1篇
排序方式: 共有754条查询结果,搜索用时 0 毫秒
111.
Two subject–verb agreement error elicitation studies tested the hierarchical feature-passing account of agreement computation in production and three timing-based alternatives: linear distance to the head noun, semantic integration, and a combined effect of both (a scope of planning account). In Experiment 1, participants completed subject noun phrase (NP) stimuli consisting of a head NP followed by two prepositional phrase (PP) modifiers, where the first PP modified the first NP, and the second PP modified one of the two preceding NPs. Semantic integration between the head noun and the local noun within each PP was held constant across structures. The mismatch error pattern showed an effect of linear distance to the head noun and no influence of hierarchical distance. In Experiment 2, participants completed NP PP PP stimuli in which both PPs modified the head noun, and both the order of the two PPs and the local nouns’ degree of semantic integration with the head noun were varied. The pattern of mismatch errors reflected a combination of semantic integration and linear distance to the head noun. These studies indicate that agreement processes are strongly constrained by grammatical-level scope of planning, with local nouns planned closer to the head having a greater chance of interfering with agreement computation.  相似文献   
112.
The correlation between cognitive ability test scores and performance was separately meta-analyzed for Asian, Black, Hispanic, and White racial/ethnic subgroups. Compared to the average White observed correlation ( = .33, N = 903,779), average correlations were lower for Black samples ( = .24, N = 112,194) and Hispanic samples ( = .30, N = 51,205) and approximately equal for Asian samples ( = .33, N = 80,705). Despite some moderating effects (e.g., type of performance criterion, decade of data collection, job complexity), validity favored White over Black and Hispanic test takers in almost all conditions that included a sizable number of studies. Black-White validity comparisons were possible both across and within the 3 broad domains that use cognitive ability tests for high-stakes selection and placement: civilian employment, educational admissions, and the military. The trend of lower Black validity was repeated in each domain; however, average Black-White validity differences were largest in military studies and smallest in educational and employment studies. Further investigation of the reasons for these validity differences is warranted.  相似文献   
113.
A literature search identified 17 articles reporting data on 34 subjects who engaged in precursors to severe problem behavior, which we examined to identify topographical and functional characteristics. Unintelligible vocalization was the most common precursor to aggression (27%) and property destruction (29%), whereas self- or nondirected movement was the most common precursor to SIB (32%). Unintelligible vocalization and object-directed movement were the most common precursors to behavior maintained by social-positive reinforcement (27% each), and unintelligible vocalization was the most common precursor to behavior maintained by social-negative reinforcement (29%). Only one precursor was reported for behavior maintained by automatic reinforcement.  相似文献   
114.
The purpose of this study is empirically evaluate a coping response that is thought to be unique among older Catholics - suffering in silence. Two hypotheses are examined. The first predicts that older Catholics will be more likely than older Protestants to suffer in silence when ongoing economic difficulty is encountered. The second hypothesis specifies that the potentially deleterious effects of financial problems on depressive symptoms will be offset for older adults who prefer to suffer in silence. Data from an ongoing nationwide survey of older people in the United States provide support for both hypotheses.  相似文献   
115.
116.
117.
Regulatory focus theory distinguishes between two independent structures of strategic inclination, promotion versus prevention. However, the theory implies two potentially independent definitions of these inclinations, the self-guide versus the reference-point definitions. Two scales (the Regulatory Focus Questionnaire, Higgins al., 2001, and the General Regulatory Focus Measure, Lockwood, Jordan, & Kunda, 2002) have been widely used to measure dispositional regulatory focus. We suggest that these two scales align respectively with the two definitions, and find that the two scales are largely uncorrelated. Both conceptual and methodological implications are discussed.  相似文献   
118.
Objectification theory suggests that women internalize an observer’s perspective on the body (self objectification; Fredrickson and Roberts, Psychol Women Q 22:173–206, 1997); however, certain contexts and thoughts may make self-objectification more likely. Because the pursuit of relationships is tied to attractiveness, the present study examines whether women have an automatic link between self-objectification and romantic relationships. Using a US undergraduate sample, women (N?=?86) of different relationship statuses were either exposed to relationship-related or neutral words in a lexical decision making task. Following relationship priming, single women showed greater self-objectification and women in relationships showed less self-objectification. These findings are discussed in terms of self-objectification theory and the importance of attractiveness and beauty in the pursuit of relationships.  相似文献   
119.
Activation of β-adrenergic receptors (β-ARs) enhances hippocampal memory consolidation and long-term potentiation (LTP), a likely mechanism for memory storage. One signaling pathway linked to β-AR activation is the cAMP-PKA pathway. PKA is critical for the consolidation of hippocampal long-term memory and for the expression of some forms of long-lasting hippocampal LTP. How does β-AR activation affect the PKA-dependence, and persistence, of LTP elicited by distinct stimulation frequencies? Here, we use in vitro electrophysiology to show that patterns of stimulation determine the temporal phase of LTP affected by β-AR activation. In addition, only specific patterns of stimulation recruit PKA-dependent LTP following β-AR activation. Impairments of PKA-dependent LTP maintenance generated by pharmacologic or genetic deficiency of PKA activity are also abolished by concurrent activation of β-ARs. Taken together, our data show that, depending on patterns of synaptic stimulation, activation of β-ARs can gate the PKA-dependence and persistence of synaptic plasticity. We suggest that this may allow neuromodulatory receptors to fine-tune neural information processing to meet the demands imposed by numerous synaptic activity profiles. This is a form of “metaplasticity” that could control the efficacy of consolidation of hippocampal long-term memories.The hippocampus importantly contributes to memory function in the mammalian brain (Zola-Morgan et al. 1986; Eichenbaum et al. 1990; Otto and Eichenbaum 1992; Phillips and LeDoux 1992; Remondes and Schuman 2004). It has reciprocal connections with numerous cortical areas, including those responsible for high-level integration of spatial and contextual data from the external environment (Lavenex and Amaral 2000). As such, the hippocampus is well positioned to receive and survey a broad range of information and select behaviorally salient data for long-term storage. Activity-dependent enhancement of hippocampal synaptic strength can store information carried in patterns of afferent neural activity (Bliss and Collingridge 1993; Moser et al. 1998; Nathe and Frank 2003; Whitlock et al. 2006). Substantial evidence suggests that long-term potentiation (LTP) of synaptic strength plays important roles in the formation of long-term memory (LTM) (Doyere and Laroche 1992; Bourtchuladze et al. 1994; Abel and Lattal 2001; Genoux et al. 2002). As such, mechanistic studies of LTP have shed valuable light on how the mammalian brain stores new information.The hippocampus receives dense noradrenergic projections from the locus coeruleus, a brain structure that can influence many vital brain functions, including attention, sleep, arousal, mood regulation, learning, and memory (Berridge and Waterhouse 2003). Both α- and β-adrenergic receptor subtypes are present on hippocampal neurons (Morrison and Foote 1986; Berridge and Waterhouse 2003), and noradrenaline (NA) acts on hippocampal β-adrenergic receptors (β-ARs) to facilitate the retention and recall of memory (Izquierdo et al. 1998; Ji et al. 2003; Murchison et al. 2004). In humans, stimulation of the noradrenergic neuromodulatory system enhances memory for emotional stimuli, and inhibition of β-ARs prevents this memory enhancement (Cahill et al. 1994; van Stegeren et al. 1998; O’Carroll et al. 1999).Consistent with the notion that selective enhancement of LTM may occur following β-AR activation, stimulation of β-ARs can also facilitate the persistence of LTP. In areas CA3 and CA1, β-AR activation facilitates the induction of long-lasting LTP when paired with certain patterns of electrical stimulation (Huang and Kandel 1996; Gelinas and Nguyen 2005). However, the mechanisms by which different patterns of stimulation control synaptic responsiveness to β-AR activation are unclear.β-ARs couple to guanine-nucleotide-binding regulatory Gs proteins to stimulate adenylyl cyclase activity and increase intracellular cAMP (Seeds and Gilman 1971; Maguire et al. 1977). A main target of cAMP signaling is activation of cAMP-dependent protein kinase (PKA), a kinase that is required for some forms of long-lasting LTP and for consolidation of hippocampal LTM (Frey et al. 1993; Abel et al. 1997; Nguyen and Woo 2003). Interestingly, the PKA-dependence of hippocampal LTP displays plasticity: Specific temporal patterns of synaptic stimulation, such as repeated and temporally spaced 100-Hz stimulation, elicit LTP that requires PKA for its expression (Woo et al. 2003). Also, spatial “enrichment” can increase the PKA-dependence of LTP in mice, and this is correlated with improved hippocampal memory function (Duffy et al. 2001). However, it is unclear whether activation of β-ARs can critically gate the PKA-dependence of LTP. In this study, we examine the effects of β-AR activation on LTP generated by various patterns of afferent stimulation in area CA1 of the hippocampus, and we determine the role of PKA in these β-AR-modulated forms of LTP.  相似文献   
120.
We used a systems perspective to examine relationships between adolescents’ perceptions of overall family system functioning and selected parental behaviors. Self-report questionnaire data from 160 ninth and tenth grade students were analyzed using MANCOVA and discriminant analysis. The results showed two parental behaviors, support and monitoring distinguished between types of overall family system functioning. Adolescents in balanced and moderately balanced overall family functioning reported greater parental support, while adolescents in balanced and extreme overall family functioning reported greater parental monitoring. We present the implications of our findings for parent education and assessment.  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