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   2391篇
  免费   145篇
  2536篇
  2023年   13篇
  2022年   28篇
  2021年   38篇
  2020年   70篇
  2019年   67篇
  2018年   100篇
  2017年   98篇
  2016年   111篇
  2015年   77篇
  2014年   86篇
  2013年   284篇
  2012年   144篇
  2011年   127篇
  2010年   95篇
  2009年   98篇
  2008年   114篇
  2007年   84篇
  2006年   59篇
  2005年   58篇
  2004年   98篇
  2003年   52篇
  2002年   52篇
  2001年   41篇
  2000年   37篇
  1999年   46篇
  1998年   33篇
  1997年   22篇
  1996年   17篇
  1995年   22篇
  1994年   24篇
  1993年   26篇
  1992年   21篇
  1991年   23篇
  1990年   19篇
  1989年   11篇
  1988年   11篇
  1987年   10篇
  1986年   10篇
  1985年   9篇
  1984年   11篇
  1980年   12篇
  1978年   12篇
  1976年   14篇
  1975年   11篇
  1974年   18篇
  1973年   11篇
  1972年   9篇
  1970年   9篇
  1968年   12篇
  1966年   10篇
排序方式: 共有2536条查询结果,搜索用时 15 毫秒
81.
This study explored the applicability of previous research (obtained with groups of college-educated women) about the subjective experience of aging in midlife to men and less-educated people. Two-hundred fifty-nine men and women who graduated from a public high school in 1955-1957 retrospectively assessed their feelings of identity certainty, confident power, generativity, and concern about aging for their 60s, 40s, and 20s. Participants reported higher levels of identity certainty, confident power, and concern about aging at each age, and a leveling off of generativity in their 60s. There were some gender and social class differences. Although men and women recalled the same trajectory of these feelings, men reported higher levels of identity certainty and confident power across age. Non-college-educated men recalled the highest levels of concern about aging across age. We discuss how these findings add to our understanding of the experience of aging in these domains.  相似文献   
82.
This study examined the emotional response of 110 adolescents living in the New York metropolitan area one month and five months after the destruction of the World Trade Center (WTC) by terrorists. The purpose of the study was to assess emerging hypotheses in political psychology that suggest that there are differential emotional responses to a national trauma that recede in predictable directions. The results followed predictions and indicate that adolescents experienced a higher level of emotions related to the Crisis and Bereavement dimension than affect associated with Vulnerability and that the emotional response decreased during the four-month follow-up period. There was no effect on emotional response from the biological sex or political orientation of the respondents, which is inconsistent with other studies in the literature. The absence of a political orientation effect is explained in terms of the lack of a domestic ideological difference in response to the terrorist attack.  相似文献   
83.
As people study more facts about a concept, it takes longer to retrieve a particular fact about that concept. This fan effect (Anderson, 1974) has been attributed to competition among associations to a concept. Alternatively, the mental-model theory (Radvansky & Zacks, 1991) suggests that the fan effect disappears when the related concepts are organized into a single mental model. In the present study, attentional focus was manipulated to affect the mental model to be constructed. One group of participants focused on the person dimension of personlocation pairs, whereas the other group focused on the location dimension. The result showed that the fan effect with the focused dimension was greater than the fan effect with the nonfocused dimension, which is contrary to the mental-model theory. The number of associations with a concept is indeed crucial during retrieval, and the importance of the information seems to be accentuated with attentional focus.  相似文献   
84.
A number of lines of study suggest that word meanings are not always fully exploited in comprehension. In two experiments, we used a text-change paradigm to study depth of semantic processing during reading. Participants were instructed to detect words that changed across two consecutive presentations of short texts. The results suggest that the full details of word meanings are not always incorporated into the interpretation and that the degree of semantic detail in the representation is a function of linguistic focus. The results provide evidence for the idea that representations are only good enough for the purpose at hand (Ferreira, Bailey, & Ferraro, 2002).  相似文献   
85.
Substantial evidence suggests that alterations in noradrenergic function contribute to the cognitive impairments of schizophrenia. Activation of post-junctional alpha 2a-adrenergic receptors in the prefrontal cortex by the alpha 2a-selective agonist guanfacine has demonstrated some preliminary benefit in subjects with schizophrenia treated with atypical antipsychotics. alpha 1-adrenergic receptor activity may be less important in mediating the cognitive impairments of schizophrenia. beta-adrenergic receptors may serve as another potential target for cognitive remediation in schizophrenia. However, the potential increase in memory consolidation in schizophrenia patients produced by beta-adrenergic agonists may be outweighed by the impairment in cognitive flexibility and executive functioning produced by beta-adrenergic agonists. Finally, norepinephrine reuptake inhibitors, such as atomoxetine, hold promise as potential cognitive enhancers in schizophrenia because of their ability to indirectly but selectively increase extracellular dopamine concentrations in the prefrontal cortex.  相似文献   
86.
The concept of informed consent was one of the most fruitful ideas that deeply changed the relationships between physicians and their patients from paternalism to respect for the personal autonomy of subjects needing professional medical care. The great progress in medicine, also involving the pharmaceutical industry, has created an increasing need to perform different clinical and experimental trials. The evolution of clinical research in the last decades has influenced strongly the design of these studies. One of the most important changes in this field has been the use of placebo groups in double-blind controlled studies. The controversies have involved not only the use of placebo when standard or proven treatment was available, but also some specific problems concerning the procedure of obtaining informed consent in such trials. This paper briefly presents the evolution of informed consent in Poland as well as different ethical and legal problems concerning informed consent and the use of placebo controls in clinical trials. An earlier version of this paper was presented at an international conference, “Placebo: Its Action and Place in Health Research Today,” held in Warsaw, Poland on 12–13 April, 2003.  相似文献   
87.
Neurophysiological experiments with monkeys have demonstrated that working memory (WM) is associated with persistent neural activity in multiple brain regions, such as the prefrontal cortex (PFC), the parietal cortex, and posterior unimodal association areas. WM maintenance is believed to require the coordination of these brain regions, which do not function in isolation but, rather, interact to maintain visual percepts that are no longer present in the environment. However, single-unit physiology studies and traditional univariate analyses of functional brain imaging data cannot evaluate interactions between distant brain regions, and so evidence of regional integration during WM maintenance is largely indirect. In this study, we utilized a recently developed multivariate analysis method that allows us to explore functional connectivity between brain regions during the distinct stages of a delayed face recognition task. To characterize the neural network mediating the on-line maintenance of faces, the fusiform face area (FFA) was defined as a seed and was then used to generate whole-brain correlation maps. A random effects analysis of the correlation data revealed a network of brain regions exhibiting significant correlations with the FFA seed during the WM delay period. This maintenance network included the dorsolateral and ventrolateral PFC, the premotor cortex, the intraparietal sulcus, the caudate nucleus, the thalamus, the hippocampus, and occipitotemporal regions. These findings support the notion that the coordinated functional interaction between nodes of a widely distributed network underlies the active maintenance of a perceptual representation.  相似文献   
88.
J. B. Miner and N. S. Raju (2004) contended that there are additional studies that compare the risk propensity of entrepreneurs and managers, which, when added to the data from W. H. Stewart and P. L. Roth (2001) and meta-analyzed, produce relationships between risk propensity and entrepreneurial status that are substantially weaker than previously believed. This conclusion was evaluated by identifying and examining methodological problems associated with their inclusion of effect sizes (i.e., ds) from studies with variables not relevant to research questions, dependent samples, extraneous variance in outcome variables, and confusion of constructs. When these methodological issues were addressed, a new meta-analysis indicated an overall conclusion consistent with that of Stewart and Roth, but the results varied according to instrumentation, particularly objective instrumentation (observed d = 0.31) versus the Miner Sentence Completion Scale-Form T (observed d = -0.35).  相似文献   
89.
The present experiment examined the one-target advantage (OTA) with regard to saccadic eye movements. The OTA, previously found with manual pointing responses, refers to the finding that movements are executed faster when the limb is allowed to stop on the target compared to the situation where it has to proceed and hit a second target. Using an adapted limb movement OTA task, saccades of 5 degrees and 15 degrees were made to (a) a single target (one-target), (b) one target and immediately to another target without a change in direction (two-target-extension), and (c) one target and immediately back to the start location (two-target-reversal). Unlike manual movements, the movement times for the initial saccade in the two-target-extension condition were not prolonged compared to either of the other two conditions. Moreover, this pattern of results was found for both the shorter and longer amplitude saccades. The results indicate that the OTA does not occur in the oculomotor system and therefore is not a general motor control phenomenon.  相似文献   
90.
Substantial variation exists in the importance of olfaction in influencing individuals' preferences, yet the sources of this variation remain elusive. The authors explored responsivity to 2 odorants as 1 potential source. Participants (N = 258) completed the Affective Impact of Odor Scale and were assessed for responsivity to the putative human pheromone androstenone and amyl acetate. Results showed a significant relationship between odorant responsivity and self-reports of the influence of odors. People able to smell androstenone more commonly reported odors as having a negative effect on interpersonal relationships than did people anosmic to androstenone, whereas responsivity to amyl acetate was associated with positive effects of odors on relationships. Responsivity to certain odorants may be an important factor affecting human social interactions.  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