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   24036篇
  免费   195篇
  国内免费   3篇
  24234篇
  2023年   27篇
  2022年   31篇
  2021年   60篇
  2020年   70篇
  2019年   90篇
  2018年   3562篇
  2017年   2907篇
  2016年   2360篇
  2015年   287篇
  2014年   188篇
  2013年   553篇
  2012年   770篇
  2011年   2549篇
  2010年   2642篇
  2009年   1575篇
  2008年   1852篇
  2007年   2333篇
  2006年   183篇
  2005年   336篇
  2004年   294篇
  2003年   232篇
  2002年   168篇
  2001年   97篇
  2000年   113篇
  1999年   65篇
  1998年   58篇
  1997年   57篇
  1996年   61篇
  1995年   38篇
  1994年   31篇
  1993年   34篇
  1992年   49篇
  1991年   29篇
  1990年   42篇
  1989年   29篇
  1988年   38篇
  1987年   35篇
  1986年   20篇
  1985年   20篇
  1984年   31篇
  1983年   16篇
  1982年   30篇
  1981年   22篇
  1980年   20篇
  1978年   24篇
  1973年   13篇
  1972年   15篇
  1971年   13篇
  1969年   15篇
  1968年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
We tested the effects of using a prosthesis for substitution of vision with audition (PSVA) on sensitivity to the Ponzo illusion. The effects of visual experience on the susceptibility to this illusion were also assessed. In one experiment, both early-blind and blindfolded sighted volunteers used the PSVA to explore several variants of the Ponzo illusion as well as control stimuli. No effects of the illusion were observed. The results indicate that subjects focused their attention on the two central horizontal bars of the stimuli, without processing the contextual cues that convey perspective in the Ponzo figure. In a second experiment, we required subjects to use the PSVA to consider the two converging oblique lines of the stimuli before comparing the length of the two horizontal bars. Here we were able to observe susceptibility to the Ponzo illusion in the sighted group, but to a lesser extent than in a sighted non-PSVA control group. No clear effect of the ilusion was obtained in early-blind subjects. These results suggest that, at least in sighted subjects, perception obtained with the PSVA shares perceptual processes with vision. Visual experience appears mandatory for a Ponzo illusion to occur with the PSVA.  相似文献   
212.
The Russian Jewish intellectual, Chaim Zhitlovsky (1865–1943), a leading architect of secular Jewish culture and thought, was a central figure in the progressive Jewish intelligentsia of the late nineteenth and early twentieth century. In an essay written in 1927, Yidn un Yiddishkayt (Jews and Jewishness), he sought to define the secular essence of what he calls Yiddishkayt. This essay is not the first in Zhitlovskys long publicistic career in which he searches for new, secular definitions of Jewish identity and culture. But this essay differs, since it is marked by Zhitlovskys use of contemporary social scientific notions of race and racial traits to conceptualize what he believes constitutes Jewishness in a non-religious context, along with his adoption of the mystical Jewish concept of the pintele yid, the theory of an innate Jewishness embodied by a Jewish spark. Zhitlovskys desire to craft a truly secular theory of Jewish identity led him ironically to accept models of Jewish identity at odds with his stated larger vision. In turning to contemporary racial theory, as well as long nurtured mystical models of Yiddishkayt, Zhitlovsky reveals the wide range of ideological discourses that led him to innovative and controversial notions of modern Jewish identity.  相似文献   
213.
214.
Previous studies on human causal learning (De Houwer & Beckers, 2003; De Houwer, Beckers, & Glautier, 2002) showed that secondary task difficulty (performing an easy vs. a difficult secondary task during the main causal learning task) and ceiling information (outcome occurs with a maximal vs. submaximal intensity) had an influence on forward blocking (i.e., lower causal ratings for cue T when AT+ trials are preceded by A+ trials than when no A+ trials are presented). We extended these studies by also examining self-reports of participants about the reasons behind their causal ratings. Blocking was found only for participants who reported an appropriate blocking inference. Furthermore, secondary task difficulty and ceiling information influenced the number of participants who reported an appropriate blocking inference. These findings point to a major impact of inferential reasoning in human causal learning.  相似文献   
215.
Results obtained with preschool children (Homo sapiens) were compared with results previously obtained from capuchin monkeys (Cebus apella) in matching-to-sample tasks featuring hierarchical visual stimuli. In Experiment 1, monkeys, in contrast with children, showed an advantage in matching the stimuli on the basis of their local features. These results were replicated in a 2nd experiment in which control trials enabled the authors to rule out that children used spurious cues to solve the matching task. In a 3rd experiment featuring conditions in which the density of the stimuli was manipulated, monkeys' accuracy in the processing of the global shape of the stimuli was negatively affected by the separation of the local elements, whereas children's performance was robust across testing conditions. Children's response latencies revealed a global precedence in the 2nd and 3rd experiments. These results show differences in the processing of hierarchical stimuli by humans and monkeys that emerge early during childhood.  相似文献   
216.
Much previous research has demonstrated that visual search is typically disrupted by the presence of a unique “singleton” distractor in the search display. Here we show that attentional capture by an irrelevant color singleton during shape search critically depends on availability of working memory to the search task: When working memory is loaded in a concurrent yet unrelated verbal short-term memory task, capture increases. These findings converge with previous demonstrations that increasing working memory load results in greater distractor interference in Stroop-like tasks (de Fockert, Rees, Frith, & Lavie, 2001; Lavie, Hirst, de Fockert, & Viding, 2004), which support the hypothesis that working memory provides goal-directed control of visual selective attention allowing to minimize interference by goal-irrelevant distractors.  相似文献   
217.
Short measures of child inattention-overactivity (IO), aggression-defiance (AG), and anxiety-depression or emotionality (EM) derived through a double validation procedure are administered to mothers of 243 clinic-referred suburban New York boys between 6 and 10 years of age. Mother-rated IO is uniquely related to poor performance on cognitive and achievement tests; observed inattentive, hyperactive, and impulsive behaviors in a restricted academic setting; less father education and lower family income; and most mother-reported impairments and treatment use. Mothers of high-IO boys describe themselves and their sons as having similar childhood symptoms. AG is uniquely related to child-reported disruptive behavior and sensation seeking, many measures of family conflict and negative parenting styles, and mother-reported symptom pervasiveness and number of treatments. EM is uniquely related only to poorer cognitive and achievement test performance, living with one parent, parents who considered themselves too busy, and fewer friends. Each dimension also is associated with parallel teacher-rated factors.  相似文献   
218.
Animal models are considered essential in research ensuing elucidation of human disease processes and subsequently, testing of potential therapeutic strategies. This is especially true for neurodegenerative disorders, in which the first steps in pathogenesis are often not accessible in human patients. Alzheimer's disease is vastly becoming a major medical and socioeconomic problem in our aging society. Valid animal models for this uniquely human condition should exhibit histopathological, biochemical, cognitive, and behavioral alterations observed in Alzheimer's disease patients. Major progress has been made since the understanding of the genetic basis of Alzheimer's disease and the development and improvement of transgenic mouse models. All present Alzheimer's disease models developed are partial but nevertheless essential in further unraveling the nature and spatial and temporal development of the complex molecular pathology underlying this condition. One of the more recent transgenic attempts to model Alzheimer's disease is the APP23 transgenic mouse. This article describes the development and assessment of this human amyloid precursor protein overexpression model. We summarize histopathological and biochemical, cognitive and behavioral observations made in heterozygous APP23 mice, thereby emphasizing the model's contribution to clarification of neurodegenerative disease mechanisms. In addition, the first therapeutic interventions in the APP23 model are included.  相似文献   
219.
This article argues that there is no sound basis for thinking that we have a general and strong duty to rectify disparities of wealth around the world, apart from the special case where some become wealthy by theft or fraud. The nearest thing we have to a rational morality for all has to be built on the interests of all, and they include substantial freedoms, but not substantial entitlements to others assistance. It is also pointed out that the situation of the worlds poor is not that of victims of disasters, but simply of less-developed technology, which can be repaired by full and free trade relations with others. The true savior of the worlds poor is the businessman, not the missionary. What we do need to do is strike down barriers to commerce, rather than requisition aid.  相似文献   
220.
Attentional bias to negative information has been proposed to be a cognitive vulnerability factor for the development of depression. In 2 experiments, the authors examined mood-congruent attentional bias in dysphoria. In both experiments, dysphoric and nondysphoric participants performed an attentional task with negative, positive, and neutral word cues preceding a target. Targets appeared either at the same or at the opposite location of the cue. Overall, results indicate that dysphoric participants show maintained attention for negative words at longer stimulus presentations, which is probably caused by impaired attentional disengagement from negative words. Furthermore, nondysphoric participants maintain their attention more strongly to positive words. These results are discussed in relation to recent developments in the pathogenesis and treatment of depression.  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