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   294篇
  免费   6篇
  300篇
  2020年   5篇
  2018年   4篇
  2017年   5篇
  2016年   9篇
  2015年   2篇
  2014年   8篇
  2013年   25篇
  2012年   7篇
  2011年   7篇
  2010年   7篇
  2009年   9篇
  2008年   9篇
  2007年   9篇
  2006年   10篇
  2005年   9篇
  2004年   11篇
  2003年   7篇
  2002年   7篇
  2001年   8篇
  2000年   6篇
  1999年   4篇
  1998年   2篇
  1997年   4篇
  1995年   2篇
  1994年   4篇
  1993年   4篇
  1992年   7篇
  1991年   3篇
  1990年   5篇
  1987年   4篇
  1986年   5篇
  1985年   2篇
  1982年   4篇
  1980年   2篇
  1979年   7篇
  1978年   2篇
  1977年   2篇
  1975年   6篇
  1974年   4篇
  1973年   6篇
  1972年   6篇
  1971年   4篇
  1970年   4篇
  1968年   7篇
  1967年   3篇
  1966年   2篇
  1965年   3篇
  1959年   3篇
  1953年   3篇
  1937年   3篇
排序方式: 共有300条查询结果,搜索用时 15 毫秒
221.
In the ordinary way of representing relations, the order of the relata plays a structural role, but in the states themselves such an order often does not seem to be intrinsically present. An alternative way to represent relations makes use of positions for the arguments. This is no problem for the love relation, but for relations like the adjacency relation and cyclic relations, different assignments of objects to the positions can give exactly the same states. This is a puzzling situation. The question is what is the internal structure of relations? Is the use of positions still justified, and if so, what is their ontological status? In this paper mathematical models for relations are developed that provide more insight into the structure of relations “out there” in the real world.  相似文献   
222.
Leo PD  Greene AJ 《Memory & cognition》2008,36(6):1079-1086
In transitive inference, participants learn a set of context-dependent discriminations that can be organized into a hierarchy that supports inference. Several studies show that inference occurs with or without task awareness. However, some studies assert that without awareness, performance is attributable to pseudoinference. By this account, inference-like performance is achieved by differential stimulus weighting according to the stimuli's proximity to the end items of the hierarchy. We implement an inference task that cannot be based on differential stimulus weighting. The design itself rules out pseudoinference strategies. Success on the task without evidence of deliberative strategies would therefore suggest that true inference can be achieved implicitly. We found that accurate performance on the inference task was not dependent on explicit awareness. The finding is consistent with a growing body of evidence that indicates that forms of learning and memory supporting inference and flexibility do not necessarily depend on task awareness.  相似文献   
223.
This study examined whether children exposed to prenatal smoking show deficits in “hot” and/or “cool” executive functioning (EF). Hot EF is involved in regulation of affect and motivation, whereas cool EF is involved in handling abstract, decontextualized problems. Forty 7 to 9-year-old children (15 exposed to prenatal smoking, 25 non-exposed) performed two computerized tasks. The Sustained Attention Dots (SA-Dots) Task (as a measure of “cool” inhibitory control) requires 400 non-dominant hand and 200 dominant hand responses. Inhibitory control of the prepotent response is required for dominant hand responses. The Delay Frustration Task (DeFT) (as a measure of “hot” inhibitory control) consists of 55 simple maths exercises. On a number of trials delays are introduced before the next question appears on the screen. The extent of response-button pressing during delays indicates frustration-induced inhibitory control. Prenatally exposed children showed poorer inhibitory control in the DeFT than non-exposed children. A dose–response relationship was also observed. In addition, prenatally exposed children had significantly higher (dose-dependent) conduct problem- and hyperactivity-inattention scores. There were no significant group differences in inhibitory control scores from the SA-Dots. These results indicate that children exposed to prenatal smoking are at higher risk of hot but not cool executive function deficits.  相似文献   
224.
Current knowledge of suicidal behavior in the Western Pacific region is relatively limited when compared to other areas of the world. This area is characterized by a wide diversity of social, economic, and cultural aspects that do not permit any homogenous reading of suicide phenomena. Data from countries of the region included in this article suggest the existence of important differences among nations in terms of gender, age, and methods of suicide, as well role of mental illness. In addition, the Western Pacific region appears to be affected by higher rates of suicide than other areas in the world, with signs of progressive worsening in recent years and worrying predictions for the next two decades. The Suicide Trends in At‐Risk Territories (START) Study, initiated by the World Health Organization Regional Office in Manila, seeks to research the incidence of both fatal and nonfatal suicidal behavior in countries of the region and to implement interventions for suicide attempters. This ambitious project is expected to standardize data collection procedures and improve the knowledge cultural factors in suicide.  相似文献   
225.
226.
227.
228.
229.
This qualitative interview study explored and examined the transitions surrounding emerging adulthood within the family from the parents' perspective. Interviews conducted with a purposive sample of parents (N = 59) revealed the perceived difficulties parents have in ‘letting go’ of their grown‐up children, and in acknowledging their developing autonomy; and demonstrated a range of perceived parental strategies in response to young people's growing independence. The significance of these intertwined elements of perceived dependency, emotional tensions, and interactive behaviours for relationships in the family, and the implications for ‘emerging adulthood’, was discussed.  相似文献   
230.
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