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   165篇
  免费   2篇
  2020年   3篇
  2019年   2篇
  2018年   3篇
  2017年   7篇
  2016年   7篇
  2015年   3篇
  2014年   5篇
  2013年   21篇
  2012年   9篇
  2011年   7篇
  2010年   3篇
  2009年   3篇
  2008年   6篇
  2007年   6篇
  2006年   2篇
  2005年   2篇
  2003年   4篇
  2001年   3篇
  2000年   4篇
  1999年   2篇
  1997年   3篇
  1994年   2篇
  1990年   2篇
  1989年   3篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   4篇
  1980年   1篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1976年   1篇
  1975年   4篇
  1974年   4篇
  1972年   3篇
  1971年   1篇
  1970年   3篇
  1969年   1篇
  1968年   3篇
  1967年   1篇
  1966年   1篇
  1965年   2篇
  1964年   1篇
  1954年   1篇
  1951年   1篇
排序方式: 共有167条查询结果,搜索用时 15 毫秒
91.
Studies of acoustic interactions in animal groups, such as chorusing insects, anurans, and birds, have been invaluable in showing how cooperation and competition shape signal structure and use. The begging calls of nestling birds are ideal for such studies, because they function both as a cooperative signals of the brood's needs and as competitive signals for parental allocation within the brood. Nonetheless, studies of acoustic interactions among nestlings are rare. Here we review our work on acoustic interactions in nestling tree swallows (Tachycineta bicolor), especially how calls are used in competition for parental feedings. Nestlings attracted parental attention and responded to acoustic interference mainly by increasing call output. However, nestlings also gave more similar calls when they called together and decreased their call bandwidth when exposed to elevated noise. We suggest that these competitive uses of calls might intensify the cooperative brood signal, affecting both parental provisioning and vocal development. Given their tremendous variation across species, begging calls offer promising opportunities for developmental and comparative studies of acoustic signaling.  相似文献   
92.
Both natural languages and cell biology make use of one-dimensional encryption. Their investigation calls for syntactic deciphering of the text and semantic understanding of the resulting structures. Here we discuss recently published algorithms that allow for such searches: automatic distillation of structure (ADIOS) that is successful in discovering syntactic structures in linguistic texts and its motif extraction (MEX) component that can be used for uncovering motifs in DNA and protein sequences. The underlying principles of these syntactic algorithms and some of their results will be described.  相似文献   
93.
94.
American Indian (AI) communities have high levels of stress and trauma and are disproportionately affected by numerous preventable diseases. Here, we describe an academic–community partnership based on a collaboration between Blackfeet Community College students and faculty in Psychology and Immunology at Montana State University (MSU). The collaboration, which has spanned over 5 years, was sparked by community interest in the relationship between stress and disease on the Blackfeet reservation. Specifically, community members wanted to understand how the experience of psychological stress and trauma may affect disease risk in their community and identify factors that promote resilience. In doing so, they hoped to identify pathways through which health could be improved for individual community members. Here, we discuss all stages of the collaborative process, including development of measures and methods and themes of research projects, challenges for community members and non‐indigenous collaborators, future directions for research, and the lessons learned. Finally, we note the ways in which this partnership and experience has advanced the science of community engagement in tribal communities, with the hope that our experiences will positively affect future collaborations between indigenous community members and non‐indigenous scientists.  相似文献   
95.
The state of the art of definition of community violence as it relates to child development was examined in terms of the definitions used in 23 empirical studies. In all cases community violence was defined in terms of what were assumed to be measurements obtained as linear combinations of a priori numerical weighting of responses to questions--asked either of a child or of the parent of a child--about experiencing and/or witnessing and/or hearing about instances of violence. Thus, the definitions can be seen to represent the perspectives of 2 kinds of observers--the child or the child's parent--and 3 levels of closeness to violence--experiencing, witnessing, or hearing about violence. Combining these perspectives and levels, the following 8 different definitions could be seen to be used in the practice of 1 or more of the 23 empirical studies: Child Self-Report (perception) of either (1) experiencing, or (2) witnessing, or (3) experiencing and witnessing, and hearing about violence; or Parent Report (perception) of the Child (4) experiencing, or (5) witnessing, or (6) experiencing and witnessing and hearing about violence, or (7) = (1) + (4), or (8) = (3) + (6). In almost all the examples of research definitions it was assumed implicitly and without test of the assumption that different violent events were interchangeable, and usually it was assumed (again without test) that the magnitudes of different violence events were equal. Usually, an unstated theory of stress appeared to guide the measurement definition, but in one study definitions were developed and tested in terms of a clearly-stated theory of learning. It was concluded that definition of community violence is a measurement problem; that very likely it is multidimensional; that it could be more nearly solved if better attention were given to specifying it in terms of theory that can be put to test and by attending to basic assumptions and principles of measurement.  相似文献   
96.
Ninth- and 11th-grade students (N = 379) were surveyed regarding their evaluations of excluding someone from a social group solely on the basis of his or her social reference group membership. Individuals evaluated exclusion in ambiguous and nonambiguous situations. Judgments and reasoning about exclusion were compared with judgments and reasoning about a more prototypically moral situation (denial of resources). Overall, participants evaluated exclusion as less wrong than denial of resources and used fewer moral and more conventional reasons to justify their judgments. Participants relied more on their group knowledge or stereotypes in evaluating ambiguous situations and more on their personal knowledge in evaluating nonambiguous situations. Age- and gender-related differences in evaluations, reasoning, and use of stereotypes were also found.  相似文献   
97.
98.
In a sample of 263 male GO players at 48 levels of expertise and ranging from 18 to 78 years of age, it was found that factors of expertise deductive reasoning (EDR) and expertise working memory (EWM) were independent of factors of fluid reasoning (Gf) and short-term working memory (STWM) that, along with cognitive speed (Gs), have been found to characterize decline of intelligence in adulthood. The main effects of analyses of cross-sectional age differences indicated age-related decline in EDR and EWM as well as in Gf, STWM, and Gs. However, interaction and partialing analyses indicated that decline in EDR and EWM decreased to no decline with increase in level of expertise. The results thus suggest that with increase in factors known to raise the level of expertise--particularly, intensive, well-designed practice--there may be no age-related decline in the intelligence that is measured in the abilities of expertise.  相似文献   
99.
Social capital plays a key role in college and career success, and research indicates that a dearth of on‐campus connections contributes to challenges first‐generation college students face in effectively navigating the college environment. This study investigates a novel intervention that focuses on the development of skills and attitudes to empower first‐generation college students to cultivate social capital and on‐campus connections during the transition to college. A mixed methods, explanatory design was used to evaluate impacts and processes of the intervention among first‐generation college students (= 164) in the context of an ethnically diverse, urban, public university in the Northeast. Results indicated that students who participated in the intervention demonstrated improved attitudes and behaviors around seeking support in college, closer relationships with instructors, and higher GPAs at the end of their first year in college. These results suggest the potential benefits of a relatively scalable approach to supporting the needs of first‐generation college students.  相似文献   
100.
People with low Self-directedness (SD) tend to explain their behaviour as being significantly influenced by events in the external environment. One important dimension of external cues is their level of salience: highly salient external stimuli are more likely to capture attention, even when such stimuli are not relevant to goals. We examined whether adults reporting low SD would exhibit greater susceptibility to distraction by highly salient external stimuli. Fifty-four (42 males) subjects completed the Attention Modulation by Salience Task (AMST) measuring reaction times to early- or late-onset auditory stimuli in the presence of high- or low-salience visual distractors. SD was assessed via self-report, and analyses tested the relationship between SD and performance on the AMST. Results showed a slowed early response to auditory cues during high salience compared to low salience. Indeed, individuals reporting low SD showed stronger salience interference, suggesting that external causality attribution is accompanied by a subconscious perceptual deficit.  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