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   363篇
  免费   11篇
  374篇
  2023年   3篇
  2021年   5篇
  2020年   3篇
  2019年   9篇
  2018年   13篇
  2017年   14篇
  2016年   9篇
  2015年   6篇
  2014年   7篇
  2013年   37篇
  2012年   17篇
  2011年   23篇
  2010年   14篇
  2009年   5篇
  2008年   12篇
  2007年   20篇
  2006年   21篇
  2005年   15篇
  2004年   11篇
  2003年   9篇
  2002年   10篇
  2001年   7篇
  2000年   7篇
  1999年   6篇
  1998年   6篇
  1997年   2篇
  1996年   3篇
  1995年   2篇
  1994年   5篇
  1993年   3篇
  1992年   9篇
  1991年   8篇
  1990年   6篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1981年   3篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1976年   1篇
  1975年   5篇
  1974年   5篇
  1971年   2篇
  1970年   2篇
  1969年   6篇
  1968年   5篇
  1966年   2篇
  1965年   2篇
排序方式: 共有374条查询结果,搜索用时 0 毫秒
51.
This article examines some of the story conventions of network television news to explain the ways in which healthcare interest groups develop and maintain their presence in this medium—a process that has significant implications for public understanding of healthcare issues, and therefore to bioethics. The article is divided into three sections. The first section focuses on three major normative conventions of television news: adherence to a simple narrative structure, the balance ethic, and avoidance of the “think-piece” and outlines the basic strategies available to interest groups for exploiting these normative conventions. Section two introduces three case studies of organizations and individuals who have run high-profile media campaigns. Section three explores the implications for bioethics of the observations made in this article.  相似文献   
52.
53.
The present study investigated the associations among gender, gender-typed behavior, and peer preference in 54 Year 5 (9–10 year-old) children in the United Kingdom. Children completed self-reports about their gendered behavior, nominated friends, and participated in a one-on-one interview regarding their preference and non-preference for hypothetical classmates. Results indicated that children were similar to their friends in terms of gender and engagement in gender-typed activities. Regarding potential classmates, the gender nonconforming boy was the most at risk for peer rejection. Students preferred the gender conforming boy and gender nonconforming girl—most often citing masculine activities as reasons why they liked the potential classmate, and feminine activities as reasons why they did not like the potential classmate. Results suggest that feminine activities are devalued in current society, even for girls. Children’s own engagement in gendered activities was also associated with their choice of potential classmate. These results are interpreted in line with social constructionist, social dominance, and hegemonic masculinity theories of gender development and socialization. Knowledge about these patterns of preference and non-preference will help teachers identify students at risk for rejection, enabling them to work proactively to create a positive social environment.  相似文献   
54.
55.
The freshwater snail Lymnaea stagnalis (L.) is considered a calciphile and exhibits reduced growth and survival in environments containing less than 20 mg/l environmental calcium. Although it has no apparent effect on survival at 20 mg/l, reducing environmental calcium increases metabolic demand, and as such we consider that this level of calcium acts as a stressor on the snail. We exposed snails to acute periods of low environmental calcium and tested their ability to form intermediate-term memory (ITM) and long-term memory (LTM) following one trial operant conditioning (1TT) to reduce aerial respiratory activity in hypoxic conditions. We also assessed whether there were changes in the electrophysiological properties of a single neuron, right pedal dorsal 1 (RPeD1), which has been demonstrated to be necessary for LTM formation. Following training in high (80 mg/l) environmental calcium, L. stagnalis formed ITM and LTM lasting 24 h and demonstrated a significant reduction in all activity measured from RPeD1; however when snails were exposed to low (20 mg/l) environmental calcium they were able to form ITM but not LTM. Although no behavioral LTM was formed, a partial reduction in RPeD1 activtiy measured 24 h after training was observed, indicating a residual effect of training. The strong effect that environmental calcium concentration had on physiology and behavior in response to training to reduce aerial respiration in L. stagnalis suggests that it is an element of gastropod husbandry that needs to be carefully considered when studying other traits. This study also indicates that L. stagnalis found naturally in low calcium environments may be less able to adapt to novel stressors than populations found in harder waters.  相似文献   
56.
The aim of this study was to adapt to Catalan the parents' and children's global report forms of the Alabama Parenting Questionnaire (APQ), using a community sample of 364 children between 10 and 15 years old and their families. Sociodemographic information (from parents) and the presence of externalizing problems (from parents and teachers) were collected. The results suggest a 3-factor structure corresponding to the scales of Positive Parenting Practices (PPP), Inconsistent and Negative Discipline (IND) and Poor Monitoring/Supervision (PMS). The internal consistency is acceptable in all the scales, except for the IND in the children's format. The scales also present good convergent and discriminant validity, and the relations with the external variable studied pointed in the expected direction: inefficient parenting practices are related to the presence of more behavior problems in children. To sum up, the Catalan version of the parents' and children's global report forms of the APQ are considered suitable for use in the area of children's and adolescents' behavior problems.  相似文献   
57.
58.
Linear regression analysis is one of the most important tools in a researcher’s toolbox for creating and testing predictive models. Although linear regression analysis indicates how strongly a set of predictor variables, taken together, will predict a relevant criterion (i.e., the multiple R), the analysis cannot indicate which predictors are the most important. Although there is no definitive or unambiguous method for establishing predictor variable importance, there are several accepted methods. This article reviews those methods for establishing predictor importance and provides a program (in Excel) for implementing them (available for direct download at . The program investigates all 2 p – 1 submodels and produces several indices of predictor importance. This exploratory approach to linear regression, similar to other exploratory data analysis techniques, has the potential to yield both theoretical and practical benefits.  相似文献   
59.
Numbers are fundamental entities in mathematics, but their cognitive bases are unclear. Abundant research points to linear space as a natural grounding for number representation. But, is number representation fundamentally spatial? We disentangle number representation from standard number-to-line reporting methods, and compare numerical estimations in educated participants using line-reporting with three nonspatial reporting conditions (squeezing, bell-striking, and vocalizing). All three cases of nonspatial-reporting consistently reproduced well-established results obtained with number-line methods. Furthermore, unlike line-reporting—and congruent with the psychophysical Weber–Fechner law—nonspatial reporting systematically produced logarithmic mappings for all nonsymbolic stimuli. Strikingly, linear mappings were obtained exclusively in conditions with culturally mediated elements (e.g., words). These results suggest that number representation is not fundamentally spatial, but builds on a deeper magnitude sense that manifests spatially and nonspatially mediated by magnitude, stimulus modality, and reporting condition. Number-to-space mappings—although ubiquitous in the modern world—do not seem to be rooted directly in brain evolution but have been culturally privileged and enhanced.  相似文献   
60.
Adequate short-term responses to stressors are of great importance for the health and well-being of individuals and factors modulating the physiological stress response (e.g., controllability, suddenness, familiarity) of a stimulus are well described under laboratory conditions. In the present study we aimed at investigating the stress response in greylag geese (Anser anser) in the field, confronting individuals with naturally occurring stressors. We measured beat-to-beat heart rate (HR) via fully implanted transmitters during three different experimental challenges: (1) catching and holding, (2) confrontation with a model predator, and (3) approach by different humans. We compared this to a control period and HR during agonistic encounters, a naturally occurring stressor. All three experimental situations evoked a HR increase. Highest HR responses were elicited by catching and holding the animals. In the third experiment, HR responses were greatest when the geese were approached by a human stranger (i.e., somebody the geese have never seen before). Hence, geese discriminated between different kinds of stressors and adjusted their physiological response depending on the type of stressor. Our results show that geese were able to discriminate between individual humans. In line with a number of lab studies, we suggest that particularly the controllability of certain situation determines the intensity of the HR response, also in a natural setting in the field.  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