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   152篇
  免费   5篇
管理学   21篇
人口学   16篇
理论方法论   25篇
综合类   2篇
社会学   71篇
统计学   22篇
  2024年   1篇
  2023年   1篇
  2021年   4篇
  2020年   6篇
  2019年   9篇
  2018年   5篇
  2017年   11篇
  2016年   9篇
  2015年   6篇
  2014年   5篇
  2013年   17篇
  2012年   17篇
  2011年   7篇
  2010年   4篇
  2009年   5篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   3篇
  2004年   3篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1999年   3篇
  1997年   1篇
  1995年   1篇
  1994年   5篇
  1992年   3篇
  1991年   5篇
  1990年   1篇
  1989年   1篇
  1985年   2篇
  1979年   1篇
  1977年   2篇
排序方式: 共有157条查询结果,搜索用时 15 毫秒
21.
22.
Financial liaisons between clinical researchers, research institutions, and industrial sponsors have gained momentum in recent years. In the process, it has been argued by many that trust in the research infrastructure is being eroded by the financial conflicts of interest that emerge from these arrangements. Yet, the financial resources of industry are needed to continue technology transfer from the bench to the bedside. Policy makers and government regulators are currently struggling to determine how to best manage financial conflicts of interest that emerge from these liaisons. Various organizations and government entities have proposed different strategies. This paper explores the limitations of existing measures and recommends that a unified national agenda is needed. We propose 10 steps to develop an agenda to address financial conflicts of interest in industry-sponsored clinical research.  相似文献   
23.
24.
In the social choice literature studying the problem of designing institutions for collective decision making, it is customary to (implicitly) assume that each dimension of the social outcome is of public interest (i.e., that each individual's welfare depends on every dimension of the outcome). Thus, the scope of the conclusions obtained is very limited. Here social decision problems with and without that public character are considered and it is shown that the same negative results arise in most cases; namely, that only dictatorial mechanisms are immune to the participants' manipulations. These results are obtained without requiring that the mechanisms produce Pareto optimal outcomes (they must simply be minimally responsive to the participants' preferences), which deepens their pessimistic character.I am deeply grateful to my advisor, Mark Walker, for his continuous guidance and encouragement. I wish also to thank Salvador Barberà, John Weymark, and two anonymous referees for helpful comments.  相似文献   
25.
26.
This qualitative research on the socioeconomic and political environments of public relations in Mexico documents how national context influences the practice of the profession. The evolution of public relations in Mexico has accelerated since the establishment of the North America Free Trade Agreement with the United States and Canada. This advancement is attributed to the practices of transnational corporations and the democratization process that motivates openness, greater professionalism and the expansion of public relations across diverse organizations.  相似文献   
27.
The problem of selecting the best of k exponential distributions with different guarantee times and the same unknown variance is considered. A two-stage procedure, similar to the one considered by Bechhofer, Dunnett and Sobel (1954), is given. Some specific guidelines for selecting the first-stage sample size are also given.  相似文献   
28.
The aim of this study was to analyse the interpersonal relationships in the school context of children living in different care settings (adoptive families, residential care centres, birth families). Participants were 76 children between eight and fourteen years of age (M = 10.78, SD = 1.38), belonging to one of three groups: international adoptees, children living in residential care in Spanish institutions, and a comparison sample of Spanish children living with their birth families with no connection with child protection. Sociometric information was collected in the classroom of each child during school hours. Internationally adopted children from Russia showed considerable difficulties in their relationships with peers; they were more likely to be rejected and their peers described them as less prosocial and somewhat more aggressive. With a better sociometric position than the adoptees, children in residential care were rated by their peers as more aggressive and less prosocial than the normative population. Coordination and integrated work between the family, protection centres, schools, and other social services should be a strategic priority in the promotion of healthy social development in these groups of children.  相似文献   
29.
Maximum likelihood (ML) estimation of relative risks via log-binomial regression requires a restricted parameter space. Computation via non linear programming is simple to implement and has high convergence rate. We show that the optimization problem is well posed (convex domain and convex objective) and provide a variance formula along with a methodology for obtaining standard errors and prediction intervals which account for estimates on the boundary of the parameter space. We performed simulations under several scenarios already used in the literature in order to assess the performance of ML and of two other common estimation methods.  相似文献   
30.
A high prevalence of youth is overweight or obese, and a frequent lack of monitoring of their weight control strategies is observed. Consequently, this paper compares the eating habits and physical activities of male and female dieters and non-dieters. Data are obtained from the large cross-national WHO collaborative study “Health Behavior in School-aged Children 2010”. The current sample consists of 9,444 students aged 11, 13 and 15 years from England and Spain. Participants are asked about dieting, vigorous and moderate-to-vigorous physical activity, breakfast frequency and fruit, vegetable, sweet and soft drink consumption. A logistic regression is used to examine the differences between dieters and non-dieters with regard to the aforementioned eating and physical activity habits. Differences between genders, countries, and those associated with BMI (body mass index) are also considered. The results suggest that the reality of weight control differs from the major health promotion recommendations during adolescence.  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