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   932篇
  免费   26篇
管理学   80篇
民族学   2篇
人口学   137篇
丛书文集   2篇
理论方法论   135篇
综合类   6篇
社会学   548篇
统计学   48篇
  2023年   6篇
  2021年   5篇
  2020年   20篇
  2019年   31篇
  2018年   21篇
  2017年   38篇
  2016年   18篇
  2015年   19篇
  2014年   33篇
  2013年   164篇
  2012年   32篇
  2011年   48篇
  2010年   20篇
  2009年   32篇
  2008年   37篇
  2007年   32篇
  2006年   31篇
  2005年   34篇
  2004年   29篇
  2003年   31篇
  2002年   38篇
  2001年   16篇
  2000年   19篇
  1999年   18篇
  1998年   17篇
  1997年   20篇
  1996年   16篇
  1995年   9篇
  1994年   16篇
  1993年   6篇
  1992年   15篇
  1991年   13篇
  1990年   11篇
  1989年   5篇
  1988年   2篇
  1986年   2篇
  1985年   5篇
  1984年   7篇
  1983年   9篇
  1982年   6篇
  1981年   5篇
  1980年   5篇
  1978年   2篇
  1975年   3篇
  1974年   1篇
  1972年   3篇
  1971年   2篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有958条查询结果,搜索用时 672 毫秒
951.
Nonparametric regression can be considered as a problem of model choice. In this article, we present the results of a simulation study in which several nonparametric regression techniques including wavelets and kernel methods are compared with respect to their behavior on different test beds. We also include the taut-string method whose aim is not to minimize the distance of an estimator to some “true” generating function f but to provide a simple adequate approximation to the data. Test beds are situations where a “true” generating f exists and in this situation it is possible to compare the estimates of f with f itself. The measures of performance we use are the L2- and the L-norms and the ability to identify peaks.  相似文献   
952.
The paper presents some key findings of qualitative research with older primary school children in Wales on their attachments to places and cultures. There is discussion of children's perspectives on the global, national and local arenas. We argue both that there are continuities with adult perspectives and that the children's views on place and identity need to be understood in the context of the social location of middle childhood. The study shows children making relatively little use of culturally-filled categories of local, national and global place-identifications. The differences they articulate are largely framed in terms of divisions between groups of people rather than in the characteristics of place, and generally related back to the self.  相似文献   
953.
This study examined how ethnic identity relates to large-scale brain networks implicated in social interactions, social cognition, self-definition, and cognitive control. Group Iterative Multiple Model Estimation (GIMME) was used to create sparse, person-specific networks among the default mode and frontoparietal resting-state networks in a diverse sample of 104 youths aged 17–21. Links between neural density (i.e., number of connections within and between these networks) and ethnic identity exploration and resolution were evaluated in the full sample. Ethnic identity resolution was positively related to frontoparietal network density, suggesting that having clarity about one’s ethnic group membership is associated with brain network organization reflecting cognitive control. These findings help fill a critical knowledge gap about the neural underpinnings of ethnic identity.  相似文献   
954.
Variation in infants’ home environment is implicated in their cognitive and psycho-social development. The pandemic has intensified variations in home environments through exacerbating socioeconomic inequalities, and increasing psychological stressors for some families. This study investigates the effects of parental (predominantly maternal) mental health, enriching activities and screen use on 280 24- to 52-month-olds’ executive functions, internalising and externalising problems, and pro-social behaviour; with socioeconomic status and social support as contextual factors. Our results indicate that aspects of the home environment are differentially associated with children’s cognitive and psycho-social development. Parents who experienced sustained mental distress during the pandemic tended to report higher child externalising and internalising problems, and executive function difficulties at follow-up. Children who spent more time engaged in enriching activities with their parents showed stronger executive functions and social competence six months later. Screen use levels during the first year of the pandemic were not associated with outcomes. To mitigate the risk of persistent negative effects for this ‘pandemic generation’ of infants, our study highlights the importance of supporting parents’ mental health. As our results demonstrate the impact of social support on mental health, investing in support services and interventions promoting building support networks are likely to be beneficial.  相似文献   
955.
The correct interpretation of a natural language statement is determined as much by convention and shared meanings as by logical content. Therefore, when the word “probability” is used in the statement of a decision problem, the intended interpretation is not always clear. If such a statement also contains explicit probability formulae, confusion and even paradox may result. In this article, a problem involving cascaded inference is interpreted in four ways, three of which are regarded by the authors as legitimate or reasonable. The problem was originally suggested by Einhorn [3] and further discussed by Libby [10]. It is suggested here that a formal, mathematicist interpretation of the word “probability” might lead to inappropriate analyses of some decisions.  相似文献   
956.
Tuberculosis (TB) is one of the biggest killers among infectious diseases worldwide. Together with the identification of drugs that can provide benefits to patients, the challenge in TB is also the optimisation of the duration of these treatments. While conventional duration of treatment in TB is 6 months, there is evidence that shorter durations might be as effective but could be associated with fewer side effects and may be associated with better adherence. Based on a recent proposal of an adaptive order-restricted superiority design that employs the ordering assumptions within various duration of the same drug, we propose a non-inferiority (typically used in TB trials) adaptive design that effectively uses the order assumption. Together with the general construction of the hypothesis testing and expression for type I and type II errors, we focus on how the novel design was proposed for a TB trial concept. We consider a number of practical aspects such as choice of the design parameters, randomisation ratios, and timings of the interim analyses, and how these were discussed with the clinical team.  相似文献   
957.
Global research has shown that most young people who are care experienced are not prepared to transition to independent living at 18 years of age and require support into early adulthood. We used rigorous systematic methods to identify English-based peer reviewed and grey literature describing innovations relevant to care experienced young people as they transition into adulthood, with a focus upon lessons for their implementation and diffusion. We synthesised the evidence narratively and organise data linked to seven key areas important to the transition to adulthood: (1) Health and well-being; (2) relationships; (3) education and training; (4) employment; (5) participation in society; (6) accommodation; (7) other. Twenty-five papers met our inclusion criteria. This review has found that, whilst there are a broad spectrum of innovations taking place within the social care environment for care experienced young people to support their transition into adulthood, there exists limited insight into how best to support implementation and diffusion of evidence-based innovation. We drew upon the ‘Consolidated Framework for Implementation Research’, developed in the setting of clinical service delivery, to highlight challenges in implementing and diffusing evidence-based innovation for care experienced young people transitioning into adulthood.  相似文献   
958.
ABSTRACT: This paper examines modes of child care choice for young children in urban Brazil. Analysis of child care in developing countries is rare, in spite of its relevance to many policy issues. We model child care choice as a function of characteristics of the child and the mother, including the mother's predicted wage and probability of employment, the presence of other young children and potential caregivers. The results highlight the importance of the institutional structure of the labour market and the formal child care market and reveal policy-relevant information regarding the allocation of child care responsibility among household members.  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