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   19921篇
  免费   491篇
  国内免费   1篇
管理学   2640篇
民族学   80篇
人才学   1篇
人口学   1717篇
丛书文集   108篇
教育普及   2篇
理论方法论   1802篇
综合类   458篇
社会学   9645篇
统计学   3960篇
  2020年   295篇
  2019年   376篇
  2018年   396篇
  2017年   609篇
  2016年   443篇
  2015年   373篇
  2014年   420篇
  2013年   3426篇
  2012年   614篇
  2011年   502篇
  2010年   380篇
  2009年   382篇
  2008年   462篇
  2007年   484篇
  2006年   389篇
  2005年   495篇
  2004年   421篇
  2003年   382篇
  2002年   401篇
  2001年   475篇
  2000年   432篇
  1999年   436篇
  1998年   322篇
  1997年   314篇
  1996年   327篇
  1995年   287篇
  1994年   275篇
  1993年   298篇
  1992年   358篇
  1991年   336篇
  1990年   321篇
  1989年   313篇
  1988年   290篇
  1987年   284篇
  1986年   275篇
  1985年   251篇
  1984年   306篇
  1983年   293篇
  1982年   250篇
  1981年   191篇
  1980年   220篇
  1979年   262篇
  1978年   198篇
  1977年   188篇
  1976年   167篇
  1975年   179篇
  1974年   159篇
  1973年   141篇
  1972年   114篇
  1971年   103篇
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
681.
682.
We examined how perceived acculturation expectations from parents and school, and ethnic discrimination predicted early adolescents’ heritage and mainstream acculturation orientations at home (private domain) and in school (public domain) one year later. We surveyed 263 early adolescents of immigrant background in Germany (Mage = 10.44 years, 60% female). Multigroup path analyses revealed that perceived acculturation expectations and ethnic discrimination were more strongly related to adolescents’ private than public acculturation orientations. Parental heritage expectations were the strongest predictor of adolescents’ acculturation orientations. Boys were more susceptible than girls to ethnic discrimination and acculturation expectations in school, which affected their private and public acculturation orientations. Results highlight the importance of integrating domain‐specific and gendered experiences when analyzing adolescents’ acculturative development.  相似文献   
683.
Urban Ecosystems - Residential yardscapes are at the forefront of human interaction with nature for those living in urban areas across Europe and North America. In recent years a significant amount...  相似文献   
684.
Urban Ecosystems - Generalist wildlife species often thrive in urban environments because of increased anthropogenic resources. However, human-wildlife interactions, especially if negative, raise...  相似文献   
685.
In recent decades, sociolinguists have begun to challenge the traditional view that multilingualism is fundamentally composed of discrete systems known as ‘languages’. Supporting the assessment that languages are not bounded entities but sociocultural and ideological constructions, this article explores commercial advertisements in France, which are subject to language policies assuming that ‘French’ is easily separable from ‘foreign languages’. Employing the Bakhtinian‐influenced notion of bivalency developed by Woolard (1998), the article argues for a special consideration of mixed‐language advertising in France, rooted not only in linguistic form, but also in the specific contextual tension produced by the socio‐political statuses of French and English. The resulting creativity challenges the monolectal assumptions within French language management, indicating a clash of segregational language ideology with integrational language practices. The article further argues that this language mixing is bidirectional, as advertisements may both erase and emphasise the assumed boundaries between codes.  相似文献   
686.
Individual differences in infants’ engagement with their environment manifest early in development and are noticed by parents. Three views have been advanced to explain differences in seeking novel stimulation. The optimal stimulation hypothesis suggests that individuals seek further stimulation when they are under‐responsive to current sensory input. The processing speed hypothesis proposes that those capable of processing information faster are driven to seek stimulation more frequently. The information prioritization hypothesis suggests the differences in stimulation seeking index variation in the prioritization of incoming relative to ongoing information processing. Ten‐month‐old infants saw 10 repetitions of a video clip and changes in frontal theta oscillatory amplitude were measured as an index of information processing speed. Stimulus‐locked P1 peak amplitude in response to checkerboards briefly overlaid on the video at random points during its presentation indexed processing of incoming stimulation. Parental report of higher visual seeking did not relate to reduced P1 peak amplitude or to a stronger decrease in frontal theta amplitude with repetition, thus not supporting either the optimal stimulation or the processing speed hypotheses. Higher visual seeking occurred in those infants whose P1 peak amplitude was greater than expected based on their theta amplitude. These findings indicate that visual sensory seeking in infancy is explained by a bias toward novel stimulation, thus supporting the information prioritization hypothesis.  相似文献   
687.
Identifying patterns of fearful behaviors early and accurately is essential to identify children who may be at increased risk for psychopathology. Previous work focused on the total amount of fear by using composites across time. However, considering the temporal dynamics of fear expression might offer novel insights into the identification of children at risk. One hundred and twenty‐five toddlers participated in high‐ and low‐fear tasks. Data were modeled using a novel two‐step approach. First, a hidden Markov model estimated latent fear states and transitions across states over time. Results revealed children's behavior was best represented by six behavioral states. Next, these states were analyzed using sequence clustering to identify groups of children with similar dynamic trajectories through the states. A four‐cluster solution found groups of children varied in fear response and regulation process: “external regulators” (using the caregiver as a regulation tool), “low reactive” (low reaction to stimulus), “fearful explorers” (managing their own internal state with minimal assistance from the caregiver), and “high fear” (fearful/at‐caregiver state regardless of task). The combination of analytic tools enabled fine‐grained examination of the processes of fearful temperament. These insights may help prevention programs target behaviors that perpetuate anxious behavior in the moment.  相似文献   
688.
To perform variable selection in expectile regression, we introduce the elastic-net penalty into expectile regression and propose an elastic-net penalized expectile regression (ER-EN) model. We then adopt the semismooth Newton coordinate descent (SNCD) algorithm to solve the proposed ER-EN model in high-dimensional settings. The advantages of ER-EN model are illustrated via extensive Monte Carlo simulations. The numerical results show that the ER-EN model outperforms the elastic-net penalized least squares regression (LSR-EN), the elastic-net penalized Huber regression (HR-EN), the elastic-net penalized quantile regression (QR-EN) and conventional expectile regression (ER) in terms of variable selection and predictive ability, especially for asymmetric distributions. We also apply the ER-EN model to two real-world applications: relative location of CT slices on the axial axis and metabolism of tacrolimus (Tac) drug. Empirical results also demonstrate the superiority of the ER-EN model.  相似文献   
689.
A criticism of linear programming has been that the data which are available in practice are too inexact and unreliable for linear programming to properly work. Managers are therefore concerned with how much actual values may differ from the estimates that were used in the model before the results become irrelevant. Sensitivity analysis emerged to help deal with the uncertainties inherent in the linear programming model. However, the ranges calculated are generally valid only when a single coefficient is varied. An extension of sensitivity analysis, the 100 Percent Rule, allows the simultaneous variation of more than one element in a vector, but does not permit the independent variation of the elements. A tolerance approach to sensitivity analysis enables the consideration of simultaneous and independent change of more than one coefficient. However, the ranges developed are unnecessarily restricted and may be reduced in width to zero when primal or dual degeneracy exists. This paper presents an extension of the tolerance approach which reduces the limitations of both the traditional and tolerance approaches to sensitivity analysis.  相似文献   
690.
Based on likely future changes in faculty evaluation practices, this paper examines how institutions of higher education might operationalize performance evaluation as related to research, teaching, and service. A model is developed that allows coupling performance evaluation and relevant market considerations with merit pay, tenure, and promotion decisions. The approach is specifically applicable to tenure-track faculty members in colleges and universities.  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