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   19481篇
  免费   597篇
  国内免费   1篇
管理学   2594篇
民族学   111篇
人口学   1725篇
丛书文集   74篇
教育普及   1篇
理论方法论   1745篇
综合类   181篇
社会学   9896篇
统计学   3752篇
  2023年   130篇
  2022年   80篇
  2021年   133篇
  2020年   346篇
  2019年   513篇
  2018年   607篇
  2017年   790篇
  2016年   609篇
  2015年   407篇
  2014年   569篇
  2013年   3508篇
  2012年   732篇
  2011年   681篇
  2010年   498篇
  2009年   403篇
  2008年   531篇
  2007年   484篇
  2006年   521篇
  2005年   406篇
  2004年   418篇
  2003年   350篇
  2002年   363篇
  2001年   468篇
  2000年   412篇
  1999年   402篇
  1998年   311篇
  1997年   261篇
  1996年   278篇
  1995年   288篇
  1994年   246篇
  1993年   256篇
  1992年   299篇
  1991年   294篇
  1990年   288篇
  1989年   253篇
  1988年   238篇
  1987年   201篇
  1986年   229篇
  1985年   249篇
  1984年   216篇
  1983年   191篇
  1982年   159篇
  1981年   130篇
  1980年   155篇
  1979年   170篇
  1978年   133篇
  1977年   114篇
  1976年   87篇
  1975年   91篇
  1974年   93篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
421.
Statistical process monitoring (SPM) is a very efficient tool to maintain and to improve the quality of a product. In many industrial processes, end product has two or more attribute-type quality characteristics. Some of them are independent, but the observations are Markovian dependent. It is essential to develop a control chart for such situations. In this article, we develop an Independent Attributes Control Chart for Markov Dependent Processes based on error probabilities criterion under the assumption of one-step Markov dependency. Implementation of the chart is similar to that of Shewhart-type chart. Performance of the chart has been studied using probability of detecting shift criterion. A procedure to identify the attribute(s) responsible for out-of-control status of the process is given.  相似文献   
422.
423.
We introduce two classes of multivariate log-skewed distributions with normal kernel: the log canonical fundamental skew-normal (log-CFUSN) and the log unified skew-normal. We also discuss some properties of the log-CFUSN family of distributions. These new classes of log-skewed distributions include the log-normal and multivariate log-skew normal families as particular cases. We discuss some issues related to Bayesian inference in the log-CFUSN family of distributions, mainly we focus on how to model the prior uncertainty about the skewing parameter. Based on the stochastic representation of the log-CFUSN family, we propose a data augmentation strategy for sampling from the posterior distributions. This proposed family is used to analyse the US national monthly precipitation data. We conclude that a high-dimensional skewing function lead to a better model fit.  相似文献   
424.
This study investigated the longitudinal relation between therapeutic alliance and treatment motivation in a sample of 174 adolescents receiving residential treatment in the Netherlands. Structural equation modeling with a cross-lagged panel design was used to examine the relation between therapeutic alliance and treatment motivation up to 9 months of treatment. Results revealed that autoregressive associations between initial therapeutic alliance and alliance at subsequent time points were significant, whereas for treatment motivation a significant association was found after 6 months, but not after 9 months. Results also showed that a higher level of therapeutic alliance after 3 months was predictive of a higher level of treatment motivation after 6 months. Furthermore, a higher level of therapeutic alliance after 6 months was predictive of a higher level of treatment motivation after 9 months. Implications for research and clinical practice are discussed.  相似文献   
425.
This study sheds light on women's perceptions of pregnancy‐related discrimination committed by the discriminated woman's immediate leader. The purpose is to show how women describe this perception during pregnancy and after their return to working life after maternity leave. Further, the study explores the ways in which the quality of the leader–follower relationship is revealed during the narration process. The research draws on five individual stories, collected in two rounds of interviews. Representations of several kinds of discriminatory practices can be found in the narratives and reveal that even being a partner in a good‐quality leader–follower relationship does not necessarily protect a woman from pregnancy‐related discrimination. However, women involved in a high‐quality leader–follower relationship described their perceptions in a more positive manner than those in a low‐quality relationship. The contribution of the article to the literature is twofold: firstly, the results challenge the traditional view that high‐quality leader–member exchange relationships lead to positive outcomes. Secondly, examining the different ways in which people describe their perceptions of discrimination deepens our understanding of the equality problems that working women face.  相似文献   
426.
New mothers frequently seek information and community on social networking sites as they seek to establish their parenting practices. As social networking sites for mothers (SNSM) present an environmental influence on the family system, a mother’s experience with social comparison, belonging, and emotion on SNSM can bear significant influence over her satisfaction with her parenting. The present study utilized survey methods to explore mothers’ (n= 336) reported experiences of these variables. We use structural equation modeling to specify a model with good fit, which indicated that greater downward comparison directly related to greater parenting satisfaction, with belonging and negative emotion as mediating indirect relationships. Implications for family communication and mothers’ SNSM practices are discussed.  相似文献   
427.
Although numerous studies document a link between child sexual abuse and later sexual assault perpetration in men, little research has examined why this relationship exists. One potential mechanism may be emotional regulation difficulties. The current study utilizes a college sample of 132 men to examine the mediating role of emotion regulation difficulties on the relationship between experiencing child sexual abuse and later sexual aggression. Although emotion regulation difficulties in general was not significantly related to sexual aggression, one facet, impulse control difficulties, emerged as a significant mediator of the relationship between child sexual abuse and sexual aggression. Intervention programs should focus on the care that children receive following sexual abuse, with particular emphasis on how emotion regulation abilities may be impacted.  相似文献   
428.
The depths, which have been used to detect outliers or to extract a representative subset, can be applied to classification. We propose a resampling-based classification method based on the fact that resampling techniques yield a consistent estimator of the distribution of a statistic. The performance of this method was evaluated with eight contaminated models in terms of Correct Classification Rates (CCRs), and the results were compared with other known methods. The proposed method consistently showed higher average CCRs and 4% higher CCR at the maximum compared to other methods. In addition, this method was applied to Berkeley data. The average CCRs were between 0.79 and 0.85.  相似文献   
429.
An approach is presented for strengthening middle school standards‐based English language arts (ELA) classroom instruction by infusing theory‐ and research‐supported career development constructs and practices. Over an 8‐week period, 90 urban 7th graders participated in an integrated ELA–career development curriculum. Career agency emerged as an important construct for students. It was related to key markers of ELA achievement (i.e., standardized test scores, grades, and positive change in 6th‐ to 7th‐grade test scores) and elaborated on in nuanced ways by students in their written narratives. Four themes related to career agency were identified in student writings: time perspective, challenges of self‐direction, career development, and social and emotional development. Advantages for students and schools related to synergy, scale, and sustainability are discussed.  相似文献   
430.
Urban-associated changes can have immediate or long-term consequences on animal populations. Such changes may be assessed through parasite prevalence and abundance in wildlife hosts, as urbanization can influence parasitism and disease transmission in wildlife. Snakes are widespread and diverse vertebrates that often persist in urban environments; however, parasitism of snakes in urban environments has yet to be studied, leaving the roles of snakes in parasite transmission uncharacterized. Field ecology, microscopy, molecular techniques, and geographic information science (GIS) were integrated to characterize parasitism of snakes in an urban old-growth forest park. The species, sex, mass, length, location, and prevalence of ecto-, hemo-, and fecal parasites were determined for 34 snakes of 6 species. Ectoparasites (mite), hemoparasites (Hepatozoon spp.), and fecal parasites (Entamoeba spp., Trichomonas spp., Strongloides spp., and an unidentified helminth) were detected in snakes and 64.7?% of snakes were infected by at least one of these parasites. Parasite infections were generally not related to the sex, age, or body condition of snakes. The locations of infected snakes were used to produce risk maps indicating where parasite prevalence is predicted to be greatest. The analysis of these maps indicated that snakes with fecal parasites were closer than non-infected snakes to the edge of the forest. This study confirms that snakes may be important parasite hosts or reservoirs in parasite transmission pathways in urban environments and it provides an integrative multidisciplinary approach that may be used to monitor parasitism dynamics in other urban wildlife areas.  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