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   19435篇
  免费   351篇
  国内免费   1篇
管理学   2789篇
民族学   92篇
人才学   1篇
人口学   1884篇
丛书文集   76篇
教育普及   2篇
理论方法论   1729篇
现状及发展   1篇
综合类   259篇
社会学   9375篇
统计学   3579篇
  2021年   116篇
  2020年   284篇
  2019年   385篇
  2018年   463篇
  2017年   623篇
  2016年   487篇
  2015年   364篇
  2014年   468篇
  2013年   3025篇
  2012年   634篇
  2011年   616篇
  2010年   449篇
  2009年   374篇
  2008年   445篇
  2007年   462篇
  2006年   454篇
  2005年   438篇
  2004年   403篇
  2003年   374篇
  2002年   416篇
  2001年   522篇
  2000年   529篇
  1999年   460篇
  1998年   341篇
  1997年   309篇
  1996年   322篇
  1995年   302篇
  1994年   283篇
  1993年   289篇
  1992年   343篇
  1991年   316篇
  1990年   285篇
  1989年   291篇
  1988年   288篇
  1987年   250篇
  1986年   244篇
  1985年   277篇
  1984年   266篇
  1983年   250篇
  1982年   215篇
  1981年   180篇
  1980年   165篇
  1979年   194篇
  1978年   176篇
  1977年   159篇
  1976年   134篇
  1975年   158篇
  1974年   118篇
  1973年   115篇
  1972年   93篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
771.
In this article, we introduce tempered Mittag-Leffler Lévy processes (TMLLP). TMLLP is represented as tempered stable subordinator delayed by a gamma process. Its probability density function and Lévy density are obtained in terms of infinite series and Mittag-Leffler function, respectively. Asymptotic forms of the tails and moments are given. A step-by-step procedure of the parameters estimation and simulation of sample paths is given. We also provide main results available for Mittag-Leffler Lévy processes (MLLP) and some extensions which are not available in a collective way in a single article. Our results generalize and complement the results available on Mittag-Leffler distribution and MLLP in several directions. Further, the asymptotic forms of the moments of the first-exit times of the TMLLP are also discussed.  相似文献   
772.
We analyze a class of linear regression models including interactions of endogenous regressors and exogenous covariates. We show how to generate instrumental variables using the nonlinear functional form of the structural equation when traditional excluded instruments are unknown. We propose to use these instruments with identification robust IV inference. We furthermore show that, whenever functional form identification is not valid, the ordinary least squares (OLS) estimator of the coefficient of the interaction term is consistent and standard OLS inference applies. Using our alternative empirical methods we confirm recent empirical findings on the nonlinear causal relation between financial development and economic growth.  相似文献   
773.
Lifetime Data Analysis - CD4-based multi-state back-calculation methods are key for monitoring the HIV epidemic, providing estimates of HIV incidence and diagnosis rates by disentangling their...  相似文献   
774.

There have been many advances in statistical methodology for the analysis of recurrent event data in recent years. Multiplicative semiparametric rate-based models are widely used in clinical trials, as are more general partially conditional rate-based models involving event-based stratification. The partially conditional model provides protection against extra-Poisson variation as well as event-dependent censoring, but conditioning on outcomes post-randomization can induce confounding and compromise causal inference. The purpose of this article is to examine the consequences of model misspecification in semiparametric marginal and partially conditional rate-based analysis through omission of prognostic variables. We do so using estimating function theory and empirical studies.

  相似文献   
775.
We present an algorithm for learning oblique decision trees, called HHCART(G). Our decision tree combines learning concepts from two classification trees, HHCART and Geometric Decision Tree (GDT). HHCART(G) is a simplified HHCART algorithm that uses linear structure in the training examples, captured by a modified GDT angle bisector, to define splitting directions. At each node, we reflect the training examples with respect to the modified angle bisector to align this linear structure with the coordinate axes. Searching axis parallel splits in this reflected feature space provides an efficient and effective way of finding oblique splits in the original feature space. Our method is much simpler than HHCART because it only considers one reflected feature space for node splitting. HHCART considers multiple reflected feature spaces for node splitting making it more computationally intensive to build. Experimental results show that HHCART(G) is an effective classifier, producing compact trees with similar or better results than several other decision trees, including GDT and HHCART trees.  相似文献   
776.
We conduct an experiment that examines the relationship between girls only schooling and risk taking and competitive behavior. In it, we compare decisions made by students in an all‐girls' school to those made by students in a closely matched coeducational school. We further investigate the developmental nature of this behavior by comparing choices made by younger students (Grades 7 and 8) with those of older students (Grades 11 and 12). We focus on the differences between those who select into the all‐girls' school, and find that although girls educated in a single sex environment are the most risk averse, they are also among the most competitive. These results lend texture to the hypothesis that “nurture matters” in the gender differences debate. (JEL C93, J16, I21)  相似文献   
777.
Emotionally Focused Couple Therapy (EFT) is an effective approach to working with distressed couples. It is not only effective in reducing relationship distress, but also in successfully maintaining gains over time. In the current study, we sought to understand the therapy processes that result in the creation of safety during stage one of EFT. Safety is a key ingredient in stage one, setting the stage for deeper interpersonal and intrapsychic work in later stages of treatment. In order to achieve the study aim, we analyzed video recordings of the first six sessions of a single couple case from an EFT randomized controlled trial. Using a theory building case study approach, results reveal that all expected components related to the creation of safety were achieved. Additional findings from our analyses indicate that the therapist was highly active, especially in seizing key moments in the therapy provided by this particular case, which shifted the couple in the direction of safety and deescalated their interactional cycle. Implications of key findings are discussed.  相似文献   
778.
When working with clients in another language, having culturally relevant and properly translated clinic materials is vital to effective clinical practice. Not having them presents a barrier for bilingual therapists and their clients. This paper reviews common translation methods and introduces a multi‐level, community‐based approach for translating clinic materials for non‐English speaking clients. Informed by decolonizing practices, this five‐tier method includes members from the target community as cultural brokers to verify the accuracy and nuances of language for their cultural group, as well as a constant comparative method to ensure methodological rigor in the process of inclusion. We present community member's feedback and recommendations, as well as discuss advantages and challenges of using this collaborative culturally responsive translation method.  相似文献   
779.
In this content analysis, researchers examine articles published from 2000 to 2015 in three family therapy journals, yielding a total of 948 empirical articles. The purpose is to provide an overview of the research being published, assess who is publishing, and investigate the current state of clinical effectiveness research in marriage and family therapy (MFT). Most first authors were affiliated with MFT programs and primarily included diversity and couples in their research. There was a significant increase of research on clinical process—though the number of clinical outcome studies held steady. There were no significant changes with regard to research funding. Implications support the use of innovative research methods to provide evidence of clinical effectiveness.  相似文献   
780.
Scholars have theorized that public relations contributes to societies and communities by bringing attention to pressing public issues and fostering social capital in civil society networks. However, the extant research has studied civil society networks of NGOs, donors, and the media in transitional countries. This study extends the public relations model of civil society in two ways. First, it broadens the scope to an international context. Second, it draws from the multi-stakeholder issue network perspective to conceptualize a civil society network as a space where stakeholders of an issue mix their interests as they collectively address a pressing public issue. The literature on international and multi-stakeholder networks suggest that the international scope and the mixing of interests across sectors may restrict the production of social capital. The results from the social network analysis suggests that the mixing of interests across sectoral and geopolitical boundaries did not restrict the production of social capital. Rather, the patterns of the relationships among those on the core and those on the periphery of the network restricted the production of social capital. Such finding demonstrates how public relations’ functions like relationship building can have profound influences on social capital and civil society networks. The implications for public relations theorizing and research are discussed.  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