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   29889篇
  免费   798篇
管理学   3725篇
民族学   151篇
人才学   7篇
人口学   2724篇
丛书文集   176篇
教育普及   4篇
理论方法论   2788篇
现状及发展   1篇
综合类   553篇
社会学   15068篇
统计学   5490篇
  2023年   150篇
  2021年   160篇
  2020年   465篇
  2019年   661篇
  2018年   687篇
  2017年   975篇
  2016年   717篇
  2015年   563篇
  2014年   679篇
  2013年   5035篇
  2012年   995篇
  2011年   881篇
  2010年   669篇
  2009年   650篇
  2008年   728篇
  2007年   763篇
  2006年   680篇
  2005年   744篇
  2004年   697篇
  2003年   648篇
  2002年   640篇
  2001年   735篇
  2000年   654篇
  1999年   658篇
  1998年   490篇
  1997年   454篇
  1996年   474篇
  1995年   441篇
  1994年   447篇
  1993年   407篇
  1992年   494篇
  1991年   490篇
  1990年   432篇
  1989年   451篇
  1988年   414篇
  1987年   381篇
  1986年   378篇
  1985年   397篇
  1984年   422篇
  1983年   414篇
  1982年   324篇
  1981年   277篇
  1980年   293篇
  1979年   318篇
  1978年   266篇
  1977年   247篇
  1976年   217篇
  1975年   205篇
  1974年   185篇
  1973年   159篇
排序方式: 共有10000条查询结果,搜索用时 819 毫秒
991.
The properties of three lack-of-fit tests that are related to non-parametric cosine regression analysis are examined in the context of testing for a constant mean function. Analytic power comparisons of these tests vs a most powerful test are made using intermediate asymptotic relative efficiency. In particular, a data-driven test is produced which is asymptotically as efficient as the most powerful test over a class of alternatives. A small scale simulation experiment is conducted to ascertain the extent that the large sample comparisons are applicable to finite samples.  相似文献   
992.
993.
This paper considers a class of summary measures of the dependence between a pair of failure time variables over a finite follow-up region. The class consists of measures that are weighted averages of local dependence measures, and includes the cross-ratio-measure and finite region version of Kendall's τ; recently proposed by the authors. Two new special cases are identified that can avoid the need to estimate the bivariate survivor function and that admit explicit variance estimators. Nonparametric estimators of such dependence measures are proposed and are shown to be consistent and asymptotically normal with variances that can be consistently estimated. Properties of selected estimators are evaluated in a simulation study, and the method is illustrated through an analysis of Australian Twin Study data.  相似文献   
994.
The EM algorithm is a popular method for computing maximum likelihood estimates. One of its drawbacks is that it does not produce standard errors as a by-product. We consider obtaining standard errors by numerical differentiation. Two approaches are considered. The first differentiates the Fisher score vector to yield the Hessian of the log-likelihood. The second differentiates the EM operator and uses an identity that relates its derivative to the Hessian of the log-likelihood. The well-known SEM algorithm uses the second approach. We consider three additional algorithms: one that uses the first approach and two that use the second. We evaluate the complexity and precision of these three and the SEM in algorithm seven examples. The first is a single-parameter example used to give insight. The others are three examples in each of two areas of EM application: Poisson mixture models and the estimation of covariance from incomplete data. The examples show that there are algorithms that are much simpler and more accurate than the SEM algorithm. Hopefully their simplicity will increase the availability of standard error estimates in EM applications. It is shown that, as previously conjectured, a symmetry diagnostic can accurately estimate errors arising from numerical differentiation. Some issues related to the speed of the EM algorithm and algorithms that differentiate the EM operator are identified.  相似文献   
995.
Empirical Bayes is a versatile approach to “learn from a lot” in two ways: first, from a large number of variables and, second, from a potentially large amount of prior information, for example, stored in public repositories. We review applications of a variety of empirical Bayes methods to several well‐known model‐based prediction methods, including penalized regression, linear discriminant analysis, and Bayesian models with sparse or dense priors. We discuss “formal” empirical Bayes methods that maximize the marginal likelihood but also more informal approaches based on other data summaries. We contrast empirical Bayes to cross‐validation and full Bayes and discuss hybrid approaches. To study the relation between the quality of an empirical Bayes estimator and p, the number of variables, we consider a simple empirical Bayes estimator in a linear model setting. We argue that empirical Bayes is particularly useful when the prior contains multiple parameters, which model a priori information on variables termed “co‐data”. In particular, we present two novel examples that allow for co‐data: first, a Bayesian spike‐and‐slab setting that facilitates inclusion of multiple co‐data sources and types and, second, a hybrid empirical Bayes–full Bayes ridge regression approach for estimation of the posterior predictive interval.  相似文献   
996.
The main objective of this work is to evaluate the performance of confidence intervals, built using the deviance statistic, for the hyperparameters of state space models. The first procedure is a marginal approximation to confidence regions, based on the likelihood test, and the second one is based on the signed root deviance profile. Those methods are computationally efficient and are not affected by problems such as intervals with limits outside the parameter space, which can be the case when the focus is on the variances of the errors. The procedures are compared to the usual approaches existing in the literature, which includes the method based on the asymptotic distribution of the maximum likelihood estimator, as well as bootstrap confidence intervals. The comparison is performed via a Monte Carlo study, in order to establish empirically the advantages and disadvantages of each method. The results show that the methods based on the deviance statistic possess a better coverage rate than the asymptotic and bootstrap procedures.  相似文献   
997.
Four hundred and seventy-nine undergraduates reported on family discussions about the 2016 election that occurred over that same year’s Thanksgiving break. Family Communication Patterns Theory was used to predict the perceived outcomes of such discussion on family members. Higher conversation orientation predicted a more positive perceived effect of political talk on family closeness. Perceived similarity of political views partially moderated the relationship between conformity orientation and perceived effect of political talk on family closeness. Reported stress levels since the election were negatively predicted by the perceived (positive) effect of political talk on family closeness. Practical and theoretical implications for families and political socialization processes are discussed.  相似文献   
998.
This study uses intersectional methodology to critically explore vulvodynia, chronic female genital pain, as it disrupts norms governing gender roles in heterosexual sex and reproduction. Interviews with 26 women with vulvodynia illuminate core tenets of the critical interpersonal and family communication (CIFC) framework, which include power; private and public sphere bidirectionality; the critique, resistance, and transformation of the status quo; and considerations of author reflexivity. As the author is herself a heterosexual woman navigating vulvodynia, reflexivity is particularly salient. Status quo social constructs are explicated. Results demonstrate how participants experience losses of relational power and problematic media depictions establishing standards for “normal” heterosexual sex. Discourses and practices concerning the perpetuation, resistance, and potential transformation of the status quo are described.  相似文献   
999.
Private English language schools market the language as a tool that helps one connect with others from different cultures. Despite their promotion of English aiding in intercultural communication, these institutions may believe that only the white native speaker is the ideal teacher of the language. This valuing of the white native speaker can consequently act as an organisational inequality regime that marginalises nonwhite teachers. Using qualitative interviews with 10 nonwhite instructors working in schools in Toronto, Canada, this article investigates the ways in which these teachers experience the inequality regime of the white native speaker at work. The findings indicate that the teachers experience this inequality regime as a series of microaggressions that involve space, competence and customer desire. The article concludes with suggestions to dismantle inequality regimes in private institutions.  相似文献   
1000.
This study aimed to explore the correlation between job burnout and self-stigma of seeking help among nonmedical mental health care providers (psychologists, social workers, and counselors) in two countries – Lithuania and the US. The study included 234 professionals (111 social workers and 123 psychologists) from Lithuania and 93 professionals (33 counselors, 23 social workers, and 37 psychologists) from the US on a voluntary basis (93% females, mean age – 39.81?years). They completed a self-reported questionnaire with the Self-Stigma of Seeking Help Scale (SSOSH) and the Maslach Burnout Inventory-General Survey (MBI-GS). The results revealed a statistically significant positive correlation between self-stigmatization and burnout in the Lithuanian sample, but only weak positive correlation between depersonalization and self-stigma of seeking help in the US sample. The relationship between the self-stigma of seeking help and burnout was stronger in the Lithuanian sample of professionals when compared to their colleagues in the US.  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