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   6357篇
  免费   160篇
  国内免费   3篇
管理学   989篇
民族学   55篇
人才学   9篇
人口学   510篇
丛书文集   47篇
理论方法论   774篇
综合类   51篇
社会学   3283篇
统计学   802篇
  2023年   38篇
  2022年   29篇
  2021年   46篇
  2020年   114篇
  2019年   163篇
  2018年   197篇
  2017年   203篇
  2016年   204篇
  2015年   143篇
  2014年   167篇
  2013年   1000篇
  2012年   224篇
  2011年   245篇
  2010年   188篇
  2009年   155篇
  2008年   191篇
  2007年   218篇
  2006年   198篇
  2005年   222篇
  2004年   193篇
  2003年   171篇
  2002年   169篇
  2001年   114篇
  2000年   150篇
  1999年   126篇
  1998年   110篇
  1997年   103篇
  1996年   96篇
  1995年   83篇
  1994年   108篇
  1993年   91篇
  1992年   96篇
  1991年   64篇
  1990年   55篇
  1989年   56篇
  1988年   68篇
  1987年   53篇
  1986年   47篇
  1985年   57篇
  1984年   67篇
  1983年   55篇
  1982年   58篇
  1981年   50篇
  1980年   51篇
  1979年   44篇
  1978年   32篇
  1977年   31篇
  1976年   47篇
  1975年   26篇
  1974年   35篇
排序方式: 共有6520条查询结果,搜索用时 15 毫秒
181.
Levels of father participation in parenting interventions are often very low, yet little is known about the factors which influence father engagement. We aimed to qualitatively explore perceived barriers to, and preferences for, parenting interventions in a community sample of fathers. Forty‐one fathers across nine focus groups were interviewed using a semi‐structured interview. Data were analysed using inductive thematic analysis. Key barriers to father participation identified included: the perception that interventions are mother‐focused; beliefs about gender roles regarding parenting and help‐seeking; mothers’ role as ‘gatekeeper’; lack of knowledge and awareness of parenting interventions; and lack of relevance of interventions. Fathers reported preferences for specific content and intervention features, facilitator characteristics, practical factors, and highlighted the need for father‐targeted recruitment and advertising. Many of the barriers and preferences identified are consistent with previous research; however, fathers’ beliefs and attitudes around gender roles and help‐seeking, as well as the perception that interventions are predominantly mother‐focused, may be key barriers for community fathers. Strategies to overcome these barriers and better meet the needs of fathers in promoting and delivering parenting interventions are discussed.  相似文献   
182.
183.
We investigate the association between a subjective measure of social status and the reasons for immigration among Asian immigrants in the US. We use data from the National Latino and Asian American Study to test several hypotheses about this association. Our analyses show the positive effect on perceived social standing of migrating for better education, the negative effect of migrating to seek employment, and the negative impact of refugee status. Migrating for family reunification can be associated with various circumstances, which lead to differing outcomes. The results suggest that the notion that immigrants arrive in the US with limited resources and few skills and move slowly up the socioeconomic ladder must be reassessed in light of the complex social context and factors such as ethnicity, gender, divergent immigration paths, and a range of associated circumstances.  相似文献   
184.
Summary.  A general method for exploring multivariate data by comparing different estimates of multivariate scatter is presented. The method is based on the eigenvalue–eigenvector decomposition of one scatter matrix relative to another. In particular, it is shown that the eigenvectors can be used to generate an affine invariant co-ordinate system for the multivariate data. Consequently, we view this method as a method for invariant co-ordinate selection . By plotting the data with respect to this new invariant co-ordinate system, various data structures can be revealed. For example, under certain independent components models, it is shown that the invariant co- ordinates correspond to the independent components. Another example pertains to mixtures of elliptical distributions. In this case, it is shown that a subset of the invariant co-ordinates corresponds to Fisher's linear discriminant subspace, even though the class identifications of the data points are unknown. Some illustrative examples are given.  相似文献   
185.
In this note we provide a counterexample which resolves conjectures about Hadamard matrices made in this journal. Beder [1998. Conjectures about Hadamard matrices. Journal of Statistical Planning and Inference 72, 7–14] conjectured that if HH is a maximal m×nm×n row-Hadamard matrix then m is a multiple of 4; and that if n   is a power of 2 then every row-Hadamard matrix can be extended to a Hadamard matrix. Using binary integer programming we obtain a maximal 13×3213×32 row-Hadamard matrix, which disproves both conjectures. Additionally for n being a multiple of 4 up to 64, we tabulate values of m   for which we have found a maximal row-Hadamard matrix. Based on the tabulated results we conjecture that a m×nm×n row-Hadamard matrix with m?n-7m?n-7 can be extended to a Hadamard matrix.  相似文献   
186.
In response surface methodology, one is usually interested in estimating the optimal conditions based on a small number of experimental runs which are designed to optimally sample the experimental space. Typically, regression models are constructed from the experimental data and interrogated in order to provide a point estimate of the independent variable settings predicted to optimize the response. Unfortunately, these point estimates are rarely accompanied with uncertainty intervals. Though classical frequentist confidence intervals can be constructed for unconstrained quadratic models, higher order, constrained or nonlinear models are often encountered in practice. Existing techniques for constructing uncertainty estimates in such situations have not been implemented widely, due in part to the need to set adjustable parameters or because of limited or difficult applicability to constrained or nonlinear problems. To address these limitations a Bayesian method of determining credible intervals for response surface optima was developed. The approach shows good coverage probabilities on two test problems, is straightforward to implement and is readily applicable to the kind of constrained and/or nonlinear problems that frequently appear in practice.  相似文献   
187.
Summary.  Meta-analysis in the presence of unexplained heterogeneity is frequently undertaken by using a random-effects model, in which the effects underlying different studies are assumed to be drawn from a normal distribution. Here we discuss the justification and interpretation of such models, by addressing in turn the aims of estimation, prediction and hypothesis testing. A particular issue that we consider is the distinction between inference on the mean of the random-effects distribution and inference on the whole distribution. We suggest that random-effects meta-analyses as currently conducted often fail to provide the key results, and we investigate the extent to which distribution-free, classical and Bayesian approaches can provide satisfactory methods. We conclude that the Bayesian approach has the advantage of naturally allowing for full uncertainty, especially for prediction. However, it is not without problems, including computational intensity and sensitivity to a priori judgements. We propose a simple prediction interval for classical meta-analysis and offer extensions to standard practice of Bayesian meta-analysis, making use of an example of studies of 'set shifting' ability in people with eating disorders.  相似文献   
188.
Most migration research is focused on migrant experiences after mobility and settlement. We argue that empirical researchers would benefit from studying how cognitive migration, the narrative imagining of oneself inhabiting a foreign destination prior to the actual physical move, influences migration behaviour. This article notes a gap in our current understanding of the process by which individuals decide to cross international borders and offers an agenda for remedying this. The interdisciplinarity of migration research has not fully extended to social psychology or cognitive social sciences, where a dynamic research agenda has examined human decision-making processes, including prospection and the connections between culture and cognition. The study of socio-cognitive processes in migration decision-making has been largely overlooked because of the after-the-fact nature of data collection and analysis rather than an aversion to these approaches per se. We highlight a number of strategic findings from this diverse field, provide examples of migration scholarship that has benefited from these insights, and raise questions about the sides of migration process that have received insufficient attention. A more nuanced understanding of prospective thinking—imagining potential futures—can shed light on the classic puzzle of why some people move while others in comparable situations do not.  相似文献   
189.
Economic activity among Muslim women in the UK remains considerably lower and their unemployment rate significantly higher than among the majority group even after controlling for qualifications and other individual characteristics. This study utilises two data sets to explore possible factors underlying these differences, such as overseas qualifications, language skills and religiosity. It reveals that while religiosity is negatively associated with labour market participation among British Christian-White women, economic activity among Muslim women are not negatively affected by high religiosity. Furthermore, family structure and the presence of dependent children were among the most important factors explaining the latter’s labour market participation, although these relationships were moderated by qualifications. More women with higher qualifications were economically active even if married and with children, although some of them experienced greater unemployment, probably due to discrimination in recruiting practices and choices and preferences on religious grounds.  相似文献   
190.
This paper develops a warning zone approach to make variance investigation decisions for a multiperiod process. The assumed cost generation process varies between an in-control and out-of-control state. These states cannot be directly observed, but must be inferred from the reported cost variances. Using the warning zone method of inference, the manager investigates the process whenever an upper threshold is exceeded or a lower threshold is exceeded for two consecutive periods. A four-state Markov chain models the resulting decision process. Steady state probabilities are derived for this chain and are used to obtain explicit formulas for the effectiveness and efficiency of the decision process. These formulas permit computation of the cost savings attainable by the warning zone method. Compared to other decision rules, the warning zone method is much simpler than the theoretically optimal Bayesian revision method, but uses more information than the Markovian control limit method. Numerical comparison of results shows that the warning zone method usually captures most of the available cost savings, even in cases where the Markovian control limit method does not perform well.  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