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   9913篇
  免费   214篇
  国内免费   20篇
管理学   1391篇
民族学   43篇
人口学   1080篇
丛书文集   43篇
理论方法论   788篇
综合类   311篇
社会学   4342篇
统计学   2149篇
  2020年   122篇
  2019年   180篇
  2018年   194篇
  2017年   309篇
  2016年   259篇
  2015年   182篇
  2014年   196篇
  2013年   1556篇
  2012年   410篇
  2011年   330篇
  2010年   214篇
  2009年   175篇
  2008年   246篇
  2007年   237篇
  2006年   200篇
  2005年   712篇
  2004年   418篇
  2003年   277篇
  2002年   186篇
  2001年   264篇
  2000年   198篇
  1999年   150篇
  1998年   138篇
  1997年   128篇
  1996年   126篇
  1995年   110篇
  1994年   83篇
  1993年   127篇
  1992年   138篇
  1991年   127篇
  1990年   130篇
  1989年   111篇
  1988年   107篇
  1987年   111篇
  1986年   100篇
  1985年   86篇
  1984年   117篇
  1983年   98篇
  1982年   95篇
  1981年   64篇
  1980年   94篇
  1979年   106篇
  1978年   74篇
  1977年   83篇
  1976年   71篇
  1975年   87篇
  1974年   68篇
  1973年   55篇
  1972年   62篇
  1971年   53篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
171.
The effect of bioaerosol size was incorporated into predictive dose‐response models for the effects of inhaled aerosols of Francisella tularensis (the causative agent of tularemia) on rhesus monkeys and guinea pigs with bioaerosol diameters ranging between 1.0 and 24 μm. Aerosol‐size‐dependent models were formulated as modification of the exponential and β‐Poisson dose‐response models and model parameters were estimated using maximum likelihood methods and multiple data sets of quantal dose‐response data for which aerosol sizes of inhaled doses were known. Analysis of F. tularensis dose‐response data was best fit by an exponential dose‐response model with a power function including the particle diameter size substituting for the rate parameter k scaling the applied dose. There were differences in the pathogen's aerosol‐size‐dependence equation and models that better represent the observed dose‐response results than the estimate derived from applying the model developed by the International Commission on Radiological Protection (ICRP, 1994) that relies on differential regional lung deposition for human particle exposure.  相似文献   
172.
Abstract

This paper discusses participatory research with young people who are leaving public care in Finland to begin independent lives. The aim of the research, organised by SOS Children's Villages International, was to bring about change in alternative care arrangements, particularly those involving young people's transition to independence. The project used a participatory research design based on employing care-leaving peers as co-researchers. This paper adheres to the methodological principles of empowerment in analysing the personal experiences of young people leaving alternative care with the goal of informing good practice. The findings suggest that the peer research method can be an effective means of empowering young people to develop research skills and to be involved in knowledge production, as well as serving as a means of promoting improved services for “care-leavers”, those young people who are leaving either foster care or institutional care. The participatory and peer research method challenges the traditional understandings of expertise and knowledge production. Although the hierarchy between adult researchers and young people as co-researchers is still evident, the method provides possibilities for better understanding the social- and health-service systems and their challenges and pitfalls from a user's perspective.  相似文献   
173.
174.
An extended single‐index model is considered when responses are missing at random. A three‐step estimation procedure is developed to define an estimator for the single‐index parameter vector by a joint estimating equation. The proposed estimator is shown to be asymptotically normal. An algorithm for computing this estimator is proposed. This algorithm only involves one‐dimensional nonparametric smoothers, thereby avoiding the data sparsity problem caused by high model dimensionality. Some simulation studies are conducted to investigate the finite sample performances of the proposed estimators.  相似文献   
175.
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   
176.
Peer nominations, a central method for measuring peer relationships in developmental research, typically involve asking children or adolescents to choose peers who fit various criteria from an alphabetized roster of classmates or grade‐mates. Although such measures have been used for decades, very little research has investigated the effects of alphabetical name order on the number of nominations received by peers. This study collected peer nominations for 20 items among 607 eighth grade participants in two schools. Regression analyses showed that earlier name order significantly predicted higher nomination counts for eight of the items, and explained over 5 percent of the variance in four affective variables (friendship, acceptance, acquaintanceship, and received liking). Across variables, name order effects were negatively correlated with internal reliability of nominations, implying that order effects may be related to the consensus of the peer group. Name order also had a minimal effect on inter‐correlations among a subset of variables. Implications and concrete recommendations for controlling and reducing name order effects in future research are discussed.  相似文献   
177.
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   
178.
This study contributes to earlier research on homeownership and childbearing by taking into account the potential simultaneity between these two life events. A dataset comprising three different Swedish birth cohorts suggests that these are events that are indeed simultaneous. Different tests indicate that taking this simultaneity into account gives an overall statistically significant improvement of the model fit. However, this result is most obvious for those young adults who faced increasing problems on the housing market. The childbearing decision of these cohorts also seems to be more sensitive to changes in the user cost.  相似文献   
179.
Among policymakers, a common perception surrounding the effects of cash transfer programmes, particularly unconditional programmes targeted to families with children, is that they induce increased fertility. We evaluate the Zambian Child Grant Programme, a government unconditional cash transfer targeted to families with a child under the age of 5 and examine impacts on fertility and household composition. The evaluation was a cluster randomized control trial, with data collected over 4 years from 2010 to 2014. Our results indicate that there are no programme impacts on overall fertility. Our results contribute to a small evidence base demonstrating that there are no unintended incentives related to fertility due to cash transfers.  相似文献   
180.
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