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   2302篇
  免费   154篇
  国内免费   13篇
管理学   203篇
民族学   8篇
人口学   60篇
丛书文集   170篇
理论方法论   356篇
综合类   691篇
社会学   300篇
统计学   681篇
  2024年   2篇
  2023年   36篇
  2022年   28篇
  2021年   26篇
  2020年   73篇
  2019年   81篇
  2018年   90篇
  2017年   105篇
  2016年   81篇
  2015年   86篇
  2014年   130篇
  2013年   361篇
  2012年   135篇
  2011年   139篇
  2010年   117篇
  2009年   104篇
  2008年   119篇
  2007年   109篇
  2006年   102篇
  2005年   84篇
  2004年   92篇
  2003年   70篇
  2002年   65篇
  2001年   54篇
  2000年   45篇
  1999年   21篇
  1998年   23篇
  1997年   18篇
  1996年   13篇
  1995年   9篇
  1994年   10篇
  1993年   5篇
  1992年   7篇
  1991年   5篇
  1990年   4篇
  1989年   2篇
  1988年   5篇
  1986年   3篇
  1985年   4篇
  1984年   1篇
  1983年   5篇
排序方式: 共有2469条查询结果,搜索用时 203 毫秒
1.
Legal judgments require one to make sense of a complex set of typically contradicting pieces of information that can easily be interpreted in a biased manner. This systematic judgment bias can be caused by biased information search (i.e., confirmatory search) as well as biased information processing (i.e., coherence effects) in which the interpretation of information is changed to fit the emerging favored option. In four studies, we investigate the complex interplay between both kinds of influences. Participants completed three legal cases in which they could freely search for information. We manipulated between subjects whether systematic search was possible or not and measured the assessment of each selected piece of information. In line with previous studies, we observe strong coherence effects in each study, in that the evidence interpretation strongly depended on the current tendency towards acquittal or conviction. In contrast to our expectation, however, people searched for information that was contrary to their current belief in the given case (i.e., disconfirmatory information search). We also observed a trend towards an interaction between both factors, in that coherence effects were slightly stronger for neutral and pro-guilty evidence when systematic information search was possible. Our results underline an unconscious striving for coherence when making complex judgments that is not easily corrected.  相似文献   
2.
We investigate the problem of estimating geodesic tortuosity and constrictivity as two structural characteristics of stationary random closed sets. They are of central importance for the analysis of effective transport properties in porous or composite materials. Loosely speaking, geodesic tortuosity measures the windedness of paths, whereas the notion of constrictivity captures the appearance of bottlenecks resulting from narrow passages within a given materials phase. We first provide mathematically precise definitions of these quantities and introduce appropriate estimators. Then, we show strong consistency of these estimators for unboundedly growing sampling windows. In order to apply our estimators to real data sets, the extent of edge effects needs to be controlled. This is illustrated using a model for a multiphase material that is incorporated in solid oxide fuel cells.  相似文献   
3.
Many research fields increasingly involve analyzing data of a complex structure. Models investigating the dependence of a response on a predictor have moved beyond the ordinary scalar-on-vector regression. We propose a regression model for a scalar response and a surface (or a bivariate function) predictor. The predictor has a random component and the regression model falls in the framework of linear random effects models. We estimate the model parameters via maximizing the log-likelihood with the ECME (Expectation/Conditional Maximization Either) algorithm. We use the approach to analyze a data set where the response is the neuroticism score and the predictor is the resting-state brain function image. In the simulations we tried, the approach has better performance than two other approaches, a functional principal component regression approach and a smooth scalar-on-image regression approach.  相似文献   
4.
For the unbalanced one-way random effects model with heterogeneous error variances, we propose the non-informative priors for the between-group variance and develop the first- and second-order matching priors. It turns out that the second-order matching priors do not exist and the reference prior and Jeffreys prior do not satisfy a first-order matching criterion. We also show that the first-order matching prior meets the frequentist target coverage probabilities much better than the Jeffreys prior and reference prior through simulation study, and the Bayesian credible intervals based on the matching prior and reference prior give shorter intervals than the existing confidence intervals by examples.  相似文献   
5.
Proportional hazards are a common assumption when designing confirmatory clinical trials in oncology. This assumption not only affects the analysis part but also the sample size calculation. The presence of delayed effects causes a change in the hazard ratio while the trial is ongoing since at the beginning we do not observe any difference between treatment arms, and after some unknown time point, the differences between treatment arms will start to appear. Hence, the proportional hazards assumption no longer holds, and both sample size calculation and analysis methods to be used should be reconsidered. The weighted log‐rank test allows a weighting for early, middle, and late differences through the Fleming and Harrington class of weights and is proven to be more efficient when the proportional hazards assumption does not hold. The Fleming and Harrington class of weights, along with the estimated delay, can be incorporated into the sample size calculation in order to maintain the desired power once the treatment arm differences start to appear. In this article, we explore the impact of delayed effects in group sequential and adaptive group sequential designs and make an empirical evaluation in terms of power and type‐I error rate of the of the weighted log‐rank test in a simulated scenario with fixed values of the Fleming and Harrington class of weights. We also give some practical recommendations regarding which methodology should be used in the presence of delayed effects depending on certain characteristics of the trial.  相似文献   
6.
Children who are more proficient in cooperation with peers tend to be more preferred. To date, the development of peer cooperation has been studied mainly in two research traditions, one focusing on action coordination and the other focusing on interaction quality. Both aspects of cooperation are relevant for children's peer relations, but it is unclear whether both aspects of children's earliest cooperation skills predict their later preference by peers after the transition into organized social groups in school. In this study, we assessed coordination proficiency and interaction quality of 181 Dutch children longitudinally from 2 to 4 years of age. No relation between early action coordination and later preference by peers at school was found. However, especially in girls more affiliative and fewer antagonistic behaviors at the age of two predicted likeability among classmates at school at the age of four. The findings shine new light on the earliest foundations of children's peer evaluations.  相似文献   
7.
Work on democratization typically considers the diffusion of democracy through interstate partnerships. However, such partnerships constitute complex networks that scholars have yet to fully explore as vectors for the spread of democracy. We develop a network theory of democratization which characterizes these networks as epistemic communities that influence elites’ attitudes towards favorable regime types. Our theory predicts, and our empirical strategy confirms, that direct and indirect ties in the alliance network are vectors for democratization. In contrast to conventional wisdom, we find that direct influence is only transmitted through the defensive alliance network and find evidence of higher-order effects.  相似文献   
8.
Abstract

Objective: The purpose of the study was to investigate whether peer support and demographic characteristics predicted food security among deaf college students. Participants: The sample included 166 deaf college students at Gallaudet University. Methods: Participants completed a bilingual online survey in American Sign Language (ASL) and English. This survey included USDA’s 6-item food security survey, questions about peer support and socio-demographic characteristics. Results: Out of 166 students (mean age =23; SD?=?6), 60.7% were food secure. About 26.4% were at-risk for low food security and another 12.9% had very low food security. The sample included respondents who identified as people of color (54%) and women (52%). Binary logistic regression revealed that compared to people who reported always receiving peer support, people who never received peer support were 16.3 times more likely to experience food insecurity (adj OR: 16.325, 95% CI 1.824–146.107). Conclusions: This study demonstrates a strong relationship between peer support and deaf college students' food security experiences.  相似文献   
9.
Abstract

Romantic relational aggression is related to numerous mental health consequences but risk and protective factors of perpetrating this type of aggression, historically, have been unclear. This study fills in the research gap by evaluating the impact of parental control, parental care, and peer social support on later perpetration in romantic relational aggression among 84 predominately Chinese college students. Results revealed the positive association between parental control and perpetration in romantic relational aggression, however, this association diminished in the presence of high peer social support (HSS). Despite insignificance in the main effect, parental care was negatively correlated with later perpetration in romantic relationship in the HSS group while a positive association was found in the low peer social support (LSS) group. These highlights provided evidences how parental control and parental care during childhood could be risk factors for later romantic relational aggression as well as how current social support from peer could serve as a protective factor on the negative influence from parent–child relationships.  相似文献   
10.
This study examined the differences in risk behavior between men and women using a household survey that captured the risk preferences of two members in a household and recorded wealth at the individual level instead of the usual approach of representing wealth at the household level. After controlling for commonly used explanatory variables, such as gender, education, age, and wealth, household fixed effects explain about 15% of the variation in risk behavior. This highlights the magnitude of household effects in shaping one’s risk behavior. In general, females in the study area are more risk averse than males based on a risk game with real payout. The gender differences disappear when focusing on only the top land owners. However, even in those cases, females consider themselves more risk averse, supporting results from previous studies that link culture and societal norms to the gender differences in risk behavior.  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