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   1085篇
  免费   75篇
  国内免费   12篇
管理学   111篇
民族学   5篇
人口学   28篇
丛书文集   37篇
理论方法论   65篇
综合类   227篇
社会学   110篇
统计学   589篇
  2023年   4篇
  2022年   6篇
  2021年   21篇
  2020年   16篇
  2019年   42篇
  2018年   53篇
  2017年   29篇
  2016年   39篇
  2015年   38篇
  2014年   44篇
  2013年   128篇
  2012年   79篇
  2011年   98篇
  2010年   75篇
  2009年   102篇
  2008年   81篇
  2007年   72篇
  2006年   24篇
  2005年   15篇
  2004年   14篇
  2003年   17篇
  2002年   15篇
  2001年   23篇
  2000年   3篇
  1999年   7篇
  1998年   4篇
  1997年   5篇
  1996年   8篇
  1995年   13篇
  1994年   10篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1985年   7篇
  1984年   18篇
  1983年   12篇
  1982年   15篇
  1981年   8篇
  1980年   9篇
  1979年   3篇
  1978年   10篇
排序方式: 共有1172条查询结果,搜索用时 15 毫秒
41.
Schools at the P-12 level increasingly face crises related to school shootings, violence, and other tragedies. Understanding the communication challenges schools face is paramount to assisting schools with communication before, during, and after crisis events. The current study focuses on the challenges created by media interest in such crises and the strategies implemented to overcome these challenges and provide responsible information to stakeholders. Interviews conducted with 21 school crisis teams at the P-12 level revealed that sensationalism, seeking alternative routes to information, and framing were key challenges in working with the media. In light of these challenges, administrators focused on creating media plans, building relationships with the media, being accurate but guarded, and communicating reassurance and reunification. Implications are discussed for school districts nationally.  相似文献   
42.
人类已经进入"第五媒体时代".继报纸、广播、电视、互联网之后的第五媒体抑或是手机媒体.具有媒介粘滞、瞬时精准、病毒式营销等无与伦比的传播特性.第五媒体是柄"双刃剑",它在给政府公共关系带来前所未有的挑战的同时,也带来了前所未有的机遇.利用第五媒体开拓政府公共关系的新视野,是一个政治、社会问题,也是一个技术、法律问题.  相似文献   
43.
This paper studies the estimation in the proportional odds model based on randomly truncated data. The proposed estimators for the regression coefficients include a class of minimum distance estimators defined through weighted empirical odds function. We have investigated the asymptotic properties like the consistency and the limiting distribution of the proposed estimators under mild conditions. The finite sample properties were investigated through simulation study making comparison of some of the estimators in the class. We conclude with an illustration of our proposed method to a well-known AIDS data.  相似文献   
44.
We investigate how to combine marginal assessments about the values that random variables assume separately into a model for the values that they assume jointly, when (i) these marginal assessments are modelled by means of coherent lower previsions and (ii) we have the additional assumption that the random variables are forward epistemically irrelevant to each other. We consider and provide arguments for two possible combinations, namely the forward irrelevant natural extension and the forward irrelevant product, and we study the relationships between them. Our treatment also uncovers an interesting connection between the behavioural theory of coherent lower previsions, and Shafer and Vovk's game-theoretic approach to probability theory.  相似文献   
45.
In this paper, we consider finite populations and investigate their characterizations by regressions of order statistics under sampling without replacement. We also investigate some asymptotic results when the size of the population goes to infinity.  相似文献   
46.
47.
In this paper, we consider the partial linear model with the covariables missing at random. Empirical likelihood ratios for the regression coefficients and the baseline function are investigated, the empirical log-likelihood ratios are proven to be asymptotically chi-squared and the corresponding confidence regions for the parameters of interest are then constructed. The finite sample behavior of the proposed method is evaluated with simulation and illustrated with an AIDS clinical trial dataset.  相似文献   
48.
The equality of ordinary least squares estimator (OLSE), best linear unbiased estimator (BLUE) and best linear unbiased predictor (BLUP) in the general linear model with new observations is investigated through matrix rank method, some new necessary and sufficient conditions are given.  相似文献   
49.
In this article we study the problem of classification of three-level multivariate data, where multiple qq-variate observations are measured on uu-sites and over pp-time points, under the assumption of multivariate normality. The new classification rules with certain structured and unstructured mean vectors and covariance structures are very efficient in small sample scenario, when the number of observations is not adequate to estimate the unknown variance–covariance matrix. These classification rules successfully model the correlation structure on successive repeated measurements over time. Computation algorithms for maximum likelihood estimates of the unknown population parameters are presented. Simulation results show that the introduction of sites in the classification rules improves their performance over the existing classification rules without the sites.  相似文献   
50.
Continuous non-Gaussian stationary processes of the OU-type are becoming increasingly popular given their flexibility in modelling stylized features of financial series such as asymmetry, heavy tails and jumps. The use of non-Gaussian marginal distributions makes likelihood analysis of these processes unfeasible for virtually all cases of interest. This paper exploits the self-decomposability of the marginal laws of OU processes to provide explicit expressions of the characteristic function which can be applied to several models as well as to develop efficient estimation techniques based on the empirical characteristic function. Extensions to OU-based stochastic volatility models are provided.  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