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   433篇
  免费   26篇
  国内免费   3篇
管理学   10篇
民族学   3篇
人口学   6篇
丛书文集   23篇
理论方法论   11篇
综合类   154篇
社会学   24篇
统计学   231篇
  2023年   4篇
  2022年   3篇
  2021年   5篇
  2020年   10篇
  2019年   11篇
  2018年   13篇
  2017年   26篇
  2016年   16篇
  2015年   18篇
  2014年   16篇
  2013年   57篇
  2012年   45篇
  2011年   21篇
  2010年   22篇
  2009年   16篇
  2008年   23篇
  2007年   27篇
  2006年   27篇
  2005年   23篇
  2004年   20篇
  2003年   12篇
  2002年   13篇
  2001年   9篇
  2000年   8篇
  1999年   3篇
  1998年   3篇
  1997年   3篇
  1996年   1篇
  1995年   3篇
  1993年   1篇
  1988年   1篇
  1982年   1篇
  1978年   1篇
排序方式: 共有462条查询结果,搜索用时 15 毫秒
1.
综合英语课是一门综合性的语言基础课。在综合英语课教学中,结合所教学生的实际英语水平,采用不同的教学方法,并组织形式多样的课堂教学活动,使学生在大量的语言实践活动中掌握并具备听、说、读、写等综合语言能力。  相似文献   
2.
A controlled clinical trial was conducted to investigate the efficacy effect of a chemical compound in the treatment of Premenstrual Dysphoric Disorder (PMDD). The data from the trial showed a non-monotone pattern of missing data and an ante-dependence covariance structure. A new analytical method for imputing the missing data with the ante-dependence covariance is proposed. The PMDD data are analysed by the non-imputation method and two imputation methods: the proposed method and the MCMC method.  相似文献   
3.
作者运用教育心理学的课堂成就动机理论结合化学教学实际 ,选取了 14种化学学习动机进行问卷调查 ,并进行总体统计分析和抽样统计分析 ,得出了这样的结论。化学教师可以在教学中有效地培养 ,激发和强化学生的化学学习动机 ,提高教与学的效率 ,更好地培养学生的创新精神和实践能力。  相似文献   
4.
中等收入者论   总被引:1,自引:0,他引:1  
中等收入者指一个国家的中等富裕群体。为确保社会经济健康、协调、持续发展 ,必须努力提高低收入者素质 ,降低转化门槛 ,扩大中等收入者比重。  相似文献   
5.
突发的疫情使得线上教学在所有高校全面铺开。为了了解这次“应急线上教学”的教学效果,上海理工大学教师发展中心对全校师生从线上教学的评价、线上线下教学体验对比、线上教学带给师生的改变等方面进行了线上教学效果的问卷调查。研究对专项调查的数据进行了深入分析,得出了线上与线下学习效果基本等效、线上线下教学各具优势、线上教学带来深刻改变的调查结果,提出了线上教学存在的主要问题,并给出了相应提升线上教学效果的建议。  相似文献   
6.
众筹教育通过打造并完善教育资源共享平台,推动教育资源的虚拟重组、均衡发展,实现跨区域教育的协同发展,有助于实现知识增值的目标。众筹教育所具备的创意性筹资、柔性化生产、互动化交流、区域化共享等特征使其与当下的高校美育选修课教育体制改革的需求高度契合。从实现路径来看,众筹教育介入高校美育选修课改革可以从校内模拟众筹、区域内课程共享、完善教育资源共享平台3个层面逐步铺开,形成高校美育选修课线上与线下互动发展的新模式,为推动我国教育体制改革困局的破解提供思路。  相似文献   
7.
This paper develops a test for comparing treatment effects when observations are missing at random for repeated measures data on independent subjects. It is assumed that missingness at any occasion follows a Bernoulli distribution. It is shown that the distribution of the vector of linear rank statistics depends on the unknown parameters of the probability law that governs missingness, which is absent in the existing conditional methods employing rank statistics. This dependence is through the variance–covariance matrix of the vector of linear ranks. The test statistic is a quadratic form in the linear rank statistics when the variance–covariance matrix is estimated. The limiting distribution of the test statistic is derived under the null hypothesis. Several methods of estimating the unknown components of the variance–covariance matrix are considered. The estimate that produces stable empirical Type I error rate while maintaining the highest power among the competing tests is recommended for implementation in practice. Simulation studies are also presented to show the advantage of the proposed test over other rank-based tests that do not account for the randomness in the missing data pattern. Our method is shown to have the highest power while also maintaining near-nominal Type I error rates. Our results clearly illustrate that even for an ignorable missingness mechanism, the randomness in the pattern of missingness cannot be ignored. A real data example is presented to highlight the effectiveness of the proposed method.  相似文献   
8.
Motivated by classification issues that arise in marine studies, we propose a latent-class mixture model for the unsupervised classification of incomplete quadrivariate data with two linear and two circular components. The model integrates bivariate circular densities and bivariate skew normal densities to capture the association between toroidal clusters of bivariate circular observations and planar clusters of bivariate linear observations. Maximum-likelihood estimation of the model is facilitated by an expectation maximization (EM) algorithm that treats unknown class membership and missing values as different sources of incomplete information. The model is exploited on hourly observations of wind speed and direction and wave height and direction to identify a number of sea regimes, which represent specific distributional shapes that the data take under environmental latent conditions.  相似文献   
9.
Business establishment microdata typically are required to satisfy agency-specified edit rules, such as balance equations and linear inequalities. Inevitably some establishments' reported data violate the edit rules. Statistical agencies correct faulty values using a process known as edit-imputation. Business establishment data also must be heavily redacted before being shared with the public; indeed, confidentiality concerns lead many agencies not to share establishment microdata as unrestricted access files. When microdata must be heavily redacted, one approach is to create synthetic data, as done in the U.S. Longitudinal Business Database and the German IAB Establishment Panel. This article presents the first implementation of a fully integrated approach to edit-imputation and data synthesis. We illustrate the approach on data from the U.S. Census of Manufactures and present a variety of evaluations of the utility of the synthetic data. The paper also presents assessments of disclosure risks for several intruder attacks. We find that the synthetic data preserve important distributional features from the post-editing confidential microdata, and have low risks for the various attacks.  相似文献   
10.
Recent developments have made model-based imputation of network data feasible in principle, but the extant literature provides few practical examples of its use. In this paper, we consider 14 schools from the widely used In-School Survey of Add Health (Harris et al., 2009), applying an ERGM-based estimation and simulation approach to impute the network missing data for each school. Add Health's complex study design leads to multiple types of missingness, and we introduce practical techniques for handing each. We also develop a cross-validation based method – Held-Out Predictive Evaluation (HOPE) – for assessing this approach. Our results suggest that ERGM-based imputation of edge variables is a viable approach to the analysis of complex studies such as Add Health, provided that care is used in understanding and accounting for the study design.  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