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   1125篇
  免费   56篇
  国内免费   17篇
管理学   57篇
民族学   6篇
人口学   44篇
丛书文集   56篇
理论方法论   45篇
综合类   559篇
社会学   102篇
统计学   329篇
  2024年   2篇
  2023年   5篇
  2022年   6篇
  2021年   10篇
  2020年   20篇
  2019年   23篇
  2018年   33篇
  2017年   56篇
  2016年   30篇
  2015年   51篇
  2014年   66篇
  2013年   175篇
  2012年   100篇
  2011年   92篇
  2010年   69篇
  2009年   47篇
  2008年   48篇
  2007年   52篇
  2006年   50篇
  2005年   44篇
  2004年   21篇
  2003年   34篇
  2002年   30篇
  2001年   25篇
  2000年   20篇
  1999年   14篇
  1998年   8篇
  1997年   10篇
  1996年   8篇
  1995年   6篇
  1994年   5篇
  1993年   6篇
  1992年   3篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1986年   2篇
  1985年   3篇
  1984年   4篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   2篇
  1975年   2篇
排序方式: 共有1198条查询结果,搜索用时 62 毫秒
71.
Rank tests are considered that compare t treatments in repeated measures designs. A statistic is given that contains as special cases several that have been proposed for this problem, including one that corresponds to the randomized block ANOVA statistic applied to the rank transformed data. Another statistic is proposed, having a null distribution holding under more general conditions, that is the rank transform of the Hotelling statistic for repeated measures. A statistic of this type is also given for data that are ordered categorical rather than fully rankedo Unlike the Friedman statistic, the statistics discussed in this article utilize a single ranking of the entire sample. Power calculations for an underlying normal distribution indicate that the rank transformed ANOVA test can be substantially more powerful than the Friedman test.  相似文献   
72.
Canonical correlation has been little used and little understood, even by otherwise sophisticated analysts. An alternative approach to canonical correlation, based on a general linear multivariate model, is presented. Properties of principal component analysis are used to help explain the method. Standard computational methods for full rank canonical correlation, techniques for canonical correlation on component scores, and canonical correlation with less than full rank are discussed. They are seen to be essentially equivalent when the model equation for canonical correlation on component scores is presented. The two approaches to less than full rank situations are equivalent in some senses, but quite different in usefulness, depending on the application. An example dataset is analyzed in detail to help demonstrate the conclusions.  相似文献   
73.
Experiments in which very few units are measured many times sometimes present particular difficulties. Interest often centers on simple location shifts between two treatment groups, but appropriate modeling of the error distribution can be challenging. For example, normality may be difficult to verify, or a single transformation stabilizing variance or improving normality for all units and all measurements may not exist. We propose an analysis of two sample repeated measures data based on the permutation distribution of units. This provides a distribution free alternative to standard analyses. The analysis includes testing, estimation and confidence intervals. By assuming a certain structure in the location shift model, the dimension of the problem is reduced by analyzing linear combinations of the marginal statistics. Recently proposed algorithms for computation of two sample permutation distributions, require only a few seconds for experiments having as many as 100 units and any number of repeated measures. The test has high asymptotic efficiency and good power with respect to tests based on the normal distribution. Since the computational burden is minimal, approximation of the permutation distribution is unnecessary.  相似文献   
74.
针对低孔低渗储层产能预测模型受敏感因素影响大,主次因素在低产情况下区别不明显,产能预测评价相对较困难等实际问题,以准噶尔盆地夏子街地区夏77井、夏79井为例,开展低孔低渗储层产能预测的前期试验研究,对多个产能预测模型及其适用条件进行了对比分析,从Darcy模型、Jones(1976)模型、Vogel/Harrison(1968)模型、裂缝模型中进行优选和调试。通过分析产能预测模型结果与测试结果在产量上的相关性,表明基于测井资料的预测结果与试油测试结果相当吻合,从而确认产能预测模型结果的可靠性。  相似文献   
75.
高校“课堂教学低效”原因及解决策略   总被引:2,自引:0,他引:2  
信息化时代,社会发展对人才提出了新的需求。而众多高等学府的课堂教学更新的速度远远跟不上时代发展的脉搏。从教学内容到教学模式虽有所调整,但无实质的变化,“课堂教学低效”成为制约高素质人才培养的“瓶颈”。本文分析了高校“课堂教学低效”的原因,并提出了解决问题的策略,以期提高高校课堂教学的质量。  相似文献   
76.
Korean society is facing unprecedentedly higher population ageing, particularly in the first half of the 21st century. The implications of population ageing have a much wider effect than the welfare of the elderly. From a broader and long‐term perspective, understanding population ageing may require a new paradigm. Korea has attempted to model its policies for ageing society on those of advanced welfare states, but as these no longer seem viable, Korean policy‐makers are searching for more effective and efficient measures to deal with its rapid ageing population. Reflecting a broader and long‐term perspective, the Korean government recently produced a comprehensive national policy plan to deal with the consequences of rapid population ageing. This article outlines the phenomenon of population ageing in Korea and the recent development of national policies for population ageing, describing the Korean comprehensive national policy plan for responding to it and examining major issues and problems related to developing and implementing the plan. This article finally suggests a new, age‐integrated social system approach to an ageing society.  相似文献   
77.
ABSTRACT

Annual net cash returns and net capital gains provide farmers with their actual and potential monetary rewards, respectively. This article reports on a national farm survey showing both actual and potential returns, on average, are not as high as might be imagined. This is supported by the findings of earlier studies and has implications for rural societies and their associated economies. Data on income, expenses and profit is presented as is data on farm value changes over the life of each farm. The information is adjusted for inflation to provide ‘real’ data. The profit and net capital gain figures are divided into groupings based on a range of criteria such as total farm capital, and labour compliment as a reflection of farm size. Statistically significant differences occur for some groupings such as farm type and farm size.  相似文献   
78.
A class of linear rank tests is suggested for testing a shift in scale at an unknown time point in a sequence of independent observations. The tests,based on inverse normal scores and on ordered exponential scores,are shown to be asymptotically as efficient as their distribution-oriented competitors. Critical values and powers for these two rank tests are also discussed.  相似文献   
79.
This paper proposes an optimal rank test procedure for testing an umbrella alternative when the peak of the umbrella is known. It is referred to as maximin efficient linear rank test. Also when the peak of the umbrella is unknown, a test procedure is proposed and its performance is discussed.  相似文献   
80.
本文考虑在低频度事件中保险产品选择问题,用效用理论及模糊数学知识建立了产品选择模型,并给出了算例,找到了使双方均满意的最优产品。  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