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   7844篇
  免费   202篇
管理学   1125篇
民族学   32篇
人才学   1篇
人口学   721篇
丛书文集   33篇
理论方法论   698篇
综合类   283篇
社会学   3348篇
统计学   1805篇
  2021年   52篇
  2020年   90篇
  2019年   129篇
  2018年   167篇
  2017年   244篇
  2016年   199篇
  2015年   149篇
  2014年   175篇
  2013年   1359篇
  2012年   296篇
  2011年   217篇
  2010年   175篇
  2009年   158篇
  2008年   192篇
  2007年   180篇
  2006年   138篇
  2005年   197篇
  2004年   174篇
  2003年   215篇
  2002年   231篇
  2001年   217篇
  2000年   192篇
  1999年   185篇
  1998年   143篇
  1997年   112篇
  1996年   127篇
  1995年   105篇
  1994年   97篇
  1993年   105篇
  1992年   125篇
  1991年   115篇
  1990年   112篇
  1989年   102篇
  1988年   110篇
  1987年   110篇
  1986年   103篇
  1985年   121篇
  1984年   97篇
  1983年   105篇
  1982年   74篇
  1981年   74篇
  1980年   69篇
  1979年   74篇
  1978年   77篇
  1977年   54篇
  1976年   45篇
  1975年   59篇
  1974年   48篇
  1973年   41篇
  1972年   39篇
排序方式: 共有8046条查询结果,搜索用时 234 毫秒
691.
A prevalence of heavy-tailed, peaked and skewed uncertainty phenomena have been cited in literature dealing with economic, physics, and engineering data. This fact has invigorated the search for continuous distributions of this nature. In this paper we shall generalize the two-sided framework presented in Kotz and van Dorp (Beyond beta: other continuous families of distributions with bounded support and applications. World Scientific Press, Singapore, 2004) for the construction of families of distributions with bounded support via a mixture technique utilizing two generating densities instead of one. The family of Elevated Two-Sided Power (ETSP) distributions is studied as an instance of this generalized framework. Through a moment ratio diagram comparison, we demonstrate that the ETSP family allows for a remarkable flexibility when modeling heavy-tailed and peaked, but skewed, uncertainty phenomena. We shall demonstrate its applicability via an illustrative example utilizing 2008 US income data.  相似文献   
692.
Abstract

Health science students, along with the health professionals they hope to become, are at increased risk for certain occupational injuries and illnesses. One of these risks is occupational exposure to blood-borne pathogens, such as human immunodeficiency virus (HIV) and hepatitis, which may result in severe illnesses or even death. Two case studies demonstrate postexposure care of exposed individuals at the University of Texas Medical Branch Student Health Services before and after policy changes and prevention strategies were strengthened in response to exposure incidents.  相似文献   
693.
694.
695.
696.
697.
“毛泽东精神”研究四题   总被引:6,自引:1,他引:5  
毛泽东思想体系具有层次性,毛泽东精神是毛泽东的智慧、情感、意志、理想、信念、人格的结晶,是毛泽东的思想、理论、诗词、书品、生活和实践中蕴含的最深层的本质。毛泽东精神是中华民族的民族精神在20世纪的集中体现,是振兴中华民族强大的精神动力。加强对毛泽东精神的研究、宣传和弘扬,是人民的呼声,时代的需要,是理论工作者责无旁贷的职责。  相似文献   
698.
699.
The conclusions of alogically consistent economic theory which strictly adheres to Aristotle's axioms of logic are factually true if its sufficient conditions are all factually true. Alternatively, if a conclusion of such a theory is false, then at- least one of its assumptions is false. Unfortunately, the factual truth of sufficient conditions cannot be established because the problem of induction i s impossible t o solve. It is algo true that the falsity of a conclusion cannot be established in the presence of uncertainty. While the philosophy of instrumentalism applied to sufficient and logically consistent explanations may provide useful solutions to immediate practical problems, the principles of simplicity, parsimony and profligacy--all of them requiring conditional deductive arguments--are useless as criteria for model choice.  相似文献   
700.
Summary.  We consider the stochastic mechanisms behind the data that were collected by the solar X-ray sensor (XRS) on board the GOES-8 satellite. We discover and justify a non-trivial mean–variance relationship within the XRS data. Transforming such data so that their variance is stable and its distribution is taken closer to the Gaussian distribution is the aim of many techniques (e.g. Anscombe and Box–Cox). Recently, new techniques based on the Haar–Fisz transform have been introduced that use a multiscale method to transform and stabilize data with a known mean–variance relationship. In many practical cases, such as the XRS data, the variance of the data can be assumed to increase with the mean, but other characteristics of the distribution are unknown. We introduce a method, the data-driven Haar–Fisz transform, which uses the Haar–Fisz transform but also estimates the mean–variance relationship. For known noise distributions, the data-driven Haar–Fisz transform is shown to be competitive with the fixed Haar–Fisz methods. We show how our data-driven Haar–Fisz transform method denoises the XRS series where other existing methods fail.  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