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   12565篇
  免费   332篇
管理学   1801篇
民族学   73篇
人才学   1篇
人口学   1295篇
丛书文集   72篇
教育普及   1篇
理论方法论   1084篇
现状及发展   2篇
综合类   146篇
社会学   6052篇
统计学   2370篇
  2023年   86篇
  2021年   75篇
  2020年   196篇
  2019年   257篇
  2018年   307篇
  2017年   407篇
  2016年   326篇
  2015年   218篇
  2014年   275篇
  2013年   2185篇
  2012年   432篇
  2011年   372篇
  2010年   296篇
  2009年   281篇
  2008年   334篇
  2007年   305篇
  2006年   280篇
  2005年   287篇
  2004年   270篇
  2003年   242篇
  2002年   281篇
  2001年   311篇
  2000年   312篇
  1999年   289篇
  1998年   197篇
  1997年   182篇
  1996年   181篇
  1995年   184篇
  1994年   150篇
  1993年   160篇
  1992年   179篇
  1991年   163篇
  1990年   175篇
  1989年   196篇
  1988年   161篇
  1987年   148篇
  1986年   155篇
  1985年   186篇
  1984年   176篇
  1983年   169篇
  1982年   137篇
  1981年   118篇
  1980年   114篇
  1979年   149篇
  1978年   97篇
  1977年   91篇
  1976年   98篇
  1975年   89篇
  1974年   86篇
  1973年   73篇
排序方式: 共有10000条查询结果,搜索用时 750 毫秒
771.
This paper considers a likelihood ratio test for testing hypotheses defined by non-oblique closed convex cones, satisfying the so called iteration projection property, in a set of k normal means. We obtain the critical values of the test using the Chi-Bar-Squared distribution. The obtuse cones are introduced as a particular class of cones which are non-oblique with every one of their faces. Examples with the simple tree order cone and the total order cone are given to illustrate the results.  相似文献   
772.
This article outlines the structure of a generalized family of two-stage chain sampling plans, extending the concept of two-stage chain sampling plans of Dodge and Stephens (1966) which is an extension of the original work of Dodge (1955). Expressions are derived for the OC curves for two-stage chain sampling plans with (c1,c2) = (0,2) and (1,2). In the original work of Dodge (1955) only acceptance numbers of 0,1 were used and in the extension work of Dodge and Stephens (1966) acceptance numbers of (c1,c2) = (0,1), (0,2), (1,2), (0,3), (1,3), (0,4) and (1,4) were used with selected sets of values of k1 and k2 (the number of lots considered for cumulation in the first and second stage respectively). In this paper the OC curves are derived more generally for any k1 and k2combination for two-stage chain sampling plans with (c1,c2) = (0,2) and (1,2) and comparisons are made with respect to sample sizes and discriminating power, with the corresponding single and double sampling plans.  相似文献   
773.
Response surface methodology is widely used for developing, improving, and optimizing processes in various fields. In this article, we present a method for constructing three-level designs in order to explore and optimize response surfaces combining orthogonal arrays and covering arrays in a particular manner. The produced designs achieve the properties of rotatability, predictive performance and efficiency for the estimation of a second-order model.  相似文献   
774.
775.
A framework for time varying parameter regression models is developed and employed in modeling and forecasting price expectations, using the Livingston data. Alternative model formulations, which include various choices for both the stochastic processes generating the varying parameters and the sets of explanatory variables, are examined and compared by using this framework. These models, some of which have appeared elsewhere and some of which are new, are estimated and used to assess the expectations formation process.  相似文献   
776.
This case study sought to identify the relationships that can exist between open innovation, entrepreneurship, and the introduction of new business models at the enterprise level. Eleven Korean enterprises and five Indonesian enterprises were chosen, to obtain minimum research generality. While the number of enterprises is not great, it provides enough samples to determine the concrete relationships among these factors. The article starts by pointing out the general relationship between entrepreneurship, open innovation, and the introduction of a new business model. It examines two different contexts: the difference between the Seoul and Daegu regional innovation systems, and the difference between the Indonesian and Korean national innovation systems.  相似文献   
777.
This article provides an expository account of the multivariate autoregressive moving average models and proposes an extended sample cross-correlation approach for practical model identification. An iterative model building procedure for applying these models to real data is discussed and demonstrated by analyzing the 5-series U.S. Hog Data.  相似文献   
778.
Purpose: This study uses the selection, optimization, and compensation (SOC) model to compare older adults who have given up driving, those who still drive, and those who drive less to identify differences in the three groups. Design and Methods: This cross-sectional study of 281 older adults is part of the Naturally Occurring Retirement Community Demonstration Project. Study participants completed interviews that included questions on demographics, health and functioning, mental health, social support, and current levels of engagement in activities including current driving status. Results: Data suggest that driving retirement is a process and that a substantial number of people are in the transitional stage, where they are less functional than those who still drive and more similar to those who have retired from the road. Implications: Given the similarity of those who drive less to those who have given up driving, front-line professionals and policy makers must work together to ease the transition to driving retirement for those without adequate ability to effectively compensate for their inability to continue to drive safely.  相似文献   
779.
780.
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