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   2819篇
  免费   87篇
  国内免费   24篇
管理学   130篇
民族学   36篇
人才学   1篇
人口学   60篇
丛书文集   232篇
理论方法论   86篇
综合类   1640篇
社会学   134篇
统计学   611篇
  2024年   5篇
  2023年   10篇
  2022年   24篇
  2021年   22篇
  2020年   49篇
  2019年   50篇
  2018年   50篇
  2017年   59篇
  2016年   62篇
  2015年   73篇
  2014年   143篇
  2013年   346篇
  2012年   186篇
  2011年   160篇
  2010年   130篇
  2009年   131篇
  2008年   161篇
  2007年   169篇
  2006年   171篇
  2005年   151篇
  2004年   144篇
  2003年   126篇
  2002年   112篇
  2001年   86篇
  2000年   77篇
  1999年   30篇
  1998年   26篇
  1997年   29篇
  1996年   32篇
  1995年   19篇
  1994年   17篇
  1993年   10篇
  1992年   6篇
  1991年   6篇
  1990年   5篇
  1989年   9篇
  1988年   7篇
  1987年   4篇
  1986年   1篇
  1985年   9篇
  1984年   6篇
  1983年   4篇
  1981年   3篇
  1980年   2篇
  1979年   5篇
  1978年   2篇
  1977年   1篇
排序方式: 共有2930条查询结果,搜索用时 31 毫秒
41.
二维GPSJ分布类及其在保险中的应用   总被引:1,自引:2,他引:1  
本文给出的二维GPSJ分布类(即GPSJ2)在保险领域应用范围较广,如由机动车辆保险由财产损失索赔次数和人身伤亡索赔次数所组成的模型、超额再保险中的由自留保单数和分出报单数所组成的二维模型等。本文在GPSJ1类基础上研究二维GPSJ类,本文给出了此分布类的定义、背景意义、概率计算的递推公式,同时还对各参数的最大似然估计值的求解过程进行了分析。本文最后将这一模型应用于一组机动车辆赔付次数数据,考虑了由财产损失索赔次数、人身伤亡索赔次数组成的二维模型,拟合效果令人满意。  相似文献   
42.
大型供应链设计的基本数学模型与算法研究   总被引:2,自引:2,他引:2  
随着信息技术与全球经济一体化的发展,供应链管理成为全球管理科学的研究热点。本文在分析国内外各种关于供应链设计的数学模型与算法的基础上,提出了具有普遍性意义且简单易行的MIP供应链设计的数学模型以及求解供应链问题的有界变量广义上界算法。实例计算表明,提出的模型和方法是可靠实用的。  相似文献   
43.
关于村干部角色行为的研究有两种取向:一是对村干部应该如何的“名”的研究,二是对村干部实际如何的“实”的研究。赵村的村干部的“名”与“实”经历了从融合到偏离的历史性嬗变。改革开放后,因对村干部有了新的要求与期待,历史变迁的惯性及相应的政策及制度性规定为村干部角色行为提供了基础,包办型村干部经历了“名”与“实”的短暂融合。但随着村庄出现可赢利的巨额集体资产,村干部以派性斗争为核心争夺村庄权力,以自我获利为目的,造成村庄集体资产流失,村民利益受损,赢利型村干部的“名”与“实”严重偏离。以制度治村为核心的纠偏机制的运行,以期扭转赢利型村干部“名”与“实”偏离的行为,却导致了放任型村干部的出现,这实际上是另一种形式的“名”与“实”的偏离,村干部“名”与“实”偏离的困境依然没有摆脱。  相似文献   
44.
This article compares state policies to support childcare in Japan, South Korea and Taiwan, using fuzzy set ideal type analysis to determine the nature of institutional arrangements with respect to labour, money and time provisions. We then note their implications for familialization and defamilialization in the three countries. Our analysis suggests a common pattern towards the increased use of financial support amongst the three countries over time; however, this commonality does not mean their childcare policies are converging, as the financial supports differ in focus, with Japan concentrating on familialization by valuing family care, and Korea exclusively employing policy to facilitate the use of market‐based care services. For its part, Taiwan has been strengthening familialization by increasing the leave compensation to value time off to provide care. The different labour, money and time dimensions vis‐à‐vis the familialization/defamilialization matrix suggest varying implications of institutional arrangements for gender.  相似文献   
45.
古代社会解决纠纷的途径多种多样,调解作为其中一种主要方式有着举足轻重的作用。在介绍中国传统调解制度的类型及特点的基础上,探讨传统调解制度对于古代封建社会的价值所在,认为其虽然存在一定的缺点,但是其有益的部分对我国当前的纠纷解决机制的完善有很大的借鉴作用。  相似文献   
46.
This paper presents an effective and efficient method for solving a special class of mixed integer fractional programming (FP) problems. We take a classical reformulation approach for continuous FP as a starting point and extend it for solving a more general class of mixed integer (0–1) fractional programming problems.To stress the practical relevance of the research we focus on a real-life application in paper production industry. The constantly advancing physical knowledge of large scale pulp and paper production did have a substantial impact on an existing DSS in which mixed integer (0–1) fractional programming is introduced. We show that the motivation to solve a real-life fractional programming problem can provide the basis for a new approach in a new context that has an added value of its own, even outside the given application area. We describe the main characteristics of the DSS, the necessity to develop a non-iterative solution procedure and demonstrate both the effectiveness and efficiency of the proposed approach from practical data sets.  相似文献   
47.
如何面对国际金融危机和不断变化着的国内实践,是中国共产党必须要解决的重大理论和实践课题。胡锦涛同志"七一"重要讲话运用发展了的马克思主义对变化了的国内外形势做了最新的哲学概括,从历史唯物主义的基本原理出发提出了继续坚持以经济建设为中心,坚持经济、政治、社会、文化四位一体的和谐发展,用发展的马克思主义指导新的实践等重要思想,给我们当前及今后较长一段时间的发展指明了方向,是我们应该长期坚持的重要指导思想。  相似文献   
48.
The primary objective of a multi-regional clinical trial is to investigate the overall efficacy of the drug across regions and evaluate the possibility of applying the overall trial result to some specific region. A challenge arises when there is not enough regional sample size. We focus on the problem of evaluating applicability of a drug to a specific region of interest under the criterion of preserving a certain proportion of the overall treatment effect in the region. We propose a variant of James-Stein shrinkage estimator in the empirical Bayes context for the region-specific treatment effect. The estimator has the features of accommodating the between-region variation and finiteness correction of bias. We also propose a truncated version of the proposed shrinkage estimator to further protect risk in the presence of extreme value of regional treatment effect. Based on the proposed estimator, we provide the consistency assessment criterion and sample size calculation for the region of interest. Simulations are conducted to demonstrate the performance of the proposed estimators in comparison with some existing methods. A hypothetical example is presented to illustrate the application of the proposed method.  相似文献   
49.

In this article, the validity of procedures for testing the significance of the slope in quantitative linear models with one explanatory variable and first-order autoregressive [AR(1)] errors is analyzed in a Monte Carlo study conducted in the time domain. Two cases are considered for the regressor: fixed and trended versus random and AR(1). In addition to the classical t -test using the Ordinary Least Squares (OLS) estimator of the slope and its standard error, we consider seven t -tests with n-2\,\hbox{df} built on the Generalized Least Squares (GLS) estimator or an estimated GLS estimator, three variants of the classical t -test with different variances of the OLS estimator, two asymptotic tests built on the Maximum Likelihood (ML) estimator, the F -test for fixed effects based on the Restricted Maximum Likelihood (REML) estimator in the mixed-model approach, two t -tests with n - 2 df based on first differences (FD) and first-difference ratios (FDR), and four modified t -tests using various corrections of the number of degrees of freedom. The FDR t -test, the REML F -test and the modified t -test using Dutilleul's effective sample size are the most valid among the testing procedures that do not assume the complete knowledge of the covariance matrix of the errors. However, modified t -tests are not applicable and the FDR t -test suffers from a lack of power when the regressor is fixed and trended ( i.e. , FDR is the same as FD in this case when observations are equally spaced), whereas the REML algorithm fails to converge at small sample sizes. The classical t -test is valid when the regressor is fixed and trended and autocorrelation among errors is predominantly negative, and when the regressor is random and AR(1), like the errors, and autocorrelation is moderately negative or positive. We discuss the results graphically, in terms of the circularity condition defined in repeated measures ANOVA and of the effective sample size used in correlation analysis with autocorrelated sample data. An example with environmental data is presented.  相似文献   
50.
Likelihood ratios (LRs) are used to characterize the efficiency of diagnostic tests. In this paper, we use the classical weighted least squares (CWLS) test procedure, which was originally used for testing the homogeneity of relative risks, for comparing the LRs of two or more binary diagnostic tests. We compare the performance of this method with the relative diagnostic likelihood ratio (rDLR) method and the diagnostic likelihood ratio regression (DLRReg) approach in terms of size and power, and we observe that the performances of CWLS and rDLR are the same when used to compare two diagnostic tests, while DLRReg method has higher type I error rates and powers. We also examine the performances of the CWLS and DLRReg methods for comparing three diagnostic tests in various sample size and prevalence combinations. On the basis of Monte Carlo simulations, we conclude that all of the tests are generally conservative and have low power, especially in settings of small sample size and low prevalence.  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