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   3679篇
  免费   99篇
  国内免费   67篇
管理学   79篇
民族学   30篇
人口学   33篇
丛书文集   407篇
理论方法论   86篇
综合类   2742篇
社会学   111篇
统计学   357篇
  2024年   3篇
  2023年   14篇
  2022年   22篇
  2021年   37篇
  2020年   43篇
  2019年   54篇
  2018年   55篇
  2017年   77篇
  2016年   57篇
  2015年   88篇
  2014年   210篇
  2013年   281篇
  2012年   285篇
  2011年   295篇
  2010年   231篇
  2009年   204篇
  2008年   246篇
  2007年   271篇
  2006年   243篇
  2005年   234篇
  2004年   187篇
  2003年   189篇
  2002年   157篇
  2001年   120篇
  2000年   80篇
  1999年   36篇
  1998年   19篇
  1997年   18篇
  1996年   19篇
  1995年   14篇
  1994年   8篇
  1993年   7篇
  1992年   13篇
  1991年   6篇
  1990年   4篇
  1989年   3篇
  1988年   3篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1976年   1篇
  1975年   1篇
排序方式: 共有3845条查询结果,搜索用时 15 毫秒
61.
In this paper, we investigate the complete moment convergence and Lr convergence for maximal partial sums of asymptotically almost negatively associated random variables under some general conditions. The results obtained in the paper generalize some corresponding ones for negatively associated random variables.  相似文献   
62.
In this paper, we propose a new three-parameter model called the exponential–Weibull distribution, which includes as special models some widely known lifetime distributions. Some mathematical properties of the proposed distribution are investigated. We derive four explicit expressions for the generalized ordinary moments and a general formula for the incomplete moments based on infinite sums of Meijer's G functions. We also obtain explicit expressions for the generating function and mean deviations. We estimate the model parameters by maximum likelihood and determine the observed information matrix. Some simulations are run to assess the performance of the maximum likelihood estimators. The flexibility of the new distribution is illustrated by means of an application to real data.  相似文献   
63.
For any continuous baseline G distribution [G.M. Cordeiro and M. de Castro, A new family of generalized distributions, J. Statist. Comput. Simul. 81 (2011), pp. 883–898], proposed a new generalized distribution (denoted here with the prefix ‘Kw-G’ (Kumaraswamy-G)) with two extra positive parameters. They studied some of its mathematical properties and presented special sub-models. We derive a simple representation for the Kw-G density function as a linear combination of exponentiated-G distributions. Some new distributions are proposed as sub-models of this family, for example, the Kw-Chen [Z.A. Chen, A new two-parameter lifetime distribution with bathtub shape or increasing failure rate function, Statist. Probab. Lett. 49 (2000), pp. 155–161], Kw-XTG [M. Xie, Y. Tang, and T.N. Goh, A modified Weibull extension with bathtub failure rate function, Reliab. Eng. System Safety 76 (2002), pp. 279–285] and Kw-Flexible Weibull [M. Bebbington, C.D. Lai, and R. Zitikis, A flexible Weibull extension, Reliab. Eng. System Safety 92 (2007), pp. 719–726]. New properties of the Kw-G distribution are derived which include asymptotes, shapes, moments, moment generating function, mean deviations, Bonferroni and Lorenz curves, reliability, Rényi entropy and Shannon entropy. New properties of the order statistics are investigated. We discuss the estimation of the parameters by maximum likelihood. We provide two applications to real data sets and discuss a bivariate extension of the Kw-G distribution.  相似文献   
64.
This study examines how the interplay among crisis involvement, brand image, and message appeal impacts the effectiveness of an apology in the context of a corporate crisis. To determine apology effectiveness, a 2 (crisis involvement: high vs. low) × 2 (brand image: symbolic vs. functional) × 2 (message appeal type: emotional vs. informational) experimental design was employed. The results demonstrate that the three-way interaction is significant, especially in the low-crisis involvement condition. The study concludes with a discussion of theoretical and practical implications and directions for future research.  相似文献   
65.
研究了碎纸片的拼接复原问题,建立了合理有效的碎纸片拼接复原的数学模型;给出了数学软件实现自动拼接的具体算法;结合人工拼接得出复原图片;最后,对所给的拼接方法提出了改进方向.  相似文献   
66.
This study develops a robust automatic algorithm for clustering probability density functions based on the previous research. Unlike other existing methods that often pre-determine the number of clusters, this method can self-organize data groups based on the original data structure. The proposed clustering method is also robust in regards to noise. Three examples of synthetic data and a real-world COREL dataset are utilized to illustrate the accurateness and effectiveness of the proposed approach.  相似文献   
67.
The chances that children have to participate in child protection services are largely contingent upon the attitudes and skills of case managers. They have a crucial role in ensuring that a child's voice is being listened to and acknowledged in often sensitive dialogues. Therefore, the aim of this study is to investigate what case managers need to facilitate child participation. By handing case managers a participation toolbox developed by children and through the use of reflexive monitoring in action, we elaborated on the barriers faced in practice. The results show that the intention to facilitate child participation is quickly overruled by often subconscious thoughts and beliefs, stemming from the complex interplay of child image, protection, and participation. Case managers need to be aware of this interplay and how this unknowingly steers their actions. Therefore, iterative reflection should be facilitated within organizations for an actual change in their daily practice and to amplify the role of children in the decision‐making processes within child protection services.  相似文献   
68.
Abstract

On the basis of Wang and Cheng (J. Math. Anal. Appl. 384 (2011) 597–606), this paper further investigates elementary renewal theorems for counting processes generated by random walks with widely orthant dependent increments. The obtained results improve the corresponding ones of the above-mentioned paper mainly in the sense of weakening the moment conditions on the positive parts of the increments. Meanwhile, a revised version of strong law of large numbers for random walks with widely orthant dependent increments is established, which improves Theorem 1.4 of Wang and Cheng (2011 Wang, Y., and D. Cheng. 2011. Basic renewal theorems for a random walk with widely dependent increments and their applications. Journal of Mathematical Analysis and Applications 384 (2):597606. doi:10.1016/j.jmaa.2011.06.010.[Crossref], [Web of Science ®] [Google Scholar]) by enlarging the regions of dominating coefficients. Finally, by using the above results, some precise large deviation results for a nonstandard renewal risk model are established, in which the innovations are widely orthant dependent random variables with common heavy tails, and the inter-arrival times are also widely orthant dependent.  相似文献   
69.
70.
We introduce and study general mathematical properties of a new generator of continuous distributions with one extra parameter called the generalized odd half-Cauchy family. We present some special models and investigate the asymptotics and shapes. The new density function can be expressed as a linear mixture of exponentiated densities based on the same baseline distribution. We derive a power series for the quantile function. We discuss the estimation of the model parameters by maximum likelihood and prove empirically the flexibility of the new family by means of two real data sets.  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