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   23573篇
  免费   373篇
  国内免费   47篇
管理学   3245篇
民族学   170篇
人才学   1篇
人口学   3574篇
丛书文集   358篇
教育普及   1篇
理论方法论   1555篇
现状及发展   1篇
综合类   1818篇
社会学   9757篇
统计学   3513篇
  2023年   87篇
  2022年   99篇
  2021年   107篇
  2020年   195篇
  2019年   253篇
  2018年   1929篇
  2017年   2039篇
  2016年   1372篇
  2015年   294篇
  2014年   385篇
  2013年   2118篇
  2012年   839篇
  2011年   1632篇
  2010年   1484篇
  2009年   1236篇
  2008年   1259篇
  2007年   1392篇
  2006年   396篇
  2005年   595篇
  2004年   575篇
  2003年   480篇
  2002年   380篇
  2001年   322篇
  2000年   311篇
  1999年   279篇
  1998年   184篇
  1997年   175篇
  1996年   198篇
  1995年   167篇
  1994年   136篇
  1993年   152篇
  1992年   170篇
  1991年   145篇
  1990年   157篇
  1989年   181篇
  1988年   162篇
  1987年   137篇
  1986年   148篇
  1985年   167篇
  1984年   165篇
  1983年   156篇
  1982年   121篇
  1981年   105篇
  1980年   102篇
  1979年   137篇
  1978年   88篇
  1977年   87篇
  1976年   87篇
  1975年   80篇
  1974年   80篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
81.
82.
Summary. The paper develops methods for the design of experiments for mechanistic models when the response must be transformed to achieve symmetry and constant variance. The power transformation that is used is partially justified by a rule in analytical chemistry. Because of the nature of the relationship between the response and the mechanistic model, it is necessary to transform both sides of the model. Expressions are given for the parameter sensitivities in the transformed model and examples are given of optimum designs, not only for single-response models, but also for experiments in which multivariate responses are measured and for experiments in which the model is defined by a set of differential equations which cannot be solved analytically. The extension to designs for checking models is discussed.  相似文献   
83.
84.
Banks winners in tournaments are difficult to recognize   总被引:1,自引:0,他引:1  
Given a tournament T, a Banks winner of T is the top vertex of any maximal (with respect to inclusion) transitive subtournament of T. In this technical note, we show that the problem of deciding whether some fixed vertex v is a Banks winner for T is NP-complete. Received: 22 February 2002/Accepted: 20 June 2002 Supported by the START program Y43-MAT of the Austrian Ministry of Science. I would like to thank two thank the referees for a careful reading of the paper, for helpful remarks, and for many suggestions how to improve the presentation.  相似文献   
85.
国际反垄断法对国家垄断的规制探讨   总被引:1,自引:0,他引:1  
国家垄断是国际反垄断法的重要调整对象之一。为协调国际经济秩序与国家经济利益的关系,国际反垄断法既要对妨害国际公平竞争的国家垄断予以限制,也要对一些特定行业、特定情形和特定国家的国家垄断予以豁免。  相似文献   
86.
The collapse of the USSR was accompanied by transformation of the South Caucasian latent ethnopolitical conflicts into local wars. Today the situation in the area of the conflicts is “neither war, nor peace”. Three unresolved conflicts of the South Caucasus can be considered as one of the most serious obstacles for establishing a regional security system.The article gives the general characteristics of these conflicts, the trends of their development, taking into account the time factor, and analyzes the behavioral models of the main players – de jure recognized and unrecognized de facto states of the South Caucasus. The basic objective of the main players should be to keep the situation on a level preventing the resumption of the armed conflicts. The attempts of forced resolution of the conflicts are fraught with destabilization of the situation not only in the area of any of these conflicts but in the whole region.  相似文献   
87.
汉字的表意性使得文字与社会文化有紧密联系。甲骨文作为最早的成系统的汉字在一定程度上可以反映出商朝的社会面貌。通过比较甲骨文里"子""女"诸字,可以了解商朝尽管有部分女性地位尊贵,但男女处于不平等的地位已是一种普遍的社会现象。  相似文献   
88.
Lu Lin 《Statistical Papers》2004,45(4):529-544
The quasi-score function, as defined by Wedderburn (1974) and McCullagh (1983) and so on, is a linear function of observations. The generalized quasi-score function introduced in this paper is a linear function of some unbiased basis functions, where the unbiased basis functions may be some linear functions of the observations or not, and can be easily constructed by the meaning of the parameters such as mean and median and so on. The generalized quasi-likelihood estimate obtained by such a generalized quasi-score function is consistent and has an asymptotically normal distribution. As a result, the optimum generalized quasi-score is obtained and a method to construct the optimum unbiased basis function is introduced. In order to construct the potential function, a conservative generalized estimating function is defined. By conservative, a potential function for the projected score has many properties of a log-likelihood function. Finally, some examples are given to illustrate the theoretical results. This paper is supported by NNSF project (10371059) of China and Youth Teacher Foundation of Nankai University.  相似文献   
89.
Starting with its early twentieth century origins, the development of Labor Economics is traced to the present. We describe an intellectual revolution in which an earlier tra-dition that focused primarily on the institution of the labor union has been replaced by a perspective that emphasizes the various roles played by labor markets in an eco-nomic system. That earlier tradition contained very significant ideological elements, whereas its successor deals much more with the world of ideas. In the course of the debate, which still continues, ideas triumphed over ideology and created modern Labor Economics.  相似文献   
90.
A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori.  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