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   3055篇
  免费   90篇
  国内免费   4篇
管理学   208篇
民族学   38篇
人才学   4篇
人口学   51篇
丛书文集   437篇
理论方法论   176篇
综合类   1619篇
社会学   205篇
统计学   411篇
  2024年   1篇
  2023年   6篇
  2022年   11篇
  2021年   35篇
  2020年   48篇
  2019年   27篇
  2018年   40篇
  2017年   64篇
  2016年   40篇
  2015年   57篇
  2014年   141篇
  2013年   305篇
  2012年   244篇
  2011年   285篇
  2010年   217篇
  2009年   170篇
  2008年   161篇
  2007年   215篇
  2006年   206篇
  2005年   156篇
  2004年   151篇
  2003年   167篇
  2002年   136篇
  2001年   91篇
  2000年   66篇
  1999年   20篇
  1998年   14篇
  1997年   11篇
  1996年   14篇
  1995年   10篇
  1994年   4篇
  1993年   3篇
  1992年   5篇
  1991年   1篇
  1990年   3篇
  1989年   4篇
  1987年   3篇
  1986年   4篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
排序方式: 共有3149条查询结果,搜索用时 15 毫秒
31.
本文介绍了杭州汽轮机厂计算机集成制造系统HTW-CIMS的总体方案以及开发和应用该系统时遵循的技术路线。  相似文献   
32.
The Effect of Drop-Out on the Efficiency of Longitudinal Experiments   总被引:1,自引:0,他引:1  
It is shown that drop-out often reduces the efficiency of longitudinal experiments considerably. In the framework of linear mixed models, a general, computationally simple method is provided, for designing longitudinal studies when drop-out is to be expected, such that there is little risk of large losses of efficiency due to the missing data. All the results are extensively illustrated using data from a randomized experiment with rats.  相似文献   
33.
In this investigation a test of goodness of fit for exponentiality is proposed. This procedure applies equally whether the scale and/or the location parameters of the distribution are known or not. The limiting null and non-null distributions of the test statistic are normal under minimal conditions. Monte Carlo critical values for small sample sizes are given and the power of the test is calculated for various alternatives showing that it compares favourably relatively to other more complicated published procedures.  相似文献   
34.
A challenge for large‐scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co‐occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure‐relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new “Tiered Exposure Ranking” (TiER) framework, developed to support various aspects of risk‐relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both “discovery‐driven” and “hypothesis‐driven” analyses. “Tier 1” applications focus on “exposomic” pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk‐relevant exposure metrics for populations and individuals. In this article, “tier 1” applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A “tier 2” application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk‐relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data.  相似文献   
35.
Since the 1980s outsourcing has been a major topic in both economic and management literature. Economic literature tends to focus on the transaction cost perspective. In management literature the core competence approach prevails. An emerging alternative view on outsourcing is the power and dependence perspective. Aspects of power and dependence become visible in four case studies involving the maintenance of capital assets. In each instance both the buyer and supplier sides of the dyad are examined. The paper concludes with managerial implications and research opportunities.  相似文献   
36.
世界各地的华侨华人经济联系建构了世界华商网络 ,并以此融入世界体系 ,形成了整个“中华经济圈” ;而包括粤港澳台闽桂琼在内的“华南经济圈”则构筑了“中华经济圈”的圆心 ,并维系其经济增长 (“圆周半径”)的动态平衡。“华南经济圈”由闽台经济区、珠江三角洲经济区、环北部湾沿岸经济区和环南中国海经济区所构成 ,它参与中国———东盟自由贸易区的优势主要在于地缘经济优势、特区经济优势和会展经济优势  相似文献   
37.
自治市法律地位刍议   总被引:2,自引:0,他引:2  
民族自治地方城市化是我国城市化的重要组成部分。我国自治地方城市化水平相对滞后,原因之一是宪法和自治法没有赋予自治市以自治地方的法律地位。宪法和自治法赋予自治市以自治州、自治县同样的法律地位,是自治地方城市化的必由之路和必然选择。  相似文献   
38.
元代回回人的宗教制度与伊斯兰教法   总被引:3,自引:1,他引:3  
王东平 《回族研究》2002,7(4):44-50
本文研究了元代回回社会中的宗教制度和伊斯兰教法。作者认为,元代回回社会中存在着官方认可的管理者和更小的民间宗教事务管理者两套系统。伊斯兰教法约束了回回人的行为规范,并且对元代多元法律文化的形成产生了影响。在多元文化的发展过程中,“回回法”同“汉法”及“蒙古法”有一个冲突和融合的过程。  相似文献   
39.
This article investigates the choice of working covariance structures in the analysis of spatially correlated observations motivated by cardiac imaging data. Through Monte Carlo simulations, we found that the choice of covariance structure affects the efficiency of the estimator and power of the test. Choosing the popular unstructured working covariance structure results in an over-inflated Type I error possibly due to a sample size not large enough relative to the number of parameters being estimated. With regard to model fit indices, Bayesian Information Criterion outperforms Akaike Information Criterion in choosing the correct covariance structure used to generate data.  相似文献   
40.
In this article, we use cumulative residual Kullback-Leibler information (CRKL) and cumulative Kullback-Leibler information (CKL) to construct two goodness-of-fit test statistics for testing exponentiality with progressively Type-II censored data. The power of the proposed tests are compared with the power of goodness-of-fit test for exponentiality introduced by Balakrishnan et al. (2007 Balakrishnan, N., Habibi Rad, A., Arghami, N.R. (2007). Testing exponentiality based on Kullback-Leibler information with progressively type-II censored data. IEEE Transactions on Reliability 56(2):301307.[Crossref], [Web of Science ®] [Google Scholar]). We show that when the hazard function of the alternative is monotone decreasing, the test based on CRKL has higher power and when the hazard function of the alternative is non-monotone, the test based on CKL has higher power. But, when it is monotone increasing the power difference between test based on CKL and their proposed test is not so remarkable. The use of the proposed tests is shown in an illustrative example.  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