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   4945篇
  免费   856篇
管理学   938篇
劳动科学   2篇
民族学   31篇
人口学   303篇
丛书文集   43篇
理论方法论   832篇
综合类   57篇
社会学   2790篇
统计学   805篇
  2023年   29篇
  2022年   9篇
  2021年   94篇
  2020年   200篇
  2019年   387篇
  2018年   232篇
  2017年   337篇
  2016年   332篇
  2015年   318篇
  2014年   316篇
  2013年   823篇
  2012年   288篇
  2011年   278篇
  2010年   232篇
  2009年   177篇
  2008年   231篇
  2007年   171篇
  2006年   192篇
  2005年   147篇
  2004年   130篇
  2003年   127篇
  2002年   98篇
  2001年   106篇
  2000年   77篇
  1999年   48篇
  1998年   23篇
  1997年   25篇
  1996年   30篇
  1995年   24篇
  1994年   28篇
  1993年   33篇
  1992年   28篇
  1991年   30篇
  1990年   12篇
  1989年   20篇
  1988年   18篇
  1987年   12篇
  1986年   8篇
  1985年   15篇
  1984年   15篇
  1983年   13篇
  1982年   10篇
  1981年   17篇
  1980年   10篇
  1979年   8篇
  1978年   5篇
  1976年   5篇
  1975年   8篇
  1974年   9篇
  1966年   3篇
排序方式: 共有5801条查询结果,搜索用时 31 毫秒
21.
If a population contains many zero values and the sample size is not very large, the traditional normal approximation‐based confidence intervals for the population mean may have poor coverage probabilities. This problem is substantially reduced by constructing parametric likelihood ratio intervals when an appropriate mixture model can be found. In the context of survey sampling, however, there is a general preference for making minimal assumptions about the population under study. The authors have therefore investigated the coverage properties of nonparametric empirical likelihood confidence intervals for the population mean. They show that under a variety of hypothetical populations, these intervals often outperformed parametric likelihood intervals by having more balanced coverage rates and larger lower bounds. The authors illustrate their methodology using data from the Canadian Labour Force Survey for the year 2000.  相似文献   
22.
Lin  Tsung I.  Lee  Jack C.  Ni  Huey F. 《Statistics and Computing》2004,14(2):119-130
A finite mixture model using the multivariate t distribution has been shown as a robust extension of normal mixtures. In this paper, we present a Bayesian approach for inference about parameters of t-mixture models. The specifications of prior distributions are weakly informative to avoid causing nonintegrable posterior distributions. We present two efficient EM-type algorithms for computing the joint posterior mode with the observed data and an incomplete future vector as the sample. Markov chain Monte Carlo sampling schemes are also developed to obtain the target posterior distribution of parameters. The advantages of Bayesian approach over the maximum likelihood method are demonstrated via a set of real data.  相似文献   
23.
Conservation biology aims at assessing the status of a population, based on information which is often incomplete. Integrated population modelling based on state‐space models appears to be a powerful and relevant way of combining into a single likelihood several types of information such as capture‐recapture data and population surveys. In this paper, the authors describe the principles of integrated population modelling and they evaluate its performance for conservation biology based on a case study, that of the black‐footed albatross, a northern Pacific albatross species suspected to be impacted by longline fishing  相似文献   
24.
This article aims to makes a contribution to redressing a methodological and theoretical imbalance in existing research on refugee and asylum‐seeking children. It draws on two qualitative studies from Wales with children and young people. The samples include unaccompanied minors and children living with families as well as both children who are supported in the asylum system and those who have been granted refugee status. The focus on ecological post‐migratory stressors and coping processes that young people identify as being integral to their well‐being and, once granted status, to how they adapt to settlement includes a selective study of some of the sources of resilience referred to in the children's talk. Recognising the interplay between individual and environment leads to a discussion of both personal attributes and collective cultural identities.  相似文献   
25.
The 1998 Korean Survey of Family Income and Expenditures was used to examine the overall consumption and saving behavior of Korean baby boomers and compared the differences in consumption and saving behavior between older and younger boomers. The t -test results indicated that the younger boomers allocated a significantly higher percentage of their expenditures on food away from home, household appliances, transportation and communication than did the older boomers, whereas the older boomers spent higher amounts and allocated larger budget shares on their children's education than did the younger boomers. The results of Ordinary Least-Squares (OLS) regression analysis showed that, holding other factors constant, older boomers not only spent significantly more in the total consumption expenditures and education expenditures, but older boomers also saved significantly less than did younger boomers.  相似文献   
26.
We consider the assessment of outliers and influential observation in non-linear measurement error models. Residuals, leverage measures and case-deletiondiagonostics are examined. The method of local influence is also applied to the models. In particular, the perturbation of measurement error variances has been found useful in assessing the adequancy of the model assumptions. A numerical example is given to illustrate the application of the diagonostics.  相似文献   
27.
D. E. Super's (1957) theory of career development has long been of interest to careers researchers (M. Savickas, 1994; S. C. Whiston & B. K. Brecheisen, 2002). Its insightful illustration of career stages has made it widely applied by careers practitioners. Image norms may influence the career decisions and developmental tasks inherent in each stage. An image norm is the belief that individuals must present or possess a certain image, consistent with occupational, organizational, or industry standards, in order to achieve career success. Understanding the effects of image norms across D. E. Super's (1957) career stages has important implications for individuals, organizations, and career counseling professionals.  相似文献   
28.
The purpose of this study was to examine the various aspects of international public relations by other countries in the U.S. Based on the Foreign Agency Registration Act (FARA) report in 2002, this study analyzed client, activity types, purpose of activity, and key U.S. partners for activity. This study found that (1) business organizations and central governments were major clients of international public relations in the U.S., (2) meeting with governmental officials and congressional leaders was the primary type of activity followed by information dissemination, and (3) economic purpose led by trade promotion was the primary motive for these activities.  相似文献   
29.
The objective of this study was to examine the links between coping and attachment. In a longitudinal study of 112 participants, coping behavior was assessed at five points in time during adolescence (starting at the age of 14 years) and early adulthood. In addition, at the age of 21 years, state of mind regarding current and earlier attachment experiences was assessed by employing the Adult Attachment Interview (AAI). In both adolescence and early adulthood, differences in coping styles were found to be related to differences in attachment. Individuals classified as secure dealt with their problems more actively by using their social network during adolescence and at the age of 21 years. Both secure and dismissing individuals used more internal coping than those with a preoccupied state of mind. Latent growth curve modeling revealed that differences in active and internal coping between secure and insecure individuals applied to the rate of change in these coping styles between 14 and 21 years, with participants in the secure group showing much steeper growth in both coping styles. Only minor differences were found with respect to withdrawal as a coping style. The results represent first evidence that coping trajectories during adolescence and young adulthood are linked with attachment state of mind.  相似文献   
30.
The authors review the trends in the use of computers in the delivery and support of career guidance and counseling identified at the symposium International Perspectives on Career Development. The papers presented emphasized that 20th‐century computer‐based systems continue to be used, mainly delivered via the World Wide Web. These systems are enhanced through audio, video, graphics, strategies to provide needs assessment, and support by cybercounselors or expert system design. The papers also revealed a new trend: the use of elegant Web sites to store and search immense libraries of resources needed by professionals and clients and to facilitate communication and collaboration among professionals in cyberspace. Concerns, issues, and resources related to many areas, including the readiness of clients to use computer‐based systems, were also raised; existing sources of guidelines are noted.  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