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   2477篇
  免费   72篇
管理学   338篇
民族学   15篇
人才学   1篇
人口学   217篇
丛书文集   6篇
理论方法论   296篇
综合类   24篇
社会学   1348篇
统计学   304篇
  2023年   21篇
  2022年   8篇
  2021年   24篇
  2020年   46篇
  2019年   67篇
  2018年   64篇
  2017年   89篇
  2016年   97篇
  2015年   62篇
  2014年   68篇
  2013年   337篇
  2012年   126篇
  2011年   102篇
  2010年   81篇
  2009年   80篇
  2008年   88篇
  2007年   119篇
  2006年   98篇
  2005年   83篇
  2004年   81篇
  2003年   76篇
  2002年   64篇
  2001年   67篇
  2000年   50篇
  1999年   56篇
  1998年   38篇
  1997年   29篇
  1996年   35篇
  1995年   27篇
  1994年   29篇
  1993年   17篇
  1992年   28篇
  1991年   22篇
  1990年   19篇
  1989年   20篇
  1988年   19篇
  1987年   12篇
  1986年   20篇
  1985年   16篇
  1984年   14篇
  1983年   20篇
  1982年   16篇
  1981年   10篇
  1980年   18篇
  1979年   23篇
  1978年   14篇
  1976年   7篇
  1974年   7篇
  1972年   4篇
  1969年   4篇
排序方式: 共有2549条查询结果,搜索用时 343 毫秒
251.
252.
The Best Linear Unbiased Predictor (BLUP) in mixed models is a function of the variance components and they are estimated using maximum likelihood (ML) or restricted ML methods. Nonconvergence of BLUP would occur due to a drawback of the standard likelihood-based approaches. In such situations, ML and REML either do not provide any BLUPs or all become equal. To overcome this drawback, we provide a generalized estimate (GE) of BLUP that does not suffer from the problem of negative or zero variance components, and compare its performance against the ML and REML estimates of BLUP. Simulated and published data are used to compare BLUP.  相似文献   
253.
We have reviewed disaster management research papers published in major operations management, management science, operations research, supply chain management and transportation/logistics journals. In reviewing these studies, our objective is to assess and present the macro level “architectural blue print” of disaster management research with the hope that it will attract new researchers and motivate established researchers to contribute to this important field. The secondary objective is to bring this disaster research to the attention of disaster administrators so that disasters are managed more efficiently and more effectively. We have mapped the disaster management research on the following five attributes of a disaster: (1) Disaster Management Function (decision‐making process, prevention and mitigation, evacuation, humanitarian logistics, casualty management, and recovery and restoration), (2) Time of Disaster (before, during and after), (3) Type of Disaster (accidents, earthquakes, floods, hurricanes, landslides, terrorism and wildfires etc.), (4) Data Type (Field and Archival data, Real data and Hypothetical data), and (5) Data Analysis Technique (bidding models, decision analysis, expert systems, fuzzy system analysis, game theory, heuristics, mathematical programming, network flow models, queueing theory, simulation and statistical analysis). We have done cross tabulations of data among these five parameters to gain greater insights into disaster research. Recommendations for future research are provided.  相似文献   
254.
255.
Considerable public health literature focuses on relationships between problematic human characteristics (e.g., psychopathology) and unhealthy behaviors. A recent movement termed positive psychology emphasizes the advantages of assessing relationships between human strengths (e.g., altruism) and beneficial health behaviors. The present study assessed social responsibility, an orientation to help or protect others even when there is nothing to be gained as an individual, and its relationship to HIV-relevant behaviors. In our sample of 350 men who have sex with men (MSM), social responsibility was negatively correlated with substance use and HIV risk behaviors. Men who had been tested for HIV and knew their HIV status—a behavior that helps men protect their partners but does not protect themselves from the virus—also scored higher in social responsibility. Interventions designed to reduce HIV risk behavior in MSM may benefit from efforts to promote human strengths.  相似文献   
256.
The impetus towards basing practice and policy decisions moreexplicitly on sound research requires tools to facilitate thesystematic appraisal of the quality of research encompassinga diverse range of methods and designs. Five exemplar toolswere developed and assessed in terms of their usefulness inselecting studies for inclusion in a systematic review. Thewidely used ‘hierarchy of evidence’ was adaptedand used to appraise internal validity. Four tools were thendeveloped to appraise the external validity dimensions of generalizability(two scales) and methods of data collection (two scales). Methodsof combining the scores generated by each tool were explored.Qualitative and quantitative studies were appraised, not separatedinto two spheres but by using complementary tools developedto appraise different aspects of rigour. There was a high levelof agreement between researchers in applying the tools to twenty-twostudies on decision making by professionals about the long-termcare of older people. The scales for internal validity and generalizabilitydiscriminated between the qualities of studies appropriately.The two tools to appraise data collection gave diverse results.Excluding studies that scored in the lowest category on anyscale appeared to be the scoring system that was most justifiable.This approach is presented to stimulate debate about the practicalapplication of the evidence-based initiative to social workand social care. This study may assist in developing clearerdefinitions and common language about appraising rigour thatshould further the process of selecting robust research forsynthesis to inform practice and policy decisions.  相似文献   
257.
Rural dwelling elders who experience mental health problems often have difficulty finding help since rural communities often lack adequate mental health service providers. This paper reports on the initial phase of a 5-year, interdisciplinary clinical research study that is testing the effectiveness of providing a home delivered, therapeutic psychosocial intervention, aimed at improving the emotional wellbeing and the quality of life of medically frail elders who live in rural communities. In the early phases of this study, the clinical research team encountered a number of interesting and often unanticipated challenges as it attempted to recruit study participants and provide services to them. In this article, we examine these challenges and share what we have learned so far about providing mental health services to elderly persons living in rural environments.  相似文献   
258.
259.
This paper presents a formal framework that purports to capture some aspects of Kant's theory of freedom. In particular, we argue that the analysis sheds further light on Kant's distinction between a negative and a positive concept of freedom. The paper shows that the two concepts are not equivalent: we not only argue that in a Kantian perspective negative freedom need not entail positive freedom, but also that there are situations in which a person can be said to be positively but not negatively free (in a Kantian sense).  相似文献   
260.
We know from Li's theorem (1993) that the stability set of order d may be empty for some preference profiles. However, one may wonder whether such situations are just rare oddities or not. In this paper, we partially answer this question by considering the restrictive case where the number of alternatives is the smallest compatible with an empty stability set. More precisely, we provide an upper bound on the probability for having an empty stability set of order d for the majority game under the Impartial Weak Ordering Culture assumption. This upper bound is already extremely low for small population and tends to zero as the number of individuals goes to infinity.  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