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   934篇
  免费   29篇
管理学   115篇
民族学   5篇
人口学   65篇
丛书文集   4篇
理论方法论   138篇
综合类   5篇
社会学   482篇
统计学   149篇
  2023年   6篇
  2022年   3篇
  2021年   9篇
  2020年   22篇
  2019年   39篇
  2018年   33篇
  2017年   51篇
  2016年   30篇
  2015年   32篇
  2014年   29篇
  2013年   138篇
  2012年   42篇
  2011年   33篇
  2010年   33篇
  2009年   31篇
  2008年   52篇
  2007年   37篇
  2006年   45篇
  2005年   30篇
  2004年   26篇
  2003年   24篇
  2002年   30篇
  2001年   21篇
  2000年   21篇
  1999年   15篇
  1998年   13篇
  1997年   13篇
  1996年   15篇
  1995年   9篇
  1994年   15篇
  1993年   7篇
  1992年   5篇
  1991年   6篇
  1990年   5篇
  1989年   7篇
  1988年   4篇
  1987年   1篇
  1986年   6篇
  1985年   7篇
  1984年   1篇
  1982年   1篇
  1981年   6篇
  1980年   3篇
  1978年   1篇
  1976年   1篇
  1974年   2篇
  1963年   1篇
  1961年   1篇
  1960年   1篇
排序方式: 共有963条查询结果,搜索用时 0 毫秒
11.
Many thousands of people in developing country cities depend on recycling materials from waste for their livelihoods. With the focus of the Millennium Development Goals on poverty reduction, and of waste strategies on improving recycling rates, one of the major challenges in solid waste management in developing countries is how best to work with this informal sector to improve their livelihoods, working conditions and efficiency in recycling.The general characteristics of informal recycling are reviewed, highlighting both positive and negative aspects. Despite the health and social problems associated with informal recycling, it provides significant economic benefits that need to be retained. Experience shows that it can be highly counterproductive to establish new formal waste recycling systems without taking into account informal systems that already exist. The preferred option is to integrate the informal sector into waste management planning, building on their practices and experience, while working to improve efficiency and the living and working conditions of those involved. Issues associated with integrating informal recycling into the formal waste management sector are discussed.  相似文献   
12.
13.
Chris Chapman  Mike Howden 《Omega》1997,25(6):707-714
This paper illustrates the value of several particular features of a first phase parametric approach to discounted cash flow (DCF) decision analysis when significant uncertainty is involved. It also illustrates the value of second phase probabilistic approaches to selected parameters for five quite different example reasons. The most controversial example reason concerns the discount rate. The particular example used to illustrate both phases may stimulate general interest because of the important issues involved, but it is argued that the two phase approach as a whole has a wide range of applications for decisions large and small.  相似文献   
14.
Motivated by problems in linguistics we consider a multinomial random vector for which the number of cells N is not much smaller than the sum of the cell frequencies, i.e. the sample size n . The distribution function of the uniform distribution on the set of all cell probabilities multiplied by N is called the structural distribution function of the cell probabilities. Conditions are given that guarantee that the structural distribution function can be estimated consistently as n increases indefinitely although n / N does not. The natural estimator is inconsistent and we prove consistency of essentially two alternative estimators.  相似文献   
15.
Industrial statistics plays a major role in the areas of both quality management and innovation. However, existing methodologies must be integrated with the latest tools from the field of Artificial Intelligence. To this end, a background on the joint application of Design of Experiments (DOE) and Machine Learning (ML) methodologies in industrial settings is presented here, along with a case study from the chemical industry. A DOE study is used to collect data, and two ML models are applied to predict responses which performance show an advantage over the traditional modeling approach. Emphasis is placed on causal investigation and quantification of prediction uncertainty, as these are crucial for an assessment of the goodness and robustness of the models developed. Within the scope of the case study, the models learned can be implemented in a semi-automatic system that can assist practitioners who are inexperienced in data analysis in the process of new product development.  相似文献   
16.
This paper explores the ways in which the work-life balance choices made by heterosexual couples differ in different generations, how such choices are gendered, and the extent to which 'individualization' provides an adequate conceptualization of the effects of social change on heterosexual couples. It argues that processes of individualization need to be seen in the context of changing social institutions, and that it is the de-institutionalization of 'the family' and the life course that is leading to a de-gendering of work-life balance choices. The paper draws on findings from a restudy of the family and social change and a study of the gender dimensions of job insecurity both of which were carried out in the same geographical location. The studies provide evidence of generational change in work-life balance choices and increasing occupational differentiation between heterosexual partners. This leads to a situation where increasingly choices are made which blur gendered boundaries and which has been made possible by a process of de-institutionalization of the male breadwinner family. Our findings support the contention that processes of individualization are more apparent amongst younger than older generations and that, because of changes external to the family, there is more negotiation and pragmatism amongst younger generations about work-life choices.  相似文献   
17.
Objective: To examine differences in complete response rates for depression screening questions based on demographic characteristics. Methods: Cross-sectional study examining associations between demographic characteristics and completely responding depression-screening questions. Participants: “Healthy Minds Study” data, collected in a public University in February 2016, where 7,326 students participated. Results: women (AOR: 0.69; 95% CI =0.57–0.83) and gay/lesbian students (AOR: 0.24; 95% CI =0.10–0.60) had better complete response rates. Non-US (AOR: 1.46; 95% CI =1.03–2.07), black (AOR: 3.32; 95% CI =1.92–5.77), and Middle-Eastern students (AOR: 3.73; 95% CI =1.73–8.02) had lower complete response rates. Conclusions: Our study shows sex, gender, citizenship, and race categories have significant differences in complete response rates for the outcome. Our findings have several implications; including recognizing interventions for depression based on responders may not target those that tend to be “partial-responders”. Efforts in survey design, recruiting and completion of surveys should be maximized.  相似文献   
18.
Urban Ecosystems - White-tailed deer (Odocoileus virginianus) are becoming increasingly common in urban environments. How they respond to potential changes (i.e. increased human interactions,...  相似文献   
19.
20.
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