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   355篇
  免费   15篇
管理学   29篇
民族学   6篇
人口学   23篇
丛书文集   1篇
理论方法论   47篇
综合类   5篇
社会学   223篇
统计学   36篇
  2024年   1篇
  2023年   6篇
  2022年   1篇
  2021年   5篇
  2020年   11篇
  2019年   17篇
  2018年   12篇
  2017年   24篇
  2016年   16篇
  2015年   11篇
  2014年   20篇
  2013年   80篇
  2012年   15篇
  2011年   14篇
  2010年   11篇
  2009年   9篇
  2008年   5篇
  2007年   7篇
  2006年   10篇
  2005年   12篇
  2004年   7篇
  2003年   6篇
  2002年   4篇
  2001年   3篇
  2000年   6篇
  1999年   5篇
  1998年   5篇
  1997年   4篇
  1996年   1篇
  1995年   3篇
  1994年   3篇
  1993年   2篇
  1992年   5篇
  1991年   1篇
  1990年   4篇
  1989年   3篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   5篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1972年   2篇
排序方式: 共有370条查询结果,搜索用时 15 毫秒
101.
Given a graph G=(V,E) with edge weights w e ∈ℝ, the optimum cooperation problem consists in determining a partition of the graph that maximizes the sum of weights of the edges with nodes in the same class plus the number of the classes of the partition. The problem is also known in the literature as the optimum attack problem in networks. Furthermore, a relevant physics application exists.  相似文献   
102.
State environmental agencies in the United States are charged with making risk management decisions that protect public health and the environment while managing limited technical, financial, and human resources. Meanwhile, the federal risk assessment community that provides risk assessment guidance to state agencies is challenged by the rapid growth of the global chemical inventory. When chemical toxicity profiles are unavailable on the U.S. Environmental Protection Agency's Integrated Risk Information System or other federal resources, each state agency must act independently to identify and select appropriate chemical risk values for application in human health risk assessment. This practice can lead to broad interstate variation in the toxicity values selected for any one chemical. Within this context, this article describes the decision‐making process and resources used by the federal government and individual U.S. states. The risk management of trichloroethylene (TCE) in the United States is presented as a case study to demonstrate the need for a collaborative approach among U.S. states toward identification and selection of chemical risk values while awaiting federal risk values to be set. The regulatory experience with TCE is contrasted with collaborative risk science models, such as the European Union's efforts in risk assessment harmonization. Finally, we introduce State Environmental Agency Risk Collaboration for Harmonization, a free online interactive tool designed to help to create a collaborative network among state agencies to provide a vehicle for efficiently sharing information and resources, and for the advancement of harmonization in risk values used among U.S. states when federal guidance is unavailable.  相似文献   
103.
In the days following the collapse of the World Trade Center (WTC) towers on September 11, 2001 (9/11), the U.S. Environmental Protection Agency (EPA) initiated numerous air monitoring activities to better understand the ongoing impact of emissions from that disaster. Using these data, EPA conducted an inhalation exposure and human health risk assessment to the general population. This assessment does not address exposures and potential impacts that could have occurred to rescue workers, firefighters, and other site workers, nor does it address exposures that could have occurred in the indoor environment. Contaminants evaluated include particulate matter (PM), metals, polychlorinated biphenyls, dioxins, asbestos, volatile organic compounds, particle-bound polycyclic aromatic hydrocarbons, silica, and synthetic vitreous fibers (SVFs). This evaluation yielded three principal findings. (1) Persons exposed to extremely high levels of ambient PM and its components, SVFs, and other contaminants during the collapse of the WTC towers, and for several hours afterward, were likely to be at risk for acute and potentially chronic respiratory effects. (2) Available data suggest that contaminant concentrations within and near ground zero (GZ) remained significantly elevated above background levels for a few days after 9/11. Because only limited data on these critical few days were available, exposures and potential health impacts could not be evaluated with certainty for this time period. (3) Except for inhalation exposures that may have occurred on 9/11 and a few days afterward, the ambient air concentration data suggest that persons in the general population were unlikely to suffer short-term or long-term adverse health effects caused by inhalation exposures. While this analysis by EPA evaluated the potential for health impacts based on measured air concentrations, epidemiological studies conducted by organizations other than EPA have attempted to identify actual impacts. Such studies have identified respiratory effects in worker and general populations, and developmental effects in newborns whose mothers were near GZ on 9/11 or shortly thereafter. While researchers are not able to identify specific times and even exactly which contaminants are the cause of these effects, they have nonetheless concluded that exposure to WTC contaminants (and/or maternal stress, in the case of developmental effects) resulted in these effects, and have identified the time period including 9/11 itself and the days and few weeks afterward as a period of most concern based on high concentrations of key pollutants in the air and dust.  相似文献   
104.
Spearman's rank correlation coefficient is not entirely suitable for measuring the correlation between two rankings in some applications because it treats all ranks equally. In 2000, Blest proposed an alternative measure of correlation that gives more importance to higher ranks but has some drawbacks. This paper proposes a weighted rank measure of correlation that weights the distance between two ranks using a linear function of those ranks, giving more importance to higher ranks than lower ones. It analyses its distribution and provides a table of critical values to test whether a given value of the coefficient is significantly different from zero. The paper also summarizes a number of applications for which the new measure is more suitable than Spearman's.  相似文献   
105.
This paper examines whether or not survey measures asked to two linguistic groups exhibit invariance within a country. It tests configural, metric and scalar invariance in a model that distinguishes the response component and the cognitive component of the measurement process using survey items. Our findings show that when differences in the response process are allowed, concepts are (partially) invariant across groups. The analysis is conducted for items measuring some aspects of political trust and satisfaction with politics for six linguistic groups including French, Dutch, Estonian, German, Ukrainian and Russian in four countries. Data comes from the European Social Survey.  相似文献   
106.
For a long‐term, longitudinal study that used BlackBerry smartphones for passive ambulatory assessment among older adolescents, this study focused on three areas of ethical concern: (1) adolescents’ competence to give assent; (2) understanding of confidentiality, the protection of information, and project goals; and (3) awareness of procedures and benefits, and comfort with the research design. One hundred and seventy‐eight participants were 17 and 18 years old (84 girls). Results suggested that participants freely gave consent and understood most, but not all of the informed consent information. Participants reported a high level of satisfaction. Participants showed less understanding of when their confidentiality would be broken and how data would be protected.  相似文献   
107.
According to many, sociology is facing a crisis of relevance. Of particular concern is sociology's inability to impact policy. Sociologists, who should be the go‐to on major policy issues have been sidelined as other social scientists take up roles as policy advisors. Recent efforts aimed at encouraging public engagement have focused on disseminating research and producing more policy‐relevant knowledge. These are welcome resources, but they reflect a deep ambivalence toward policy sociology and a tendency to conflate participation in public discussions with policy impact. In contrast, this essay draws on recent findings about the power of policy experts to develop an organic policy sociology. Organic policy sociology depends on co‐designing and carrying out research with policymakers with whom we share critical and professional commitments. By working collaboratively with policymakers, sociologists can foster equity‐promoting policy, change how policymakers understand social problems, and improve how citizens experience policy on the ground. To that end, I offer six orienting strategies for developing and maintaining organic policy sociology projects, from finding the right partner to assessing the impact of our work.  相似文献   
108.
109.
Whereas the current public interest in the relation of transformation of paid work and gender is focused a lot on men and masculinities, sociological analysis is mostly focused on women and feminity. Few studies on work and masculinity suggest that with the erosion of industrial working conditions traditional constructions of masculinity are challenged to the core. It is our thesis that three mechanisms are working in stabilizing the relationship between paid work and masculinity: reconfigured standard employment relationship, entrepreneurial self, and hegemonic masculinity. Supposably, the new adjusted social order opens a range between two poles: the adherence to traditional patterns of masculinity on the one hand, which tends do enforce insecurity, and a pattern of hegemonic masculinity on the other side, which is characterized by a proactive and positive attitudes of dealing with present tendencies of uncertainty, seeing change as chance of creating.  相似文献   
110.
The generation growing and diversified of Municipal Solid Waste is configured as an environmental problem, economic and social deterioration, especially, by application of inappropriate management of them. Faced with this urban context, the research in development presents as specific objective assessment of the quality of life of the gatherers of recyclable materials were active in the city of Juiz de Fora, in the brazilian state of Minas Gerais. In addition, the objective is, still, the recognition of the activity of sorting performed by "scavengers" in order to maximize the reduction, reuse and recycling energy and material waste daily. The proposed methodology is based on the application of the questionnaire Word Health Organization Quality of Life (WHOQOL-100), prepared by the World Health Organization, in order to value the quality of life of the gatherers of recyclable materials, involved, even in educational workshops in order to discuss and organize strategies of health care and scouting to the basement to public policies.  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