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   13553篇
  免费   273篇
  国内免费   4篇
管理学   1950篇
民族学   87篇
人才学   9篇
人口学   1248篇
丛书文集   77篇
理论方法论   1380篇
综合类   142篇
社会学   6758篇
统计学   2179篇
  2023年   77篇
  2021年   82篇
  2020年   209篇
  2019年   298篇
  2018年   359篇
  2017年   437篇
  2016年   370篇
  2015年   265篇
  2014年   321篇
  2013年   2269篇
  2012年   443篇
  2011年   440篇
  2010年   327篇
  2009年   283篇
  2008年   336篇
  2007年   352篇
  2006年   358篇
  2005年   363篇
  2004年   340篇
  2003年   296篇
  2002年   316篇
  2001年   274篇
  2000年   309篇
  1999年   292篇
  1998年   242篇
  1997年   228篇
  1996年   219篇
  1995年   191篇
  1994年   208篇
  1993年   198篇
  1992年   212篇
  1991年   191篇
  1990年   177篇
  1989年   199篇
  1988年   152篇
  1987年   153篇
  1986年   139篇
  1985年   169篇
  1984年   164篇
  1983年   154篇
  1982年   137篇
  1981年   130篇
  1980年   126篇
  1979年   122篇
  1978年   114篇
  1977年   91篇
  1976年   111篇
  1975年   89篇
  1974年   94篇
  1973年   68篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
To quantify the health benefits of environmental policies, economists generally require estimates of the reduced probability of illness or death. For policies that reduce exposure to carcinogenic substances, these estimates traditionally have been obtained through the linear extrapolation of experimental dose-response data to low-exposure scenarios as described in the U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment (1986). In response to evolving scientific knowledge, EPA proposed revisions to the guidelines in 1996. Under the proposed revisions, dose-response relationships would not be estimated for carcinogens thought to exhibit nonlinear modes of action. Such a change in cancer-risk assessment methods and outputs will likely have serious consequences for how benefit-cost analyses of policies aimed at reducing cancer risks are conducted. Any tendency for reduced quantification of effects in environmental risk assessments, such as those contemplated in the revisions to EPA's cancer-risk assessment guidelines, impedes the ability of economic analysts to respond to increasing calls for benefit-cost analysis. This article examines the implications for benefit-cost analysis of carcinogenic exposures of the proposed changes to the 1986 Guidelines and proposes an approach for bounding dose-response relationships when no biologically based models are available. In spite of the more limited quantitative information provided in a carcinogen risk assessment under the proposed revisions to the guidelines, we argue that reasonable bounds on dose-response relationships can be estimated for low-level exposures to nonlinear carcinogens. This approach yields estimates of reduced illness for use in a benefit-cost analysis while incorporating evidence of nonlinearities in the dose-response relationship. As an illustration, the bounding approach is applied to the case of chloroform exposure.  相似文献   
42.
43.
State governments exercise significant powers to regulate the economic and social activities of resident aliens. We review the laws of the six leading states of immigrant settlement regulating access of noncitizens to 23 occupations, updating existing studies from 1946–77. Citizenship requirements for these occupations have plummeted, a change we attribute to federal court decisions, advisory opinions of state attorneys general, and state legislative and administrative action. There are numerous additional citizenship requirements in the statutes of the six states, although these appear to be poorly enforced. The authority of states to regulate their political communities is the most important remaining constitutionally valid basis of citizenship requirements. States define their political community broadly, leading to questionable exclusions of noncitizens from important activities.  相似文献   
44.
Veneziano, Veneziano and LeGrand (2000) found support for the victim to victimizer hypothesis of sexual aggression with 74 sexually abusive youth. This project, a further step in examining this theory (Burton, 2000, Burton, Miller, & Shill, 2002) builds on their ideas with data from 179 adolescent sexual abusers, and supports their findings. In an examination of relationships, gender, modus operandi, and acts, the sexually abused youth were likely to repeat what was done to them. This project also offers a further analysis of how victimization accounts for a significant portion of the variance in perpetration by these youth. Implications for research and practice are offered.  相似文献   
45.
This article explores two problems analysts face in determining how to estimate values for children's health and safety risk reductions. The first addresses the question: Do willingness‐to‐pay estimates for health risk changes differ across children and adults and, if so, how? To answer this question, the article first examines the potential effects of age and risk preferences on willingness to pay. A summary of the literature reporting empirical evidence of differences between willingness to pay for adult health and safety risk reductions and willingness to pay for health and safety risk reductions in children is also provided. The second dimension of the problem is a more fundamental issue: Whose perspective is relevant when valuing children's health effects—society's, children's, adults‐as‐children, or parents'? Each perspective is considered, followed ultimately by the conclusion that adopting a parental perspective through an intrahousehold allocation model seems closest to meeting the needs of the estimation problem at hand. A policy example in which the choice of perspective affects the outcome of a regulatory benefit‐cost analysis rounds out the article and emphasizes the importance of perspective.  相似文献   
46.
47.
48.
This study concerned the immunological correlates of stress and work. Self reported stress, emotional state, ego-strength, and defensiveness were examined in relation to measures of cellular immunity (T-cell response to Con A and number of T4 and T8 cells) and humoral immunity (concentrations of immunoglobulins and complement components in plasma) in a group of 96 Norwegian female bank employees. The analyses showed that workload, the stress factor with the highest group mean, was associated with number of T-cells, while strain due to body posture during work was related to concentrations of IgM and C3. Further, depression was significantly correlated with IgM concentration and T-cell number, and anxiety with C3 concentration. T-cell activity was the immunological parameter most consistently associated with psychological well-being, showing positive correlations with defensiveness and ego-strength and negative correlations with anxiety and depression. In conclusion, T-cell number and concentrations of IgM and C3 were sensitive to both work-related stress experience and emotional distress. Coping abilities, indicated by the MMPI Ego-strength scale and emotional distress, were reflected in T-cell activity; insufficient coping was associated with low T-cell activity.  相似文献   
49.
50.
Many studies have shown that multinational firms pay more than domestic firms in Third World countries. Economists who criticize sweatshops have responded that multinational firms’ wage data do not address whether sweatshop jobs are above average because many of these jobs are with domestic subcontractors. We compare apparel industry wages and the wages of individual firms accused of being sweatshops to measures of the standard of living in Third World economies. We find that most sweatshop jobs provide their workers an above average standard of living. The authors thank Jeffery Hummel, Charles Murray, Larry Pratt, and Edward Stringham for helpful comments on earlier drafts. Financial support from the American Institute for Economic Research is gratefully acknowledged. The usual disclaimer applies.  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