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   19619篇
  免费   398篇
管理学   2300篇
民族学   109篇
人才学   7篇
人口学   1813篇
丛书文集   112篇
教育普及   2篇
理论方法论   1842篇
现状及发展   1篇
综合类   241篇
社会学   9889篇
统计学   3701篇
  2023年   103篇
  2022年   85篇
  2021年   109篇
  2020年   319篇
  2019年   514篇
  2018年   517篇
  2017年   720篇
  2016年   512篇
  2015年   401篇
  2014年   478篇
  2013年   3300篇
  2012年   692篇
  2011年   632篇
  2010年   504篇
  2009年   458篇
  2008年   520篇
  2007年   533篇
  2006年   491篇
  2005年   442篇
  2004年   439篇
  2003年   415篇
  2002年   420篇
  2001年   495篇
  2000年   409篇
  1999年   394篇
  1998年   325篇
  1997年   293篇
  1996年   304篇
  1995年   275篇
  1994年   263篇
  1993年   254篇
  1992年   306篇
  1991年   292篇
  1990年   266篇
  1989年   259篇
  1988年   245篇
  1987年   232篇
  1986年   222篇
  1985年   247篇
  1984年   238篇
  1983年   242篇
  1982年   180篇
  1981年   155篇
  1980年   172篇
  1979年   172篇
  1978年   141篇
  1977年   141篇
  1976年   122篇
  1975年   117篇
  1974年   96篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
Racial differences in urban neighboring   总被引:2,自引:0,他引:2  
Despite mixed expectations generated by existing theories and evidence, this analysis documents clear racial differences in urban neighboring behavior. Using data from a survey of Nashville, Tennessee, residents, we show that blacks interact with their neighbors more often than whites do, and in a greater variety of ways. The only noteworthy similarity between the two groups is the positive impact of neighboring on feelings of community affect. Overall, our results support the view that neighbor relations — like other kinds of informal participation — have helped blacks cope with constrained social opportunities and provided them with access to resources unavailable through formal institutional channels.Revised version of a paper presented at the annual meeting of the American Sociological Association, San Francisco, August 1989.  相似文献   
53.
Readers wishing to correspond with Mr. O’Connell may do so through the editorial office of the Journal.  相似文献   
54.
Differential participation after recruitment remains a black box in the social-movement and voluntary-association literatures. This paper identifies several dimensions of membership participation in a professional social-movement organization (SMO) with a national membership and analyzes the determinants of differential involvement in these forms. In general, members' ideological beliefs, social and organizational ties, perceptions about their SMO, and communication with SMO officials all predict participation across the various forms. Our findings extend previous work on differential participation in three ways. First, we statistically isolate cultural dimensions of postrecruitment participation and, in so doing, complement recent ethnographic research. Second, our findings suggest that the distinct dimensions of external and internal participation found by Knoke (1988) in a national sample of voluntary associations may not generalize to national SMOs studied individually. Third, our results indicate that models combining ideological and microstructural factors should explain the multiple forms of participation in SMOs lacking these distinct dimensions.  相似文献   
55.
56.
In this paper, the history of atmospheric science is traced, from the earliest discussions from meteorologists, and the first meetings to describe this new research area. The development of atmospheric science proceeded in three phases with each phase being marked by the attempt to organize resources, and bring into the atmospheric science network, scientists from other fields. I argue here that this construction of a science provides evidence of the social nature of science as well as the importance of organizations to the creation of a science.  相似文献   
57.
58.
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   
59.
60.
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