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   93608篇
  免费   1973篇
  国内免费   4篇
管理学   12719篇
民族学   542篇
人才学   25篇
人口学   7302篇
丛书文集   528篇
教育普及   2篇
理论方法论   9559篇
现状及发展   1篇
综合类   2186篇
社会学   43713篇
统计学   19008篇
  2023年   511篇
  2021年   571篇
  2020年   1517篇
  2019年   2211篇
  2018年   2139篇
  2017年   3210篇
  2016年   2418篇
  2015年   2068篇
  2014年   2640篇
  2013年   18925篇
  2012年   2462篇
  2011年   2295篇
  2010年   2026篇
  2009年   2215篇
  2008年   2081篇
  2007年   1912篇
  2006年   2145篇
  2005年   2335篇
  2004年   2196篇
  2003年   1938篇
  2002年   2038篇
  2001年   2104篇
  2000年   1894篇
  1999年   1768篇
  1998年   1531篇
  1997年   1401篇
  1996年   1363篇
  1995年   1368篇
  1994年   1339篇
  1993年   1332篇
  1992年   1336篇
  1991年   1272篇
  1990年   1241篇
  1989年   1095篇
  1988年   1185篇
  1987年   1051篇
  1986年   955篇
  1985年   1117篇
  1984年   1183篇
  1983年   1066篇
  1982年   983篇
  1981年   884篇
  1980年   832篇
  1979年   909篇
  1978年   796篇
  1977年   713篇
  1976年   665篇
  1975年   648篇
  1974年   540篇
  1973年   456篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
871.
The level of asbestos risk varies widely, with insulation workers facing risks many orders of magnitude greater than other groups, such as school children. After a period of regulatory neglect, asbestos risks are now among the mos stringently regulated risks, with costs per case of cancer prevented on the order of $100 million. Asbestos litigation triggered much of the public action against asbestos, as asbestos cases constituted the majority of all product liability cases in the federal courts from 1988 to 1991. The litigation costs have, however, been substantial, almost three times as great as the amounts transferred to asbestos disease victims. Risk communication potentially could promote efficient risk levels and victim compensation.  相似文献   
872.
The government, the market, and the problem of catastrophic loss   总被引:1,自引:0,他引:1  
This article addresses the comparative advantage of the government to the private property/casualty insurance industry for the provision of insurance coverage for catastrophic losses. That the government can play an important role as an insurer of societal losses has been a central public policy principle since at least the New Deal. In addition, our government typically automatically provides forms of specific relief following unusually severe or unexpected disasters, which itself can be viewed as a form of ex post insurance. This article argues that, for systemic reasons, the government is much less effective than the private property/casualty insurance market in providing coverage of losses generally, but especially of losses in contexts of catastrophes.  相似文献   
873.
Summary The evaluation of the performance of seasonal adjustment procedures is an issue of practical importance in view of the unobservable nature of the components. Looking at just one indicator when judging the overall quality of a procedure may be misleading, even though this is common practice when many series are involved. The main purpose of this paper is to compare the information content of different synthetic indicators with reference to the X-11-ARIMA procedure. Sixty-six different types of monthly seasonal series are generated and the seasonal component then extracted by carrying out X-11-ARIMA with standard options. The correlation between the pseudo-true error for each series and various synthetic indicators allows us to compare the latter's reliability, under both the hypotheses of minimum and maximum variance of the pseudo-true seasonal component. We show that the overall quality indexQ-the indicator most commonly adopted by users of the X-11-ARIMA-is always outperformed by the simpler diagnostics based on the stability of the estimates. In particular, the “sliding-spans” indicator, proposed by Findley et al. (1990) and included in the diagnostics of the new X-12 procedure, shows a much stronger correlation with the pseudo-true error in the seasonal adjustment. We also show that the total forecasting errors in the one-year-ahead extrapolation of the seasonal component have a good informative power and perform almost as well as the “sliding-spans” indicator.  相似文献   
874.
This two-part study applied an ecocultural perspective to socialization of daily and long-term goals in low-income Mexican-American and European-American families with children in third, fifth, and seventh grades. The first part of the study examined family members' participation and parents' socialization goals and guidance strategies for their children's daily household chores and homework activities. The second part of the study examined parents' long-term aspirations and guidance strategies for their children's educational, vocational, and moral development. For daily activities, results showed that in Mexican-American families both parents and siblings played important roles, whereas in European-American families parents were the primary socialization agents. As predicted, in both groups parents' expertise influenced their guidance strategies. Finally, Mexican-American and European-American parents differed in their relative endorsement of gender, relational, and self-reliance goals for household chores. For long-term goals, parents in both groups held high educational, vocational, and moral aspirations for their children. However, some parents of seventh-graders had lower educational and vocational aspirations than those of fifth- and third-graders. Although expertise consistently influenced Mexican-American parents' guidance strategies, the pattern for European-American parents was mixed. The discussion highlights between- and within-group differences in daily and long-term socialization practices with an emphasis on resources and vulnerabilities in the families.  相似文献   
875.
876.
877.
Men,women, and sustainability   总被引:1,自引:1,他引:0  
  相似文献   
878.
Which countries tend to sign international environmental treaties and why? This study tests the ability of quantitative cross-national political and economic analysis to predict participation in international environmental agreements over the period 1963–1987. Cross-sectional ordinary least squares regressions suggest that poor, highly indebted countries that are dependent on very few trading partners and that have repres-sive regimes are far more likely to be nonsignatories. The results suggest strategies for increasing the likelihood that nations will ratify hture environmental treaties.  相似文献   
879.
TOWARD A SYNTHESIS OF FEMINIST AND DEMOGRAPHIC PERSPECTIVES ON FERTILITY   总被引:1,自引:0,他引:1  
In explaining fertility and reproduction and emerging patterns of childbearing, both demographers and feminists have centered their thinking on women's status (economic and social), women's changing roles and life experiences (increased labor force participation, increased availability of reproductive options, declining marriage rates in many parts of the industrialized world, and the centrality of women to development), and women as agents in micro- and macrolevel changes in family, fertility, and economic change. Although demography has recently begun to integrate feminist perspectives into fertility explanations, there is not yet a synthesis of feminist theoretical insights with demographic questions. Drawing from recent thinking on global and national political and policy challenges in the less and more developed worlds, to the epistemological shifts in knowledge of reproduction/mothering, to changes in the technologies of reproduction, this article moves toward an integration of feminist and demographic perspectives on fertility.
…far from the economic dependence of women working in the interests of motherhood, it is the steadily acting cause of a pathological maternity and a declining birthrate.
Charlotte Perkins Stetson, Women and Economics , 1899  相似文献   
880.
We consider the problem of estimating the scale parameter of an exponential or a gamma distribution under squared error loss when the scale parameter θ is known to be greater than some fixed value θ0. Natural estimators in this setting include truncated linear functions of the sufficient statistic. Such estimators are typically inadmissible, but explicit improvements seem difficult to find. Some are presented here. A particularly interesting finding is that estimators which are admissible in the untruncated problem which take values only in the interior of the truncated parameter space are found to be inadmissible for the truncated problem.  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