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   92355篇
  免费   3012篇
  国内免费   18篇
管理学   12530篇
民族学   568篇
人才学   26篇
人口学   7079篇
丛书文集   619篇
教育普及   1篇
理论方法论   9637篇
综合类   2692篇
社会学   43307篇
统计学   18926篇
  2023年   508篇
  2021年   588篇
  2020年   1537篇
  2019年   2237篇
  2018年   2116篇
  2017年   3216篇
  2016年   2416篇
  2015年   2084篇
  2014年   2672篇
  2013年   19101篇
  2012年   2517篇
  2011年   2353篇
  2010年   2120篇
  2009年   2291篇
  2008年   2221篇
  2007年   2041篇
  2006年   2275篇
  2005年   2408篇
  2004年   2227篇
  2003年   1944篇
  2002年   2063篇
  2001年   2033篇
  2000年   1802篇
  1999年   1709篇
  1998年   1517篇
  1997年   1348篇
  1996年   1313篇
  1995年   1335篇
  1994年   1307篇
  1993年   1293篇
  1992年   1276篇
  1991年   1208篇
  1990年   1186篇
  1989年   1033篇
  1988年   1131篇
  1987年   1000篇
  1986年   905篇
  1985年   1076篇
  1984年   1138篇
  1983年   1009篇
  1982年   941篇
  1981年   869篇
  1980年   810篇
  1979年   872篇
  1978年   770篇
  1977年   694篇
  1976年   662篇
  1975年   648篇
  1974年   522篇
  1973年   439篇
排序方式: 共有10000条查询结果,搜索用时 416 毫秒
991.
The possibility that carbon dioxide emissions from fossil fuel use might lead to global warming has become a leading environmental concern. Many scientific and environmental organizations have called for immediate action to limit carbon dioxide production. For the most part, however, public debate has focused on a single policy instrument: a carbon tax applied to fossil fuels in proportion to their carbon content. We present a detailed model of the U.S. economy and use it to compare carbon taxes with two other instruments that could achieve the same reduction in carbon dioxide emissions: a tax on the energy content of fossil fuels (a BTU tax) and an ad valorem tax on fuel use. We find that carbon taxes can achieve a given reduction with the least overall effect on the economy, but with a large effect on coal mining. Energy taxes are fairly similar to carbon taxes but have slightly less impact on coal mining and slightly greater overall cost. In contrast, ad valorem taxes fall much more lightly on coal mining but have a much greater effect on the economy as a whole.  相似文献   
992.
993.
The contemporary retreat from marriage in the United States has had a differential impact across socioeconomic and racial groups. Here, 1990 marriage rates and propensities for Virginia, North Carolina, and Wisconsin are analyzed regarding (a) the likelihood that persons in different groups ever marry and (b) patterns of partner choice with respect to race and educational level. Marriage remains strong in most race‐education groups but is substantially lower among Blacks and among those with less than 12 years of education. Patterns of partner choice have shifted to show greater symmetry between the educational levels of brides and grooms. Changes have been modest with regard to the level and pattern of interracial (Black‐White) marriage. Marriage is increasingly a union of equals, but a union chosen more by Whites than by Blacks and more by the well educated than by the poorly educated.  相似文献   
994.
A training project in a northern Canadian community providedan opportunity to examine participatory planning approachesand the meaning of work in First Nations communities. Focusgroups conducted three years after the unsuccessful interventionof a community economic development (CED) project suggest thatcomplex factors such as lack of support from community leadersand rate of pay for workers determine whether CED is alwaysappropriate in northern, First Nations contexts.  相似文献   
995.
Given the fragmented structure of child‐care assistance in the United States, it has been difficult to obtain accurate estimates of which families are assisted, through which mechanisms, and at what level. Making use of survey data from New York City, we analyze the distribution of several forms of public child‐care assistance. Results suggest that about 40% of all families with young children receive some form of child‐care assistance. Considering all forms of assistance, the distribution of child‐care help is targeted in both expected and some unexpected ways. Implications of these results are discussed in the context of U.S. child‐care policies governing access and benefit levels.  相似文献   
996.
The authors consider the issue of map positional error, or the difference between location as represented in a spatial database (i.e., a map) and the corresponding unobservable true location. They propose a fully model‐based approach that incorporates aspects of the map registration process commonly performed by users of geographic informations systems, including rubber‐sheeting. They explain how estimates of positional error can be obtained, hence estimates of true location. They show that with multiple maps of varying accuracy along with ground truthing data, suitable model averaging offers a strategy for using all of the maps to learn about true location.  相似文献   
997.
The 1995 wave of the Add Health study is used to investigate the relative influence of parent gender and residence on patterns of parental involvement with adolescents. Adolescent reports (N =17,330) of shared activities, shared communication, and relationship quality with both biological parents are utilized. A multidimensional scaling analysis reveals that parent gender explains most of the variance in parent‐adolescent involvement, with residential status playing a secondary yet a fundamental role in accounting for these patterns. Resident mothers who do not live with adolescents’ biological fathers engage in the broadest range of activities with their children. Unpartnered resident fathers display patterns of parenting that are as similar to mothers as they are to other fathers.  相似文献   
998.
Ohne Zusammenfassung Rede zum 100. Geburtstag auf einer Veranstaltung der Stadt K?ln, der René-K?nig-Gesellschaft und des Westdeutschen Rundfunks K?ln am 11. Mai 2006 in K?ln  相似文献   
999.
The article tests the thesis that globalization increases the earnings inequality of households. It extends the time series data set of Alderson and Nielsen (2002) who supported the globalization thesis. Alternative models provide no evidence that foreign trade, foreign investment, and migration increase inequality. The article gives reasons for these results and shows that OECD countries pass through an endogenous sectoral and demographic crisis in the transition to post-industrial service societies. Therefore, the paper adapts Kuznets’ theorem of sector dualism to the subsectors of the service economy. The polarization of value addition within the service sector appears as the crucial determinant of increased earnings inequality of households.  相似文献   
1000.
Are the decisions of American policymakers informed by generaltrends in the public’s ideology or by the public’spolicy-specific preferences? In this article we discuss twoexplanations for the types of public opinion information thatpoliticians collect and use. Using a unique data set of privatepolls from the White House of Richard Nixon, we find that whenopinion data on specific policies were available, the presidentrelied on them and not on general ideology data. On less importantissues, however, we find that the president often chose notto collect policy-specific data and instead relied on generalideology data. The differential collection and use of informationby policymakers reflect varying strategic calculations. Theyalso have profound implications for representative democracyand the demands placed on citizens and governors.  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