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   89655篇
  免费   2994篇
  国内免费   4篇
管理学   12342篇
民族学   543篇
人才学   25篇
人口学   6889篇
丛书文集   520篇
理论方法论   9484篇
综合类   2113篇
社会学   41858篇
统计学   18879篇
  2023年   518篇
  2021年   577篇
  2020年   1556篇
  2019年   2244篇
  2018年   2099篇
  2017年   3186篇
  2016年   2403篇
  2015年   2080篇
  2014年   2669篇
  2013年   18944篇
  2012年   2336篇
  2011年   2138篇
  2010年   1962篇
  2009年   2188篇
  2008年   2021篇
  2007年   1828篇
  2006年   2075篇
  2005年   2252篇
  2004年   2147篇
  2003年   1859篇
  2002年   1968篇
  2001年   1949篇
  2000年   1752篇
  1999年   1674篇
  1998年   1495篇
  1997年   1340篇
  1996年   1292篇
  1995年   1305篇
  1994年   1288篇
  1993年   1270篇
  1992年   1248篇
  1991年   1190篇
  1990年   1157篇
  1989年   1023篇
  1988年   1082篇
  1987年   973篇
  1986年   860篇
  1985年   1044篇
  1984年   1093篇
  1983年   991篇
  1982年   919篇
  1981年   839篇
  1980年   805篇
  1979年   850篇
  1978年   762篇
  1977年   685篇
  1976年   650篇
  1975年   623篇
  1974年   514篇
  1973年   424篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
This article examines the relationship between donations to the American Red Cross and the profits, sales, costs, and prices of health and safety classes offered by local chapters. Two important questions are examined: Do profits from sales of services “crowd out” donations to local chapters of the American Red Cross? Do managers respond to changes in donations by changing prices, output, or costs of saleable services? The results suggest that nonprofit managers should pay close attention to the potential impact on donations of any change in the prices charged for saleable goods and services, and that profits, costs, and prices of services are influenced by donations.  相似文献   
963.
964.
965.
The mean density of bacteria in a water body is commonly monitored using quantal assay. This paper describes the use of local scoring in estimating the spatial distribution of mean density from quantal assay results at a set of point locations. An application to estimating the mean density of fecal conform bacteria in a coastal pond is presented. Model diagnostics based on a parametric bootstrap are also presented.  相似文献   
966.
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   
967.
968.
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   
969.
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   
970.
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   
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