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   2610篇
  免费   40篇
管理学   419篇
民族学   21篇
人才学   1篇
人口学   214篇
丛书文集   23篇
理论方法论   219篇
综合类   24篇
社会学   1377篇
统计学   352篇
  2021年   13篇
  2020年   26篇
  2019年   30篇
  2018年   52篇
  2017年   66篇
  2016年   56篇
  2015年   34篇
  2014年   53篇
  2013年   487篇
  2012年   60篇
  2011年   88篇
  2010年   69篇
  2009年   61篇
  2008年   65篇
  2007年   87篇
  2006年   56篇
  2005年   68篇
  2004年   61篇
  2003年   63篇
  2002年   56篇
  2001年   44篇
  2000年   43篇
  1999年   39篇
  1998年   50篇
  1997年   55篇
  1996年   49篇
  1995年   51篇
  1994年   39篇
  1993年   48篇
  1992年   47篇
  1991年   45篇
  1990年   41篇
  1989年   31篇
  1988年   30篇
  1987年   35篇
  1986年   26篇
  1985年   33篇
  1984年   32篇
  1983年   39篇
  1982年   33篇
  1981年   30篇
  1980年   29篇
  1979年   27篇
  1978年   34篇
  1977年   17篇
  1976年   25篇
  1975年   20篇
  1974年   26篇
  1973年   10篇
  1971年   11篇
排序方式: 共有2650条查询结果,搜索用时 15 毫秒
11.
12.
The extent of carcinogen regulation under existing U.S. environmental statutes is assessed by developing measures of the scope and stringency of regulation. While concern about cancer risk has played an important political role in obtaining support for pollution control programs, it has not provided the predominant rationale for most regulatory actions taken to date. Less than 20% of all standards established to limit concentrations of chemicals in various media address carcinogens. Restrictions on chemical use are more frequently based on concerns about noncancer human health or ecological effects. Of the chemicals in commercial use which have been identified as potential human carcinogens on the basis of rodent bioassays, only a small proportion are regulated. There is an inverse relationship between the scope of regulatory coverage and the stringency of regulatory requirements: the largest percentages of identified carcinogens are affected by the least stringent requirements, such as information disclosure. Standards based on de minimis cancer risk levels have been established for only 10% of identified carcinogens and are restricted to one medium: water. Complete bans on use have affected very few chemicals. The general role that carcinogenicity now plays in the regulatory process is not dramatically different from that of other adverse human health effects: if a substance is identified as a hazard, it may eventually be subject to economically achievable and technically feasible restrictions.  相似文献   
13.
Extractive industries such as logging and mining are generally expected to bring significant economic benefits to rural regions, but a growing number of findings have now challenged that common expectation. Still, it is not clear whether the findings of less–than–desirable economic outcomes are isolated or representative. In this article, we assemble literally all of the relevant quantitative findings on mining that we have been able to identify in published and/or technical literature from the United States. In the interest of rigor, we limit the assessment to cases in which strictly nonmetropolitan mining regions are compared against other nonmetropolitan regions and/or against those regions’ own experiences over time. Overall, 301 findings meet the criteria for inclusion. Contrary to the long–established assumptions, but consistent with more recent critiques, roughly half of all published findings indicate negative economic outcomes in mining communities, with the remaining findings being split roughly evenly between favorable and neutral/indeterminate ones. Positive findings are more likely to be associated with incomes than with poverty or (especially) unemployment rates, and they are more likely to come from the western United States, where much of the mining involves relatively large, new coal strip mines. Over half of all positive findings come from the years prior to 1982. In virtually all other categories, the plurality or majority of findings have been negative. When the patterns of findings are subjected to one–sample means tests, the only way to produce a significantly positive outcome is by combining all neutral/indeterminate findings with the positive ones, while focusing exclusively on incomes; by contrast, in the case of poverty or unemployment rates—as well as for the overall body of findings—the results are consistently and significantly negative, whether the neutral/indeterminate findings are combined with negative ones or omitted from the equations altogether. Until or unless future studies produce dramatically different findings, there appears to be no scientific basis for accepting the widespread, “obvious” assumption that mining will lead to economic improvement.  相似文献   
14.
This paper suggests a direction for the exploration of the causes of family violence. Explanatory models of family violence were considered in this regard, with the recommendation that a multi-determined model should be considered to ensure the most accurate explanation. We suggest that family violence will be best understood and prevented or alleviated, if a model is used that considers the interaction of structural violence and the personality features of all the family members.  相似文献   
15.
16.
17.
The Alchian and Allen theorem predicts that it will be harder to find "good" apples in the State of Washington, a prime apple-growing region, than in, say, New York City, where the addition of shipping charges makes "bad" apples comparatively more expensive. We recast the theorem as a testable proposition by explicitly taking the supply side into account and identifying plausible scenarios in which a fixed cost either has no effect on the relative prices of high and low quality grades of the same good in distant markets or, indeed, causes more of the bad apples to be shipped out.  相似文献   
18.
Nonprofit organizations rely on the mission to attract resources and guide decision making. Increasingly, mission statements are recognized as a strong management tool that can motivate employees and keep them focused on the organization's purpose. This research investigated employee attitudes toward the mission in a youth and recreation service organization. In general, the employees expressed positive attitudes toward the organization's mission, and those attitudes were related to employee satisfaction and intentions to remain with the organization. However, dissatisfaction with pay tended to override employee's mission attachment as explanation of why they may leave the organization. The implication is that mission might be salient in attracting employees but less effective in retaining them.  相似文献   
19.
Surprisingly little research has sought to explain differential participation after recruitment into social movement organizations (SMOs). This study examines the influence of several sets of predictors on participation by members of a national organization in the antihunger movement. The findings highlight the importance of incentive, ideological, and microstructural factors for differential participation and suggest that favorable perceptions of SMOs also promote participation. Final remarks address the implications of the findings for the social movement and voluntary organization literatures.  相似文献   
20.
Abstract The objective of this study is to examine female labor force participation and its determinants in rural and urban China. The sociological literature has demonstrated that participation tends to increase in urban and industrialized places where women have higher levels of education and fewer children, where more workers are engaged in service pursuits, and where family structure is less traditional. With the use of data on counties and cities (N = 2,377) from the I-percent sample of the 1982 census of the People's Republic of China, it was found that female labor force participation is likely to rise in areas with increased agricultural employment, educational levels, proportion of female-headed households, and higher male-to-female sex ratios. Both the size of the service sector and the fertility rate had negligible effects on female labor force participation. Although, on average, rural places have slightly higher levels of female labor force participation, when other variables are controlled, urban places have a higher rate of female participation. In addition, the findings suggest that market factors (i.e., education) are more likely to determine the rate of female labor force participation in urban areas; whereas demographic and social factors (i.e., sex ratio and household structure) play a more important role in explaining the female labor force participation in rural counties.  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