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   342篇
  免费   7篇
管理学   63篇
人口学   25篇
理论方法论   28篇
综合类   1篇
社会学   196篇
统计学   36篇
  2019年   5篇
  2018年   9篇
  2017年   4篇
  2016年   6篇
  2015年   3篇
  2014年   7篇
  2013年   85篇
  2012年   19篇
  2011年   6篇
  2010年   2篇
  2009年   6篇
  2008年   3篇
  2007年   9篇
  2006年   6篇
  2005年   7篇
  2004年   7篇
  2003年   5篇
  2002年   5篇
  2001年   6篇
  2000年   7篇
  1999年   2篇
  1998年   7篇
  1997年   5篇
  1996年   5篇
  1995年   6篇
  1994年   9篇
  1993年   8篇
  1992年   6篇
  1991年   8篇
  1990年   9篇
  1989年   2篇
  1988年   6篇
  1987年   6篇
  1986年   4篇
  1985年   3篇
  1984年   5篇
  1983年   5篇
  1982年   5篇
  1981年   7篇
  1980年   6篇
  1979年   4篇
  1978年   2篇
  1977年   5篇
  1976年   4篇
  1975年   3篇
  1973年   2篇
  1972年   2篇
  1970年   1篇
  1968年   1篇
  1964年   1篇
排序方式: 共有349条查询结果,搜索用时 765 毫秒
341.
Mortality Risks Induced by Economic Expenditures   总被引:5,自引:0,他引:5  
Existing evidence shows that lower incomes are associated with higher mortality risks. This paper examines the implications for fatalities when the relationship is interpreted as an induced relationship, meaning that lower incomes will on average lead to higher mortality risks. A model is developed for estimating the number of fatalities possibly induced by economic expenditures. This model accounts for different allocations of the expenditures on family units with varying income levels. Illustrative calculations provide insights about the possible significance of fatalities induced by economic expenditures. These results suggest that some expensive regulations and programs intended to save lives may actually lead to increased fatalities. Important caveats to reduce the likelihood of misinterpreting or misusing the results are included.  相似文献   
342.
343.
344.
The two-stage clonal expansion model is a popular model for carcinogenesis data. One common form of this model is based on the approximate hazard function. In certain situations, this formulation is not appropriate, and the exact hazard should be applied. However, the difficulty of implementing the model based on the exact hazard has deterred many from using it. This paper presents a program implementing the exact hazard model for piecewise constant dosing using SAS, a package that is readily available to most that are interested in this type of analysis. Also, an analysis of the ED01 data is presented using this program, and comparisons are made to an earlier analysis based on the approximate hazard. By allowing for an independent background tumor mechanism, an excellent fit to the bladder tumor incidence data was obtained.  相似文献   
345.
Five potential sites nominated for the Nation's first geologic repository for disposing of nuclear waste are evaluated using multiattribute utility analysis. The analysis was designed to aid the Department of Energy in its selection of 3 sites for characterization, a detailed data-gathering process that will involve the construction of exploratory shafts for underground testing and that may cost as much as $1 billion per site. The analysis produced insights into the relative advantages and disadvantages of the nominated sites and clarified current uncertainties regarding repository performance.  相似文献   
346.
The U.S. Department of Energy has selected three sites, from five nominated, to characterize for a nuclear repository to permanently dispose of nuclear waste. This decision was made without the benefit of an analysis of this "portfolio" problem. This paper analyzes different portfolios of three sites for simultaneous characterization and strategies for sequential characterization. Characterization of each site, which involves significant subsurface excavation, is now estimated to cost $1 billion. Mainly because of the high characterization costs, sequential characterization strategies are identified which are the equivalent of $1.7-2.0 billion less expensive than the selected DOE simultaneous characterization of the three sites. If three sites are simultaneously characterized, one portfolio is estimated to be the equivalent of $100-400 million better than the selected DOE portfolio. Because of these potential savings and several other complicating factors that may influence the relative desirability of characterization strategies, a thorough analysis of characterization strategies that addresses the likelihood of finding disqualifying conditions during site characterization, uncertainties, and dependencies in forecast site repository costs, preclosure and postclosure health and safety impacts, potential delays of both sequential and simultaneous characterization strategies, and the environmental, socioeconomic, and health and safety impacts of characterization activities is recommended.  相似文献   
347.
Exploratory modelling revealed associations of individual perceptions, social factors, and physical components of air pollution with depressive symptomatology. Residents of the Los Angeles Metropolitan Area who have experienced a recent, undesirable life event and who perceive poor air quality in their neighborhood have greater symptoms of depression. These effects control for socioeconomic status and prior psychological status. In addition we show that perceived air quality is a function of both toxic components of ambient air as well as individual psychosocial experiences.This research was supported by the National Institute for Mental Health (MH 28924-10A1) and the Southern California Edison Health Effects Research Laboratory (J-1909902). We thank Jean Ospital, Len Edwards, and Julian Foon for their assistance. Reprint requests should be sent to Gary Evans, Program in Social Ecology, University of California, Irvine, CA 92717.  相似文献   
348.
349.
A major issue in value-function assessment is the possibility of receiving an indefinite response from a decision maker to a question about preferences. The conventional treatment requires a single, definite response from the decision maker. This approach either assumes that response error is zero or accepts the final solution as only approximate, without knowing how approximate it might be. In this paper we examine the issue of indefinite responses, define it more precisely, and present a method for incorporating it into decision making. The method is adaptive in that it is iterative and interactive with the decision maker who, at each iteration, is provided with information regarding the potential advantage of answering more trade-off questions and/or answering questions more carefully to reduce response error. In contrast to other approaches that “force” rationality and decisiveness, we work with irrationality and indecisiveness on the part of the decision maker. The method is demonstrated for the case of concave, increasing value functions.  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