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   510篇
  免费   11篇
管理学   72篇
民族学   1篇
人口学   43篇
丛书文集   2篇
理论方法论   63篇
综合类   3篇
社会学   285篇
统计学   52篇
  2023年   6篇
  2021年   7篇
  2020年   10篇
  2019年   13篇
  2018年   9篇
  2017年   7篇
  2016年   8篇
  2015年   10篇
  2014年   11篇
  2013年   63篇
  2012年   21篇
  2011年   17篇
  2010年   16篇
  2009年   12篇
  2008年   9篇
  2007年   20篇
  2006年   16篇
  2005年   23篇
  2004年   11篇
  2003年   13篇
  2002年   4篇
  2001年   13篇
  2000年   14篇
  1999年   7篇
  1998年   4篇
  1997年   9篇
  1996年   11篇
  1995年   6篇
  1994年   10篇
  1993年   6篇
  1992年   9篇
  1991年   15篇
  1989年   5篇
  1988年   5篇
  1987年   9篇
  1986年   8篇
  1985年   4篇
  1984年   6篇
  1983年   7篇
  1982年   4篇
  1981年   6篇
  1980年   8篇
  1978年   7篇
  1977年   3篇
  1976年   5篇
  1975年   5篇
  1974年   7篇
  1972年   5篇
  1971年   3篇
  1967年   2篇
排序方式: 共有521条查询结果,搜索用时 15 毫秒
131.
132.
133.
Editorial     
The Analysis of Verbal Behavior -  相似文献   
134.
Binge drinking and alcohol-related problems among students at traditional 4-year universities have been well documented. However, little is known about the frequency of their such behaviors and its consequences among community college students, who comprise roughly 44% of all undergraduate students in the United States. The present study examined binge drinking and alcohol-related problems in 762 (61% female) ethnically diverse (65% Caucasian, 20% Hispanic, 9% African American) community college students (mean age = 26.23, SD = 7.81). Based on gender-specific criteria, 25% engaged in binge drinking. As compared to nonbingers and current abstainers, bingers had higher rates of drinking-related problems. The implications of these findings for research and for prevention/intervention programs are discussed.  相似文献   
135.
According to Skinner''s (1957) analysis of verbal behavior, the mand and the tact are functionally independent verbal operants, each of which is acquired through a unique history of reinforcement. The present study attempted to replicate the findings of Lamarre and Holland (1985), who empirically demonstrated functional independence of mands and tacts in typically developing preschool children. Five children participated. All were initially trained to complete two 4-piece assembly tasks. Four children were then trained to tact the four pieces that comprised one of the assembly tasks, and to mand for the four pieces that comprised the other task, using arbitrary vocal response forms. The remaining child received tact training only, and only on one task. The effects of training on the untrained operant were evaluated in a multiple-probe design across tasks. Following mand training, 4 out of 4 children reliably emitted tacts under testing conditions, while the effects of tact training differed across participants. The results differ from those of Lamarre and Holland, but are not necessarily surprising from the point of view of either Skinner''s analysis or more recent behavioral accounts of language. Future research should attempt to identify variables that affect transfer between mand and tact relations.  相似文献   
136.
137.
138.
Jack A Fuller 《Omega》1978,6(6):479-484
The portion of business problems which lend themselves to solution by existing optimization techniques are a minor subset of the business problems which can be defined and attacked by logical devices. Heuristics simplify the environment of the decision maker by permitting him to make decisions quickly without considering the innumerable ways that each decision could be made. This paper compares the heuristic programming approach to more traditional operations research techniques of decision making.  相似文献   
139.
This Issue Brief develops a model that project the proportion of an individual's preretirement income that might be replaced by 401(k) plan accumulations at retirement, under several different projected scenarios. The 401(k) participant behaviors in the model are based on the year-end 2000 database collected by the Employee Benefit Research Institute (EBRI) and the Investment Company Institute (ICI) in their collaborative effort known as the EBRI/ICI Participant-Directed Retirement Plan Data Collection Project. The most significant factor affecting projected replacement rates at retirement is having access to a 401(k) plan. Projected replacement rates from 401(k) accumulations at retirement are reduced significantly when participants are not offered a 401(k) plan in all portions of their careers. Most 401(k) participants tend to have contributions in any given year. Thus, projecting that participants always have contributions (their own and/or employer contributions) every year raises projected replacement rates, but not by much compared with the importance of being offered a plan to begin with. The model simulations show that participant activities such as taking loans, taking preretirement withdrawals, or cashing out account balances at job change reduce projected 401(k) accumulations and thus replacement rates at age 65. Because loans are forecast to be paid back to the account in full, their effect on replacement rates at retirement in the model is the smallest. Even if equity returns in the future are projected to replicate the worst 50-year segment in the Standard & Poor's (S&P) 500 history (1929 to 1978), 401(k) accumulations are still projected to replace significant proportions of projected preretirement income. Another projection scenario forecasts participants experiencing a simulated three-year bear market (negative equity returns) either early in their careers, near the middle of their careers, or at the end of their careers. Forecasts of the effects of bear markets on 401(k) balances show that a bear market in equities is projected to have the largest effect the closer it occurs to age 65 (retirement), even though older participants typically have diversified their portfolios away from equities. A three-year bear market for those early in their careers would reduce median replacement rates from 401(k) accumulations by an estimated 2.9-3.7 percentage points, compared with 13.4-17.7 percentage points for those immediately before retirement. Similarly, a simulated three-year bull market (positive equity returns) is projected to have a larger positive effect on projected account balances and replacement rates the closer it occurs to retirement.  相似文献   
140.
Safety Risk Analysis of an Innovative Environmental Technology   总被引:1,自引:0,他引:1  
The authors describe a decision and risk analysis performed for the cleanup of a large Department of Energy mixed-waste subsurface disposal area governed by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). In a previous study, the authors worked with the site decision makers, state regulators, and U.S. Environmental Protection Agency regional regulators to develop a CERCLA-based multiobjective decision analysis value model and used the model to perform a screening analysis of 28 remedial alternatives. The analysis results identified an innovative technology, in situ vitrification, with high effectiveness versus cost. Since this technology had not been used on this scale before, the major uncertainties were contaminant migration and pressure buildup. Pressure buildup was a safety concern due to the potential risks to worker safety. With the help of environmental technology experts remedial alternative changes were identified to mitigate the concerns about contaminant migration and pressure buildup. The analysis results showed that the probability of an event with a risk to worker safety had been significantly reduced. Based on these results, site decision makers have refocused their test program to examine in situ vitrification and have continued the use of the CERCLA-based decision analysis methodology to analyze remedial alternatives.  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