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   2250篇
  免费   113篇
  国内免费   1篇
  2023年   16篇
  2021年   18篇
  2020年   34篇
  2019年   43篇
  2018年   50篇
  2017年   67篇
  2016年   76篇
  2015年   58篇
  2014年   65篇
  2013年   263篇
  2012年   113篇
  2011年   129篇
  2010年   78篇
  2009年   82篇
  2008年   98篇
  2007年   107篇
  2006年   94篇
  2005年   83篇
  2004年   68篇
  2003年   57篇
  2002年   59篇
  2001年   33篇
  2000年   27篇
  1999年   46篇
  1998年   32篇
  1997年   29篇
  1996年   34篇
  1995年   22篇
  1994年   29篇
  1993年   15篇
  1992年   19篇
  1991年   23篇
  1990年   19篇
  1989年   20篇
  1988年   18篇
  1987年   16篇
  1986年   24篇
  1985年   18篇
  1984年   13篇
  1983年   30篇
  1982年   14篇
  1981年   20篇
  1980年   22篇
  1979年   15篇
  1978年   15篇
  1977年   26篇
  1976年   14篇
  1975年   17篇
  1974年   25篇
  1973年   15篇
排序方式: 共有2364条查询结果,搜索用时 15 毫秒
11.
Chris Mortensen 《Erkenntnis》1989,30(3):319-337
This paper criticises necessitarianism, the thesis that there is at least one necessary truth; and defends possibilism, the thesis that all propositions are contingent, or that anything is possible. The second section maintains that no good conventionalist account of necessity is available, while the third section criticises model theoretic necessitarianism. The fourth section sketches some recent technical work on nonclassical logic, with the aim of weakening necessitarian intuitions and strengthening possibilist intuitions. The fifth section considers several a prioristic attempts at demonstrating that there is at least one necessary proposition and finds them inadequate. The final section emphasises the epistemic aspect of possibilism.  相似文献   
12.
Based on results of an experiment, hypotheses are tested concerning the effects of computer use on decision commitment. The experiment required subjects to make an adoption decision regarding a hypothetical government agency's innovation. Subjects could choose from a variety of information sets, some computer based, some not, before making the decision. After their decision the subjects were given “new evidence” that contradicted their initial position. Two experimental treatments included more difficult access to the computer-based information and higher cost for the computer-based information. Results indicate that access difficulty diminishes confidence in decisions and leads to lesser commitment. However, the cost of the computer information seems to have little bearing on decision commitment. Barry Bozeman is director of the Technology and Information Policy Program of the Maxwell School of Public Affairs, Syracuse University, Syracuse NY 13244-4010. There he is professor of public policy and administration and affiliate professor of engineering. His research has focused on organization theory and public management, science and technology policy, and the use of technical information in decision-making. R.F. Shangraw, Jr. is vice president of Independent Project Analysis, Inc., Great Falls, Virginia. Previously, he was assistant professor of public administration at Syracuse University. His research interests include information management, decision-making, and public policy applications of expert systems.  相似文献   
13.
The problems caused for the NBTS by the advent of HIV are reviewed, with particular reference to the impact on blood donor numbers, the strategies adopted to minimise the risk of HIV infection through blood transfusion, and the counselling dilemmas faced by the Service in the setting of the blood donor clinic. The notification procedure for blood donors found anti-HIV positive is described, with the importance of confirmation of such results before approach to the donor emphasised. Counselling issues arising from indeterminate and false positive lest results are explored and those arising from enquiries generated by cases of possible post-transfusion HIV infection are examined.  相似文献   
14.
15.
16.
One of the most puzzling features of “hyperactivity” in children is the importance of activity itself. Generalized overactivity has not been found to be a valid diagnostic marker. Could some qualitative features of activity be important determinants of the perceived quantity of activity? The analogue study reported here derives from a social-psychological hypothesis that anything that makes a behavior more noticeable or distracting can create an illusion of increased movement. Subjects performed a simple cognitive task while watching short films of adult actors. Two variables were manipulated: (a) The sound level was either loud or quiet, and (b) instructions to subjects were varied so that the behaviors shown were perceived as either appropriate or inappropriate. Results strongly supported the hypothesis. Loudness and contextual inappropriateness made the films more distracting, produced higher ratings of the amount of movement observed, and led to more negative evaluations of the behaviors seen. Implications for assessment and intervention are discussed.  相似文献   
17.
18.
Two studies were conducted to investigate the effects of perceived control in two men's prisons, one housing 181 inmates and the other housing 623 inmates. In both prisons, inmates' perceived control over the environment was found to be significantly related to their ratings of their living accommodations, experienced stress, and physical symptoms, even when type of cell was held constant.  相似文献   
19.
Previous research has shown that when pigeons are required to peck each of two keys four times in any order for reinforcement, stereotyped response sequences develop, though they are not required by the task. However, despite this stereotypy, sequences are not automatized. They require sufficient attention that sequence performance is disrupted by a concurrent, delayed matching-to-sample task. In the present experiments, pigeons were required to execute response sequences and delayed matching-to-sample concurrently. Experiment 1 showed that the matching task disrupts sequence performance even when the matching sample stimuli do not have to be processed concurrently with sequence execution. The presence of sample stimuli during sequence execution seems to command attention even if the sample stimuli are also available for processing when sequences are not being executed. Experiment 2 used the directed forgetting technique to show that pigeons do seem able to ignore sample stimuli if they are given information that tells them they will not be required to remember those stimuli later. Together, the experiments suggest attentional mechanisms in the pigeon that are not quite involuntary.  相似文献   
20.
Though the term “new technology” is widely used and discussed, there has been very little systematic study of attitudes to technology and their relation to other beliefs and group memberships. This article describes an initial investigation into the nature of attitudes towards new technology (n=534 undergraduates) and demonstrates that, as yet, these attitudes are only weakly structured and are not fully integrated with other social beliefs. General evaluations of the benefits of technological advance appear to be almost unrelated to beliefs about the inevitability of these advances or the desire to acquire training to deal with them. Contrary to popular expectations, evaluations of video games are unrelated to other beliefs about technology while other social beliefs are, as yet, only weakly integrated with these attitudes. This study also identifies gender differences in the assessment of potential benefits and highlights other differences attributable to academic group memberships. These finding are discussed with reference to the literature on sex-role stereotyping and group socialization processes.  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