全文获取类型
收费全文 | 454篇 |
免费 | 14篇 |
出版年
2020年 | 5篇 |
2018年 | 9篇 |
2016年 | 10篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 61篇 |
2012年 | 12篇 |
2011年 | 16篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 8篇 |
2006年 | 13篇 |
2005年 | 16篇 |
2004年 | 15篇 |
2003年 | 19篇 |
2002年 | 10篇 |
2001年 | 17篇 |
2000年 | 13篇 |
1999年 | 9篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1971年 | 9篇 |
1970年 | 5篇 |
1969年 | 5篇 |
1968年 | 7篇 |
1967年 | 5篇 |
1966年 | 8篇 |
1965年 | 4篇 |
排序方式: 共有468条查询结果,搜索用时 15 毫秒
441.
442.
443.
444.
445.
446.
447.
448.
In previous studies of saccadic targeting, the issue how visually guided saccades to unambiguous targets are programmed and executed has been examined. These studies have found different degrees of guidance for saccades depending on the task and task difficulty. In this study, we use ideal-observer analysis to estimate the visual information used for the first saccade during a search for a target disk in noise. We quantitatively compare the performance of the first saccadic decision to that of the ideal observer (ie absolute efficiency of the first saccade) and to that of the associated final perceptual decision at the end of the search (ie relative efficiency of the first saccade). Our results show, first, that at all levels of salience tested, the first saccade is based on visual information from the stimulus display, and its highest absolute efficiency is approximately 20%. Second, the efficiency of the first saccade is lower than that of the final perceptual decision after active search (with eye movements) and has a minimum relative efficiency of 19% at the lowest level of saliency investigated. Third, we found that requiring observers to maintain central fixation (no saccades allowed) decreased the absolute efficiency of their perceptual decision by up to a factor of two, but that the magnitude of this effect depended on target salience. Our results demonstrate that ideal-observer analysis can be extended to measure the visual information mediating saccadic target-selection decisions during visual search, which enables direct comparison of saccadic and perceptual efficiencies. 相似文献
449.
450.
Ronald H. Stone 《Dialog》2020,59(3):181-183
The essay celebrates the “Mirror of Princes” writing of political philosophy that appeared in Augustine's City of God, the history of Western political philosophy and in the political thought of ancient China. It upholds the tradition of the good ruler while noting the ambiguities of morality in politics. It notes the political power of the American president in the current global context. While emphasizing the need for the good ruler to love the people he serves it focuses on the need for reform in health care, education, and race relations. 相似文献