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   75945篇
  免费   2801篇
  国内免费   40篇
  2020年   782篇
  2019年   932篇
  2018年   2452篇
  2017年   2292篇
  2016年   2089篇
  2015年   969篇
  2014年   1202篇
  2013年   5762篇
  2012年   2325篇
  2011年   3141篇
  2010年   2219篇
  2009年   1858篇
  2008年   2694篇
  2007年   2858篇
  2006年   1844篇
  2005年   1756篇
  2004年   1662篇
  2003年   1538篇
  2002年   1530篇
  2001年   2311篇
  2000年   2236篇
  1999年   1699篇
  1998年   864篇
  1997年   744篇
  1996年   680篇
  1995年   667篇
  1994年   633篇
  1993年   670篇
  1992年   1368篇
  1991年   1279篇
  1990年   1293篇
  1989年   1156篇
  1988年   1096篇
  1987年   1075篇
  1986年   1097篇
  1985年   1201篇
  1984年   931篇
  1983年   817篇
  1982年   660篇
  1979年   929篇
  1978年   703篇
  1975年   830篇
  1974年   908篇
  1973年   894篇
  1972年   756篇
  1971年   679篇
  1969年   631篇
  1968年   789篇
  1967年   753篇
  1966年   714篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
Although perceived health risk plays a prominent role in theories of health behavior, its empirical role in risk taking is less clear. In Study 1 (N = 129), 2 measures of drivers' risk-taking behavior were found to be unrelated to self-estimates of accident concern but to be related to self-ratings of driving skill and the perceived thrill of driving. In Study 2 (N = 405), out of a wide range of potential influences, accident concern had the weakest relationship with risk taking. The authors concluded that although health risk is a key feature in many theories of health behavior and a central focus for researchers and policy makers, it may not be such a prominent factor for those actually taking the risk.  相似文献   
54.
55.
56.
To understand how individuals adapt to and anticipate each other in joint tasks, we employ a bidirectional delay–coupled dynamical system that allows for mutual adaptation and anticipation. In delay–coupled systems, anticipation is achieved when one system compares its own time‐delayed behavior, which implicitly includes past information about the other system’s behavior, with the other system’s instantaneous behavior. Applied to joint music performance, the model allows each system to adapt its behavior to the dynamics of the other. Model predictions of asynchrony between two simultaneously produced musical voices were compared with duet pianists’ behavior; each partner performed one voice while auditory feedback perturbations occurred at unpredictable times during live performance. As the model predicted, when auditory feedback from one musical voice was removed, the asynchrony changed: The pianist’s voice that was removed anticipated (preceded) the actions of their partner. When the auditory feedback returned and both musicians could hear each other, they rapidly returned to baseline levels of asynchrony. To understand how the pianists anticipated each other, their performances were fitted by the model to examine change in model parameters (coupling strength, time‐delay). When auditory feedback for one or both voices was removed, the fits showed the expected decrease in coupling strength and time‐delay between the systems. When feedback about the voice(s) returned, the coupling strength and time‐delay returned to baseline. These findings support the idea that when people perform actions together, they do so as a coupled bidirectional anticipatory system.  相似文献   
57.
Do the conditions under which promises are made determine whether they ought to be kept? Philosophers have placed a number of conditions on promising which, they hold, must be met in order to make promise-keeping obligatory. In so doing, they have distinguished valid promises from invalid promises and justified promises from promises that are not justified. Considering such conditions, one by one, we argue that they are mistaken. In the first place, the conditions they lay down are not necessary for either valid or justified promise-making. In the second place, promises need not meet such conditions in order to create moral obligations. In general, such analyses of promising fail because they suffer from a confusion between promise-making and promise-keeping. Philosophers have wrongly supposed that obligations to keep promises are dependent upon, or derivable from, the quality of the promises themselves, at the time they are made, instead of focusing on conditions that must be satisfied at the time when promises are supposed to be kept. It is not the quality of a promise that determines an obligation to keep it but the rightness or wrongness of performing the promised act.  相似文献   
58.
59.
60.
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