全文获取类型
收费全文 | 6876篇 |
免费 | 151篇 |
国内免费 | 54篇 |
出版年
2018年 | 16篇 |
2012年 | 625篇 |
2011年 | 729篇 |
2010年 | 186篇 |
2009年 | 84篇 |
2008年 | 559篇 |
2007年 | 624篇 |
2006年 | 516篇 |
2005年 | 459篇 |
2004年 | 426篇 |
2003年 | 457篇 |
2002年 | 356篇 |
2001年 | 246篇 |
2000年 | 305篇 |
1999年 | 153篇 |
1998年 | 44篇 |
1997年 | 34篇 |
1996年 | 33篇 |
1995年 | 34篇 |
1994年 | 37篇 |
1993年 | 27篇 |
1992年 | 40篇 |
1991年 | 47篇 |
1990年 | 41篇 |
1989年 | 45篇 |
1988年 | 46篇 |
1987年 | 41篇 |
1986年 | 31篇 |
1985年 | 39篇 |
1984年 | 27篇 |
1983年 | 45篇 |
1982年 | 35篇 |
1981年 | 32篇 |
1980年 | 15篇 |
1978年 | 24篇 |
1976年 | 18篇 |
1965年 | 27篇 |
1964年 | 14篇 |
1963年 | 20篇 |
1959年 | 19篇 |
1958年 | 61篇 |
1957年 | 53篇 |
1956年 | 48篇 |
1955年 | 37篇 |
1954年 | 34篇 |
1953年 | 28篇 |
1952年 | 27篇 |
1951年 | 27篇 |
1950年 | 24篇 |
1949年 | 14篇 |
排序方式: 共有7081条查询结果,搜索用时 109 毫秒
81.
82.
83.
84.
85.
禁地,亦即指由于地形原因而不可进入的地区,尤其是指出于政治、宗教或其他动机而作出的决策所禁止入内的区域(场所、城市、国家)。禁地往往蒙上了一种神秘的气氛.几乎必然会引起人们的好奇。到达拉萨曾是几代探险家的梦想。这一地区不仅对外人封闭,而且对“内部人”也封闭:任何人不得离开“外出”。德川幕府对日本实行的隔绝就是这样一种双向隔离。当然.地理条件也有助于这种隔离,因而使之轻易地付诸实行。有人指出(或许这种说法不够严肃).举世闻名的中国长城不仅意味着防范匈奴入侵,更意味着防止中国人逃离。史料也表明中国过… 相似文献
86.
A series of studies investigated the capacity of children between the ages of 7 and 12 to give free and informed consent to participation in psychological research. Children were reasonably accurate in describing the purpose of studies, but many did not understand the possible benefits or especially the possible risks of participating. In several studies children's consent was not affected by the knowledge that their parents had given their permission or by the parents saying that they would not be upset if the children refused. In contrast, other studies found that children were much more likely to stop their participation if the experimenter said explicitly that she would not be upset if they stopped. We suggest that experimenters should pay more attention to describing the possible risks and benefits of participation in research, and that they should also make it clearer to children that they are free to stop once they have begun. 相似文献
87.
Hull R 《The Journal of medical humanities》1995,16(2):93-103
As I have suggested, from the perspective of distributive justice MinnesotaCare's reforms are inadequate. But to coin (and alter slightly) a phrase of Kant's, if its authors do not deserve our moral esteem, perhaps they do merit our encouragement, and it is on a note of the latter that I will conclude. MinnesotaCare is an experiment in systemic incremental change being performed in a complex health care system, the only true laboratory for such an experiment. For this reason, it will provide us important information concerning the ethics, economics, [and] the politics of health care reform while improving the position of some Minnesotans in a significant way. Thus, while MinnesotaCare is susceptible to forceful moral criticism, as an experiment in reform it holds out the promise of providing us some of the data necessary for discovering a just solution. 相似文献
88.
89.
90.