全文获取类型
收费全文 | 520篇 |
免费 | 42篇 |
出版年
2022年 | 7篇 |
2021年 | 12篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 21篇 |
2014年 | 13篇 |
2013年 | 32篇 |
2012年 | 27篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 15篇 |
2008年 | 14篇 |
2007年 | 32篇 |
2006年 | 17篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 6篇 |
2000年 | 11篇 |
1999年 | 15篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 18篇 |
1986年 | 13篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1970年 | 4篇 |
1961年 | 3篇 |
排序方式: 共有562条查询结果,搜索用时 0 毫秒
551.
The naturalistic fallacy is mentionedfrequently by evolutionary psychologists as anerroneous way of thinking about the ethicalimplications of evolved behaviors. However,evolutionary psychologists are themselvesconfused about the naturalistic fallacy and useit inappropriately to forestall legitimateethical discussion. We briefly review what thenaturalistic fallacy is and why it is misusedby evolutionary psychologists. Then we attemptto show how the ethical implications of evolvedbehaviors can be discussed constructivelywithout impeding evolutionary psychologicalresearch. A key is to show how ethicalbehaviors, in addition to unethical behaviors,can evolve by natural selection. 相似文献
552.
553.
554.
555.
556.
557.
Jennifer L. Sloan & James F. Hare 《Ethology : formerly Zeitschrift fur Tierpsychologie》2008,114(5):436-443
Richardson’s ground squirrels (RGS) produce alarm calls that warn conspecifics of potential predators. We presented free‐living adult and juvenile RGS with playbacks of repetitive alarm calls from one vs. two juvenile callers broadcast sequentially through two spatially separated loudspeakers. Adult RGS spent a greater proportion of time vigilant in response to two vs. one calling squirrel, whereas juvenile RGS did not respond differentially to two vs. one caller. Apparently then, the relative inexperience of juvenile RGS with alarm calls and the context in which such calls are emitted precludes their enumeration of alarm callers. Taken together with our earlier finding that adult but not juvenile RGS ignore information regarding response urgency encoded in the rate of juvenile produced repetitive calls, our present results suggest a developmental shift in response‐urgency perception. Adult RGS selectively extract information regarding response urgency via discrimination of the number of callers, ignoring less reliable information encoded in the rate of repetitive calls issued by inexperienced juvenile signallers. 相似文献
558.
559.
L Jamieson D Stribling N J Rothwell M J Stock 《Canadian journal of physiology and pharmacology》1984,62(1):136-141
Metabolic rate and tissue blood flow were measured by indirect calorimetry and the radioactive microsphere technique, respectively, in anaesthetized pigs aged 10, 17, and 28 days during infusions of saline or noradrenaline. Noradrenaline produced a rise in oxygen consumption in all pigs but the magnitude of the response declined with age in Large White pigs (percent increase: 10 days old, 29.5 +/- 3.3; 17 days old, 15.3 +/- 3.2; 28 days old, 5.4 +/- 0.17) and was less in 10-day-old Minipigs (9.1 +/- 5.1). Regional blood flow per gram of tissue was similar for pigs of all ages and noradrenaline produced increases in flow to heart and skin, and small reductions in blood flow to skeletal muscle. Noradrenaline increased average blood flow to adipose tissue (four sites) by 21-fold in 10-day-old Large White pigs, but had less effect in 10-day-old Minipigs (9.5-fold) and in older Large White pigs (9-fold), where the effect on metabolic rate was diminished. It is calculated that adipose tissue could be responsible for the increase in metabolic rate during infusion of noradrenaline. Macroscopically there are no gross differences between various adipose tissue depots in the pig but those which showed the greatest response to noradrenaline correspond to areas where brown adipocytes have previously been identified by electron microscopy. 相似文献
560.