全文获取类型
收费全文 | 172160篇 |
免费 | 7788篇 |
国内免费 | 155篇 |
出版年
2021年 | 1498篇 |
2020年 | 2766篇 |
2019年 | 3428篇 |
2018年 | 3517篇 |
2017年 | 3932篇 |
2016年 | 4596篇 |
2015年 | 3911篇 |
2014年 | 4783篇 |
2013年 | 23372篇 |
2012年 | 4558篇 |
2011年 | 3631篇 |
2010年 | 3847篇 |
2009年 | 4748篇 |
2008年 | 3843篇 |
2007年 | 3359篇 |
2006年 | 3967篇 |
2005年 | 3930篇 |
2004年 | 3451篇 |
2003年 | 3079篇 |
2002年 | 2879篇 |
2001年 | 3345篇 |
2000年 | 3214篇 |
1999年 | 3190篇 |
1998年 | 2809篇 |
1997年 | 2644篇 |
1996年 | 2570篇 |
1995年 | 2418篇 |
1994年 | 2373篇 |
1993年 | 2337篇 |
1992年 | 2619篇 |
1991年 | 2475篇 |
1990年 | 2288篇 |
1989年 | 2240篇 |
1988年 | 2201篇 |
1987年 | 2181篇 |
1986年 | 2148篇 |
1985年 | 2402篇 |
1984年 | 2504篇 |
1983年 | 2295篇 |
1982年 | 2363篇 |
1981年 | 2322篇 |
1980年 | 2171篇 |
1979年 | 2203篇 |
1978年 | 2147篇 |
1977年 | 2135篇 |
1976年 | 1946篇 |
1975年 | 1970篇 |
1974年 | 2058篇 |
1973年 | 1907篇 |
1972年 | 1533篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.
Sara J. Shettleworth 《The Quarterly Journal of Experimental Psychology Section B: Comparative and Physiological Psychology》1981,33(4):241-255
Are different responses differentially associable with their consequences? An overshadowing design was used to try to answer this question for three responses previously studied in golden hamsters. In Experiment I, scrabbling was rapidly suppressed by electric shock punishment, and it overshadowed a tone which occurred between scrabbling and shock. In Experiment II, no evidence of response-shock association was obtained when open rearing was the punished response, and open rearing did not overshadow the tone. Punishment had some effect on face washing, but there was no statistically significant overshadowing with this response. These results are consistent with the idea that differences in punishment suppression among these three responses have an associative basis. They also demonstrate the usefulness of a novel paradigm for studying “preparedness” of response-reinforcer associations. 相似文献
183.
184.
185.
186.
187.
Gavin N. Rackoff Daniel W. Lagoni Mia F. Shoshany Nasreen A. Moursi Laura Hennefield 《The British journal of developmental psychology》2022,40(1):170-186
By roughly 6 years of age, children acquire the stereotype that men are more competent than women in science, technology, engineering, and mathematics (STEM), potentially leading to greater trust in scientific information provided by men. This study tested whether 3- to 8-year-old children differentially endorsed conflicting information about science and toys presented by male and female informants depicted as a ‘man’ and ‘woman’ (Exp1) or ‘scientists’ (Exp2). Children were expected to endorse toy testimony from gender-matched informants; thus, the key question concerned endorsement of science testimony. In Exp1 (N = 149), boys and girls showed a same-gender informant preference for toy testimony; however, girls endorsed the male informant's testimony more for science than for toys – but only when tested by a male experimenter. In Exp2 (N = 264), boys and girls showed a same-gender preference, irrespective of content. Findings suggest that STEM-related gender stereotypes might lead girls to trust scientific information presented by men over women in certain contexts. 相似文献
188.
An electronic apparatus using infrared beams for monitoring the movements of individual bees under dark conditions is described. The searching behavior of workers in an arena was monitored over 2-h periods. Mean ambulatory velocity for one bee over a distance of 100 mm was 45.6±1.51 mm/sec (n=45). Thigmokinesis and temporal activity patterns are illustrated. 相似文献
189.
190.