全文获取类型
收费全文 | 46206篇 |
免费 | 1905篇 |
国内免费 | 32篇 |
专业分类
48143篇 |
出版年
2020年 | 498篇 |
2019年 | 627篇 |
2018年 | 875篇 |
2017年 | 925篇 |
2016年 | 894篇 |
2015年 | 669篇 |
2014年 | 764篇 |
2013年 | 3589篇 |
2012年 | 1366篇 |
2011年 | 1535篇 |
2010年 | 961篇 |
2009年 | 924篇 |
2008年 | 1287篇 |
2007年 | 1208篇 |
2006年 | 1107篇 |
2005年 | 940篇 |
2004年 | 884篇 |
2003年 | 911篇 |
2002年 | 874篇 |
2001年 | 1736篇 |
2000年 | 1696篇 |
1999年 | 1196篇 |
1998年 | 524篇 |
1997年 | 452篇 |
1996年 | 419篇 |
1992年 | 1004篇 |
1991年 | 959篇 |
1990年 | 941篇 |
1989年 | 891篇 |
1988年 | 838篇 |
1987年 | 809篇 |
1986年 | 800篇 |
1985年 | 855篇 |
1984年 | 673篇 |
1983年 | 547篇 |
1981年 | 413篇 |
1979年 | 625篇 |
1978年 | 481篇 |
1977年 | 443篇 |
1976年 | 418篇 |
1975年 | 575篇 |
1974年 | 633篇 |
1973年 | 645篇 |
1972年 | 565篇 |
1971年 | 469篇 |
1970年 | 438篇 |
1969年 | 505篇 |
1968年 | 565篇 |
1967年 | 478篇 |
1966年 | 554篇 |
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
981.
Miller LK 《Journal of the experimental analysis of behavior》1970,13(2):215-220
The present experiment explored the punishing effect of different response-force requirements by means of a two-operant design analogous to a two-component chain schedule. The first component of the chain required a lever pull through 0.25 in. (0.64 cm) at 1 lb (4.45 N) of force. The second component required a lever pull through an additional 0.75 in. (1.90 cm) with the force varied between sessions from 1 lb to 50 lb (4.45 N to 223 N). Completion of the second component of the chain was reinforced after variable intervals averaging 1 min. The average rate of first-component response decreased as the force requirement for second-component responses was increased. This rate reduction did not appear to be due to increased response duration, “fatigue”, or differing rates of reinforcement. If the force requirement for the second-component response is viewed as a consequence for the first-component response, then the results of the experiment show that a high force requirement is a punisher. 相似文献
982.
983.
A Mitscherlich A Lorenzer K Horn H Dahmer E Schwanenberg K Brede H Berndt 《Psyche》1970,24(3):157-187
984.
985.
986.
987.
988.
For a joint family story-telling task, families with a schizophrenic offspring were compared to normal families on the completeness and clarity of the final composite stories and on their interactional behavior. The composite stories from schizogenic families were more “vague and confused”, fragmented, and less complete as to the five components required to satisfy the task instructions. Schizogenic families displayed more conflict, failure, and confusion during the interactional task than control families, and, fathers and mothers of schizophrenic offspring displayed more “anxiety and tension”, “depressive mood”, “evasiveness” and “lack of interest” than fathers and mothers of normal families. Mothers of schizophrenic offspring were also described as more “hostile” than control mothers. Comparing schizogenic families from which the patient was absent during the task with schizogenic families with the patient present, and with control families, indicated that the central findings were not attributable to the immediate presence and participation of the schizophrenic member. 相似文献
989.
Effect of repetitive infant-infant separation of young monkeys 总被引:1,自引:0,他引:1
990.