全文获取类型
收费全文 | 40865篇 |
免费 | 1650篇 |
国内免费 | 28篇 |
出版年
2020年 | 455篇 |
2019年 | 468篇 |
2018年 | 852篇 |
2017年 | 784篇 |
2016年 | 888篇 |
2015年 | 602篇 |
2014年 | 669篇 |
2013年 | 2807篇 |
2012年 | 1370篇 |
2011年 | 1489篇 |
2010年 | 720篇 |
2009年 | 783篇 |
2008年 | 1060篇 |
2007年 | 1033篇 |
2006年 | 942篇 |
2005年 | 2008篇 |
2004年 | 1381篇 |
2003年 | 1155篇 |
2002年 | 821篇 |
2001年 | 1418篇 |
2000年 | 1384篇 |
1999年 | 983篇 |
1998年 | 406篇 |
1997年 | 372篇 |
1993年 | 318篇 |
1992年 | 818篇 |
1991年 | 729篇 |
1990年 | 816篇 |
1989年 | 731篇 |
1988年 | 686篇 |
1987年 | 647篇 |
1986年 | 690篇 |
1985年 | 727篇 |
1984年 | 556篇 |
1983年 | 478篇 |
1982年 | 338篇 |
1979年 | 522篇 |
1978年 | 410篇 |
1977年 | 327篇 |
1976年 | 323篇 |
1975年 | 485篇 |
1974年 | 588篇 |
1973年 | 543篇 |
1972年 | 481篇 |
1971年 | 402篇 |
1970年 | 357篇 |
1969年 | 425篇 |
1968年 | 477篇 |
1967年 | 414篇 |
1966年 | 450篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Septum and behavior: a review 总被引:2,自引:0,他引:2
P A Fried 《Psychological bulletin》1972,78(4):292-310
942.
943.
944.
Developmental trends in letter-printing skill 总被引:1,自引:0,他引:1
945.
946.
Killeen P 《Journal of the experimental analysis of behavior》1972,18(1):13-22
Pigeons were exposed to alternative pairs of variable-interval schedules correlated with red and green lights on one key (the food key). In one experimental chamber, responses on a white key (the changeover key) changed the color of the food key and initiated a 2-sec changeover delay. Pigeons in a second chamber obtained food by pecking on a colored key whenever the pigeons in the first (concurrent) chamber had obtained food for a peck on that key color. There was no changeover key in the second (multiple) chamber: changeover responses in the first chamber alternated the schedules and colors in both chambers. The pigeons in both chambers emitted the same proportion of responses on each of the variable-interval schedules, and mastered discrimination reversals at the same rate. The pigeons differed only in their absolute response rates, which were greater under the concurrent schedules. In a second experiment, changes in key color occurred automatically, with different proportions of time allocated to the two variable-interval schedules. Matching of relative response frequency to relative reinforcement frequency was affected by the relative amounts of time in each component, by rate of changeovers, and by manipulations of the variable-interval scheduling. 相似文献
947.
Leander JD Milan MA Jasper KB Heaton KL 《Journal of the experimental analysis of behavior》1972,17(2):229-235
The vocal behavior of three Cebus monkeys was maintained by fixed-ratio schedules of response dependent reinforcement at values between fixed-ratio 1 and fixed-ratio 15. In one monkey that was exposed to variable-interval, fixed-interval, and conjunctive fixed-ratio fixed-interval schedules of reinforcement, vocal responding occurred at a low rate, but schedule-appropriate patterns were maintained. The rates and patterns of responding engendered indicated that the vocal operant can be brought under schedule control in the monkey by the use of response-dependent reinforcement. 相似文献
948.
949.
950.
Ronald P. Larkin 《Behavior research methods》1972,4(1):32-33
The Rockefeller University, New York, New York 10021 Events such as barpresses or licks, which may occur at any time during the day, are often clustered into bouts. The internal structure of such bouts can be recorded using an AM tape recorder, running the tape recorder only while bouts are in progress, and can later be analyzed off-line on a digital computer. 相似文献