全文获取类型
收费全文 | 63071篇 |
免费 | 2491篇 |
国内免费 | 34篇 |
专业分类
65596篇 |
出版年
2019年 | 759篇 |
2018年 | 1094篇 |
2017年 | 1006篇 |
2016年 | 1177篇 |
2015年 | 802篇 |
2014年 | 991篇 |
2013年 | 5578篇 |
2012年 | 1771篇 |
2011年 | 1789篇 |
2010年 | 1108篇 |
2009年 | 1145篇 |
2008年 | 1616篇 |
2007年 | 1556篇 |
2006年 | 1412篇 |
2005年 | 1199篇 |
2004年 | 1175篇 |
2003年 | 1151篇 |
2002年 | 1133篇 |
2001年 | 2012篇 |
2000年 | 1962篇 |
1999年 | 1470篇 |
1998年 | 659篇 |
1996年 | 714篇 |
1995年 | 723篇 |
1994年 | 679篇 |
1993年 | 670篇 |
1992年 | 1376篇 |
1991年 | 1268篇 |
1990年 | 1247篇 |
1989年 | 1142篇 |
1988年 | 1130篇 |
1987年 | 1075篇 |
1986年 | 1072篇 |
1985年 | 1119篇 |
1984年 | 966篇 |
1983年 | 829篇 |
1982年 | 661篇 |
1979年 | 960篇 |
1978年 | 705篇 |
1976年 | 662篇 |
1975年 | 835篇 |
1974年 | 893篇 |
1973年 | 969篇 |
1972年 | 889篇 |
1971年 | 789篇 |
1970年 | 696篇 |
1969年 | 701篇 |
1968年 | 871篇 |
1967年 | 770篇 |
1966年 | 740篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
The operant conditioning of response variability: Free-operant versus discrete-response procedures 总被引:2,自引:2,他引:0 下载免费PDF全文
Morris CJ 《Journal of the experimental analysis of behavior》1987,47(3):273-277
The operant conditioning of response variability under free-operant and discrete-response procedures was investigated. Two pigeons received food only if their pattern of four pecks on two response keys differed from the patterns emitted on the two immediately preceding trials. Under the free-operant procedure, the keys remained illuminated and operative throughout each trial. There was little variability in the response patterns that resulted, and the pigeons received fewer than one third of the available reinforcers. Under the discrete-response procedure, a brief timeout period followed each response. Variability increased under this procedure, and the pigeons obtained three fourths of the available reinforcers. Previous successes and failures to produce response variability may have been due to the use or failure to use, respectively, a discrete-response procedure. Respondent effects inherent in the free-operant procedure may encourage the development of response stereotypy and, in turn, prevent the development of response variability. 相似文献
952.
A within-subjects comparison was made of pigeons' performance on two temporal discrimination procedures that were signaled by differently colored keylight samples. During stimulus trials, a peck on the key displaying a slanted line was reinforced following short keylight samples, and a peck on the key displaying a horizontal line was reinforced following long keylight samples, regardless of the location of the stimuli on those two choice keys. During position trials, a peck on the left key was reinforced following short keylight samples and a peck on the right key was reinforced following long keylight samples, regardless of which line stimulus appeared on the correct key. Thus, on stimulus trials, the correct choice key could not be discriminated prior to the presentation of the test stimuli, whereas on position trials, the correct choice key could be discriminated during the presentation of the sample stimulus. During Phase 1, with a 0-s delay between sample and choice stimuli, discrimination learning was faster on position trials than on stimulus trials for all 4 birds. During Phase 2, 0-, 0.5-, and 1.0-s delays produced differential loss of stimulus control under the two tasks for 2 birds. Response patterns during the delay intervals provided some evidence for differential mediation of the two delayed discriminations. These between-task differences suggest that the same processes may not mediate performance in each. 相似文献
953.
Two persons responded in the same session in separate cubicles, but under a single schedule of reinforcement. Each time reinforcement was programmed, only the first response to occur, that is, the response of only one of the subjects, was reinforced. “Competitive” behavior that developed under these conditions was examined in three experiments. In Experiment 1 subjects responded under fixed-interval (FI) 30-s, 60-s, and 90-s schedules of reinforcement. Under the competition condition, relative to baseline conditions, the response rates were higher and the pattern was “break-and-run.” In Experiment 2, subjects were exposed first to a conventional FI schedule and then to an FI competition schedule. Next, they were trained to respond under either a differential-reinforcement-of-low-rate (DRL) or fixed-ratio (FR) schedule, and finally, the initial FI competition condition was reinstated. In this second exposure to the FI competition procedure, DRL subjects responded at lower rates than were emitted during the initial exposure to that condition and FR subjects responded at higher rates. For all subjects, however, responding gradually returned to the break-and-run pattern that had occurred during the first FI competition condition. Experiment 3 assessed potential variables contributing to the effects of the competitive FI contingencies during Experiments 1 and 2. Subjects were exposed to FI schedules where (a) probability of reinforcement at completion of each fixed interval was varied, or (b) a limited hold was in effect for reinforcement. Only under the limited hold was responding similar to that observed in previous experiments. 相似文献
954.
Richard C. Erickson Ph.D. 《Pastoral Psychology》1987,35(3):163-171
The psychology of self-esteem bypasses consequential issues of everyday behavior and moral responsibility in favor of pursuing a global goal of enhanced self-esteem on the assumption that happiness, success, and responsible behavior will automatically follow. The goal is vague and ways of achieving it are confused and conflicting. Greater attention to concrete tasks and challenges and sensitivity to moral issues could help make therapy more clear, effective, and socially useful. 相似文献
955.
Paul G. Schurman Th.D. 《Pastoral Psychology》1987,35(3):189-199
This article on Liberation approaches the subject from the perspective ofmen. Women have taken the lead in trying to throw off the bondage of patriarchy. Men have, for the most part, been reactors to the evolving changes. The author feels that there is a more creative role for men to play, but first, we must become more conscious of the ways in which our privileged position oppresses us. The author documents this dynamic as well as points to some possible directions for men to move in their personal and professional lives. The priority on developing collegiality and inclusiveness in our professional associations gives this subject an important place in our thinking and decisionmaking.This paper was read at a workshop on male liberation at the National A.A.P.C. Convention in San Antonio, April 30,1982. 相似文献
956.
McIntire KD Cleary J Thompson T 《Journal of the experimental analysis of behavior》1987,47(3):279-285
Two cynomolgous macaques categorized six colors into two groups of three after conditional discrimination training (zero-delay symbolic match-to-sample). The procedures resulted in the establishment of relations among the elements of each set-relations that were not specifically trained and that can be characterized by the properties of reflexivity, symmetry, and transitivity. Each set of colors was related to a characteristic pattern of responding: One response pattern involved temporal duration (press and hold the response keys); the second response pattern entailed repeated pressing and releasing of the response keys (fixed ratio 8). Six combinations of two colors were trained, three combinations from each set. After discriminative performance stabilized for each monkey, they were tested with 10 additional color combinations, all of which differed from the training combinations. The conditional relations established between test combinations can be characterized as stimulus equivalence. The training procedures were analogous to the procedure of using category names, and have implications for understanding the function of language in the formation of equivalence classes. 相似文献
957.
958.
959.
960.
C Mabee 《Journal of the history of the behavioral sciences》1987,23(1):3-13
In World War II, Margaret Mead and her behavioral science colleagues actively applied their science to the American war effort on issues such as morale, food habits, psychological warfare, and the evacuation of Japanese-Americans from the West Coast. Mead's participation or lack of participation in these activities, and her varying enthusiasms and misgivings about them, raise fundamental issues about the responsibility of behavioral scientists to warn the public against dangerous policies, as well as the ethics of behavioral scientists participating in deceitful psychological warfare and the extent of their effectiveness in contributing to public policymaking. 相似文献