全文获取类型
收费全文 | 42258篇 |
免费 | 1779篇 |
国内免费 | 11篇 |
出版年
2020年 | 428篇 |
2019年 | 550篇 |
2018年 | 771篇 |
2017年 | 775篇 |
2016年 | 792篇 |
2015年 | 577篇 |
2014年 | 707篇 |
2013年 | 3101篇 |
2012年 | 1273篇 |
2011年 | 1360篇 |
2010年 | 818篇 |
2009年 | 772篇 |
2008年 | 1160篇 |
2007年 | 1127篇 |
2006年 | 1060篇 |
2005年 | 934篇 |
2004年 | 911篇 |
2003年 | 822篇 |
2002年 | 869篇 |
2001年 | 1343篇 |
2000年 | 1250篇 |
1999年 | 938篇 |
1998年 | 481篇 |
1996年 | 391篇 |
1992年 | 726篇 |
1991年 | 725篇 |
1990年 | 704篇 |
1989年 | 709篇 |
1988年 | 706篇 |
1987年 | 655篇 |
1986年 | 658篇 |
1985年 | 719篇 |
1984年 | 592篇 |
1983年 | 530篇 |
1982年 | 457篇 |
1981年 | 417篇 |
1979年 | 650篇 |
1978年 | 462篇 |
1977年 | 400篇 |
1976年 | 440篇 |
1975年 | 549篇 |
1974年 | 631篇 |
1973年 | 671篇 |
1972年 | 537篇 |
1971年 | 503篇 |
1970年 | 482篇 |
1969年 | 520篇 |
1968年 | 634篇 |
1967年 | 531篇 |
1966年 | 543篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
Pigeons' responses were reinforced on two identical and concurrently available chain variable-interval-schedules. Unlike the typical concurrent chains procedure, both links were operative throughout, thus producing three types of concurrency: (1) concurrent initial links; (2) concurrent initial and terminal links; (3) concurrent terminal links. Choice proportions in each of these three states suggested that the pigeons were sensitive to momentary likelihoods of reinforcement: choice proportions for a schedule were higher when the schedule had been operative for some time, resulting in a higher probability of reinforcement. The study also showed that the relative rates of responding did not match the relative rates of reinforcement in any of the three states of concurrency. Instead, the choice proportions in both the concurrent initial and in the concurrent terminal links were intermediate between the scheduled and the obtained relative rates of reinforcement, while the choice proportions for a terminal link concurrent with an initial link consistently overmatched the relative interreinforcement times (and were typically 1.00). These data indicate that an accurate characterization of choice may not be obtained by considering only the relative interreinforcement interval where one interreinforcement interval is segmented into a chain. Instead, the organism's choice for a schedule will be substantially lowered by the chaining operation. 相似文献
902.
Fantino E Squires N Delbrück N Peterson C 《Journal of the experimental analysis of behavior》1972,18(1):35-43
In Experiment 1, matching of relative response rates to relative rates of reinforcement was obtained in concurrent variable-interval schedules when the absolute values of the two concurrent variable-interval schedules varied from 6 sec and 12 sec to 600 sec and 1200 sec. Increases in the duration of the changeover delay, however, produced decreases in the relative response rates and, consequently, some deviation from matching. In Experiment 2, matching of relative response rates to the relative duration of the reinforcer failed to occur when the equal variable-interval schedules arranging access to the two different reinforcer durations (1.5 and 6 sec) were varied in size from concurrent variable-interval 10-sec schedules to concurrent variable-interval 600-sec schedules. 相似文献
903.
Rats pressed a lever to avoid shock on a free-operant avoidance schedule. Some subjects were also exposed to extinction in which the response-shock contingency was eliminated while the shock-shock contingency remained in effect. A specially constructed lever was used that registered not only presses, but also biting attacks on the lever. Throughout various phases of the study, shocks often elicited lever biting as well as post-shock responding. The results suggested that shock-elicited attacks that are forceful enough to activate the operandum might account for some of the responding that occurs in experiments on free-operant avoidance behavior. In particular, shock-elicited operandum attacking might account for post-shock response bursting during free-operant avoidance and the extreme persistence of responding sometimes noted when shocks are delivered during the extinction of avoidance behavior. To the extent that this is true, these phenomena should not be characterized as operant behavior in interpreting the results of experiments on free operant avoidance. 相似文献
904.
905.
Positive interaction (induction) in multiple variable-interval, differential-reinforcement-of-high-rate schedules
下载免费PDF全文
![点击此处可从《Journal of the experimental analysis of behavior》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The effect of increases in the rate of responding in one component of a multiple schedule upon the rate of responding in a second component was investigated. Pigeons were exposed to a multiple schedule where both components were initially variable-interval schedules having the same parameter value. After rate of key pecking stabilized, one component was changed to a schedule that differentially reinforced high rates of responding. Rate of reinforcement in this varied component was adjusted to remain equal to rate of reinforcement in the constant (variable-interval) component. Four of five pigeons showed a maintained increase in rate of responding during both the constant and varied components, even though rates of reinforcement did not change. 相似文献
906.
Rats trained to lever press on a fixed-interval limited-hold avoidance schedule maintained a pattern of responding similar to that maintained by fixed-interval limited-hold schedules of positive reinforcement. But this positively accelerated pattern of behavior was maintained only when the occurrence of reinforcement was signalled by the presentation of a brief flash of light. This result suggests that the discriminative function of the reinforcer in avoidance is less pronounced than the discriminative function of the reinforcer in escape or positive reinforcement. It also suggests that the distinction between positive reinforcement and avoidance is not superfluous. Although the schedule of reinforcement is an important variable in determining the pattern of behavior, other variables, such as the nature (i.e., stimulus presentation, termination, or omission) of the reinforcer, are also potent determinants of behavior. 相似文献
907.
Dr. N. J. Wade 《Psychological research》1972,35(2):131-142
Summary Four experiments are reported which involved the adjustment of two points of light in an otherwise dark room to the visual vertical. In the first two experiments different point separations (corresponding to visual angles of about 2° and 23°) were employed in an attempt to control the degree of scanning eye movements. Binocular adjustments to the visual vertical during body tilt were influenced by the point separation (Exp. 1), but monocular adjustments with the head upright were not (Exp. 2). Using the larger point separation and fixating the top point the visual vertical using the right eye was counterclockwise of that with fixation of the bottom point when the head was upright (Exp. 3), but this difference was not found for judgments during tilt (Exp. 4). The results were discussed in terms of the rotational changes in eye position accompanying scanning eye movements and ocular elevation and depression.
This research was carried out while I was a recipient of a Forschungsstipendium from the Alexander von Humboldt-Stiftung, appreciation for which is gratefully acknowledged. I also wish to thank the subjects who participated in the experiments. 相似文献
Zusammenfassung Es wird über vier Experimente berichtet, in denen es um die Einstellungen zweier Lichtpunkte in eine vertikale Richtung geht. In den ersten zwei Experimenten sollte der Einfluß der Fixierbewegungen der Augen geprüft werden. Der Winkelabstand der Lichtpunkte betrug 2° oder 23°. Bei seitwärts geneigtem Körper und binokularer Betrachtung wurde ein Unterschied gefunden (Exp. 1). Bei aufrecht gehaltenem Kopf und monokularer Betrachtung dagegen zeigte sich kein Unterschied (Exp. 2). Wurde in aufrechter Körperlage und bei einem Punktabstand von 23° der obere Punkt mit dem rechten Auge fixiert, so verschob sich die scheinbare Vertikale im Uhrzeigersinn; sie verschob sich noch weiter im Uhrzeigersinn, wenn der untere Punkt fixiert wurde (Exp. 3). Bei geneigtem Körper wurde dagegen kein Unterschied festgestellt (Exp. 4). Die Ergebnisse werden im Zusammenhang mit der Augendrehung diskutiert, die mit dem scanning sowie mit der Auf- und Abbewegung der Augen beim Fixieren verbunden ist.
This research was carried out while I was a recipient of a Forschungsstipendium from the Alexander von Humboldt-Stiftung, appreciation for which is gratefully acknowledged. I also wish to thank the subjects who participated in the experiments. 相似文献
908.
D. J. Guest M. E. Sime T. R. G. Green 《Quarterly journal of experimental psychology (2006)》1972,24(2):139-148
Errors in a serial choice-reaction time experiment employing two-finger chord responses to alphabetic stimuli are shown to be distributed in a significantly non-random fashion. Two factors are postulated which are relevant to prediction of the error response. These are the presence or absence of a common finger, and the difference in finger separation, between the actual and the required response. It is suggested that the chord response is coded in terms of a pattern (the distance between the two response components). Responses which mirror the correct response about the centre of the hand are also shown to be significantly more frequent. 相似文献
909.
910.