全文获取类型
收费全文 | 1285篇 |
免费 | 298篇 |
国内免费 | 166篇 |
专业分类
1749篇 |
出版年
2024年 | 4篇 |
2023年 | 21篇 |
2022年 | 31篇 |
2021年 | 53篇 |
2020年 | 76篇 |
2019年 | 71篇 |
2018年 | 66篇 |
2017年 | 72篇 |
2016年 | 84篇 |
2015年 | 57篇 |
2014年 | 74篇 |
2013年 | 219篇 |
2012年 | 55篇 |
2011年 | 70篇 |
2010年 | 35篇 |
2009年 | 56篇 |
2008年 | 64篇 |
2007年 | 57篇 |
2006年 | 56篇 |
2005年 | 36篇 |
2004年 | 48篇 |
2003年 | 50篇 |
2002年 | 34篇 |
2001年 | 36篇 |
2000年 | 26篇 |
1999年 | 25篇 |
1998年 | 14篇 |
1997年 | 12篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 19篇 |
1993年 | 22篇 |
1992年 | 19篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 16篇 |
1977年 | 13篇 |
1976年 | 12篇 |
1975年 | 5篇 |
排序方式: 共有1749条查询结果,搜索用时 0 毫秒
21.
22.
Choice between delayed reinforcers and fixed-ratio schedules requiring forceful responding. 总被引:1,自引:1,他引:0 下载免费PDF全文
This experiment measured pigeons' choices between delayed reinforcers and fixed-ratio schedules in which a force of approximately 0.48 N was needed to operate the response key. In ratio-delay conditions, subjects chose between a fixed-ratio schedule and an adjusting delay. The delay was increased or decreased several times a session in order to estimate an indifference point--a delay duration at which the two alternatives were chosen about equally often. Each ratio-delay condition was followed by a delay-delay condition in which subjects chose between the adjusting delay and a variable-time schedule, with the components of this schedule selected to match the ratio completion times of the preceding ratio-delay condition. The adjusting delays at the indifference point were longer when the alternative was a fixed-ratio schedule than when it was a matched variable-time schedule, which indicated a preference for the matched variable-time schedules over the fixed-ratio schedules. This preference increased in a nonlinear manner with increasing ratio size. This nonlinearity was inconsistent with a theory that states that indifference points for both time and ratio schedules can be predicted by multiplying the choice response-reinforcer intervals of the two types of schedules by different multiplicative constants. Two other theories, which predict nonlinear increases in preference for the matched variable-time schedules, are discussed. 相似文献
23.
Determinants of pigeons' waiting time: Effects of interreinforcement interval and food delay 下载免费PDF全文
Manabe K 《Journal of the experimental analysis of behavior》1990,53(1):123-132
Four pigeons performed on three types of schedules at short (i.e., 10, 30, or 60 s) interreinforcement intervals: (a) a delay-dependent schedule where interreinforcement interval was held constant (i.e., increases in waiting time decreased food delay), (b) an interreinforcement-interval-dependent schedule where food delay was held constant (i.e., increases in waiting time increased interreinforcement interval), and (c) a both-dependent schedule where increases in waiting time produced increases in interreinforcement interval but decreases in food delay. Waiting times were typically longer under the delay-dependent schedules than under the interreinforcement-interval-dependent schedules. Those under both-dependent schedules for 1 subject were intermediate between those under the other two schedule types, whereas for the other subjects waiting times under the both-dependent procedure were similar either to those under the delay-dependent schedule or to those under the interreinforcement-interval-dependent schedule, depending both on the subject and the interreinforcement interval. These results indicate that neither the interreinforcement interval nor food delay is the primary variable controlling waiting time, but rather that the two interact in a complex manner to determine waiting times. 相似文献
24.
小学儿童对习俗时间的周期性特点的认知 总被引:2,自引:0,他引:2
本研究探讨了小学儿童对习俗时间周期性特点的认知发展.实验任务是让被试判断两个给定日期之间的时间距离是正向接近还是反向接近。结果表明:儿童对习俗时间的周期性特点的认知成绩随年龄增长而不断提高;随着两个日期之间距离的增大,反应时不断增加,正确率不断降低,在两个日期相互接近的方向发生改变的边界处,反应时最长,正确率最低,表现出显著的“距离效应”和“边界效应”;儿童可以利用数字系统进行判断,他们的认知加工策略包括计数、数字运算和凭借习俗时间的空间表象进行模拟加工等等。 相似文献
25.
26.
Contrast and reallocation of extraneous reinforcers as a function of component duration and baseline rate of reinforcement 总被引:1,自引:1,他引:0 下载免费PDF全文
McLean AP 《Journal of the experimental analysis of behavior》1995,63(2):203-224
Four pigeons responded on multiple schedules arranged on a “main” key in a two-key experimental chamber. A constant schedule component was alternated with another component that was varied over conditions. On an extra response key, conjoint schedules of reinforcement that operated in both components were arranged concurrently with the multiple schedule on the main key. On the main key, changes in reinforcement rate in the varied component were inversely related to changes in response rates in the constant component (behavioral contrast). On the extra key, some reinforcers were reallocated between components, depending on the schedules in effect on the main key in the varied component. In the varied component, the obtained rates of reinforcement on the extra key were inversely related to main-key reinforcement rate. In the constant component, extra-key reinforcer rates were positively related to main-key reinforcer rates obtained in the varied component, and were not a function of response rates on the extra key. In two comparisons, the rate at which components alternated and the value of the main-key schedule in the constant component were varied. Consistent with earlier work, long components reduced the extent of contrast. Reductions in contrast as a function of component duration were accompanied by similar reductions in the extent of reinforcer reallocation on the extra key. In the second comparison, lowering the rate of reinforcement in the constant component increased the rate at which extra-key reinforcers were obtained, reduced the extent of reinforcer reallocation, and reduced contrast. Overall, the results are consistent with the suggestion that some contrast effects are due to the changes in extraneous reinforcement during the constant component, and that manipulations of component duration, and manipulations of the rate of reinforcement in the constant component, affect contrast because they influence the extent of extraneous reinforcer real-location. 相似文献
27.
Operant temporal discrimination learning was investigated in goldfish. In the first experiment, there was a fixed daily change in illumination. Eight subjects were trained to operate a lever that reinforced each press with food. The period during which responses were reinforced was then progressively reduced until it was 1 hr in every 24. The final 1-hr feeding schedule was maintained over 4 weeks. The feeding period commenced at the same time each day throughout. The food dispensers were then made inactive, and a period of extinction ensued for 6 days. The pattern of responding suggested that the fish were able to exhibit temporal discrimination in anticipation of feeding time. This pattern of responding persisted for a limited number of days during the extinction procedure. The second experiment produced evidence that operant temporal discrimination could develop under continuous illumination. 相似文献
28.
Seven undergraduates participated in a concurrent-choice experiment with monetary reinforcers. Response-independent analogues of variable-interval and variable-ratio schedules were used to assess whether subjects would maximize reinforcement rate. The optimal pattern of behavior, in terms of maximizing reinforcement rate, involved a large bias toward the ratio alternative, with only occasional sampling of the interval schedule. Most experiments with pigeons, however, demonstrate matching of response rates to reinforcement rates, with only slight biases for the ratio schedule. Although subjects in the present experiment allocated more time to the ratio alternative than required by matching, the magnitude of the bias did not approximate that predicted by a maximizing account. After exposure to clock stimuli correlated with the operation of each schedule, 1 subject's behavior did show a substantial level of bias, increasing the total number of reinforcers obtained, and lay at a point between the predictions of matching and maximizing. The other subjects, however, continued to respond less optimally. The present results can be accounted for by a view of matching that incorporates the effects of delayed reinforcement. 相似文献
29.
Children with autism were taught spontaneous requests through a time delay procedure. Unlike previous research, which usually employed food as the target stimuli to be requested, the present study used toy pieces from multi-component toys. The procedure involved presenting a child with the target stimulus, with the trainer prompting the child by immediately modeling the request response. When the response was imitated without error, prompting was delayed with the time interval gradually being increased over trials. A spontaneous or imitated response was reinforced by giving the child the requested object. As the stimulus/model interval increased, children with autism were expected to initiate the request by themselves prior to the prompt. The efficacy of the time delay procedure was assessed using a multiple baseline across subject design with three Chinese boys with autism. Results showed that the three children acquired a 100% performance within five to nine sessions of training and the skill was maintained at the one-month and three-month followups. Furthermore, the learned response transferred to various conditions when tested across setting, person, toy, and food items. These results suggest that toys, the multi-component ones in particular, served well as reinforcers for language training. Furthermore these findings confirmed the practical utility of the time delay procedure for promoting spontaneous communication skills in children with autism. 相似文献
30.
Electrodermal lability in anxiety disorders 总被引:1,自引:0,他引:1
HANS HENRIK JENSEN NICOLAS HASLE MORTEN BIRKET-SMITH 《Scandinavian journal of psychology》1996,37(1):103-108
Twenty-eight anxiety patients, aged below 50 years, were diagnosed according to DSM-III-R criteria (panic disorder with and without agoraphobia, generalised anxiety disorder, and anxiety disorder not otherwise specified). The patients were characterised by high levels of state and trait anxiety and neuroticism, compared with the controls. However, there were no differences between patients and controls in electrodermal habituation rate, non-specific activity, or skin resistance level. When the patients were divided into electrodermally labile and stable subjects, significant differences were found between patients and controls in both electrodermal activity and Eysenck's personality dimensions. The labile patients were more introverted and attained higher psychoticism scores than either the stable patients or controls. Duration of anxiety symptoms removed the difference found in extroversion, but not in any other variable. The results are discussed in relation to the utility of electrodermal measurements in validation of diagnostic entities. It is concluded, that from the psychophysiological point of view, anxiety disorders may be examined within a dimensional framework. 相似文献