全文获取类型
| 收费全文 | 791篇 |
| 免费 | 255篇 |
| 国内免费 | 4篇 |
专业分类
| 1050篇 |
出版年
| 2024年 | 17篇 |
| 2023年 | 18篇 |
| 2022年 | 12篇 |
| 2021年 | 21篇 |
| 2020年 | 44篇 |
| 2019年 | 40篇 |
| 2018年 | 38篇 |
| 2017年 | 33篇 |
| 2016年 | 35篇 |
| 2015年 | 34篇 |
| 2014年 | 26篇 |
| 2013年 | 55篇 |
| 2012年 | 32篇 |
| 2011年 | 30篇 |
| 2010年 | 19篇 |
| 2009年 | 35篇 |
| 2008年 | 29篇 |
| 2007年 | 23篇 |
| 2006年 | 27篇 |
| 2005年 | 31篇 |
| 2004年 | 12篇 |
| 2003年 | 24篇 |
| 2002年 | 30篇 |
| 2001年 | 11篇 |
| 2000年 | 21篇 |
| 1999年 | 20篇 |
| 1998年 | 16篇 |
| 1997年 | 15篇 |
| 1996年 | 11篇 |
| 1995年 | 15篇 |
| 1994年 | 16篇 |
| 1993年 | 27篇 |
| 1992年 | 18篇 |
| 1991年 | 18篇 |
| 1990年 | 9篇 |
| 1989年 | 12篇 |
| 1988年 | 12篇 |
| 1987年 | 13篇 |
| 1986年 | 6篇 |
| 1985年 | 14篇 |
| 1984年 | 13篇 |
| 1983年 | 12篇 |
| 1982年 | 16篇 |
| 1981年 | 9篇 |
| 1980年 | 15篇 |
| 1979年 | 15篇 |
| 1978年 | 16篇 |
| 1977年 | 18篇 |
| 1976年 | 7篇 |
| 1975年 | 10篇 |
排序方式： 共有1050条查询结果，搜索用时 0 毫秒
151.
Saunders RR Drake KM Spradlin JE 《Journal of the experimental analysis of behavior》1999,71(2):195-214
Preschool children were taught four two-choice match-to-sample conditional discriminations with 10 arbitrary visual stimuli. For 6 participants, 2 of the 10 stimuli served as the sample, or conditional, stimuli in all discriminations. For 5 additional participants, the same pair of stimuli served as the discriminative, or comparison, stimuli in all discriminations. Equivalence classes were established with more participants in the latter group, replicating prior research with participants with retardation. Four participants, in whom equivalence classes were established and who were available for further participation, were exposed to new conditional discriminations without trial-by-trial feedback and involving some novel and some familiar stimuli. Consistent conditional responding was observed, and tests for inclusion of the novel stimuli in the original classes showed class expansion. Training to reverse the unreinforced conditional performances produced a reversal of class membership in 3 of 4 participants, an outcome not consistent with other studies. The results are discussed with respect to the interaction of class structure and size. 相似文献
152.
Zentall TR 《Journal of the experimental analysis of behavior》1999,72(3):467-472
Staddon and Higa's (1999) trace-strength theory of timing and memory for event duration can account for pigeons' bias to \"choose short\" when retention intervals are introduced and to \"choose long\" when, following training with a fixed retention interval, retention intervals are shortened. However, it does not account for the failure of pigeons to choose short when the intertrial interval is distinct from the retention interval. That finding suggests that stimulus generalization (or ambiguity) between the intertrial interval and the retention interval may result in an effect that has been attributed to memory loss. Such artifacts must be eliminated before a theory of memory for event duration can be adequately tested. 相似文献
153.
A J Cuvo L J Lerch D A Leurquin T J Gaffaney R L Poppen 《Journal of applied behavior analysis》1998,31(1):43-63
The present experiments examined the effect of work requirements in combination with reinforcement schedule on the choice behavior of adults with mental retardation and preschool children. The work requirements of age-appropriate tasks (i.e., sorting silverware, jumping hurdles, tossing beanbags) were manipulated. Participants were presented with their choice of two response options for each trial that varied simultaneously on both work requirement and reinforcement schedule. Results showed that when responding to both choices occurred on the same reinforcement schedule, participants allocated most of their responses to the option with the easier work requirement. When the response option requiring less work was on a leaner reinforcement schedule, most participants shifted their choice to exert more work. There were individual differences across participants regarding their pattern of responding and when they switched from the lesser to the greater work requirement. Data showed that participants' responding was largely controlled by the reinforcement received for responding to each level of work. Various conceptualizations regarding the effects of work requirements on choice behavior are discussed. 相似文献
154.
A L Odum S C Haworth D W Schaal 《Journal of the experimental analysis of behavior》1998,69(3):295-310
Four pigeons pecked response keys under a multiple fixed-ratio 30 fixed-interval 5-min schedule of food presentation. Components alternated separated by 15-s timeouts; each was presented six times. Pigeons were maintained at 70%, 85%, and greater than 90% of their free-feeding weights across experimental conditions. When response rates were stable, the effects of morphine (0.56 to 10.0 mg/kg) and saline were investigated. Morphine reduced response rates in a dose-dependent manner under the fixed-ratio schedule and at high doses under the fixed-interval schedule. In some cases, low doses of morphine increased rates under the fixed-interval schedule. When pigeons were less food deprived, reductions in pecking rates occurred at lower doses under both schedules for 3 of 4 birds compared to when they were more food deprived. When pigeons were more food deprived, low doses of morphine increased rates of pecking in the initial portions of fixed intervals by a greater magnitude. Thus, food-deprivation levels altered both the rate-decreasing and rate-increasing effects of morphine. These effects may share a common mechanism with increased locomotor activity produced by drugs and with increased drug self-administration under conditions of more severe food deprivation. 相似文献
155.
The European Union is generally perceived as endorsing universalistic and multi‐cultural values. However, social identity and self‐categorization theories predict that, when certain conditions are met, a negative relation between ingroup identification and tolerance towards outgroup members should be observed. We argue that the creation of the status of ‘Citizen of the Union’ in Maastricht may contribute to meeting those conditions and therefore to increase intolerance towards resident foreigners. If that is the case, a paradoxical situation could emerge, in which people's levels of tolerance towards foreigners would contradict group values. We examined the relations between values associated with Europe, European and national identification, and tolerance towards foreigners through a survey study with a—non‐representative—sample of undergraduate French‐speaking Belgian students. Results show that Europe was generally associated with humanistic values. But they also reveal that strong European identifiers tended to express more xenophobic attitudes than weak European identifiers, whilst national identification was not related with such attitudes. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
156.
By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post-class-formation dual-option response transfer tests. With college students, two 4-node 6-member equivalence classes with nodal structures of A-->B-->C-->D-->E-->F were produced by training AB, BC, CD, DE, and EF. Then, unique responses were trained to the C and D stimuli in each class. The responses trained to C generalized to B and A, while the responses trained to D generalized to E and F. Thus, each 4-node 6-member equivalence class was bifurcated into two 3-member functional classes: A-->B-->C and D-->E-->F, with class membership precisely predicted by nodal structure. A final emergent relations test documented the intactness of the underlying 4-node 6-member equivalence classes. The coexistence of the interchangeability of stimuli in an equivalence class and the bifurcation of such a class in terms of nodal structure was explained in the following manner. The conditional discriminations that are used to establish a class also imposes a nodal structure on the stimuli in the class. Thus, the stimuli in the class acquire two sets of relational properties. If the format of a test trial allows only one response option per class, responding on those trials will be in accordance with class membership and will not express the effects of nodal distance. If the format of a test trial allows more than one response option per class, responding on those trials will be determined by the nodal structure of the class. Thus, the relational properties expressed by the stimuli in an equivalence class are determined by the discriminative function served by the format of a test trial. 相似文献
157.
Lazareva OF Smirnova AA Bagozkaja MS Zorina ZA Rayevsky VV Wasserman EA 《Journal of the experimental analysis of behavior》2004,82(1):1-19
Eight crows were taught to discriminate overlapping pairs of visual stimuli (A+ B-, B+ C-, C+ D-, and D+ E-). For 4 birds, the stimuli were colored cards with a circle of the same color on the reverse side whose diameter decreased from A to E (ordered feedback group). These circles were made available for comparison to potentially help the crows order the stimuli along a physical dimension. For the other 4 birds, the circles corresponding to the colored cards had the same diameter (constant feedback group). In later testing, a novel choice pair (BD) was presented. Reinforcement history involving stimuli B and D was controlled so that the reinforcement/nonreinforcement ratios for the latter would be greater than for the former. If, during the BD test, the crows chose between stimuli according to these reinforcement/nonreinforcement ratios, then they should prefer D; if they chose according to the diameter of the feedback stimuli, then they should prefer B. In the ordered feedback group, the crows strongly preferred B over D; in the constant feedback group, the crows' choice did not differ significantly from chance. These results, plus simulations using associative models, suggest that the orderability of the postchoice feedback stimuli is important for crows' transitive responding. 相似文献
158.
Alsop B 《Journal of the experimental analysis of behavior》2004,82(1):57-69
Quantitative analyses of stimulus control and reinforcer control in conditional discriminations and delayed matching-to-sample procedures often encounter a problem; it is not clear how to analyze data when subjects have not made errors. The present article examines two common methods for overcoming this problem. Monte Carlo simulations of performance demonstrated that both methods introduced systematic deviations into the results, and that there were genuine risks of drawing misleading conclusions concerning behavioral models of signal detection and animal short-term memory. 相似文献
159.
Choice typically is studied by exposing organisms to concurrent variable-interval schedules in which not only responses controlled by stimuli on the key are acquired but also switching responses and likely other operants as well. In the present research, discriminated key-pecking responses in pigeons were first acquired using a multiple schedule that minimized the reinforcement of switching operants. Then, choice was assessed during concurrent-probe periods in which pairs of discriminative stimuli were presented concurrently. Upon initial exposure to concurrently presented stimuli, choice approximated exclusive preference for the alternative associated with the higher reinforcement frequency. Concurrent schedules were then implemented that gave increasingly greater opportunities for switching operants to be conditioned. As these operants were acquired, the relation of relative response frequency to relative reinforcement frequency converged toward a matching relation. An account of matching with concurrent schedules is proposed in which responding exclusively to the discriminative stimulus associated with the higher reinforcement frequency declines as the concurrent stimuli become more similar and other operants-notably switching-are acquired and generalize to stimuli from both alternatives. The concerted effect of these processes fosters an approximate matching relation in commonly used concurrent procedures. 相似文献
160.
Pigeons were trained to discriminate 5 mg/kg pentobarbital from saline under concurrent variable-ratio (VR) VR schedules, in which responses on the pentobarbital-biased lever were reinforced under the VR schedule with the smaller response requirements when pentobarbital was given before the session, and responses on the saline-biased key were reinforced under the VR schedule with the larger response requirements. When saline was administered before the session, the reinforcement contingencies associated with the two response keys were reversed. When responding stabilized under concurrent VR 20 VR 30, concurrent VR 10 VR 40, or concurrent VR 5 VR 50 schedules, pigeons responded almost exclusively on the key on which fewer responses were required to produce the reinforcer. When other doses of pentobarbital and other drugs were substituted for the training dose, low doses of all drugs produced responding on the saline-biased key. Higher doses of pentobarbital and chlordiazepoxide produced responding only on the pentobarbital-biased key, whereas higher doses of ethanol and phencyclidine produced responding only on this key less often. d-Amphetamine produced responding primarily on the saline-biased key. When drugs generalized to pentobarbital, the shape of the generalization curve under concurrent VR VR schedules was more often graded than quantal in shape. Thus, drug discrimination can be established under concurrent VR VR schedules, but the shapes of drug-discrimination dose-response curves under concurrent VR VR schedules more closely resemble those seen under interval schedules than those seen under fixed-ratio schedules. Graded dose-response curves under concurrent VR VR schedules may relate to probability matching and difficulty in discriminating differences in reinforcement frequency. 相似文献