全文获取类型
收费全文 | 3828篇 |
免费 | 2193篇 |
国内免费 | 44篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 11篇 |
2021年 | 147篇 |
2020年 | 166篇 |
2019年 | 591篇 |
2018年 | 497篇 |
2017年 | 600篇 |
2016年 | 578篇 |
2015年 | 489篇 |
2014年 | 426篇 |
2013年 | 596篇 |
2012年 | 279篇 |
2011年 | 256篇 |
2010年 | 195篇 |
2009年 | 168篇 |
2008年 | 125篇 |
2007年 | 164篇 |
2006年 | 151篇 |
2005年 | 119篇 |
2004年 | 87篇 |
2003年 | 95篇 |
2002年 | 84篇 |
2001年 | 93篇 |
2000年 | 64篇 |
1999年 | 36篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有6065条查询结果,搜索用时 9 毫秒
201.
The focus of the present article was to analyze processes that determine the enactment and age effect in a multi-trial free recall paradigm by looking at the serial position effects. In an experimental study (see Schatz et al 2010), the performance-enhancing effect of enactive encoding and repeated learning was tested with older and younger participants. As expected, there was a steady improvement of memory performance as a function of repeated learning regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Furthermore, younger adults outperformed the elderly regardless of type of encoding. Analyses in the present article show that encoding by enacting seems to profit especially from remembering the last items of a presented list. Regarding age differences, younger outperformed older participants in nearly all item positions. The performance enhancement after task repetition is due to a higher amount of recalled items in the middle positions in a subject performed task (SPT) and a verbal task (VT) as well as the last positions of a learned list in VT. 相似文献
202.
Torres LV Araújo Sda C Sanchez CM Body S Bradshaw CM Szabadi E 《Journal of the experimental analysis of behavior》2011,95(1):57-74
Twelve rats made repeated choices on an adjusting-delay schedule between a smaller reinforcer (A) that was delivered immediately after a response and a larger reinforcer (B) that was delivered after a delay which increased or decreased by 20% depending on the subject's choices in successive blocks of trials. In two phases of the experiment (100 sessions and 40 sessions), reinforcer sizes were selected which enabled theoretical parameters expressing the rate of delay discounting and sensitivity to reinforcer size to be estimated from the ratio of the indifference delays obtained in the two phases. Indifference delays, calculated from adjusting delays in the last 10 sessions of each phase, were shorter when the sizes of A and B were 14 and 25 μl of a 0.6 M sucrose solution than when they were 25 and 100 μl of the same solution. The ratio of the indifference delays was significantly smaller than that predicted on the basis of an assumed linear relation between reinforcer size and instantaneous reinforcer value, consistent with a previous proposal that this relation may be hyperbolic in form. Estimates of the rate of delay discounting based on the ratio of the two indifference delays (mean, 0.08 s(-1)) were similar to values obtained previously using different intertemporal choice protocols. Estimates of the size-sensitivity parameter (mean 113 μl) were similar to estimates recently derived from performance on progressive-ratio schedules. In both phases of the experiment, adjusting delays in successive blocks of trials were analyzed using the Fourier transform. The power spectrum obtained from individual rats had a dominant frequency that corresponded to a period of oscillation of the adjusting delay between 30 and 100 trial blocks (mean, 78). Power in the dominant frequency band was highest in the early sessions of the first phase and declined with extended training. It is suggested that this experimental protocol may have utility in neurobehavioral studies of intertemporal choice. 相似文献
203.
Previous research has shown that rats can learn matching-to-sample relations with olfactory stimuli; however, the specific characteristics of this relational control are unclear. In Experiment 1, 6 rats were trained to either match or nonmatch to sample in a modified operant chamber using common household spices as olfactory stimuli. After matching or nonmatching training with 10 exemplars, the contingencies were reversed with five new stimuli such that subjects trained on matching were shifted to nonmatching and vice versa. Following these reversed contingencies, the effects of the original training persisted for many trials with new exemplars. In Experiment 2, 9 rats were trained with matching procedures in an arena that provided for 18 different spatial locations for comparison stimuli. Five subjects were trained with differential reinforcement outcomes and 4 with only one type of reinforcer. Differential outcomes and multiple exemplars facilitated learning, and there was strong evidence for generalization to new stimuli for most rats that acquired several conditional discriminations. Performances with novel samples were generally above chance, but rarely reached the high levels obtained during baseline with well-trained stimulus relations. However, taken together, the data from the two experiments extend previous work, show that rats can learn both match and nonmatch relations with different experimental protocols, and demonstrate generalization to novel sample stimuli. 相似文献
204.
Hirai M Okouchi H Matsumoto A Lattal KA 《Journal of the experimental analysis of behavior》2011,96(3):387-415
Undergraduates were exposed to a series of reinforcement schedules: first, to a fixed-ratio (FR) schedule in the presence of one stimulus and to a differential-reinforcement-of-low-rate (DRL) schedule in the presence of another (multiple FR DRL training), then to a fixed-interval (FI) schedule in the presence of a third stimulus (FI baseline), next to the FI schedule under the stimuli previously correlated with the FR and DRL schedules (multiple FI FI testing), and, finally, to a single session of the multiple FR DRL schedule again (multiple FR DRL testing). Response rates during the multiple FI FI schedule were higher under the former FR stimulus than under the former DRL stimulus. This effect of remote histories was prolonged when either the number of FI-baseline sessions was small or zero, or the time interval between the multiple FR DRL training and the multiple FI FI testing was short. Response rates under these two stimuli converged with continued exposure to the multiple FI FI schedule in most cases, but quickly differentiated when the schedule returned to the multiple FR DRL. 相似文献
205.
Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more secure foundation for assessing stability in future research. Six pigeons were exposed to a DMTS task with variable delays for 300 sessions (i.e., 18,000 total trials; 3,600 trials per retention interval). Percent-correct and log-d measures used to quantify the development of conditional stimulus control under the procedure generally and at each of five retention intervals (0, 2, 4, 8 and 16-s) individually revealed that high levels of accuracy developed relatively quickly under the shorter retention intervals, but increases in accuracy under the longer retention intervals sometimes were not observed until 100-150 sessions had passed, with some still increasing at Session 300. Analyses of errors suggested that retention intervals induced biases by shifting control from the sample stimulus to control by position, something that was predicted by observed response biases during initial training. These results suggest that although it may require a great deal of exposure to DMTS prior to obtaining asymptotic steady state, quantification of model parameters may help predict trends when extended exposure is not feasible. 相似文献
206.
This study explored the current psychological characteristics and criminal behavior history of individuals who retrospectively reported being bullies, bully-victims, victims, or controls (i.e. neither victims nor bullies) during their last 2 years of high school. College students (n = 960) completed measures of criminal thinking, aggression, psychopathy, and criminal behavior online. We predicted bullies and bully-victims would demonstrate the highest scores for criminal thinking, proactive aggression, psychopathy, and have the most criminal infractions. Bullies and bully-victims had significantly higher scores on criminal thinking, aggression, psychopathy, and criminal behaviors than victims or controls. Additionally, men were significantly higher in criminal thinking, aggression, psychopathy, and had more criminal acts than women. There were no gender by bully group interactions. Logistic regression analyses differentiated bully-victims from bullies. Bully-victims tended to be male, higher in criminal thinking, and higher in reactive aggression. In addition, bully-victims were distinct from victims, showing higher criminal thinking and higher proactive aggression. 相似文献
207.
Accurate assessment of bullying is essential to intervention planning and evaluation. Limitations to many currently available self-report measures of bullying victimization include a lack of psychometric information, use of the emotionally laden term "bullying" in definition-first approaches to self-report surveys, and not assessing all components of the definition of bullying (chronicity, intentionality, and imbalance of power) in behavioral-based self-report methods. To address these limitations, we developed the California Bullying Victimization Scale (CBVS), which is a self-report scale that measures the three-part definition of bullying without the use of the term bully. We examined test-retest reliability and the concurrent and predictive validity of the CBVS across students in Grades 5-12 in four central California schools. Concurrent validity was assessed by comparing the CBVS with a common, definition-based bullying victimization measure. Predictive validity was examined through the co-administration of measures of psychological well-being. Analysis by grade and gender are included. Results support the test-retest reliability of the CBVS over a 2-week period. The CBVS was significantly, positively correlated with another bullying assessment and was related in expected directions to measures of well-being. Implications for differentiating peer victimization and bullying victimization via self-report measures are discussed. 相似文献
208.
Male aggressiveness is a complex behavior influenced by a number of genetic and non-genetic factors. Traditionally, the contribution of each of these factors has been established from experiments using artificially selected strains for high/low aggressive phenotypes. However, little is known about the factors underlying aggressive behavior in natural populations. In this study, we assess the influence of genetic background vs. postnatal maternal environment using a set of cross-fostering experiments between two wild-derived inbred strains, displaying high (STRA, derived from Mus musculus domesticus) and low (BUSNA, derived from Mus musculus musculus) levels of aggressiveness. The role of maternal environment was tested in males with the same genetic background (i.e. strain origin) reared under three different conditions: unfostered (weaned by mother), infostered (weaned by an unfamiliar dam from the same strain), and cross-fostered (weaned by a dam from a different strain). All males were tested against non-aggressive opponents from the A/J inbred strain. Resource-holding potential was assessed through body weight gains and territory ownership. The STRA males were shown to be aggressive in both neutral cage and resident-intruder tests. On the contrary, the BUSNA males were less aggressive in all tests. We did not find a significant effect of postnatal maternal environment; however, we detected significant maternal effect on body weight with differences between the strains, fostering type and interactions between these factors. We conclude that the aggressiveness preserved in the two strains has significant genetic component whose genetic basis can be dissected by quantitative trait loci analysis. 相似文献
209.
This study examines 24‐months post‐baseline outcomes for thirty‐five Swedish antisocial youths who received either treatment in multidimensional treatment foster care (MTFC) or treatment as usual (TAU). MTFC is a community‐based treatment programme that has been successful in treating chronic juvenile offenders in the USA. This study is the first randomized control study outside the USA. The youth treated in the MTFC programme consistently showed some statistically significant positive treatment effects compared to the youth exposed to TAU. The results suggest that MTFC might be an effective method in treating youth with severe behaviour problems in a Swedish context. The authors conclude that the programme ought to be of great interest for Swedish social services as an alternative to traditional care. 相似文献
210.
In this research we examine the effect of adding a food topping to the base food on consumers' calorie estimation and consumption of the augmented food (base food plus topping). We show that consumers underestimate the calorie content of augmented food with an unhealthy base, especially when the topping is healthy. However, consumers are less likely to underestimate the calorie content of augmented food with a healthy base, regardless of whether the topping is healthy or unhealthy. Further, we show that adding a healthy topping to an unhealthy base makes consumers not only underestimate the calorie content but also eat more of the augmented food. 相似文献