全文获取类型
收费全文 | 4244篇 |
免费 | 2177篇 |
国内免费 | 27篇 |
专业分类
6448篇 |
出版年
2024年 | 21篇 |
2023年 | 39篇 |
2022年 | 19篇 |
2021年 | 135篇 |
2020年 | 160篇 |
2019年 | 595篇 |
2018年 | 488篇 |
2017年 | 606篇 |
2016年 | 582篇 |
2015年 | 492篇 |
2014年 | 426篇 |
2013年 | 741篇 |
2012年 | 295篇 |
2011年 | 252篇 |
2010年 | 207篇 |
2009年 | 171篇 |
2008年 | 118篇 |
2007年 | 160篇 |
2006年 | 156篇 |
2005年 | 138篇 |
2004年 | 98篇 |
2003年 | 119篇 |
2002年 | 99篇 |
2001年 | 129篇 |
2000年 | 91篇 |
1999年 | 53篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 16篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有6448条查询结果,搜索用时 0 毫秒
81.
An assortment of factors in modern society can be involved in the etiology and treatment of mental illness. Theories about
etiology usually underlie, and therefore guide, most strategies for treatment. Although a comprehensive bio-psycho-social
approach to mental illness can help to foster the collaboration of an interdisciplinary treatment team, a heavy emphasis on
biological factors or cultural deprivation may reduce the client's feelings of personal responsibility for change. Contemporary
psychotherapy can help clients reduce their tendency to attribute blame to biological predispositions or external societal
factors. Instead, it is more helpful to cultivate attributions for personal responsibility for change, growth, and maturation. 相似文献
82.
Hughes CE Sigmon SC Pitts RC Dykstra LA 《Journal of the experimental analysis of behavior》2005,83(3):281-296
Key pecking by 3 pigeons was maintained by a multiple fixed-ratio 10, fixed-ratio 30, fixed-ratio 90 schedule of food presentation. Components differed with respect to amount of reinforcement, such that the unit price was 10 responses per 1-s access to food. Acute administration of morphine, l-methadone, and cocaine dose-dependently decreased overall response rates in each of the components. When a rate decreasing dose of morphine was administered daily, tolerance, as measured by an increase in the dose that reduced response rates to 50% of control (i.e., the ED50 value), developed in each of the components; however, the degree of tolerance was smallest in the fixed-ratio 90 component (i.e., the ED50 value increased the least). When the l-methadone dose-effect curve was redetermined during the chronic morphine phase, the degree of cross-tolerance conferred to l-methadone was similar across components, suggesting that behavioral variables may not influence the degree of cross-tolerance between opioids. During the chronic phase, the cocaine dose-effect curve shifted to the right for 2 pigeons and to the left for 1 pigeon, which is consistent with predictions based on the lack of pharmacological similarity between morphine and cocaine. When the morphine, l-methadone, and cocaine dose-effect curves were redetermined after chronic morphine administration ended, the morphine and l-methadone ED50s replicated those obtained prior to chronic morphine administration. The morphine data suggest that the fixed-ratio value (i.e., the absolute output) determines the degree of tolerance and not the unit price. 相似文献
83.
Sealey DM Sumpter CE Temple W Foster TM 《Journal of the experimental analysis of behavior》2005,84(1):19-35
To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions. 相似文献
84.
Kalenscher T Güntürkün O Calabrese P Gehlen W Kalt T Diekamp B 《Journal of the experimental analysis of behavior》2005,84(3):521-535
Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with increasing delay duration, indicating that working memory fades across a delay. However, no such performance decrease has been found when the sample cues exist of present vs. absent stimuli, suggesting that pigeons do not rely on working memory, but seem to respond by default in those trials. We trained 3 pigeons in a DGNG task and found a similar default response pattern: The diverging slopes of the retention functions on correct Go and No-Go trials suggested that pigeons by default omitted their response following No-Go stimuli, but actively retained task-relevant information across the delay for successful responses on Go trials. We conducted single-cell recordings in the avian nidopallium caudolaterale, a structure comparable to the mammalian prefrontal cortex. On Go trials, many neurons displayed sustained elevated activity during the delay preceding the response, replicating previous findings and suggesting that task-relevant information was neurally represented and maintained across the delay. However, the same units did not show enhanced delay activity preceding correct response suppressions in No-Go trials. This activation-inactivation pattern presumably constitutes a neural correlate of the default response strategy observed in the DGNG task. 相似文献
85.
McKerchar TL Zarcone TJ Fowler SC 《Journal of the experimental analysis of behavior》2005,84(3):339-356
Recent progress in mouse genetics has led to an increased interest in developing procedures for assessing mouse behavior, but relatively few of the behavioral procedures developed involve positively reinforced operant behavior. When operant methods are used, nose poking, not lever pressing, is the target response. In the current study differential acquisition of milk-reinforced lever pressing was observed in five inbred strains (C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ, and BALB/cJ) and one outbred stock (CD-1) of mice. Regardless of whether one or two levers (an "operative" and "inoperative" lever) were in the operant chamber, a concomitant variable-time fixed-ratio schedule of milk reinforcement established lever pressing in the majority of mice within two 120-min sessions. Substantial differences in lever pressing were observed across mice and between procedures. Adding an inoperative lever retarded acquisition in C57BL/6J, DBA/2J, 129X1/SvJ, and C3H/HeJ mice, but not in CD-1 and BALB/cJ mice. Locomotor activity was positively correlated with number of lever presses in both procedures. Analyses of durations of the subcomponents (e.g., time to move from hopper to lever) of operant behavior revealed further differences among the six types of mice. Together, the data suggest that appetitively reinforced lever pressing can be acquired rapidly in mice and that a combination of procedural, behavioral, and genetic variables contributes to this acquisition. 相似文献
86.
Abreu-Rodrigues J Lattal KA dos Santos CV Matos RA 《Journal of the experimental analysis of behavior》2005,83(2):147-168
Experiment 1 investigated the controlling properties of variability contingencies on choice between repeated and variable responding. Pigeons were exposed to concurrent-chains schedules with two alternatives. In the REPEAT alternative, reinforcers in the terminal link depended on a single sequence of four responses. In the VARY alternative, a response sequence in the terminal link was reinforced only if it differed from the n previous sequences (lag criterion). The REPEAT contingency generated low, constant levels of sequence variation whereas the VARY contingency produced levels of sequence variation that increased with the lag criterion. Preference for the REPEAT alternative tended to increase directly with the degree of variation required for reinforcement. Experiment 2 examined the potential confounding effects in Experiment 1 of immediacy of reinforcement by yoking the interreinforcer intervals in the REPEAT alternative to those in the VARY alternative. Again, preference for REPEAT was a function of the lag criterion. Choice between varying and repeating behavior is discussed with respect to obtained behavioral variability, probability of reinforcement, delay of reinforcement, and switching within a sequence. 相似文献
87.
Effectiveness Research: Transporting Interpersonal Psychotherapy for Depressed Adolescents (IPT-A) From the Lab to School-Based Health Clinics 总被引:2,自引:0,他引:2
Mufson LH Dorta KP Olfson M Weissman MM Hoagwood K 《Clinical child and family psychology review》2004,7(4):251-261
This paper describes the process of modifying and transporting an evidence-based treatment, Interpersonal Psychotherapy for Depressed Adolescents (IPT-A), from a university setting to school-based health clinics. It addresses conceptual issues involved in the shift from efficacy to effectiveness research as well as operational issues specific to the transport of IPT-A into school-based health clinics. Consideration is given to the rationale for an IPT-A effectiveness study, methodological concerns, and the timing of the move from the lab to the community. The authors identify challenges and barriers to initiating effectiveness and transportability research and provide suggestions for overcoming these barriers. Recommendations for conducting research in school-based practice settings are provided. 相似文献
88.
Szawarski Z 《Science and engineering ethics》2004,10(1):57-64
This paper attempts to define the concept of placebo as it is used in the clinical context The author claims that X is a placebo
if and only if X has such a property dp, that whenever in a therapeutic situation T a stimulus S appears, then in attending conditions A, it will cause a beneficial
reaction R in the patient. Formally, the same structure may be used to define any pharmacologically active drug. The main
difference between the drug and a placebo is in the range of possible substitutions for X and the property d. For the active
drug there is only one possible substitution for X and property d and it can be scientifically explained why, and how the
drug works. In the case of a placebo a set of possible substitutions for X and d is open, and so far it is impossible to offer
any scientifically valid explanation of the action mechanism of placebo. 相似文献
89.
Fisher WW DeLeon IG Rodriguez-Catter V Keeney KM 《Journal of applied behavior analysis》2004,37(2):171-184
Recent research has shown that the noncontingent delivery of competing stimuli can effectively reduce rates of destructive behavior maintained by social-positive reinforcement, even when the contingency for destructive behavior remains intact. It may be useful, therefore, to have a systematic means for predicting which reinforcers do and do not compete successfully with the reinforcer that is maintaining destructive behavior. In the present study, we conducted a brief competing stimulus assessment in which noncontingent access to a variety of tangible stimuli (one toy per trial) was superimposed on a fixed-ratio 1 schedule of attention for destructive behavior for individuals whose behavior was found to be reinforced by attention during a functional analysis. Tangible stimuli that resulted in the lowest rates of destructive behavior and highest percentages of engagement during the competing stimulus assessment were subsequently used in a noncontingent tangible items plus extinction treatment package and were compared to noncontingent attention plus extinction and extinction alone. Results indicated that both treatments resulted in greater reductions in the target behavior than did extinction alone and suggested that the competing stimulus assessment may be helpful in predicting stimuli that can enhance the effects of extinction when noncontingent attention is unavailable. DESCRIPTORS: Attention-maintained problem behavior, competing stimuli, extinction, functional analysis, noncontingent reinforcement 相似文献
90.
We evaluated computerized training and testing programs with children who were having difficulties learning prereading skills. The programs were derived from equivalence research and were written in authoring software designed for educators. After learning to match uppercase and lowercase printed letters to the corresponding letter names (Tasks 1 and 2), the children matched the letters to one another (Tasks 4 and 5). Then, after learning to match uppercase letters to sounds (Task 3), they also matched lowercase letters to sounds (Task 6) and matched printed to spoken words (Tasks 7 and 8). The results recommend equivalence-based protocols and user-friendly software in further development of prereading instruction. 相似文献