首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1288篇
  免费   56篇
  国内免费   2篇
  2023年   8篇
  2020年   11篇
  2019年   21篇
  2018年   18篇
  2017年   23篇
  2016年   29篇
  2015年   15篇
  2014年   29篇
  2013年   126篇
  2012年   42篇
  2011年   50篇
  2010年   33篇
  2009年   28篇
  2008年   58篇
  2007年   44篇
  2006年   38篇
  2005年   34篇
  2004年   44篇
  2003年   46篇
  2002年   39篇
  2001年   17篇
  2000年   25篇
  1999年   22篇
  1998年   17篇
  1997年   23篇
  1996年   23篇
  1995年   20篇
  1994年   22篇
  1993年   19篇
  1992年   24篇
  1991年   10篇
  1990年   17篇
  1989年   12篇
  1988年   10篇
  1987年   15篇
  1986年   17篇
  1985年   16篇
  1984年   29篇
  1983年   28篇
  1982年   11篇
  1981年   22篇
  1980年   11篇
  1979年   10篇
  1978年   11篇
  1977年   26篇
  1976年   15篇
  1975年   25篇
  1974年   12篇
  1973年   16篇
  1972年   12篇
排序方式: 共有1346条查询结果,搜索用时 15 毫秒
871.
Youth discharged from a short-term residential facility and reunified with their parents were contacted at least one year after discharge to determine whether or not they had a disruption in their placement since reunification. Follow-up intervals of 149 youth contacted (82% of the eligible sample) ranged from a minimum of 12 months to a maximum of 30 months post-discharge. Differences in the time to placement disruption were analyzed using survival analysis techniques. After controlling for adjustment differences during the treatment program, youth behavior problems, and family problems, a significant interaction of youth age and treatment intensity was found: Compared to the others, younger youth who received additional treatment components had placement disruptions later and less frequently.  相似文献   
872.
Power analysis guides researchers in planning how much data to collect. This article describes BWPower, a computer program for the Windows 95 environment that performs power analyses for research designs that may or may not include both between- and within-subjects factors. We discuss how BWPower easily accommodates both between- and within-subjects factors and provide examples of BWPower’s use in performing power analyses on designs with only between-subjects factors, designs with only repeated measures, and with mixed between- and within-subjects designs. We highlight the major features of BWPower’s user interface, such as the ability to iteratively increment or decrement the number of subjects and the automatic recalculation of power when the number of subjects or effect sizes is changed.  相似文献   
873.
Flashbulb Memories are memories for the circumstances in which one first learned of a very surprising and consequential (or emotionally arousing) event. Hearing the news that President John Kennedy had been shot is the prototype case. Almost everyone can remember, with an almost perceptual clarity, where he was when he heard, what he was doing at the time, who told him, what was the immediate aftermath, how he felt about it, and also one or more totally idiosyncratic and often trivial concomitants. The present paper reports a questionnaire inquiry into the determinants of such memories by asking about other assassinations, highly newsworthy events, and personally significant events. It is shown that while the Kennedy assassination created an extraordinarily powerful and widely shared flashbulb memory, it is not the only event that has created such memories. The principal two determinants appear to be a high level of surprise, a high level of consequentiality, or perhaps emotional arousal (assessed by both rating scales and ethnic group membership). If these two variables do not attain sufficiently high levels, no flashbulb memory occurs. If they do attain high levels, they seem, most directly, to affect the frequency of rehearsal, covert and overt, which, in turn, affects the degree of elaboration in the narrative of the memory that can be elicited experimentally. Parallels are made explicit between the behavioral theory and a less elaborated, speculative neuro-physiological theory of which R. B. Livingston (1967) is the proponent Finally, an argument is made that a permanent memory for incidental concomitants of a surprising and consequential (in the sense of biologically significant) event would have high selection value and so could account for the evolution of an innate base for such a memory mechanism.  相似文献   
874.
Models of psychopathologies can be construed as modifications to the normal purposive behavior of an organism. The particular elements of purposive behavior to be emphasized here are (1) deriving facts about the environment (inferences), (2) attending to the self's needs, desires, and interests (affects), and (3) choosing directions and goals to fulfill these interests (intentions). A series of processes in a model of paranoia which performs these tasks will be described. We also describe the modifications made by the paranoid processes to the normal processes. A computer simulation has been constructed to test the model.  相似文献   
875.
Four experiments are reported which demonstrate the importance of the reinstatement of retrieval cues in partial-reinforcement experiments using spaced trials. Reinstatement occurs when the goalbox and startbox are of the same brightness (gray). Nonreinstatement occurs when the goalbox and startbox are of different brightnesses (black-and-white striped vs gray). Under reinstatement conditions, both a partial-reinforcement effect (PRE) and N-length effects were observed whether small reward or large reward was used. Under nonreinstatement conditions, a PRE was observed when large reward was used but not when small reward was used; N-length effects were not observed either with large or small reward. Finally, using a 24-hr intertrial interval, single alternation patterning was found only with a group receiving large reward, a long nonreward confinement duration, and reinstatement. These results are not consistent with the notion that massed and spaced trials are governed by separate mechanisms, and support an explanation of both massed and spaced trials based on E. J. Capaldi's sequential theory.  相似文献   
876.
A visual bar alternately presented in vertical and horizontal orientations appeared to rotate 90° through one of two pairs of opposite quadrants. Subjects judged whether a probe dot, interjected at some delay and angular deviation from the vertical bar, appeared before or after the bar “passed through” the corresponding angular orientation. When the motion was perceived in the probed quadrant, percent “before” responses dropped abruptly from near 100% to near 0% as delay increased, and the drop occurred at longer delays for probes at larger angular deviations. Under physically identical conditions, when the motion was perceived in an unprobed quadrant, percent “before” responses varied much less with delay and insignificantly with angular position. The accuracy of the judgments in the first case suggests the internal generation of an ordered sequence of intermediate representations during each apparent rotation.  相似文献   
877.
878.
It was predicted that a talker would clarify the sentential relations of an utterance if a listener indicated difficulty in hearing and understanding. Subjects read syntactically clear and distorted sentences to a listener (experimenter) in an adjoining room. The experimenter often asked “What?” Subjects changed distorted versions to clear versions, while repeating clear versions essentially as first read. Other subjects were asked to make the sentences clear and simple to understand. The same basic results were obtained. Talkers thus seem to interpret a “What?” partly as a request for clearer sentential relations and respond accordingly. The results indicate that talkers have knowledge of underlying structure. Several alternate explanations can be rejected. A relative derivational theory of complexity is presented.  相似文献   
879.
Phoneme labeling and discrimination experiments were conducted with a continuum of voiced stops produced by a Terminal Analog Speech Synthesizer. The stops ranged from |b| to |d|. Only second formant (F2) transitions changed from one sound to another. (A formant is energy concentrated in a narrow frequency range.) In the labeling experiment conducted to locate the phoneme boundary, subjects identified the individual stimuli as |b| and |d|. In discrimination, difference and identity pairs were presented, with alternative responses of same and different. This allows separate consideration of discrimination (different/Different) and recognition (same/Identity) hits, and also analysis of the data in accordance with the theory of signal detectibility. The sounds were discriminated with and without F 1 and F 3 which contained no discriminatory information, but are responsible for perceived similarity to speech. With F 1 F 3 , sensitivity (d) was highest at the |b-d| boundary, but without F 1 F 3 this was not true. Spectral analysis of the sounds both with and without F 1 F 3 revealed a phonemic energy discontinuity for the 1/3 octave around the F 2 steady-state frequency (1250 Hz). It therefore seems probable that subjects listened to frequencies which contained phonemic information when F 1 F 3 were included, but not when they were omitted. In spite of the high sensitivity at the |b-d| boundary, recognition hits (same /Identity) were lowest the boundary had to sound less like a difference to be called different than a pair away from the boundary.Indications, then, are quite strong that auditory-frequency selection helps the perception of speech, and it is clear that a strategy of criterion lowering helps it.  相似文献   
880.
The discovery of the effects of risky shift focusses the interest on the study of decision processes. Nevertheless the researches carried on until now have always shown confusion between the theoretical and experimental analysis of these processes and the risk-related behavior. In the first part of the article the authors try to clear this confusion as well as to define the conditions of a systematic study of the mechanisms of decision leading either to an averaging or to a polarization of individual views. The authors insist on the necessity to compare groups rather than individuals to groups. To start with, one hypothesis concerning the effects of group organization on the degree of polarization of views is proposed. The experiment described in the second part of the article confirms the hypothesis: A group in which individuals have the possibility to communicate with each other and to interact directly take more extreme decisions than a group deprived of this possibility. It is presumptuous and inexact to state that groups take more extreme risk than individuals whereas it is right to say that certain groups take risks when circumstances are favorable.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号