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   473篇
  免费   19篇
  2023年   5篇
  2020年   6篇
  2019年   5篇
  2018年   8篇
  2017年   12篇
  2016年   5篇
  2015年   9篇
  2014年   8篇
  2013年   44篇
  2012年   16篇
  2011年   14篇
  2010年   8篇
  2009年   11篇
  2008年   16篇
  2007年   17篇
  2006年   10篇
  2005年   17篇
  2004年   13篇
  2003年   10篇
  2002年   15篇
  2001年   15篇
  2000年   13篇
  1999年   8篇
  1998年   10篇
  1997年   4篇
  1996年   9篇
  1995年   5篇
  1994年   5篇
  1992年   9篇
  1991年   10篇
  1990年   9篇
  1989年   5篇
  1984年   4篇
  1983年   13篇
  1982年   4篇
  1981年   4篇
  1980年   7篇
  1979年   6篇
  1978年   6篇
  1977年   8篇
  1976年   8篇
  1975年   6篇
  1974年   6篇
  1973年   7篇
  1972年   3篇
  1971年   4篇
  1970年   8篇
  1968年   4篇
  1967年   11篇
  1962年   3篇
排序方式: 共有492条查询结果,搜索用时 0 毫秒
411.
BETTS GL 《Psychometrika》1950,15(4):435-439
The P50-discriminant has been reported elsewhere in connection with its use in predicting whether selective service registrants if inducted would become normal operative soldiers or would commit offenses causing their imprisonment. The standard error of the P50-discriminant is a good measure to use in determining how far to the side of this statistic a particular case falls. The standard error formula itself has also been published elsewhere; but its derivation, as the variance error, is given here.The author gratefully acknowledges the very extensive assistance kindly given to him by Dr. Truman L. Kelley and Dr. Frederick Mosteller. This assistance was given without reference to the utility of the P50-discriminant, upon which matter the author reports elsewhere and for which he takes full responsibility.  相似文献   
412.
Abstract— Experiments in cross-modal matching suggest that smells can be arranged by odor qualify along the color dimensions of hue and lightness. Here we report that subjects readily adjust the loudness-equalized pitch of on auditory tone to match a stimulus odor. The results allow odors to be arranged in sequence by their pitch-equivalents. The tone matches appear to be based on perceptual feature of olfaction other than stimulus intensity or pleasantness. The results suggest that features of odor quality may be more accessible and structured than previously acknowledged.  相似文献   
413.
414.
This study was undertaken to determine whether any EEG changes occurred during a multiple schedule of reinforcement consisting of repeated periods of avoidance behavior, a time-out (TO) period, and a period of differential reinforcement of low rates (DRL). The two monkeys were permanently implanted with bipolar electrodes in various subcortical areas. The EEG was recorded from these electrodes for several weeks before any behavioral training was undertaken. Training was then begun in the multiple schedule, and EEG recordings were taken frequently throughout the training period. When a stable performance level was achieved, drugs (dl-amphetamine and sodium pentobarbital) were introduced which disrupted the DRL performance but had little or no effect on avoidance behavior. The EEG recordings continued throughout these drug studies.

The data indicate that the marked behavioral differences noted in each component of the schedule were not reflected in the EEG. However, the EEG did correlate with the general level of alertness of the animals during the various components. The drugs which differentially affected the behavior in the components of the schedule did not differentially affect the EEG, but they did change the brain-wave activity equally in all components. Finally, EEG changes correlated with the complex motor response of lever pressing were not observed.

  相似文献   
415.
This study explores accounts and reasons for engaging in HIV risk-taking behaviors reported by heterosexual men in methadone treatment programs in the Harlem section of New York City. A convenience sample of 62 men who reported having abused their female partners in the past 12 months participated in 10 focus groups. Data analysis revealed four types of HIV risky accounts, which we labeled nihilistic, hedonistic, fatalistic, and normative. The accounts were rarely found in isolation, but were delivered in rich “performative” constellations. We conclude that normative accounts in particular have important implications for HIV prevention. They show that the (hetero)sexual act is interactive “hard work” to say the least, and condoms have no role interrupting it. In the end, the risks of losing masculine face before a female partner are very much prioritized over long-run HIV risks.  相似文献   
416.
Age-related changes in contextual associative learning   总被引:1,自引:0,他引:1  
The hippocampus plays a critical role in processing contextual information. Although age-related changes in the hippocampus are well documented in humans, nonhuman primates, and rodents, few studies have examined contextual learning deficits in old rats. The present study investigated age-related differences in contextual associative learning in young (6 mo) and old (24 mo) rats using olfactory stimuli. Stimuli consisted of common odors mixed in sand and placed in clear plastic cups. Testing was conducted in two boxes that represented two different contexts (Context 1 and Context 2). The contexts varied based on environmental features of the box such as color (black vs. white), visual cues on the walls of the box, and flooring texture. Each rat was simultaneously presented with two cups, one filled with Odor A and one filled with Odor B in each context. In Context 1, the rat received a food reward for digging in the cup containing Odor A, but did not receive a food reward for digging in the cup containing Odor B. In Context 2, the rat was rewarded for digging in the cup containing Odor B, but did receive a reward for digging in the cup containing Odor A. Therefore, the rat learned to associate Context 1 with Odor A and Context 2 with Odor B. The rat was tested for eight days using the same odor problem throughout all days of testing. The results showed no significant difference between young and old rats on the first two days of testing; however, young rats significantly outperformed old rats on Day 3. Young rats continued to maintain superior performance compared to old rats on Days 4-8. The results suggest that aging results in functional impairments in brain regions that support memory for associations between specific cues and their respective context.  相似文献   
417.
This study investigated helpful and disturbing factors in multi-family groups with hospitalized, depressed patients and their family members. Both patients and their partners reported the occurrence of different therapeutic factors such as the cohesion of the group, different observational processes, and guidance from the therapist. The frequency of the therapeutic factors seemed to increase for both the patients and their partners as the group sessions progressed and several differences in reported therapeutic factors were found between the patients and their partners. A number of therapeutic factors such as modelling and guidance from the therapist were found to be related with improvement of depressive symptoms of the patient. The results help to provide some insight into which processes are important in multi-family group therapy for depression.  相似文献   
418.
Harman (1986) asserts that logic is neither a normative nor a psychological theory and, although immediate implication and inconsistency may play a role in reasoning, there is nothing special about logic in this connection. Field (2009) purports to reject these claims but actually accepts them and concludes that, because of the semantic paradoxes, logic is 'somehow connected to norms of thought'. A real non sequitur!  相似文献   
419.
This essay focuses on what patriotism is, as opposed to the value of patriotism. It focuses further on the basic patriotic motive: one acts with this motive if one acts on behalf of one’s country as such. I first argue that pre-theoretically the basic patriotic motive is sufficient to make an act patriotic from a motivational point of view. In particular the agent need not ascribe virtues or achievements to his country nor need he feel towards it the emotions characteristic of love. Why should one ever act on behalf of one’s country as such, if one does not particularly admire it or feel a special affection for it? In answer to this question I offer a further articulation of the basic patriotic motive, invoking a particular understanding of what it is to be the member of a political society. Building on this articulation I then consider how one might characterize a patriotic act, a patriotic person, and the relationship of patriotism and pride.  相似文献   
420.
The Predominantly Inattentive (PI) and Combined (CB) subtypes of AD/HD differ in cognitive tempo, age of onset, gender ratio, and comorbidity, yet a differentiating endophenotype has not been identified. The aim of this study was to test rigorously diagnosed PI, CB, and typical children on measures selected for their potential to reveal hypothesized differences between the subtypes in specific neurocognitive systems (anterior vs. posterior attentional systems) and processes (arousal vs. activation). Thirty-four CB and 26 PI children meeting full DSM-IV criteria for subtype both in school and at home, without confounding reading disability or emotional disorder, were enrolled along with 20 typically developing children. Neurocognitive functions measured included attention, inhibitory control, working memory, learning, and executive functions. Tasks included the Stroop, Wisconsin Card Sorting Test, Continuous Performance Test (CPT). Buschke Selective Reminding Test, ad the Tower of London (TOL), as well as instruments developed by Posner and Sternberg, and tasks assessing the impact on reaction time of [corrected] varying preparatory intervals and stimulus/response complexity. After co-varying for IQ, subtypes differed primarily on measures of impulsivity during tests of vigilance (CPT) and executive function (TOL), with the CB group showing greater impulsivity than both other groups. In addition, the PI group showed worse performance than CB and control groups on the WISC-III Processing Speed Index. Whether analyzed with or without an IQ co-variate, there was no support in the data for hypothesized differences between subtypes in functioning of the anterior vs. posterior attentional systems, nor in involvement of arousal vs. activation processes. The results indicate that the PI and CB subtypes are best differentiated by ratings, observations and tests of cognitive tempo and behavioral impulsivity. Neuropsychological methods have yet to identify critical neuropsychological [corrected] substrates of these differences.  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