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   1051篇
  免费   34篇
  2023年   6篇
  2022年   3篇
  2021年   15篇
  2020年   20篇
  2019年   20篇
  2018年   18篇
  2017年   32篇
  2016年   25篇
  2015年   17篇
  2014年   19篇
  2013年   104篇
  2012年   48篇
  2011年   52篇
  2010年   42篇
  2009年   33篇
  2008年   54篇
  2007年   53篇
  2006年   41篇
  2005年   50篇
  2004年   48篇
  2003年   32篇
  2002年   44篇
  2001年   15篇
  2000年   16篇
  1999年   15篇
  1998年   21篇
  1997年   15篇
  1996年   7篇
  1995年   10篇
  1994年   11篇
  1993年   16篇
  1992年   17篇
  1991年   15篇
  1990年   12篇
  1989年   7篇
  1988年   16篇
  1987年   5篇
  1986年   10篇
  1985年   15篇
  1984年   14篇
  1983年   11篇
  1982年   9篇
  1981年   14篇
  1980年   7篇
  1979年   4篇
  1978年   7篇
  1977年   5篇
  1976年   2篇
  1967年   3篇
  1937年   3篇
排序方式: 共有1085条查询结果,搜索用时 15 毫秒
211.
A cigarette-smoke delivery system is described in which nicotine dosage was delimited by having the subject inhale a measured amount of smoke to a predetermined depth and duration of inhalation. A plastic syringe was used to “inject” a specified amount of cigarette smoke into the subject’s mouth, and an airbag containing 1 liter of air was used to provide a “chaser” with a fixed volume of inhalation for the smoke. Using plasma nicotine boost as an indicator, dose control was found to be nearly linear for the three dose levels employed; in the high-dose condition, plasma nicotine levels were moderately consistent within subjects over three successive administrations. Between-subject variability was considerably greater than within-subject variability, however, suggesting that each smoker obtained a characteristic nicotine boost that reflected individual differences in nicotine pharmacokinetics in addition to nicotine intake per se.  相似文献   
212.
213.
Despite the critical role of the goal difficulty construct in predicting the effects of goals on task performance, the choice of goal difficulty measure(s) has not played a prominent role in goal setting research. The current laboratory study, using 92 college students, examines three operationalizations of the goal difficulty construct: assigned goal level (objective or direct measure), self-referenced goal difficulty perception. and an externally-referenced goal difficulty perception. The results clearly demonstrated that the choice of a goal difficulty measure matters in relation to other constructs in goal setting theory. Furthermore, it was found that the externally-referenced goal difficulty perception measure corresponded best with assigned goal level.  相似文献   
214.
The Fear Survey Schedule for Children-Revised (FSSC-R), Revised-Children's Manifest Anxiety Scale (RCMAS), and the Modified State-Trait Anxiety Inventory for Children (STAIC-M) are three widely used self-report measures of childhood anxiety. While previous studies have established the reliability of these measures, their validity in discriminating anxious from non-anxious youngsters remains to be established. The present study examines the discriminant validity of the three measures by comparing clinic referred samples of boys with an anxiety disorder (n=105) or ADHD (n=59) with a community sample of never-psychiatrically-ill boys (n=49). Results indicated that the two patient groups differed significantly from the never-psychiatrically-ill group on the RCMAS and STAIC-M, but the anxious and ADHD groups did not differ from each other. None of the three groups differed on the FSSC-R. The implications of these findings for the assessment of childhood anxiety disorders are discussed.  相似文献   
215.
Summary Four experiments are reported that investigated idiomatic processing. Two experiments collected subjects' ratings of frozenness, familiarity, and meaningfulness for a set of idioms. The ratings obtained were used to assess the contributions of these dimensions to performance in two experiments that utilized a phoneme-identification task. Ambiguous and unambiguous phoneme targets occurred as the initial sound in the final word in idiomatic and neutral carrier phrases. Subjects' phoneme identifications were biased in the labeling of ambiguous segments in that identification responses in the idiom context tended to form an idiomatic phrase, more so than those in the neutral carrier phrase. Additional correlational analyses suggested that an idiom's degree of influence on identification depended on the rated syntactic frozenness. For subjects who knew the idioms, familiarity did not account for the biasing effect of idiomatic contexts. The experiments are discussed in terms of theories of auditory word recognition and the representation of frozenness in the mental lexicon.This research was supported by NIDCD Grant R29 NS26 587 to the first author.  相似文献   
216.
217.
The effects of selective cholinergic cell loss within the basal forebrain (BF) were determined using a task that requires shifting of attention between two visual stimuli. Discriminability between two stimuli and response bias were determined in young and old F-344 rats given BF injections of IgG-192 saporin (100 ng). The lesion reduced ChAT activity in the frontal and parietal cortices, hippocampus, and olfactory bulbs. The lesion did not significantly alter Na+/K+-ATPase activity in cortex, hippocampus, or olfactory bulbs, or endogenous levels of neuropeptide Y and neurokinin B within the BF. The BF lesions impaired both stimulus discriminability and response bias in young and old rats. The BF lesions had a significantly greater effect upon stimulus discriminability and response bias in aged rats, compared to young rats, only when the stimulus duration was very brief, i.e., when the task was most difficult to solve. At longer stimulus durations, aging and lesions showed no interaction. The results suggest that the selective loss of cholinergic cells in the BF, but not normal aging, impairs the ability to discriminate between independent sensory stimuli. The loss of these cells confers a response bias in simple operant tasks involving motor responses to reward-related visual stimuli.  相似文献   
218.
Interpreting and responding appropriately to facial expressions of emotion are important aspects of social skills. Some children, adolescents, and adults with various psychological and psychiatric disorders recognize facial expressions less proficiently than their peers in the general population. We wished to determine if such deficits existed in a group of 133 children and adolescents with emotional and behavioral disorders (EBD). The subjects were receiving in-patient psychiatric services for at least one of substance-related disorders, adjustment disorders, anxiety disorders, mood disorders or disruptive behavior disorders. After being read stories describing various emotional reactions, all subjects were tested for their ability to recognize the 6 basic facial expressions of emotion depicted in Ekman and Friesen's (1976) normed photographs. Overall, they performed well on this task at levels comparable to those occurring in the general population. Accuracy increased with age, irrespective of gender, ethnicity, or clinical diagnosis. After adjusting for age effects, the subjects diagnosed with either adjustment disorders, mood disorders, or disruptive behavior disorders were significantly more accurate at identifying anger than those without those diagnoses. In addition, subjects with mood disorders identified sadness significantly more accurately than those without this diagnosis, although the effect was greatest with younger children.  相似文献   
219.
220.
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