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   1866篇
  免费   116篇
  2023年   19篇
  2022年   12篇
  2021年   47篇
  2020年   59篇
  2019年   68篇
  2018年   76篇
  2017年   93篇
  2016年   93篇
  2015年   74篇
  2014年   78篇
  2013年   254篇
  2012年   151篇
  2011年   110篇
  2010年   64篇
  2009年   72篇
  2008年   85篇
  2007年   82篇
  2006年   62篇
  2005年   41篇
  2004年   44篇
  2003年   43篇
  2002年   31篇
  2001年   23篇
  2000年   23篇
  1999年   17篇
  1998年   12篇
  1997年   12篇
  1996年   9篇
  1994年   8篇
  1993年   9篇
  1992年   13篇
  1991年   10篇
  1990年   7篇
  1989年   5篇
  1988年   7篇
  1987年   8篇
  1986年   8篇
  1985年   6篇
  1984年   12篇
  1983年   8篇
  1982年   6篇
  1981年   7篇
  1980年   11篇
  1979年   12篇
  1978年   9篇
  1977年   5篇
  1974年   7篇
  1973年   5篇
  1972年   9篇
  1971年   6篇
排序方式: 共有1982条查询结果,搜索用时 318 毫秒
981.
In 3 experiments, the authors tested performance in simple tone matching and classification tasks. Each tone was defined on location and frequency dimensions. In the first 2 experiments, participants completed a same-different matching task on the basis of one of these dimensions while attempting to ignore irrelevant variation in the other dimension. In Experiment 3, in which the tones were classified either by frequency or location, the authors explored intertrial repetition effects. The patterns of performance across these different tasks were remarkably similar and were taken to reveal basic characteristics of stimulus encoding processes. The data suggest a processing sequence in audition that reveals an early stage in which location and frequency are treated as being integral and a latter stage in which location and frequency are separable.  相似文献   
982.
This study assessed the factor structure of the Questionnaire on Smoking Urges (QSU), a commonly used assessment of cravings for cigarettes, with a sample of smokers presenting for treatment in a smoking cessation trial. On the basis of previous research, three confirmatory factor analytic models were tested. Model 1 hypothesized a 26-item, 2-factor model using the items reported in the original QSU analysis by S. T. Tiffany and D. J. Drobes (1991). Model 2 hypothesized a 12-item, 2-factor model comprised of the 6 most robust items found in each of the 2 factors of the original factor analysis. Using the 12 items from Model 2, Model 3 hypothesized a 12-item, 1-factor model. The 2nd model was found to fit the data best. Reliability was also tested using values obtained in this 2nd model, and these estimates were found to be reasonably good. Future research directions for the QSU are discussed.  相似文献   
983.
The purpose of this study is to estimate the relationship between receiving emotional support from parents early in life and an individual's health in adulthood. Analysis of data from a nationally representative sample of adults ages 25-74 years suggests that a lack of parental support during childhood is associated with increased levels of depressive symptoms and chronic conditions in adulthood. These associations between early parental support and adult health persist with increasing age throughout adulthood. Personal control, self-esteem, and social relationships during adulthood account for a large portion of these long-term associations. These findings underscore the importance of adopting a life course perspective in studying the social determinants of health among adults.  相似文献   
984.
Learning to associate a conditioned (CS) and unconditioned stimulus (US) results in changes in the processing of CS information. Here, we address directly the question whether chemical appetitive conditioning of Lymnaea feeding behavior involves changes in the peripheral and/or central processing of the CS by using extracellular recording techniques to monitor neuronal activity at two stages of the sensory processing pathway. Our data show that appetitive conditioning does not affect significantly the overall CS response of afferent nerves connecting chemosensory structures in the lips and tentacles to the central nervous system (CNS). In contrast, neuronal output from the cerebral ganglia, which represent the first central processing stage for chemosensory information, is enhanced significantly in response to the CS after appetitive conditioning. This demonstrates that chemical appetitive conditioning in Lymnaea affects the central, but not the peripheral processing of chemosensory information. It also identifies the cerebral ganglia of Lymnaea as an important site for neuronal plasticity and forms the basis for detailed cellular studies of neuronal plasticity.  相似文献   
985.
986.
The paper summarizes the first decade of the Developmental Trends Study, a prospective longitudinal study of 177 boys. Initially, they were referred to mental health clinics in Pennsylvania (Pittsburgh), and Georgia (Athens and Atlanta). Since 1987, the boys, their parents, and their teachers have been followed up almost annually. The study is unique because the cooperation rate of participants has remained very high over the years, psychiatric diagnoses were derived from structured interviews (especially disruptive behavior disorders), and many risk factors were measured over the years. The present paper summarizes key findings on the development of disruptive behavior, especially Oppositional Defiant Disorder, Conduct Disorder, and Attention Deficit-Hyperactivity Disorder. The paper also highlights results on risk factors and comorbid conditions of disruptive behaviors.  相似文献   
987.
Tatler BW  Wade NJ 《Perception》2003,32(2):167-184
Investigations of the ways in which the eyes move came to prominence in the 19th century, but techniques for measuring them more precisely emerged in the 20th century. When scanning a scene or text the eyes engage in periods of relative stability (fixations) interspersed with ballistic rotations (saccades). The saccade-and-fixate strategy, associated with voluntary eye movements, was first uncovered in the context of involuntary eye movements following body rotation. This pattern of eye movements is now referred to as nystagmus, and involves periods of slow eye movements, during which objects are visible, and rapid returns, when they are not; it is based on a vestibular reflex which attempts to achieve image stabilisation. Post-rotational nystagmus was reported in the late 18th century (by Wells), with afterimages used as a means of retinal stabilisation to distinguish between movement of the eyes and of the environment. Nystagmus was linked to vestibular stimulation in the 19th century, and Mach, Breuer, and Crum Brown all described its fast and slow phases. Wells and Breuer proposed that there was no visual awareness during the ballistic phase (saccadic suppression). The saccade-and-fixate strategy highlighted by studies of nystagmus was shown to apply to tasks like reading by Dodge, who used more sophisticated photographic techniques to examine oculomotor kinematics. The relationship between eye movements and perception, following earlier intuitions by Wells and Breuer, was explored by Dodge, and has been of fundamental importance in the direction of vision research over the last century.  相似文献   
988.
Studies in change blindness re-enforce the suggestion that veridical, pictorial representations that survive multiple relocations of gaze are unlikely to be generated in the visual system. However, more abstract information may well be extracted and represented by the visual system. In this paper we study the types of information that are retained and the time courses over which these representations are constructed when participants view complex natural scenes. We find that such information is retained and that the resultant abstract representations encode a range of information. Different types of information are extracted and represented over different time courses. After several seconds of viewing natural scenes, our visual system is able to construct a complex information-rich representation.  相似文献   
989.
Relations of daily hassles with both anxious and depressed mood in students   总被引:10,自引:0,他引:10  
Stressful life experiences have been related to emotional distress, but whether different classes of stressful events are associated with different emotional reactions has not been assessed. In this study, 34 college students completed the Inventory of College Students' Recent Life Experiences, State-Trait Anxiety Inventory, and Beck Depression Inventory. Consistent with previous research, most classes of daily hassles were significantly related to both depression and anxiety. The nonsignificant difference for one class of life experience, Friendship Problems, to be more strongly associated with anxiety than depression should be studied carefully.  相似文献   
990.
Rats (Rattus norvegicus) were allowed to hide food items on an 8-arm radial maze by carrying the items from the center to boxes at the end of each arm. Retrieval tests given after rats had hidden 4 items showed that they selectively returned to the maze arms where food had been hidden (Experiments 1 and 2). When rats were allowed to hide pieces of cheese (refed food) and pretzels (less preferred food) on different arms, they both hid and retrieved cheese before pretzels (Experiments 2-5). In Experiment 6, rats chose between arms where cheese and pretzels were hidden,with cheese degraded at one delay interval but not the other. Together, these experiments indicate memory for what and where but not when.  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