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   64706篇
  免费   2463篇
  国内免费   30篇
  2020年   681篇
  2019年   895篇
  2018年   1204篇
  2017年   1320篇
  2016年   1285篇
  2015年   927篇
  2014年   1095篇
  2013年   5073篇
  2012年   1968篇
  2011年   2088篇
  2010年   1345篇
  2009年   1314篇
  2008年   1876篇
  2007年   1846篇
  2006年   1691篇
  2005年   1460篇
  2004年   1352篇
  2003年   1366篇
  2002年   1313篇
  2001年   2124篇
  2000年   2054篇
  1999年   1559篇
  1998年   701篇
  1997年   640篇
  1996年   612篇
  1994年   616篇
  1992年   1320篇
  1991年   1214篇
  1990年   1227篇
  1989年   1117篇
  1988年   1117篇
  1987年   1075篇
  1986年   1070篇
  1985年   1073篇
  1984年   911篇
  1983年   795篇
  1982年   610篇
  1979年   962篇
  1978年   704篇
  1977年   632篇
  1975年   799篇
  1974年   856篇
  1973年   944篇
  1972年   745篇
  1971年   674篇
  1970年   631篇
  1969年   693篇
  1968年   798篇
  1967年   723篇
  1966年   706篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
We have identified a fundamental property of human motor behavior as a tight coupling of the curvature-speed relationship in the reaching movements of 5- to 9-month-old infants. This relationship termed a movement unit, occurs regardless of the distance of duration of the reach and in spite of the developmental change that occurs in grasping during this period. Movement unit durations are tightly clustered around 200 ms regardless of overall duration or distance or the position of the unit in the reach. The curvature-speed coupling has been identified by others in adult reaching and handwriting. Models of biological motor control must account for this invariant relationship.  相似文献   
962.
Fantasy proneness and psychopathology   总被引:1,自引:0,他引:1  
Fantasy prone persons ("fantasizers") selected from "normal" populations report experiences associated with psychopathology in clinical populations (e.g., fantasies that reach hallucinatory proportions, difficulty discriminating reality from fantasy). In Study 1, we administered objective (MMPI) and projective (Rorschach) measures to high fantasy prone individuals (upper 4% of college population), medium fantasy prone individuals (middle range), and nonfantasizers (lowest 4%). Subjects who were fantasizers appeared to use fantasy for defensive or adaptive purposes compared with others and produced 8/9 modal code types on the MMPI. On the basis of the MMPI findings, a subset of fantasizers could be described as exhibiting a significant degree of psychopathology. In Study 2, a second sample of fantasy prone individuals could not be distinguished from comparison groups in contacts with professionals for help with psychological problems, use of psychotropic medication, or number of close friendships. Although fantasizers perceived themselves as less well adjusted than comparison subjects and reported greater difficulty in distinguishing fantasy from reality, most fantasizers rated their psychological functioning as adequate and above and did not differ from less fantasy prone subjects in ratings of positivity of self-concept. As demonstrated in Study 1, a subset of fantasizers did appear to be more pathological than other subjects were, with three fantasizers reporting a history of psychiatric hospitalizations. It is estimated that between 10 and 20% of fantasizers exhibit significant signs of maladjustment/psychopathology; however, as a rule, fantasy proneness does not appear to be antecedent to severe manifestations of psychopathology.  相似文献   
963.
There are wide individual differences in the characteristic intensity of affective response to the same emotion-evoking event. The processes whereby individuals come to experience strong or mild emotional responses when exposed to the same affect-provoking stimuli are still unclear. In these studies, we propose that individual differences in affect intensity are associated with certain cognitive operations used during exposure to emotion-relevant stimuli. Specifically, cognitive operations that involve personalizing, generalizing, and selective abstraction were hypothesized to discriminate subjects high and low in affect intensity. Two studies replicated support for the hypothesis that subjects high on the affect-intensity dimension engage in more personalizing/empathic and more generalizing/elaborative cognitive operations than do subjects low on the affect-intensity dimension. The same cognitive operations discriminated groups high and low in affect intensity in response to both positive and negative emotional stimuli. Also, the cognitions that discriminated subjects high and low in affect intensity occurred only in response to affective stimuli; neutral stimuli did not evoke divergent cognitive operations for these two groups. Finally, a high degree of consistency was found in the use of emotion-relevant cognitive operations across positive and negative affective stimuli.  相似文献   
964.
Neuromotor reaction times (simple, choice, and decision) were measured when Thyrotropin-releasing hormone (TRH) was administered intravenously to nine healthy men in a double-blind study. Measurements were made of simple reaction time, choice reaction time, and decision time for each subject at various intervals over a 54-hr. period. Given the observed inherent interaction of the drug with the long time used (54 hr.), most analyses were conducted across separate time epochs. Injected subjects showed inhibition in the normal improvement of simple reaction time (which occurs with practice), and they reduced the time required to make a decision. Choice reaction time, however, remained unchanged across the drug-nondrug experimental conditions.  相似文献   
965.
Subjects viewed upright photographs of faces, then attempted to recognize them unchanged, vertically reversed or inverted. In two of four conditions, hit scores were lower for inverted than vertically reversed faces, suggesting that lateral reversal is a meaningful component of inversion. The effect was not sufficiently strong, however, to overcome a generally high false-alarm rate for upside-down faces.  相似文献   
966.
The purpose of this study was to investigate the effect of response organization on reaction time (RT) and movement time (MT) of mildly mentally retarded children. Two groups of 30 subjects each were formed: a retarded group 9 yr. of age and a normal group matched for chronological age. Subjects were randomly assigned to one of three precued conditions in which they were told that the forthcoming response would be performed with the right or left hand (precue hand), be to the right or left side (precue direction), or cross or not cross the body midline (precue midline). The retarded group performed significantly more slowly than the normal group on both RT and MT. Both groups, however, were able to utilize precued hand information as opposed to other precued variables, indicating that knowing which hand to use is important when organizing responses.  相似文献   
967.
Vibrotactile thresholds for 7 male stutterers and 7 normal-speaking men (age range for both groups = 19 to 32 yr.) were obtained from the right, midline, and left sides of the lingual dorsum, and the thenar eminences of both hands. The stutterers showed slightly higher (less sensitive) mean thresholds than the normal speakers for all three lingual test sites. This was not the case for the thresholds obtained from both hands. The preliminary data suggest that oral peripheral sensory integrity might be somewhat different for stutterers than for normal-speaking individuals.  相似文献   
968.
969.
In the first ( N = 140) of two quasi-experimental field studies, trial group employees were changed from a 5/40 to a 4/40 work schedule for four months then returned to a 5/40 schedule. In a second study ( N = 102), trial group employees were changed from 5/40 to flextime. Reactions were evaluated using a model for understanding the impact of work schedules. The effects of schedule changes matched those anticipated by pre-intervention surveys of employees. Factors related to organizational effectiveness were enhanced where specific organizational needs were met. Interference with personal activities was reduced where employees had experienced specific difficulties. The most powerful effect, however, was on worker attitudes toward specific work schedules. In addition, a mild positive (perhaps Hawthorne) effect was evident for a wide range of general worker reactions.  相似文献   
970.
Previous cross-sectional field and laboratory research has provided mixed results as to whether recruiter characteristics and behaviors influence applicant reactions to employment opportunities. The present research was conducted to examine the effect of recruiter characteristics using a pre-post study design in a naturally occurring setting. In addition, the effects of several potential moderators on recruiter influence were tested. Results indicated that recruiter characteristics had an impact on perceived job attributes, regard for job and company, and likelihood of joining the company. There was little evidence that the effect of recruiter characteristics was moderated by selected applicant, job, or interviewer variables.  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