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   55954篇
  免费   1975篇
  国内免费   19篇
  57948篇
  2018年   847篇
  2017年   835篇
  2016年   913篇
  2015年   636篇
  2014年   784篇
  2013年   4917篇
  2012年   1430篇
  2011年   1510篇
  2010年   955篇
  2009年   913篇
  2008年   1359篇
  2007年   1264篇
  2006年   1176篇
  2005年   1011篇
  2004年   1000篇
  2003年   995篇
  2002年   1002篇
  2001年   1772篇
  2000年   1714篇
  1999年   1315篇
  1998年   606篇
  1996年   654篇
  1995年   615篇
  1994年   620篇
  1993年   606篇
  1992年   1269篇
  1991年   1143篇
  1990年   1169篇
  1989年   1060篇
  1988年   1043篇
  1987年   1028篇
  1986年   1033篇
  1985年   1037篇
  1984年   883篇
  1983年   749篇
  1982年   594篇
  1981年   597篇
  1979年   893篇
  1978年   674篇
  1976年   578篇
  1975年   831篇
  1974年   835篇
  1973年   881篇
  1972年   815篇
  1971年   734篇
  1970年   658篇
  1969年   704篇
  1968年   833篇
  1967年   722篇
  1966年   718篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Criterion-related validity data for the Child Behavior Checklist—Teacher's Report Form are presented. These data were collected from a sample of elementary school boys. A total behavior problem score and individual factor scores were calculated from the checklist data and were related to indices of academic achievement and overall adjustment in the classroom. Significant correlations were established between the two sets of scores. The results were interpreted as supporting the criterion-related validity of the teacher-judgment measure and its use as a screening or diagnostic device in the school.  相似文献   
972.
Three untested assumptions of the impulse-variability model were examined in two experiments utilizing rapid, uni-planar limb movements. Experiment 1 varied movement distance (A) and movement time (MT) in a rapid-timing paradigm where the subject moved a lever through a certain distance in a certain time. Experiment 2 varied A in a reversal response where the S made a rapid elbow flexion and extension in a given MT. Displacement recordings were made on every trial. KR (knowledge of results) about MT was given after every trial. The results can be summarized as follows: (a) As predicted by the model, variations in impulse size and velocity were directly related to the impulses size; (b) There was no correlation between the accelerative and decelerative impulse durations recorded during the reversal response supporting the notion that the impulses might be independent; (c) Negative correlations (-.20 to -.50) were demonstrated between peak acceleration and impulse duration for both experiments, counter to the predictions of the model; and (d) Counter to the predictions of the model, timing error (VEt) increased as A decreased for rapid-timing responses. When the correlational results are taken into account, the model has the capacity to account for curvilinear relationships between relative timing error and movement speed. Overall, the results suggest that the impulse variability model requires some restructuring before it can be considered a viable model for the control of rapid limb movements.  相似文献   
973.
The equilibrium control hypothesis (lambda model) is considered with special reference to the following concepts: (a) the length-force invariant characteristic (IC) of the muscle together with central and reflex systems subserving its activity; (b) the tonic stretch reflex threshold (lambda) as an independent measure of central commands descending to alpha and gamma motoneurons; (c) the equilibrium point, defined in terms of lambda, IC and static load characteristics, which is associated with the notion that posture and movement are controlled by a single mechanism; and (d) the muscle activation area (a reformulation of the "size principle")--the area of kinematic and command variables in which a rank-ordered recruitment of motor units takes place. The model is used for the interpretation of various motor phenomena, particularly electromyographic patterns. The stretch reflex in the lambda model has no mechanism to follow-up a certain muscle length prescribed by central commands. Rather, its task is to bring the system to an equilibrium, load-dependent position. Another currently popular version defines the equilibrium point concept in terms of alpha motoneuron activity alone (the alpha model). Although the model imitates (as does the lambda model) spring-like properties of motor performance, it nevertheless is inconsistent with a substantial data base on intact motor control. An analysis of alpha models, including their treatment of motor performance in deafferented animals, reveals that they suffer from grave shortcomings. It is concluded that parameterization of the stretch reflex is a basis for intact motor control. Muscle deafferentation impairs this graceful mechanism though it does not remove the possibility of movement.  相似文献   
974.
A consistent phonology between sequentially presented pseudoword quadrigrams was found to improve performance in a letter-detection task. Each of 8 subjects was required to judge whether an M appeared in either the initial or terminal position of letter strings. The letter N was used as a foil. For each presentation, two quadrigrams appeared sequentially, the first for 20 ms and the second for a duration that allowed approximately 75% overall accuracy. The strings differed only by the letter next to the one on the opposite end of the string from the M or N. Subjects were not told that two strings were exposed on each presentation, and when asked, none reported having been aware of this. Nevertheless, detection was significantly better when the two strings were homophones (e.g., SERM, SIRM) than when they were not (e.g., SARM, SORM). Results are discussed in terms of phonological access to the mental lexicon.  相似文献   
975.
Children aged 1.5 to 8 years were required to touch accurately an illuminated target lamp located on a vertical board. Movements were made when visual information was complete (target lit for 3 s, room illuminated; partial (target lit for 3 s, room dark, and reduced (target lit for 0.7 s, room dark). Dependent variables were response accuracy, reaction time, and movement time. Accuracy decreased with decreasing availability of visual information and improved with age under all conditions. Reaction times were shorter in the dark (Conditions 2 and 3) than in the light; they decreased with age up to age 5 and did not continue to decrease thereafter. Movement time did not change with age under Conditions 1 and 3 but tended to increase with age under Condition 2. Slower movements were more accurate at all ages, provided visual feedback could be utilized. Increased reliance on the strategy "slower movements yield higher accuracy" was held to account for developmental changes under Condition 2, whereas in Conditions 1 and 3 improvement in the efficiency of motor preprogramming was implicated.  相似文献   
976.
977.
Predicting adult temperament from minor physical anomalies   总被引:1,自引:0,他引:1  
It is known that in children, individual differences in temperament are linked to rates of minor physical anomalies (MPAs). These anomalies are a standard set of 17 nonobvious but measurable characteristics of the face, hands, and feet. We explored the relation between MPAs and temperament in adults. An intact sample of 88 undergraduates completed a battery of personality tests and lifestyle questions, and then were examined for MPAs. The index of MPAs for each subject was simply the total count out of 17. The results showed a pattern of correlates parallel to that found in children. Among male subjects, correlations with MPAs were significant for the Physical Activity and Clumsiness factors of the lifestyle inventory as well as for measures of emotionality, extraversion, masculinity, femininity, and Type A personality. The MPA index was also predictive of a behavioral index of temperament in male subjects. No correlations were significant among female subjects.  相似文献   
978.
This investigation is one of a series of studies seeking to determine the degree of control given to women with different sex role identities. This study focused on the extent to which peers were willing to grant control to women with different sex role identities if working individually with each woman on various two-person tasks. The results indicated that women with different sex role identities were granted different amounts of control by their peers as a function of the type of two-person task under consideration. Women rated high on masculinity were granted greater control on enjoyable and creative tasks, whereas women rated low in masculinity were given more control on methodical and less enjoyable tasks. Women judged high in femininity were given control on tasks requiring interpersonal skills. These findings were discussed within the context of learned helplessness theory as a possible aid in understanding why more women than men become depressed.  相似文献   
979.
Altruism and aggression: the heritability of individual differences   总被引:8,自引:0,他引:8  
Five questionnaires measuring altruistic and aggressive tendencies were completed by 573 adult twin pairs of both sexes from the University of London Institute of Psychiatry Volunteer Twin Register. The questionnaires measured altruism, empathy, nurturance, aggressiveness, and assertiveness. The intraclass correlations for the five scales, respectively, were .53, .54, .49, .40, and .52 for 296 monozygotic pairs, and .25, .20, .14, .04, and .20 for 179 same-sex dizygotic pairs, resulting in broad heritability estimates of 56%, 68%, 70%, 72%, and 64%. Additional analyses, using maximum-likelihood model-fitting, revealed approximately 50% of the variance on each scale to be associated with genetic effects, virtually 0% with the twins' common environment, and the remaining 50% with each twins' specific environment and/or error associated with the test. Correcting for the unreliability in the tests raised the maximum-likelihood heritabilities to approximately 60%. Age and sex differences were also found: altruism increased over the age span from 19 to 60, whereas aggressiveness decreased, and, at each age, women had higher scores than men on altruism and lower scores on aggressiveness.  相似文献   
980.
Depriving mother-child relationships at an early age lay the foundation for narcissistic disturbances. Here, the specific focus is on mother-daughter relationships and the lack of appropriate maternal recognition and admiration of the infant. The particular treatment modality combines individual psychotherapy with a female therapist and group therapy in an all-women's group. The transferential phenomena to the various women found in this treatment situation are instrumental in helping the female patient achieve a significant change in her narcissistic personality.  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