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   66996篇
  免费   2708篇
  国内免费   20篇
  2020年   620篇
  2019年   790篇
  2018年   1070篇
  2017年   1100篇
  2016年   1155篇
  2015年   864篇
  2014年   1022篇
  2013年   4788篇
  2012年   1959篇
  2011年   1987篇
  2010年   1216篇
  2009年   1178篇
  2008年   1755篇
  2007年   1729篇
  2006年   1577篇
  2005年   1463篇
  2004年   1393篇
  2003年   1273篇
  2002年   1304篇
  2001年   2062篇
  2000年   1931篇
  1999年   1468篇
  1998年   726篇
  1996年   606篇
  1992年   1315篇
  1991年   1235篇
  1990年   1216篇
  1989年   1141篇
  1988年   1151篇
  1987年   1095篇
  1986年   1136篇
  1985年   1234篇
  1984年   958篇
  1983年   901篇
  1982年   687篇
  1981年   660篇
  1979年   1116篇
  1978年   760篇
  1977年   684篇
  1976年   719篇
  1975年   936篇
  1974年   1073篇
  1973年   1135篇
  1972年   954篇
  1971年   879篇
  1970年   880篇
  1969年   897篇
  1968年   1145篇
  1967年   1016篇
  1966年   938篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
271.
The social support patterns of a sample of 101 suicide attempters were compared with the patterns of a control sample on the basis of structured interview data. Network characteristics and the extent of support in different functional categories were examined as to their absolute and relative power to discriminate between the suicide attempters and the controls. A clear separation of the functions of kin and of friends/acquaintances emerged. The crucial difference between the attempters and the controls lay in the number of friends with whom the subjects had agreeable everyday interactions and in the number of kin that provided crisis support, both psychological and instrumental. Other support differences between the two groups were of secondary importance. While there was no overall difference in the frequency of social interactions between the two groups, the size of the social network differed greatly. Consequences for the conceptualization and measurement of social support as well as for the prevention of suicidal behavior are discussed.  相似文献   
272.
273.
In recent years in research on intergroup relationships, the assumption has increasingly been made that discrimination dominates decisions when individuals allocate resources between (members of) own and other group. Conversely, in empirical studies of interpersonal decision-making, including an extensive literature on the development of children's allocation rules within dyadic relationships, it has been repeatedly observed that in dyadic relationships choices though responsive to various changes in the environment, are more strongly governed by fairness rules. The present research extends the interpersonal fairness paradigm to the intergroup case, and examines the effects of some of those variables, namely, children's age, input and attitudes toward other, that have been observed to influence choice behaviour within interpersonal relationships. The findings indicate that as children are socialized, fairness rules also play an increasing dominant role in intergroup allocation decisions, and that both relative input and the language of the outgroup influence such decisions. At the same time, there is some preliminary evidence to indicate that the relative strength of self-interest may be somewhat stronger in intergroup than in interpersonal relationships. Finally, a number of the issues that must be confronted in comparing the two more important forms of human social choices, interpersonal and intergroup decision-making, are considered.  相似文献   
274.
J R Lackner  P DiZio 《Perception》1988,17(1):71-80
When a limb is used for locomotion, patterns of afferent and efferent activity related to its own motion are present as well as visual, vestibular, and other proprioceptive information about motion of the whole body. A study is reported in which it was asked whether visual stimulation present during whole-body motion can influence the perception of the leg movements propelling the body. Subjects were tested in conditions in which the stepping movements they made were identical but the amount of body displacement relative to inertial space and to the visual surround varied. These test conditions were created by getting the subjects to walk on a rotatable platform centered inside a large, independently rotatable, optokinetic drum. In each test condition, subjects, without looking at their legs, compared, against a standard condition in which the floor and drum were both stationary, their speed of body motion, their stride length and stepping rate, the direction of their steps, and the perceived force they exerted during stepping. When visual surround motion was incompatible with the motion normally associated with the stepping movements being made, changes in apparent body motion and in the awareness of the frequency, extent, and direction of the voluntary stepping movements resulted.  相似文献   
275.
This study was designed to evaluate the possibility that a pattern of cognitive deficit is associated with delinquent behavior, while avoiding some of the methodological problems of previous research. The Self- Report Early Delinquency instrument and a research battery of neuropsychological tests were administered blindly to an unselected cohort of 678 13- year- olds. Because the diagnosis of attention deficit disorder (ADD) was found at markedly elevated rates in the backgrounds of these delinquents, the possibility was examined that the neuropsychological deficits of delinquents might be limited to delinquents with histories of ADD. Although delinquents with past ADD were more cognitively impaired than non-ADD delinquents, both groups scored significantly below nondelinquents on verbal, visuospatial, and visualmotor integration skills. In addition, ADD delinquents scored poorly on memory abilities. Subjects with ADD who had not developed delinquent behavior were not as cognitively impaired as ADD delinquents, suggesting that it is the specific comorbidity of ADD and delinquency that bears neuropsychological study.This work was supported by USPHS Grant 1 R23 MH-42723-01 from the Antisocial and Violent Behavior Branch of the National Institute of Mental Health. The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council of New Zealand. Appreciation is expressed for the methodological advice of Prof. Sarnoff A. Mednick, and for the data collection efforts of Mrs. Pat Brasch, Mrs. Kathleen Campbell, Mr. Rich Poulton, and the psychometrists who administered the WISC-R.  相似文献   
276.
The relationship between anxiety and depression was examined in a sample of 106 children and adolescents referred to an outpatient anxiety disorder clinic for children. Twenty-eight percent of patients with DSM-III diagnoses of anxiety disorders displayed a concurrent major depression. Children with anxiety disorders plus major depression were found (1) to be older, (2) to demonstrate more severe anxiety symptomatology, and (3) to be diagnosed with different rates of certain anxiety-disorder subtypes, when compared to anxious patients without major depression. Nondepressed anxious children and adolescents did not differ from a psychopathological control group in severity of either anxiety or depression symptoms.  相似文献   
277.
278.
Short-term memory for Chinese characters and radicals   总被引:1,自引:0,他引:1  
Short-term memory for Chinese radicals and characters, varying in orthographic complexity, frequency, and—for radicals—intercharacter frequency (the number of compound characters that contain the radical), was studied using an immediate free-recall task. When radicals or characters are relatively frequent, so that their pronunciations are well known by literate Chinese, they seem to be maintained in verbal form in short-term memory. For these stimuli, intercharacter frequency and complexity have relatively small influences on memory span. Stimuli low in frequency, with pronunciations that are not apt to be known, seem to be maintained in visual form in short-term memory. Memory span is much smaller for these stimuli and is influenced by both intercharacter frequency and complexity. Furthermore, short-term memory for relatively high-frequency characters is interfered with more by a verbal than by a visual intervening task, whereas the opposite is true for low-frequency characters.  相似文献   
279.
Sentences containing idioms used either literally or figuratively were presented repeatedly for 100 msec per presentation. Half of the sentences were preceded by a paragraph. The number of presentations required to read the sentences and cued recall of the sentences were recorded. The serial brief presentations method provided predictable and meaningful results. Sentences containing idioms used literally required more presentations than those containing idioms used figuratively. Cued recall was better for idioms used literally than for those used figuratively. These results are interpreted as support for the Idiomatic Processing Model of idiom comprehension, which suggests that the figurative meaning is processed first; only if that one is inappropriate is the literal meaning processed.  相似文献   
280.
Wistar rats of three age groups were tested in an automated tunnel-maze system of variable geometry to investigate whether changes in spontaneous locomotor activity and in learning and memory develop differentially or in a correlated fashion as a function of age. Senescent (30 months) as well as mature-adult (17 months) rats showed an age-correlated decline of locomotor activity as compared to the mature-young (5 months) group. Both working-memory (measured as within-trial arm discrimination performance) and reference-memory (measured as avoidance of "blind alley" visits) were severely affected in the senescent group, whereas the middle-aged animals suffered only from a working-memory deficit. The findings provide evidence that locomotor deficits do not necessarily interfere in the assessment of age-related changes in cognitive performance. Furthermore the results support the hypothesis that working and reference memory have different underlying physiological correlates and that these neuronal systems are differentially affected by the aging process.  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