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   46105篇
  免费   2056篇
  国内免费   73篇
  2020年   544篇
  2019年   642篇
  2018年   925篇
  2017年   879篇
  2016年   976篇
  2015年   690篇
  2014年   809篇
  2013年   3603篇
  2012年   1503篇
  2011年   1580篇
  2010年   934篇
  2009年   977篇
  2008年   1271篇
  2007年   1267篇
  2006年   1124篇
  2005年   984篇
  2004年   959篇
  2003年   887篇
  2002年   900篇
  2001年   1629篇
  2000年   1621篇
  1999年   1154篇
  1998年   486篇
  1997年   455篇
  1995年   428篇
  1992年   940篇
  1991年   860篇
  1990年   860篇
  1989年   819篇
  1988年   812篇
  1987年   731篇
  1986年   753篇
  1985年   792篇
  1984年   637篇
  1983年   574篇
  1982年   422篇
  1979年   637篇
  1978年   472篇
  1977年   427篇
  1976年   430篇
  1975年   536篇
  1974年   657篇
  1973年   638篇
  1972年   587篇
  1971年   496篇
  1970年   454篇
  1969年   514篇
  1968年   605篇
  1967年   514篇
  1966年   518篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
E K Warrington  M James 《Perception》1986,15(3):355-366
An investigation is reported of the ability of normal subjects and patients with right-hemisphere lesions to identify 3-D shadow images of common objects from different viewpoints. Object recognition thresholds were measured in terms of angle of rotation (through the horizontal or vertical axis) required for correct identification. Effects of axial rotation were very variable and no evidence was found of a typical recognition threshold function relating angle of view to object identification. Although the right-hemisphere-lesion group was consistently and significantly worse than the control group, no qualitative differences between the groups were observed. The findings are discussed in relation to Marr's theory that the geometry of a 3-D shape is derived from axial information, and it is argued that the data reported are more consistent with a distinctive-features model of object recognition.  相似文献   
912.
Earlier studies have shown the girls spend more time than boys in activities that are highly structured by adults. Structured activities may encourage feminine sex-typed behaviors such as compliance to adults; low-structure activities may encourage masculine sex-typed behaviors such as independence and assertiveness. In the present study the effects of high or low levels of adult structuring on children's social behavior during preschool free-play activities were tested in a field experiment carried out during an entire semester in one preschool classroom. For the first 15 minutes of free play, children were assigned to high- or low-structure activities. As predicted, when children were in high-structure activities, they exhibited high rates of bids for recognition and compliance to adults; in low-structure activities, they exhibited peer-directed leadership, bids for recognition, and compliance. There were no generalized effects of these treatments on their subsequent free choice of activities or social behavior. The study demonstrates powerful effects of naturally occurring variations in children's play activities on sex-typed social behaviors.  相似文献   
913.
Summary Subjects were shown eight-letter pseudowords tachistoscopically and were asked to report as many letters as possible. The pseudowords, examples of either first- or fourth-order approximation to English, were printed in normal or reversed spelling and were presented in either normal of mirror-imaged letters. Finally subjects were either free to report in any order they wished, or they were instructed to report from left to right or from right to left. With normal letters, the familiarity effect was controlled by the spelling direction, not by the direction of report or the match between direction of report and spelling direction. With mirrored letters, however, order of approximation to English had no effect. The results contradict two existing theories: Mewhort's theory claims that the familiarity of fourth-order materials aids processing at a postcategorical level; it has trouble explaining why the familiarity effect disappeared with mirrored letters and normal spelling. Wolff's theory claims that familiarity aids processing at the feature level; it has trouble explaining why the familiarity effect disappeared with mirrored letters and reversed spelling.  相似文献   
914.
915.
916.
San Diego suicide study: comparison of gay to straight males   总被引:1,自引:0,他引:1  
Previous large studies of completed suicides have not considered sexual orientation in their data analyses. In this study, data from the known homosexual subpopulation (13 males, aged 21-42) in a series of 283 suicides were examined. They were compared with all other aged male suicides 21-42 (n = 106). Both groups showed considerable substance abuse plus a variety of other psychiatric diagnoses. Both also had a high frequency of relationship difficulties near the time of death. Gays who committed suicide did not have a history of more police trouble and were no more likely to be living alone than the comparison group. They did not have more prior suicide attempts or previous psychiatric treatment. We conclude that, among the factors examined here, there appears to be little difference between gay and heterosexual male suicides.  相似文献   
917.
Younger adult students between 19 and 24 years of age (M = 21.3 years), older adult students between 61 and 76 years of age (M = 67.9 years), and older adult nonstudents between 62 and 76 years of age (M = 68.5 years) were assessed for health (self-ratings of physical and mental health), social functioning (self-ratings of physical and mental activity, perceived role activity level, perceived roles, locus of control, and age-norm expectations), and cognitive functioning (Wechsler Adult Intelligence Scale-Revised vocabulary and block design, and paired associate memory). Age differences were observed in self-ratings of health, social roles, intellectual performance, and memory. No student status differences were observed. The results are discussed in terms of plasticity of intellectual function and characteristics of student status in later adulthood.  相似文献   
918.
Age-related differences in the pleasantness of chemosensory stimuli   总被引:2,自引:0,他引:2  
Modest decrements in both taste threshold sensitivity and, more recently, suprathreshold sensitivity have been associated with the aging process. The present study was designed to investigate the existence of changes in preference for various concentrations of single tastes and of the same single tastes in more complex chemosensory mixtures. In this study, 300 participants from three different age groups (18-26, 32-45, over 65) rated for pleasantness four concentrations of sodium chloride, sucrose, and citric acid presented in both aqueous and beverage bases. Results showed significant effects of age, stimulus background, stimulus, concentration, and of several interactions, and they suggest that elderly subjects find salt and sugar pleasanter at higher concentrations than younger subjects do.  相似文献   
919.
When presented with a behavioral problem or symptom expression that involves two systems, such as a serious school-related problem, the therapist needs to design an approach that will intervene effectively and expeditiously in both systems. This paper offers a guide to stages of problem escalation and therapeutic intervention that is intended to aid the problem-solver's thinking processes in approaching a troubled situation that involves two systems, the school and the home.  相似文献   
920.
There has been interest in recent years in the relationship between marital distress and psychopathology. It has been rare, however, for investigators to follow patients after their release from the hospital and observe the course of their marital relationships. The present study included patients meeting criteria for three DSM III DISORDERS (MAjor depressive, bipolar, and schizophrenic) and a normal control sample, all of whom are participants in an ongoing longitudinal study of children at risk for psychopathology (Stony Brook High-Risk Project; Weintraub & Neale, 1984). Marital Adjustment Test (MAT; Locke & Wallace, 1959) scores were collected on patients at entry into the project (Phase I) and at a three year follow-up (Phase II). Course of marriage was defined as negative if the couple's marital adjustment was rated as poor at Phase II or resulted in divorce or separation at Phase II. It was found that only the depressed group differed from the normal group in having significantly worse course of marital relationship; 84% of the depressive couples showed a “negative” course of marital change over time. However, all three patient groups had significantly higher rates of divorce by Phase II. MAT scores at Phase I successfully predicted course of marital relationship for all diagnostic groups. Implications for aftercare of psychiatric inpatients are discussed.  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