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   4393篇
  免费   204篇
  国内免费   8篇
  2023年   39篇
  2022年   38篇
  2021年   61篇
  2020年   91篇
  2019年   115篇
  2018年   145篇
  2017年   145篇
  2016年   206篇
  2015年   89篇
  2014年   99篇
  2013年   430篇
  2012年   216篇
  2011年   231篇
  2010年   141篇
  2009年   129篇
  2008年   188篇
  2007年   178篇
  2006年   165篇
  2005年   136篇
  2004年   143篇
  2003年   130篇
  2002年   130篇
  2001年   86篇
  2000年   88篇
  1999年   60篇
  1998年   46篇
  1997年   43篇
  1996年   47篇
  1995年   40篇
  1994年   44篇
  1992年   44篇
  1991年   42篇
  1990年   52篇
  1989年   38篇
  1988年   27篇
  1987年   45篇
  1986年   46篇
  1985年   50篇
  1984年   46篇
  1983年   36篇
  1982年   34篇
  1981年   34篇
  1980年   24篇
  1979年   33篇
  1978年   25篇
  1976年   24篇
  1975年   31篇
  1974年   29篇
  1973年   35篇
  1971年   26篇
排序方式: 共有4605条查询结果,搜索用时 15 毫秒
61.
An automated system for measuring intracranial self-stimulation behavior is described. The system consists of two Commodore 6502 microcomputers interfaced with a constant-current generator and a standard operant chamber. The system hardware allows sine- and square-wave stimulation. Stimulus intensity can be varied in 256 steps between 0 and 100, 0 and 500, or 0 and 1,000 /µA. The system programs, which are written in machine language, allow the control of various schedules of reinforcement, the counting of operant responses and reinforcements, the measurement of interresponse intervals, and the storage of the data on disk. The software is designed for the determination of the threshold of reinforcement, on the basis of the titration of postreinforcement pauses caused by changeover in schedule control between concurrent continuous reinforcement and fixed ratio schedules.  相似文献   
62.
One-hundred and ninety-two children (equally split between boys and girls) were studied when they were 5 years old in two settings, school and home. The children were observed in playgroups and at home, and were rated on activity level by their parents on the Rothbart Child Behavior Questionnaire. At age 7, the children were tested in our laboratory on the Harter Test of Perceived Competence and on an achievement task, and parents filled out the Child Behavior Checklist, the Child Behavior Questionnaire, and the Conners Parent Rating Scale. Home observations of activity level were significantly related to parent ratings of activity level, but not to school observations. Activity level at age 5 was related to parents' ratings of aggression and hyperactivity and to girls' learning problems at age 7. Activity level was not related to the children's self-perceived competence, but mothers' rating of high activity level at age 5 was related to low reading comprehension at age 7.Preparation of this paper was supported in part by the Center for Research for Mothers and Children, NICHD, U.S. PHS grant HD 19739 to Beverly I. Fagot.  相似文献   
63.
It is the opinion of the present writer that endogenous and symptomatic schizophrenia are two completely different matters. By classical symptomatology it is impossible to establish the distinction in every individual case. Nevertheless, in not one of the published cases known to us did Bonhoeffer err in his diagnosis of the one or the other. Evidently he made use of additional characteristica gathered in practice, about which he himself may not always have been quite clear.  相似文献   
64.
65.
An investigation was made into the extent and time course of anticipatory coarticulation in the speech of two normal and two anterior aphasic, German-speaking subjects. Both labial and velar coarticulation gestures were investigated. Subjects produced sentences containing target words contrasting in postconsonantal vowel rounding (e.g., [geli:ge]/[gely:gel]) and in nasality (e.g., [ti:de]/[ti:ne]). Speech kinematics were monitored by means of electromagnetic articulography. The data revealed that for correct productions, aphasic speakers' coarticulatory patterns were more highly variable than those of control subjects. These differences, however, were found chiefly for spatial displacement characteristics, while the temporal aspects of articulator movement necessary for anticipatory coarticulation appeared largely intact. Articulator mistiming did not appear to explain a small corpus of stop/nasal substitution errors produced by one of the aphasic speakers.  相似文献   
66.
67.
African American women's sexual satisfaction in heterosexual relationships was examined as a dimension of their sex roles. Responses to questions about sexual behaviors and interactions they preferred in primary relationships were selected from a larger study of a stratified random sample of 126 African American women. Three factors were identified: sexual responsiveness, sexual expression, and sexual interest and enthusiasm. The factors are described as profiles that may enhance or limit women's male-female sexual relationships. The implications of African American women's sexual satisfaction as an important dimension to understand in today's AIDS related sexual climate is discussed within a socio-cultural context.A modified version of this paper was presented at the American Anthropological Association, November 1987, Chicago, Illinois. The research was funded by The Center for Prevention and Control of Rape, NIMH Grant, R01 MH33603 and through a Research Scientist Career Development Award to the first author, K01 MH00269.  相似文献   
68.
The cognitive study of the underlying mental abnormalities in autism has advanced rapidly, while the biological study of the underlying brain abnormalities and of putative genetic mechanisms is lagging somewhat behind. However, the linking of cognitive and biological studies has become a real possibility. Developmental cognitive neuroscience has transformed our understanding of this enigmatic disorder, which was once misguidedly thought to be caused by maternal rejection. The hypothesis of a specific theory of mind deficit was a crucial step in this process. It explains the puzzle of the characteristic social and communication impairments of autism and allows for the fact that they can coexist with good general abilities. This hypothesis has been widely accepted and a start has been made at pinpointing the brain basis of theory of mind. The non-social impairments of autism have now become a major focus for cognitive research. One theory proposes dysfunction in executive processes, in an attempt to explain repetitive behaviour and inflexibility. Another theory proposes weak information integration, in an attempt to explain narrow interests and special talents. Autism research has thus stimulated ideas on important mind-brain systems that may be dedicated to the development of social awareness, executive functions and integrative processing.  相似文献   
69.
ABSTRACT College students who had yet to marry and begin a family were asked about their desire to have children and their beliefs and expectations about themselves as parents (Study 1) and the characteristics of their prospective children (Study 2). Persons with more avoidant and anxious-ambivalent models of close adult relationships harbored more negative models of parent-hood and parent-child relationships. These findings indicate that working models of parenting and parent-child relationships form well before marriage and the birth of children and that these models are systematically associated with attachment styles in adult relationships. The findings also suggest ways in which insecure attachments between child and parent may be influenced by the caregiver's models of parenting and parent-child relationships.  相似文献   
70.
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