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   62152篇
  免费   2545篇
  国内免费   26篇
  64723篇
  2020年   748篇
  2019年   865篇
  2018年   1247篇
  2017年   1261篇
  2016年   1320篇
  2015年   949篇
  2014年   1138篇
  2013年   5489篇
  2012年   2131篇
  2011年   2155篇
  2010年   1307篇
  2009年   1370篇
  2008年   1880篇
  2007年   1891篇
  2006年   1711篇
  2005年   1442篇
  2004年   1473篇
  2003年   1462篇
  2002年   1390篇
  2001年   2012篇
  2000年   1889篇
  1999年   1451篇
  1998年   699篇
  1997年   631篇
  1996年   692篇
  1995年   650篇
  1994年   618篇
  1993年   628篇
  1992年   1185篇
  1991年   1095篇
  1990年   1062篇
  1989年   1026篇
  1988年   1004篇
  1987年   946篇
  1986年   927篇
  1985年   982篇
  1984年   821篇
  1983年   737篇
  1982年   569篇
  1979年   850篇
  1978年   655篇
  1977年   560篇
  1976年   570篇
  1975年   678篇
  1974年   754篇
  1973年   772篇
  1972年   656篇
  1971年   597篇
  1968年   648篇
  1967年   560篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
Summary Simple motor responses of different similarity were assigned to geometric figures of different similarity. Subsequently, subjects had to learn hierarchical classifications of visually similar or dissimilar figures which were associated with either similar or dissimilar responses. In this way, the visual and the functional similarity of the conceptually united figures were orthogonally varied. It was found that visually similar figures are conceptually classified fastest regardless of their functional similarity. In contrast, functional similarity has a considerable impact on the hierarchical classification of visually dissimilar figures. Functionally similar figures are conceptually faster classified than dissimilar ones. From the results we conclude that concepts are autonomously formed as mediating representations in stimulus-response coordinations. The hierarchical organization of concepts is thereby based on the sequential organization of both the visual input and the behavioral output. Further consequences of this approach are discussed.Portions of this research were presented at the International Symposium on Structure and Function of Human Memory, in Memoriam Hermann Ebbinghaus, Berlin, July 1985  相似文献   
952.
953.
Alcoholism and suicide   总被引:5,自引:0,他引:5  
  相似文献   
954.
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   
955.
956.
957.
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   
958.
This study focuses on Divorce-Prone individuals and the question of why some persons fail in one marriage after another. The authors studied 12 individuals who had each been divorced two or more times. They found that the cases fell into one of three broad and overlapping groups. The groups have been called the Self-Involved Narcissists, the Compliant Depressed, and the Casualties of Life's Vicissitudes. The individuals and the groups demonstrate a different etiology, different treatment problems, and a very different prognosis.  相似文献   
959.
960.
A method of hardware reaction timing with millisecond accuracy, using one of the Amiga’s CIA 8520 chips, is described. The registers of this chip can be set to enable cascaded timing that functions independently of the CPU and, thereby, avoids the problems of software timing in a multitasking environment. In addition, the interfacing of a pair of reaction-time keys to one of the Amiga’s game controller connectors and a program for polling this port for keypresses are described.  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