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   9329篇
  免费   357篇
  国内免费   6篇
  9692篇
  2021年   76篇
  2020年   98篇
  2019年   128篇
  2018年   204篇
  2017年   206篇
  2016年   217篇
  2015年   161篇
  2014年   195篇
  2013年   886篇
  2012年   366篇
  2011年   349篇
  2010年   225篇
  2009年   219篇
  2008年   301篇
  2007年   330篇
  2006年   280篇
  2005年   257篇
  2004年   246篇
  2003年   211篇
  2002年   215篇
  2001年   272篇
  2000年   248篇
  1999年   200篇
  1998年   94篇
  1997年   76篇
  1996年   102篇
  1993年   70篇
  1992年   152篇
  1991年   145篇
  1990年   142篇
  1989年   118篇
  1988年   114篇
  1987年   120篇
  1986年   127篇
  1985年   121篇
  1984年   123篇
  1983年   98篇
  1979年   103篇
  1978年   82篇
  1977年   69篇
  1975年   75篇
  1974年   103篇
  1973年   111篇
  1972年   85篇
  1971年   79篇
  1970年   85篇
  1969年   87篇
  1968年   115篇
  1967年   87篇
  1966年   97篇
排序方式: 共有9692条查询结果,搜索用时 0 毫秒
121.
In two separate experiments, 40 Ss were presented with recorded sentences during each of which a click occurred. Ss had to depress a key as soon as they heard the click. RTs were f aster when the click was located at the major syntactic break of the sentence compared with RTs to clicks not at a break. This confirmed the hypothesis that processing load is a function of the surface structure of sentences, although the role of minor breaks was not clear. A second finding was that RTs were slower when the click was in the first rather than in the second half of the sentence. This can also be explained in terms of differential processing loads.  相似文献   
122.
123.
124.
125.
The quartimax and varimax algorithms for orthogonal rotation attempt to maximize particular simplicity criteria by a sequence of two-factor rotations. Derivations of these algorithms have been fairly complex. A simple general theory for obtaining two factor at a time algorithms for any polynomial simplicity criteria satisfying a natural symmetry condition is presented. It is shown that the degree of any symmetric criterion must be a multiple of four. A basic fourth degree algorithm, which is applicable to all symmetric fourth degree criteria, is derived and applied using a variety of criteria. When used with the quartimax and varimax criteria the algorithm is mathematically identical to the standard algorithms for these criteria. A basic eighth degree algorithm is also obtained and applied using a variety of eighth degree criteria. In general the problem of writing a basic algorithm for all symmetric criteria of any specified degree reduces to the problem of maximizing a trigonometric polynomial of degree one-fourth that of the criteria.This research was supported by the Bell Telephone Laboratories, Murray Hill, New Jersey and NIH Grant FR-3.  相似文献   
126.
127.
128.
129.
The study attempted to isolate some of the environmental conditions that controlled the self-destructive behavior of three severely retarded and psychotic children. In the extinction study subjects were placed in a room where they were allowed to hurt themselves, isolated from interpersonal contact. They eventually ceased to hurt themselves in that situation, the rate of self-destruction falling gradually over successive days. In the punishment study, subjects were administered painful electric shock contingent on the self-destructive behavior. (1) The self-destructive behavior was immediately suppressed. (2) The behavior recurred when shock was removed. (3) The suppression was selective, both across physical locales and interpersonal situations, as a function of the presence of shock. (4) Generalized effects on other, non-shock behaviors, appeared in a clinically desirable direction. Finally, a study was reported where self-destructive behavior increased when certain social attentions were given contingent upon that behavior.  相似文献   
130.
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