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   52979篇
  免费   2122篇
  国内免费   33篇
  55134篇
  2020年   523篇
  2019年   632篇
  2018年   897篇
  2017年   884篇
  2016年   974篇
  2015年   673篇
  2014年   816篇
  2013年   4034篇
  2012年   1520篇
  2011年   1555篇
  2010年   978篇
  2009年   1017篇
  2008年   1389篇
  2007年   1351篇
  2006年   1236篇
  2005年   1070篇
  2004年   1064篇
  2003年   1011篇
  2002年   1050篇
  2001年   1588篇
  2000年   1579篇
  1999年   1205篇
  1998年   547篇
  1997年   539篇
  1995年   528篇
  1992年   1042篇
  1991年   971篇
  1990年   941篇
  1989年   894篇
  1988年   897篇
  1987年   818篇
  1986年   880篇
  1985年   894篇
  1984年   763篇
  1983年   697篇
  1982年   538篇
  1979年   827篇
  1978年   628篇
  1977年   566篇
  1976年   583篇
  1975年   663篇
  1974年   810篇
  1973年   878篇
  1972年   702篇
  1971年   662篇
  1970年   605篇
  1969年   653篇
  1968年   810篇
  1967年   728篇
  1966年   715篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
942.
943.
We evaluated the effects of adding a social support component to a worksite controlled smoking treatment program. Twenty-four participants were randomly assigned to either a controlled smoking or a controlled smoking plus partner support condition. Within a multiple baseline across behaviors design, smokers in both conditions made efforts to achieve sequential 50% reductions in: (a) nicotine content of brand smoked, (b) number of cigarettes smoked per day, and (c) percentage of each cigarette smoked. Self-monitoring records, laboratory analyses of spent cigarette butts, and carbon monoxide determinations indicated that both conditions were effective in producing significant reductions in each of the three target behaviors and in carbon monoxide levels. All participants who quit smoking during the program maintained their abstinence at a 6-month follow-up, and those who did not quit were smoking less at follow-up than they had at pretest on all dependent variables. However, few differences were observed between controlled smoking and controlled smoking plus partner support conditions either during treatment or at the 6-month follow-up. Results are discussed with regard to previous worksite studies, future directions for research on social support, and variables that may have mediated treatment outcome.  相似文献   
944.
945.
946.
Five-year-old children were tested for perceptual trading relations between a temporal cue (silence duration) and a spectral cue (F1 onset frequency) for the “say-stay” distinction. Identification functions were obtained for two synthetic “say-stay” continua, each containing systematic variations in the amount of silence following the /s/ noise. In one continuum, the vocalic portion had a lower F1 onset than in the other continuum. Children showed a smaller trading relation than has been found with adults. They did not differ from adults, however, in their perception of an “ay-day” continuum formed by varying F1 onset frequency only. The results of a discrimination task in which the two acoustic cues were made to “cooperate” or “conflict” phonetically supported the notion of perceptual equivalence of the temporal and spectral cues along a single phonetic dimension. The results indicate that young children, like adults, perceptually integrate multiple cues to a speech contrast in a phonetically relevant manner, but that they may not give the same perceptual weights to the various cues as do adults.  相似文献   
947.
In two longitudinal studies, infants were trained at 12 and 18 months to find an object hidden in one of two identical wells in a Plexiglas box. On the test trial, normal access was blocked and infants were either guided by their mother or allowed to move on their own to another opening on the opposite side. In Experiment 1 significantly more correct responding occurred after active movement than after passive at 12 months, with correct responding related to high visual tracking. In contrast, at 18 months correct search without tracking predominated among both movement conditions. A difference between the conditions in the position of the mother on the test trial was ruled out as a contributor to performance on the basis of data from Experiment 2. When opaque sides were inserted to prevent tracking in Experiment 3, active movement no longer facilitated correct search at 12 months, thus indicating that the tracking and not the active movement per se was the critical factor.  相似文献   
948.
In three experiments, the effect of additional "contextual" elements on the discrimination of the orientation of linear and curvilinear segments was investigated with 4-month-old infants. In Experiment 1, paired visual matrices (one which contained some irregularity in orientation of internal elements, vs one which contained no irregularities) were presented. Infants detected irregular matrices significantly better than chance, but such detection was not aided by contextual elements. Discrimination of orientation in Experiment 2 was assessed with a paired-comparison familiarization-novelty paradigm. It was found that the addition of elements here significantly aided discrimination of linear segment orientation, but not curvilinear segment orientation. Experiment 3 investigated why this effect was not found for curvilinear segments; after equating the curvilinear stimuli to linear ones used in Experiment 2 with respect to the closedness of figure, discrimination of curvilinear orientation was observed.  相似文献   
949.
950.
This study investigated the effect of television-mediated aggression and real-life aggression on the behavior of Lebanese children. The sample consisted of 48 boys and 48 girls of Lebanese origin who were students in an elementary school in Beirut, Lebanon. After controlling for pre-experimental aggression, the subjects were randomly assigned to one of the following treatment conditions: human-film aggression, cartoon-film aggression, neutral film, or real-life (act of war) aggression. The results indicated that boys as a group were more aggressive than girls and exhibited more imitative aggression after viewing both violent film and real-life violence. Girls were not more violent after viewing filmed aggression but were affected by the real-life violence. Comparisons of Bandura's work within the Lebanese culture are made.  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