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   45459篇
  免费   1784篇
  国内免费   23篇
  2019年   477篇
  2018年   738篇
  2017年   711篇
  2016年   753篇
  2015年   514篇
  2014年   699篇
  2013年   3330篇
  2012年   1208篇
  2011年   1293篇
  2010年   790篇
  2009年   828篇
  2008年   1194篇
  2007年   1131篇
  2006年   1077篇
  2005年   945篇
  2004年   912篇
  2003年   913篇
  2002年   886篇
  2001年   1370篇
  2000年   1370篇
  1999年   1050篇
  1998年   477篇
  1997年   482篇
  1996年   455篇
  1992年   936篇
  1991年   836篇
  1990年   879篇
  1989年   786篇
  1988年   778篇
  1987年   746篇
  1986年   808篇
  1985年   849篇
  1984年   689篇
  1983年   599篇
  1982年   457篇
  1981年   448篇
  1979年   705篇
  1978年   564篇
  1977年   479篇
  1976年   485篇
  1975年   611篇
  1974年   755篇
  1973年   775篇
  1972年   600篇
  1971年   598篇
  1970年   527篇
  1969年   571篇
  1968年   711篇
  1967年   635篇
  1966年   662篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
This research examined the effects of structural complexity and sex of stepchild on the quality of stepfather-stepchild relationships. Sixteen simple stepfather families (the wife had custody of a child from a previous marriage, but the stepfather has no biological children) and 16 complex stepfather families (the wife had custody of a child from a previous marriage, and the stepfather was a noncustodial biological parent) with half of each type (N = 8) having a male and half having a female, 9-12-year-old target child participated in a multimethod-multimeasure assessment of the stepfather-stepchild relationship. Families were recruited from marriage license records, and data collection was accomplished in a single three-and-a-half-hour home visit. Dependent variables included: (a) questionnaire measures of love and detachment relationship dimensions independently obtained from parents, stepparents, and (step)children, and (b) proportions of positive and negative stepparent and stepchild communication behaviors derived from videotaped interaction tasks. Findings revealed that simple and complex stepfather families did not differ on any questionnaire or behavioral measures. Girls, however, engaged in a lower proportion of positive verbal and greater proportion of negative problem-solving behaviors toward their stepfathers than boys did. Stepfathers did not differ on proportions of communication behaviors emitted toward boys and girls. No sex-of-child differences were obtained on the questionnaire measures. Directions for future research on structural complexity and stepfather families are discussed.  相似文献   
992.
993.
This study was a comparison of the effects of oral speech with total communication (speech plus sign language) training on the ability of mentally retarded children to repeat 4-word sentences. Three children were chosen who used single words to communicate but who did not combine words into complete sentences. Three sentence pairs were trained, with each pair having one sentence trained using oral methods and an equivalent one trained using the total communication approach. Both training procedures involved chaining sentence parts, reinforcement, and prompting. Oral methods involved presenting vocal stimuli and requiring vocal responses whereas total communication methods involved presenting vocal and signed stimuli and requiring vocal and signed responses. For the initial sentence pair with each child, an alternating treatments design was used to determine the relative efficacy of the two language training approaches. This was repeated with a second and third sentence pair using a multiprobe technique within a multiple baseline design. Results pointed to the superiority of the total communication approach in facilitating sentence repetition. Possible explanations of these results are offered and the utility of the alternating treatments experimental design is discussed.  相似文献   
994.
We investigated the programming of generalization and maintenance of correspondence between verbal and nonverbal behavior in a preschool setting. Four children participated in a series of multiple-baseline designs. In Experiment 1, delayed reinforcement of verbal behavior effectively controlled maintenance of correspondence with previously trained responses and also resulted in generalization of correspondence to one untrained response. As the latter effect was limited, Experiment 2 was a further assessment of the effects of delayed reinforcement of generalization of correspondence to untrained responses, and consistent generalization was shown. Experiment 2 also showed that generalization, if lost, could be recovered through use of "booster training," in which the original contingencies were reinstated for a brief period. Experiment 3 provided replications, with two additional children, of the effects of delayed reinforcement on maintenance of correspondence. Results are discussed in terms of using delayed reinforcement as an indiscriminable contingency.  相似文献   
995.
996.
997.
998.
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   
999.
1000.
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