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   1771篇
  免费   21篇
  国内免费   12篇
教育   946篇
科学研究   290篇
各国文化   6篇
体育   347篇
综合类   22篇
文化理论   2篇
信息传播   191篇
  2023年   12篇
  2022年   11篇
  2021年   4篇
  2018年   3篇
  2016年   7篇
  2015年   5篇
  2014年   11篇
  2013年   16篇
  2012年   142篇
  2011年   206篇
  2010年   78篇
  2009年   17篇
  2008年   108篇
  2007年   140篇
  2006年   118篇
  2005年   106篇
  2004年   88篇
  2003年   93篇
  2002年   87篇
  2001年   48篇
  2000年   67篇
  1999年   49篇
  1998年   12篇
  1997年   19篇
  1996年   14篇
  1995年   23篇
  1994年   14篇
  1993年   23篇
  1992年   27篇
  1991年   26篇
  1990年   25篇
  1989年   16篇
  1988年   11篇
  1987年   17篇
  1986年   17篇
  1985年   15篇
  1984年   12篇
  1983年   19篇
  1982年   9篇
  1981年   16篇
  1980年   8篇
  1978年   3篇
  1977年   5篇
  1968年   3篇
  1967年   3篇
  1958年   3篇
  1957年   3篇
  1948年   3篇
  1937年   3篇
  1927年   3篇
排序方式: 共有1804条查询结果,搜索用时 15 毫秒
21.
In this study, the relationship between latent constructs of phonological awareness (PA) and rapid automatized naming (RAN) were investigated and related to later measures of reading and spelling in children learning to read in different alphabetic writing systems (i.e., Norwegian/Swedish vs. English). 750 U.S./Australian children and 230 Scandinavian children were followed longitudinally between kindergarten and 2nd grade. PA and RAN were measured in kindergarten and Grade 1, while word recognition, phonological decoding, and spelling were measured in kindergarten, Grade 1, and Grade 2. In general, high stability was observed for the various reading and spelling measures, such that little additional variance was left open for PA and RAN. However, results demonstrated that RAN was more related to reading than spelling across orthographies, with the opposite pattern shown for PA. In addition, tests of measurement invariance show that the factor loadings of each observed indicator on the latent PA factor was the same across U.S./Australia and Scandinavia. Similar findings were obtained for RAN. In general, tests of structural invariance show that models of early literacy development are highly transferable across languages.  相似文献   
22.
RESEARCH FINDINGS: The purpose of this study was to examine the relations of children's effortful control and quality of relationships with teachers to school attitudes longitudinally in an ethnically diverse and economically disadvantaged sample. Data were collected as part of a larger intervention project during mid-fall, winter, and late spring (ns = 823, 722, and 758, respectively) for 2 cohorts of 3- to 5-year-olds (collected during 2 different school years). Children's effortful control was assessed in the fall with parents' and teachers' reports and 2 behavioral measures. Teacher-child relationship quality was assessed mid-year with teachers' reports of closeness and conflict. Attitudes toward school were assessed in late spring using teachers' and students' reports of school avoidance and liking. Effortful control, in general, was positively correlated with teacher-child closeness and school liking and negatively correlated with conflict and school avoidance. Using structural equation modeling and controlling for sex and ethnicity, we found that effortful control was positively related to teacher-child relationship quality, which in turn was positively related to school attitudes. Furthermore, the relation of effortful control to school attitudes was mediated by teacher-child relationship quality. PRACTICE OR POLICY: Results provide evidence for the importance of relational processes that take place within the classroom context and have implications for teachers and clinicians working to increase school success in ethnic minority and low-income children.  相似文献   
23.
This article examines the effect that postsecondary education has on earnings and the duration of time spent in the Social Security disability programs for young persons who are deaf or hard of hearing. Our hypothesis is that investments in postsecondary training increase the likelihood of employment for persons who are deaf or hard of hearing and thus reduce dependency on disability-related income support programs. A longitudinal data set based upon records from the National Technical Institute for the Deaf and Social Security administrative records is used for this analysis. We find that those who graduate, even those who graduate with vocational degrees, experience significant earnings benefits and reductions in the duration of time spent on federal disability programs when compared with those who do not graduate with a degree. This finding suggests that reductions in the duration of time spent on Social Security programs are not limited to those with the highest level of scholastic aptitude and that investments in post-secondary education can benefit a broad group of deaf and hard-of-hearing persons. In addition, the data show that individuals who attend college, but withdraw before graduation, fair no better economically than individuals who never attended college.  相似文献   
24.
Preschool children (3–4 years old) were trained to perform two actions to gain different outcomes, in the form of video clips from different cartoons, before one of these outcomes was devalued by noncontingent exposure. The effect of outcome devaluation was subsequently assessed in an extinction test by giving children the opportunity to perform both actions in the absence of any outcomes. When the two actions were trained concurrently, performance during the test was modulated by outcome value and children showed a preference for the action trained with the currently valued outcome. By contrast, when each action was trained separately on different trials, test performance was insensitive to outcome devaluation. These effects of the training schedules are interpreted in terms of dual-process theories of action control.  相似文献   
25.
OBJECTIVE: This study examined specific aspects of child sexual abuse in relation to symptom severity among hospitalized patients diagnosed with bulimia nervosa. METHOD: Participants were 45 hospitalized bulimic women who reported a history of child sexual abuse. Structured interviews were conducted in order to obtain detailed information regarding specific features of the abusive event(s). Participants also completed instruments that measured depression and eating pathology. RESULTS: There were no significant differences in severity of depression or eating disturbance among women reporting differing abusive experiences including intrafamilial versus extrafamilial abuse, abuse with or without the use of physical force, one versus multiple incidents, early abuse versus abuse occurring after age 14, contact versus noncontact abuse, disclosed versus undisclosed, and combined physical/sexual abuse versus sexual abuse alone. CONCLUSION: The specific characteristics of child sexual abuse are not related to the level of symptomatology for hospitalized bulimic patients. This study suggests that differences in the nature of the abuse may not be as important as the fact that the abuse occurred in the first place.  相似文献   
26.
Pigeons' keypecking was reinforced by food on baseline schedules of multiple variable interval (VI) x VI x and on contrast schedules of multiple VI x VI y. Deprivation of food was varied by maintaining subjects at 75%, 85%, and 95% (+/- 2%) of their free-feeding weights. Positive and negative behavioral contrast were observed. The size of the contrast was not systematically altered by changes in deprivation. Positive and negative contrast were both larger later in the session than they were earlier. Within-session decreases in responding were steeper for the baseline than for the contrast schedules for positive contrast. Within-session decreases were steeper for the contrast than for the baseline schedules for negative contrast. These results were predicted by the idea that different amounts of habituation to the reinforcer during the baseline and contrast schedules contribute to behavioral contrast. The results show that contrast occurs under conditions that reduce the effect of the following component. The results support the assumption that positive and negative contrast are produced by symmetrical theoretical variables.  相似文献   
27.
OBJECTIVE: This study compared recidivism rates for alleged maltreatment perpetrators whose initial report was substantiated and those whose initial report was not substantiated, to determine whether they returned to the child welfare system at differing rates. METHOD: Statewide administrative child welfare services data over a period of 4 1/2 years was analyzed. The sample included 31,531 perpetrators of intrafamilial maltreatment. Separate analyses were conducted for each type of maltreatment (sexual abuse, physical abuse, and neglect). RESULTS: Bivariate relationships (substantiation status and recidivism) were analyzed using survival curves, and the study found that recidivism patterns differed by type of maltreatment and by substantiation status at the index event. Multivariate analyses using Cox Proportional Hazards models found that bivariate relationships held true even when controlling for neighborhood mean income, ethnicity, and gender. CONCLUSIONS: The study's finding that perpetrators whose index event was not substantiated return to the child welfare system at a high rate suggests the need to learn how to discriminate those unsubstantiated alleged perpetrators who are most at risk for recidivism. The finding of frequent cross-type recidivism indicates that intervention should focus on common themes across maltreatment types.  相似文献   
28.
The effects of identical context on pattern recognition by pigeons for outline drawings of faces were investigated by training pigeons to identify (Experiment 1) and categorize (Experiment 2) these stimuli according to the orientation of the mouth—an upright U shape representing a smiling mouth or an inverted U shape representing a sad mouth. These target stimuli were presented alone (Pair 1), with three dots in a triangular orientation to represent a nose and eyes (Pair 2), and with the face pattern surrounded by an oval (Pair 3). In Experiment 1, the pigeons trained with Pair 1 were most accurate, those trained with Pair 2 were less so, and those trained with Pair 3 failed to acquire the discrimination within eighty 100-trial sessions. The same ordering was found in Experiment 2 for pigeons trained on the three pairs simultaneously. The authors suggest that a contrasting finding in humans, the face superiority effect, might be due to a gain in discriminability resulting from recognition of the pattern as a face. An exemplar model of information processing that excludes linguistic coding accounts for the present results.  相似文献   
29.
This study investigated for the first time several characteristics of underachievement in a large sample of Hong Kong elementary schoolchildren. More males were identified as underachievers than females, but the ratio was substantially less than the two-to-one rate typically found in the American literature. The stability and persistence of underachievement increased during the elementary school years, and the stability of underachievement tended to be higher in subject matter that was relatively more difficult, which varied with gender. Underachievement became more specific to particular academic subjects rather than more general across the elementary grades. Parents and teachers, but not the children themselves, perceived that underachievers were more capable than same-grade nonunderachievers (who score lower on ability tests), although this awareness is more likely directed at male than female underachievers, which has been observed in other samples. In grades 1-4, teachers provided extra mentoring, communications, and support to underachievers. Thereafter, underachievers became more disruptive, impatient, and aggressive in school and perhaps at home. At that point, teachers became less supportive, offered less extra mentoring, and applied greater behavioral control over underachievers. Underachieving children also perceived that their parents became less supportive and used more discipline in grades 5-6 relative to grades 3-4. These correlates of underachievement suggests the existence of a syndrome of underachievement that separates underachievers from children who have the same grades but lower mental ability.  相似文献   
30.
织物风格特征是由织物组织结构和纱的特性决定的,新型纱线结构的不断出现和发展对织物性能和质量提出了更高的要求。研究表明:通过改变纺纱工艺可以获得不同的纱线结构,从而改变织物的风格特征。DREF-Ⅲ型摩擦纺包芯纱具有典型的皮芯结构,可以是双组分也可以是多组分,而且组分的不同会对织物性能产生不同的影响,纱的性能也会由于芯皮之间压力、摩擦力大小的不同而改变。以前的研究主要集中在包芯纱的拉伸性能上,而对空心纱几乎没有什么新的研究和讨论。  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