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   3934篇
  免费   52篇
  国内免费   2篇
教育   2920篇
科学研究   249篇
各国文化   34篇
体育   486篇
综合类   2篇
文化理论   80篇
信息传播   217篇
  2023年   37篇
  2022年   73篇
  2021年   102篇
  2020年   156篇
  2019年   247篇
  2018年   297篇
  2017年   305篇
  2016年   228篇
  2015年   166篇
  2014年   151篇
  2013年   810篇
  2012年   160篇
  2011年   109篇
  2010年   100篇
  2009年   94篇
  2008年   88篇
  2007年   77篇
  2006年   74篇
  2005年   62篇
  2004年   52篇
  2003年   58篇
  2002年   45篇
  2001年   30篇
  2000年   25篇
  1999年   30篇
  1998年   29篇
  1997年   20篇
  1996年   34篇
  1995年   23篇
  1994年   26篇
  1993年   23篇
  1992年   13篇
  1991年   23篇
  1990年   16篇
  1989年   20篇
  1988年   20篇
  1987年   18篇
  1986年   8篇
  1985年   6篇
  1984年   10篇
  1983年   10篇
  1982年   9篇
  1981年   9篇
  1980年   7篇
  1979年   7篇
  1978年   8篇
  1977年   6篇
  1976年   8篇
  1975年   10篇
  1974年   6篇
排序方式: 共有3988条查询结果,搜索用时 0 毫秒
991.
Using a genetic design of 840 60-month-old twins, this study investigated the genetic and environmental contributions to (a) individual differences in four components of cognitive school readiness, (b) the general ability underlying these four components, and (c) the predictive association between school readiness and school achievement. Results revealed that the contribution of the shared environment for cognitive school readiness was substantial. Genetic effects were more important for the core abilities underlying school readiness than for each specific skill, although shared environment remained the largest factor overall. Genetic, shared, and nonshared environmental factors all accounted for the predictive association between school readiness and early school achievement. These results contribute to a better understanding of the early determinants of school readiness.  相似文献   
992.
OBJECTIVE: To present prevalence rates of child psychological aggression and physical violence from a population survey conducted in 2004 and to compare the rates with the rates obtained in the 1999 edition of the survey. METHODS: The survey used a randomly generated telephone number methodology. Interviews were conducted using a computer-assisted telephone interview system with a representative sample of 3,148 mothers living in Quebec province, Canada. Responses relating to psychological aggression, minor and severe physical violence were collected using the Parent-Child Conflict Tactics Scales. RESULTS: Eighty percent of the mothers reported the use of psychological aggression towards a child by an adult living in the household, 43% reported at least one episode of minor violence, and 6% reported at least one episode of severe physical violence. When compared to the 1999 surveys, mothers reported 5% less minor physical violence in 2004, a result that is counterbalanced by a similar significant increase in the report of repeated psychological violence towards children in a year. Results also reveal a significant decrease in attitudes favoring the use of violence for discipline purpose between 2004 and 1999. CONCLUSIONS: The trends observed in violence towards children over the 5-year period may partly be attributed to a change in mother's attitudes concerning methods of disciplining children. Findings support the need to promote alternative methods of firm discipline that do not involve violence.  相似文献   
993.
This paper presents the results of an analysis of secondary students’ computer use, aimed at understanding how different factors influence the profile of activities carried out by students with computers. The analysis is based on the data from a national study aimed at measuring students’ Information and Communication Technology (ICT) skills for learning. A factor analysis was carried out to categorize students’ activities with computers and several indexes were constructed to define the comparison groups. Finally, a multiple linear regression analysis was performed to explain the frequency of the activities. Results show that students with access to computers at home mainly perform activities categorized as Socializing, Academic, Gaming and Production and that although the absolute frequency of these activities differs across groups, the profiles of computer use are surprisingly similar for groups based on students’ socio-economic group, experience with ICT, and self-confidence in the use of ICT. The only variable that discriminates user profiles is gender. Based on these findings, it can be claimed that Chilean secondary students with access to computers at home tend to show a rather homogenous computer-use profile, once access is equated.  相似文献   
994.
Knowledge Creation and Management (KCM) is one of the main strategies for fostering improvement in any kind of organisation, including educational organisations, on which this paper is focused. While KCM is being widely studied, little attention has been given to KCM in organisations supplying education, training and/or assessment services to learners (i.e., primary and secondary schools or higher education institutions, among others). From an educational management approach, the aim of this paper is to describe and analyse the factors that foster or inhibit KCM processes conducted within educational organisations. Professionals (n=84), moderators and managers or institutional leaders of four selected cases were surveyed and interviewed. Results show the importance of the main organisational and procedural factors (i.e., organisational values and goals, leadership, structure, culture, dynamics, Information and Communications Technologies, KCM processes and people) to improve KCM results in educational organisations.  相似文献   
995.
This study tested a set of hypotheses derived from the model of academic achievement in mathematics of the Social Cognitive Career Theory in a sample of Argentinean middle school students. To this aim, 277 students (male and female; age: 13–15 years) were assessed using the following instruments: logical–mathematical self-efficacy scale, mathematics outcome expectations, mathematics performance goals, and mathematics ability test. All of these instruments had been adapted for use in Argentinean students. Academic achievement in mathematics (i.e., grades obtained on regular school exams) was the variable to be modeled through the path analysis technique. The analysis allowed identification of interrelations among the variables and identification of direct and indirect effects. Academic achievement in mathematics was partially explained by the model. Overall, the results support the theoretical postulates of Social Cognitive Career Theory.  相似文献   
996.
Processing of derived forms in high-functioning dyslexics   总被引:1,自引:0,他引:1  
We report on an experiment designed to evaluate processing of derived forms in high-functioning dyslexics, defined as university students with a history of reading difficulties who have age-appropriate reading comprehension skills. We compared high-functioning dyslexics with a group of normal adult readers in their performance on a lexical decision task with derived items (such as cloudy and ably) and pseudo-derived items (such as belly and gravy). Some items contained an orthographic change (such as able-ably and gravy) and others did not (such as cloud - cloudy). The results indicated that although control participants’ response times varied systematically as a function of morphological complexity, those of high-functioning dyslexics did not. Further, there was some evidence of a relationship between derivational processing and reading. It seems that high-functioning dyslexics have persistent difficulties in processing one particular aspect of morphology; that of derived forms.  相似文献   
997.
The serial position effect in Long-Evans rats was evaluated in two experiments. In Experiment 1, the effect in a group for which an interstimulus interval (ISI) was introduced between items in a list of demonstrators was compared with that in a group without an ISI. With an ISI, a recency effect was produced. In Experiment 2, a serial position effect group was compared with four groups in which either the distinctiveness or the context of the middle item was changed, relative to the items on either side of it. A von Restorff effect was produced when a rat from a different strain was used as a demonstrator in Position 2. The results for Experiment 1 are discussed in relation to interstimulus effects in monkeys and those for Experiment 2 with respect to changes in the physical properties of middle items.  相似文献   
998.
Whey protein concentrate (WPC 80) and sodium caseinate were hydrolyzed by Protamex to 5%, 10%, 15%, and 20% degree of hydrolysis (DH). WPC 80, sodium caseinate and their hydrolysates were then analyzed, compared and evaluated for their nutritional qualities. Their chemical composition, protein solubility, amino acid composition, essential amino acid index (EAA index), biological value (BV), nutritional index (NI), chemical score, enzymic protein efficiency ratio (E-PER) and in vitro protein digestibility (IVPD) were determined. The results indicated that the enzymatic hydrolysis of WPC 80 and sodium caseinate by Protamex improved the solubility and IVPD of their hydrolysates. WPC 80, sodium caseinate and their hydrolysates were high-quality proteins and had a surplus of essential amino acids compared with the FAO/WHO/UNU (1985) reference standard. The nutritive value of WPC 80 and its hydrolysates was superior to that of sodium caseinate and its hydrolysates as indicated by some nutritional parameters such as the amino acid composition, chemical score, EAA index and predicted BV. However, the E-PER was lower for the WPC hydrolysates as compared to unhydrolyzed WPC 80 but sodium caseinate and its hydrolysates did not differ significantly. The nutritional qualities of WPC 80, sodium caseinate and their hydrolysates were good and make them appropriate for food formulations or as nutritional supplements.  相似文献   
999.
Background: Question‐answering systems (or QA Systems) stand as a new alternative for Information Retrieval Systems. Most users frequently need to retrieve specific information about a factual question to obtain a whole document. Objectives: The study evaluates the efficiency of QA systems as terminological sources for physicians, specialised translators and users in general. It assesses the performance of one open‐domain QA system, START, and one restricted‐domain QA system, MedQA. Method: The study collected two hundred definitional questions (What is…?), either general or specialised, from the health website WebMD. Sources used by the open‐domain QA system, START, and the restricted‐domain QA system, MedQA, were studied to retrieve answers, and later a range of evaluation measures (precision, Mean Reciprocal Rank, Total Reciprocal Rank, First Hit Success) were applied to mark the quality of answers. Results: It was established that both systems are useful in the retrieval of valid definitional healthcare information, with an acceptable degree of coherent and precise responses from both. The answers supplied by MedQA were more reliable that those of START in the sense that they came from specialised clinical or academic sources, most of them showing links to further research articles. Conclusions: Results obtained show the potential of this type of tool in the more general realm of information access, and the retrieval of health information. They may be considered a good, reliable and reasonably precise alternative in alleviating the information overload. Both QA systems can help professionals and users can obtain healthcare information.  相似文献   
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