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   572篇
  免费   5篇
教育   380篇
科学研究   46篇
各国文化   3篇
体育   105篇
综合类   1篇
文化理论   11篇
信息传播   31篇
  2024年   2篇
  2023年   4篇
  2022年   15篇
  2021年   22篇
  2020年   38篇
  2019年   52篇
  2018年   42篇
  2017年   44篇
  2016年   36篇
  2015年   19篇
  2014年   26篇
  2013年   96篇
  2012年   29篇
  2011年   27篇
  2010年   11篇
  2009年   16篇
  2008年   11篇
  2007年   12篇
  2006年   5篇
  2005年   5篇
  2004年   8篇
  2003年   9篇
  2002年   9篇
  2001年   3篇
  2000年   1篇
  1999年   2篇
  1998年   3篇
  1996年   2篇
  1995年   4篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   4篇
  1988年   2篇
  1987年   2篇
  1985年   2篇
  1982年   1篇
  1981年   2篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1972年   1篇
  1970年   1篇
排序方式: 共有577条查询结果,搜索用时 0 毫秒
41.
Abstract

Purpose

Information technology (IT) has tremendous potential for fostering grassroots development and the Indian government has created various capital-intensive computer networks to promote agricultural development. However, research studies have shown that information technology investments are not always translated into productivity gains due to poor computer use by employees. In this context, a research investigation was conducted to develop a Computer Utilization Model that explains how individual and organizational factors influence computer utilization in extension organizations in India.  相似文献   
42.
Abstract

This study aims to show how the integration of passive and active learning approaches contributes towards the significant understanding of problems associated with sustainable development. To do this, a case study from the municipality of San Miguel de Achiutla in Oaxaca, Mexico, is used as a general method, with the specific procedure including an instrument based on secondary sources representing the passive learning phase, as well as an instrument created on the basis of primary sources, designed in relation to the active learning component. The passive learning phase enabled us to identify variables pertaining to the highly vulnerable dimensions of sustainable development, and to also detect areas in which there is a deficit of information, since not all data are available, while the active learning phase revealed the causes of vulnerability from the perspective of different agents, including those who experienced the issues directly. In view of the above, we conclude that rather than being exclusive, these two different approaches should in fact be complementary.  相似文献   
43.
En el campo del lenguaje y la lectoescritura, la renovación educativa parece estar situándose en la batalla por el diseño abierto y la evaluación informal. En este artículo se propone un modelo teórico para la lectoescritura flexible que pueda soportar las posibilidades que se abren y evitar los inconvenientes que amenazan a los actuales métodos informales de renovación a los que está dedicado el tema central de este número.  相似文献   
44.
This paper presents conditions to assure the exponential stability in probability for autonomous switching linear systems. The switching signal acting on the autonomous system produces intervals that follow independent, identically distributed stochastic processes—the stability then follows by verifying simple-to-check linear matrix inequalities.  相似文献   
45.
In this study, the fibers of invasive species Agave americana L. and Ricinus communis L. were successfully used for the first time as new sources to produce cytocompatible and highly crystalline cellulose nanofibers. Cellulose nanofibers were obtained by two methods, based on either alkaline or acid hydrolysis. The morphology, chemical composition, and crystallinity of the obtained materials were characterized by scanning electron microscopy(SEM) together with energy-dispersive X-ray spectroscopy(EDX), dynamic light scattering(DLS), X-ray diffraction(XRD), and Fourier transform infrared(FTIR)spectroscopy. The crystallinity indexes(CIs) of the cellulose nanofibers extracted from A. americana and R. communis were very high(94.1% and 92.7%, respectively). Biological studies evaluating the cytotoxic effects of the prepared cellulose nanofibers on human embryonic kidney 293 T(HEK293 T) cells were also performed. The nanofibers obtained using the two different extraction methods were all shown to be cytocompatible in the concentration range assayed(i.e., 0-500 μg/mL). Our results showed that the nanocellulose extracted from A. americana and R. communis fibers has high potential as a new renewable green source of highly crystalline cellulose-based cytocompatible nanomaterials for biomedical applications.  相似文献   
46.
A Chebyshev collocation method, an expansion method, has been proposed in order to solve the systems of higher-order linear integro-differential equations. This method transforms the IDE system and the given conditions into the matrix equations via Chebyshev collocation points. By merging these results, a new system which corresponds to a system of linear algebraic equations is obtained. The solution of this system yields the Chebyshev coefficients of the solution function. Some numerical results are also given to illustrate the efficiency of the method. Moreover, this method is valid for the systems of differential and integral equations.  相似文献   
47.
The current state of the planet’s environmental deterioration calls for formal educational contexts to implement effective environmental proposals which nurture action competence. The aim of this paper is to examine the educational proposals in formal contexts that have been published in the two research journals of greatest impact on Environmental Education during the period 2008–2013, and to analyse how they contribute to the development of action competence. Special attention is paid to research (i) based on real participation by students; (ii) promotes reflection on the complexity of environmental issues; (iii) facilitates critical thinking; (iv) encourages autonomous and responsible decision-making and (v) involves communities. Our results show that these approaches can help improve the development of action-focused environmental education and bring to light a series of challenges for future research.  相似文献   
48.
Expressive reading is considered one of the subprocesses involved in reading fluency, and good readers show greater changes in tone and fewer unnecessary pauses than bad ones. Given the high frequency of reading difficulties in specific language impairment (SLI), there may be certain differences in the use of prosody among children with SLI. The purpose of this study was to research whether prosody in the reading of children with Spanish SLI differs from that in the reading of typical readers. To do so, 44 children (SLI and control) read aloud a text which contained declarative, interrogative and exclamatory sentences. Different prosodic parameters referring to length, tone and intensity were measured. The results showed that the children with SLI read slower, commit more errors and make more inappropriate pauses. Furthermore, fewer pitch variations were found in the interrogative sentence and in the final features of the sentence. These results confirm the relationship between decoding and prosody; therefore, interventions with these children should bear in mind the practice of expressive reading while learning reading fluency.  相似文献   
49.

Notes and Reviews

Some recent Unesco publications  相似文献   
50.
The present study examined whether or not different input delivery modes have an effect on listening comprehension of Turkish students learning English at the university level. It investigated the effect of one single mode, which is audio-only, and three dual input delivery modes, which were audio-video, audio-video with target language subtitles and audio with PowerPoint presentation, on listening comprehension. The data have been gathered through: a listening proficiency exam, a topic familiarity questionnaire, listening comprehension tests, think-aloud protocols and a semi-structured focus group interview. Analysis of data demonstrated that the students’ listening comprehension scores were significantly lower in audio-video with subtitles mode. In addition to this, the students stated that they experienced most confusion and anxiety in understanding through audio-video with subtitles. Moreover, the students mentioned that they were most successful in the audio with PowerPoint presentation mode. Results also indicated that the students were influenced by their pre-university listening class experiences, meaning that they were most accustomed to the audio-only mode, and therefore felt most relaxed when they listened only.  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