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   20016篇
  免费   68篇
  国内免费   7篇
教育   15193篇
科学研究   1902篇
各国文化   147篇
体育   848篇
综合类   5篇
文化理论   476篇
信息传播   1520篇
  2021年   55篇
  2020年   84篇
  2019年   157篇
  2018年   2338篇
  2017年   2278篇
  2016年   1752篇
  2015年   276篇
  2014年   326篇
  2013年   2112篇
  2012年   379篇
  2011年   870篇
  2010年   989篇
  2009年   580篇
  2008年   824篇
  2007年   1321篇
  2006年   252篇
  2005年   574篇
  2004年   611篇
  2003年   506篇
  2002年   274篇
  2001年   130篇
  2000年   145篇
  1999年   133篇
  1998年   113篇
  1997年   130篇
  1996年   118篇
  1995年   147篇
  1994年   121篇
  1993年   106篇
  1992年   114篇
  1991年   112篇
  1990年   102篇
  1989年   107篇
  1988年   98篇
  1987年   96篇
  1986年   88篇
  1985年   99篇
  1984年   106篇
  1983年   99篇
  1982年   109篇
  1981年   82篇
  1980年   61篇
  1979年   74篇
  1978年   77篇
  1977年   85篇
  1976年   68篇
  1975年   56篇
  1974年   59篇
  1973年   60篇
  1971年   45篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
911.
912.
Peer collaboration is a pedagogical method currently used to facilitate learning in classrooms. Similarly, computer-learning environments (CLEs) are often used to promote student learning in science classrooms, in particular. However, students often have difficulty utilizing these environments effectively. Does peer collaboration help students learn with these environments? Little research looking closely at face-to-face peer collaboration with computer learning environments exists. Utilizing a social-cognitive theoretical framework, this study investigated the relation between the conceptual-knowledge learning and the collaborative regulatory behaviors of students working with a peer as they studied about the human circulatory system using a hypermedia CLE. Fifty-four high-school students from the East Coast of the United States were audiotaped to identify the collaborative regulatory behaviors they evidenced as they studied. Results revealed significant correlations among students’ proportion of categories of regulatory behaviors and their learning gains (from pretest to posttest). Moreover, qualitative analyses revealed particular behaviors that larger-gain collaborative pairs engaged in to a greater extent than smaller-gain pairs as they learned with the hypermedia environment.  相似文献   
913.
Pedagogical innovation—whether involving technology or not—is shaped by a complex interaction of the innovation with contextual factors such as school and school district policy, leadership, cultural norms and values, teacher attitudes and skills, and student characteristics. This study examined school and classroom contexts in which pedagogical innovations employing technology were successfully sustained. Data were obtained from 59 cases drawn from the Second Information Technology in Education Study—Module 2, a project that examined 174 cases of innovative pedagogical practice in schools in 28 countries. An explanatory model of sustainability was derived from a qualitative analysis of the cases using grounded theory techniques. Essential conditions for the sustainability of classroom innovation were teacher and student support of the innovation, teacher perceived value of the innovation, teacher professional development, and principal approval. Contributing factors for sustainability were supportive plans and policies, funding, innovation champions, and internal and external recognition and support. An interactive website that allows for searching of SITES-M2 case reports on various attributes such as sustainability, transferability, level of school, and evidence of supportive policies and plans is available at http://sitesm2.org.  相似文献   
914.
The effects of isolation and handling on the reactivity of rats to two tactile stimuli were assessed in two experiments. In the first experiment, reactivity to more intense footshock was increased in rats raised in isolation but was not affected by handling by an experimenter. In the second experiment, increased reactivity to airpuff stimuli presented to the dorsal surface of isolation-reared rats was reduced by handling. The data suggest that the effects of handling on shock-motivated behaviors are not due to altered reactivity to shock and that the effect of housing or handling must be considered in behavioral tests in which reactivity to tactile stimulation might play a role as dependent or independent variables.  相似文献   
915.
Verbal energy: attending to poetry   总被引:1,自引:0,他引:1  
This paper contends that the current English curriculum does not adequately acknowledge the potential of poetry to make meaning through sound. It reflects on how sound may embody or communicate meaning, and seeks enhanced conceptions of this aspect of poetry for pedagogy and the curriculum. It begins with the attention the mainstream press gave to Seamus Heaney's remarks about Eminem, and progresses to consider Heaney's notion of ‘verbal energy’ in the light of developing conceptions of multimodal ‘new literacies’. It suggests that new approaches could accord with an oral heritage approach to poetry while also acknowledging the influence of the communicational environments pupils experience beyond English classrooms. Throughout, the author draws on material that has informed his on‐going Teacher Training Agency‐sponsored project exploring the ways in which pupils approach poetry as sound, soon to be detailed on web resources for the English teaching community.  相似文献   
916.
This article examines the construct validity of the Course Experience Questionnaire (CEQ) in Hong Kong and investigates the similarities and differences in the process of learning among students in different disciplinary studies. It is based on a survey of 1,563 undergraduate students in two disciplines, humanities and sciences, and of principally Chinese ethnicity. Findings from exploratory and confirmatory factor analyses support the scale structure of the four subscales of a modified version of the CEQ (good teaching, clear goals and standards, appropriate work, and appropriate assessment) in a non-Western context and could provide a basis for cross cultural research and international benchmarking. While there was variation across subgroups, there was a genuine pattern of relationships between the perceptions of learning environment and learning strategies shown by structural modeling. This information could be used to inform the design of discipline-specific programs in the new curriculum.  相似文献   
917.
Quantitative trait loci (QTL) analysis was conducted in bread wheat for 14 important traits utilizing data from four different mapping populations involving different approaches of QTL analysis. Analysis for grain protein content (GPC) sug- gested that the major part of genetic variation for this trait is due to environmental interactions. In contrast, pre-harvest sprouting tolerance (PHST) was controlled mainly by main effect QTL (M-QTL) with very little genetic variation due to environmental interactions; a major QTL for PHST was detected on chromosome arm 3AL. For grain weight, one QTL each was detected on chromosome arms 1AS, 2BS and 7AS. QTL for 4 growth related traits taken together detected by different methods ranged from 37 to 40; nine QTL that were detected by single-locus as well as two-locus analyses were all M-QTL. Similarly, single-locus and two-locus QTL analyses for seven yield and yield contributing traits in two populations respectively allowed detection of 25 and 50 QTL by composite interval mapping (CIM), 16 and 25 QTL by multiple-trait composite interval mapping (MCIM) and 38 and 37 QTL by two-locus analyses. These studies should prove useful in QTL cloning and wheat improvement through marker aided selection.  相似文献   
918.
The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles (AgNPs) were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction: AgNO3+NaBH4→ Ag+1/2H2+1/2B2H6+NaNO3. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells (MC3T3-E1) from mice and mesenchymal stem cells (BMSC) from rats. The antibacterial properties of dental alloys incorporating three different concentrations (10, 4, and 2 μmol/L) of AgNPs were tested on Staphylococcus aureus (SA) and Streptococcus mutans (MS). High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs (the control groups). The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorporation of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.  相似文献   
919.
The initiatives attempting to forge links between the academia and the industry flourished in France after World War I. The so-called “industrial institutes” shared a common goal: to reinvigorate the French economy through science. Because of their focus on applied research, they differed from traditional engineering schools that usually neglected laboratory work and innovation. However, while the industrial institutes were a distinct category that shows broader trends in science-industry relations, from a formal point of view they did not constitute a coherent category. The term “institute” was ambiguous and applied to various legal and administrative arrangements. While the French state attempted to unify terminology by introducing “faculty institutes” through the 1920 Decree on the constitution of universities, the measure was not sufficient to englobe all types of institutions. The diversity of organizational realities behind the industrial institutes is, however, useful for analyzing power structures and hierarchies in a given industrial sector. The legal form of an industrial institute was conditioned by the state and the robustness of the industry that funded it. As such, the history of the French industrial institutes may constitute a fertile ground for broader analyses on the impact of power relations on the legal reality behind the initiatives uniting science and industry.  相似文献   
920.
Both macroappraisal and the Australian records continuum-based DIRKS methodology have been influential in the New Zealand debate on appraisal in recent years. The primary influence of macroappraisal has been in the area of prioritisation of appraisal work. This paper considers New Zealand thinking on prioritisation, and the influences of risk management and functional analysis on this issue. A lack of agreement on the purpose of appraisal in the professional literature is noted, and some personal suggestions are offered on a model taking elements from macroappraisal and other methodologies.  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