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   13899篇
  免费   459篇
  国内免费   497篇
教育   9821篇
科学研究   2292篇
各国文化   110篇
体育   545篇
综合类   876篇
文化理论   21篇
信息传播   1190篇
  2024年   5篇
  2023年   104篇
  2022年   143篇
  2021年   304篇
  2020年   427篇
  2019年   363篇
  2018年   304篇
  2017年   303篇
  2016年   369篇
  2015年   423篇
  2014年   474篇
  2013年   894篇
  2012年   1018篇
  2011年   1029篇
  2010年   557篇
  2009年   691篇
  2008年   955篇
  2007年   1108篇
  2006年   1179篇
  2005年   1005篇
  2004年   847篇
  2003年   635篇
  2002年   477篇
  2001年   325篇
  2000年   271篇
  1999年   143篇
  1998年   92篇
  1997年   84篇
  1996年   79篇
  1995年   44篇
  1994年   48篇
  1993年   37篇
  1992年   34篇
  1991年   23篇
  1990年   18篇
  1989年   21篇
  1988年   3篇
  1987年   6篇
  1985年   5篇
  1984年   2篇
  1983年   2篇
  1980年   1篇
  1979年   1篇
  1976年   1篇
  1957年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Zoo educators are important communicators of the targets in education for sustainable development and therefore carry great responsibility for global environmental change. However, German zoo educators form a heterogeneous group, many of them working in non-permanent job positions and facing multiple challenges at work. Applying the job demands-resources model, our study aims at revealing factors influencing zoo educators’ job strain. Our data from eight in-depth interviews with German zoo educators confirm that they perceive common factors known from other studies, such as demands (e.g. workload) and resources (e.g. supervisory support). Besides this, job-specific factors were identified (e.g. working with humans and animals). The demands zoo educators mentioned could be classified either as job hindrances (e.g. lack of equipment) or job challenges (e.g. learning). Future studies should quantify these results to facilitate the development of appropriate measures to reduce educators’ job strain, thus enhancing their performance.  相似文献   
62.
Quality assurance in engineering education is a multifaceted problem further augmented by the stakeholders of engineering education. Students, parents and employers are rightfully questioning the quality of the curriculum, the instructional delivery, the learning environment, accessibility to learning technologies and equipment, employability as well as the possibilities of lifelong learning and the improvement of knowledge (Karapetrovic 2002 Karapetrovic, S. 2002. Why and how to develop a meaningful quality assurance system in engineering schools. Int. J. Engg. Educ, 18(3): 285294. [Web of Science ®] [Google Scholar]). The purpose of the study is, therefore, to identify the parameters that influence the quality of an engineering education system and develop an integrated model of hierarchical structuring and a concept map for pre-identified concept elements through a process of iterative-interactive consensus-driven methodology, as advocated by second-generation system design paradigm for evolving knowledge scenario of concepts related to quality engineering education.  相似文献   
63.
目的:比较分析高等院校女生人格状况,为高校女生人格教育提供实证依据。方法:运用大学人格问卷(UPI)在湖南省的某理工院校对504名2005级女生进行人格测查,并抽取男生样本858名作为性别比较因素。结果:(1)有第一类人格问题的女大学生比例显著高于男大学生;女大学生UPI分数显著高于男大学生。(2)女大学生人格问题症状选择率排前列的项目依次为:在乎别人的视线,缺乏自信心,过于担心将来的事情,父母期望过高,情绪起伏过大。(3)非独生女与独生女的UPI分数不存在显著差异;农村生源女生UPI分数显著高于城镇生源女生;文科类女生UPI分数显著高于理工类女生。结论:女大学生人格问题比男生严重,农村生源女生人格问题比城镇生源女生严重,文科类女生人格问题比理工科女生严重;应高度重视女大学生尤其是农村生源女生和理工院校中文科类女生的人格健康教育,以优化她们的心理素质。  相似文献   
64.
A new stem rot disease is found to occur naturally on Arabidopsis plants in greenhouses of Fuzhou, China. In order to identify its pathogen, we conducted a series of fimgal isolation and purification, plant reinoculation, and ascus and ascospore induction from the sclerotia. The isolate caused typical water-soaked lesions after reinoeulation and produced sclerotia both on Arabidopsis plants and culture medium plates, and the sclerotia could be induced to produce discal apothecia and 8 binucleate ascospores per ascus. These disease symptom and fungal morphology data revealed that the fungus Sclerotinia sclerotiorum (Lib.) de Bary was the pathogen for Arabidopsis stem rot. To confirm this, we further amplified its large subunit ribosomal DNA (LSU rDNA) by polymerase chain reaction (PCR), and compared the sequence with the known LSU rDNA sequences in GenBank. The results show that the sequence shares the highest identities with the LSU rDNAs of different S. sclerotiorum strains. Taking all these data together, we concluded that the fungus that caused the Arabidopsis stem rot is S. sclerotiorum (Lib.) de Bary. This is the first report that Arabidopsis is naturally infected by S. sclerotiorum.  相似文献   
65.
Critical Religious Education (CRE) is a contemporary pedagogy of religious education developed by Andrew Wright and various colleagues over the past two decades. There has been widespread academic discourse about the pedagogy in theory but increasingly commentators have called for examples of it in practice. Over the past seven years a writing group associated with The Forum of Religious and Spiritual Education at King’s College London have been developing practical materials aimed at supporting teachers in embedding the pedagogy in practice. Of particular relevance to this paper is the development of an introductory scheme of work, aimed at year 7 students, which has been trialled in a number of schools in and around London. In 2013, focus group interviews took place in four of these schools in order to ascertain the reception that the materials had received. The data suggests a very positive response to the introductory scheme of work and the CRE approach in general, partially dispelling some criticisms levelled at it in academic discourse. The author has thus suggested that the approach and the work of the writing group need further exposure, especially in schools, at conferences and on initial teacher education programmes.  相似文献   
66.
Fluidized-bed reactor is a candidate for dimethyl ether (DME) synthesis from syngas because of its excellent heat removal capability. In order to improve the attrition resistance of catalyst, an amount of silica sol as binder was added to the catalyst composed of methanol synthesis component CuO/ZnO/Al2O3 and methanol dehydration component HZSM-5, which was prepared by coprecipitation and shaped by spray drying to get spherical particles. The effect of silica sol on the catalytic activity was investigated in a fixed-bed flow microreactor. Based on the experiment results, silica sol in the range of 0-20wt% had small effect on the catalytic activity. Generally, the CO conversion and DME yield decreased with the increase in concentration of silica sol, while the attrition resistance of catalysts increased with increasing silica sol, indicating that it was feasible to improve the attrition resistance without greatly sacrificing the activity of catalyst. In addition, the characterizations of catalysts were carried out using Brunauer-Emmett-Teller (BET), X-ray powder diffraction (XRD) and temperature programmed reduction (TPR).  相似文献   
67.
Waste hops are good sources of flavonoids. Extraction of flavonoids from waste hops (SC-CO2 extracted hops) using supercritical fluids technology was investigated. Various temperatures, pressures and concentrations of ethanol (modifier) and the ratio (w/w) of solvent to material were tested in this study. The results of single factor and orthogonal experiments showed that at 50°C, 25 MPa, the ratio of solvent to material (50%), ethanol concentration (80%) resulted in maximum extraction yield flavonoids (7.8 mg/g). HPLC-MS analysis of the extracts indicated that flavonoids obtained were xanthohumol, the principal prenylflavonoid in hops. Project (No. Y304203) supported by the Natural Science Foundation of Zhejiang Province, China  相似文献   
68.
半个多世纪以来 ,简帛佚籍不断出土问世 ,其中包含有不少重要的教育史料 ,这些史料给中国教育史研究提供了新的内容和领域 :第一 ,有望促成《老子》一书现其历史真面目 ,并使先秦黄老道家学派的著作与思想体系渐趋明朗 ,从而极大地推动关于先秦道家教育思想体系的确立与完善 ;第二 ,极大地丰富了研究孔子及其后学八派教育思想的史料 ,使加深对孔子教育思想的认识 ,弥补从孔子到孟子之间儒家教育思想长期存在的研究空白成为可能 ;第三 ,对于明确先秦两汉经学教育的细节有着举足轻重的作用 ;第四 ,重要字书《仓颉篇》的出土 ,为研究秦汉语文教育提供了极其重要的文献  相似文献   
69.
Feedback can play a vital role in fostering teacher self-efficacy. Social comparisons and feedback valence (positive vs. negative feedback) are assumed to have a large impact on self-efficacy. Therefore, how pre-service teachers perceive social comparisons and feedback valence in peer feedback and the extent to which pre-service teachers (bachelor/master students) and teacher trainers incorporate comments that can have an impact on self-efficacy into their peer feedback merit investigation. Two studies were conducted. The first showed that peer feedback consisting of a social comparison and with positive feedback valence resulted in greater willingness to improve and positive affect. The second study revealed that teacher trainers’ feedback was more specific, whereas bachelor students’ feedback contained more social comparisons than did master students’ and teacher trainers’. Future research and practical implications are discussed.  相似文献   
70.
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