全文获取类型
收费全文 | 13549篇 |
免费 | 124篇 |
国内免费 | 33篇 |
专业分类
教育 | 9015篇 |
科学研究 | 1702篇 |
各国文化 | 97篇 |
体育 | 1432篇 |
综合类 | 45篇 |
文化理论 | 183篇 |
信息传播 | 1232篇 |
出版年
2022年 | 70篇 |
2021年 | 127篇 |
2020年 | 157篇 |
2019年 | 239篇 |
2018年 | 377篇 |
2017年 | 422篇 |
2016年 | 463篇 |
2015年 | 308篇 |
2014年 | 335篇 |
2013年 | 1937篇 |
2012年 | 431篇 |
2011年 | 457篇 |
2010年 | 326篇 |
2009年 | 261篇 |
2008年 | 309篇 |
2007年 | 315篇 |
2006年 | 286篇 |
2005年 | 883篇 |
2004年 | 649篇 |
2003年 | 482篇 |
2002年 | 295篇 |
2001年 | 262篇 |
2000年 | 206篇 |
1999年 | 199篇 |
1998年 | 96篇 |
1997年 | 94篇 |
1996年 | 121篇 |
1995年 | 86篇 |
1994年 | 103篇 |
1993年 | 89篇 |
1992年 | 160篇 |
1991年 | 147篇 |
1990年 | 147篇 |
1989年 | 134篇 |
1988年 | 108篇 |
1987年 | 115篇 |
1986年 | 136篇 |
1985年 | 127篇 |
1984年 | 111篇 |
1983年 | 127篇 |
1982年 | 105篇 |
1981年 | 101篇 |
1980年 | 84篇 |
1979年 | 161篇 |
1978年 | 106篇 |
1977年 | 96篇 |
1976年 | 100篇 |
1975年 | 79篇 |
1974年 | 90篇 |
1972年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
93.
94.
B. G. C. Maisonneuve T. Honegger J. Cordeiro O. Lecarme T. Thiry D. Fuard K. Berton E. Picard M. Zelsmann D. Peyrade 《Biomicrofluidics》2016,10(2)
With the rise of microfluidics for the past decade, there has come an ever more pressing need for a low-cost and rapid prototyping technology, especially for research and education purposes. In this article, we report a rapid prototyping process of chromed masks for various microfluidic applications. The process takes place out of a clean room, uses a commercially available video-projector, and can be completed in less than half an hour. We quantify the ranges of fields of view and of resolutions accessible through this video-projection system and report the fabrication of critical microfluidic components (junctions, straight channels, and curved channels). To exemplify the process, three common devices are produced using this method: a droplet generation device, a gradient generation device, and a neuro-engineering oriented device. The neuro-engineering oriented device is a compartmentalized microfluidic chip, and therefore, required the production and the precise alignment of two different masks. 相似文献
95.
96.
97.
Univ.-Prof. Dr. Jürgen Court 《Sportwissenschaft》2011,41(2):91-99
This article deals with the first years of foundation of the private Deutsche Hochschule für Leibesübungen (DHfL). It focuses on the question of why August Bier’s application for a Doktor der Leibesübungen in 1920 was refused. In the same year the DHfL also made an application for the education in state-run schools which was already task of the state-run Preußische Landesturnanstalt at Spandau. As the DHfL combined this application with its insistence on its autonomous status an application for a Doktor der Leibesübungen had implied financial, conceptual and institutional obligations for Prussia and at the same time a renuncitation of its sovereign rights. This thesis was proved by a comparison between the doctorate in physical education and the doctorate for businessmen at Cologne University. 相似文献
98.
Rocío Cupeiro Miguel A. Rojo-Tirado Cristina Cadenas-Sanchez Enrique G. Artero Ana B. Peinado Idoia Labayen 《Journal of sports sciences》2020,38(13):1506-1515
ABSTRACT The aim of the present study was to investigate the existence of a relative age effect (RAE) on physical fitness of preschoolers. Anthropometry and physical fitness were assessed in 3147 children (3–5 years old) using the PREFIT battery. Based on the birth year, participants were divided into 3year groups (3-, 4- and 5-years). Within each year group, 4quarter groups were created: quarter 1, preschoolers born from January to March; quarter 2, from April to June; quarter 3, from July to September; quarter 4, from October to December. The MANCOVA analysis revealed a main effect of year group (Wilks’ λ = 0.383; F10,5996 = 369.64; p < 0.001, ηp 2 = 0.381) and of quarter (Wilks’ λ = 0.874; F15,8276.6 = 27.67; p < 0.001; ηp 2 = 0.044) over the whole battery of tests. To the best of our knowledge, this is the first study to report the existence of RAE at the preschool stage. In general, performance improved as the relative age increased (i.e., those born in quarter 1 performed better than those in the other quarters). Individualization strategies should be addressed within the same academic year not only in elementary or secondary years but also in preschoolers. 相似文献
99.
Dylan J.H.A. Henssen Loes van den Heuvel Guido De Jong Marc A.T.M. Vorstenbosch Anne-Marie van Cappellen van Walsum Marianne M. Van den Hurk Jan G.M. Kooloos Ronald H.M.A. Bartels 《Anatomical sciences education》2020,13(3):353-365
Neuroanatomy education is a challenging field which could benefit from modern innovations, such as augmented reality (AR) applications. This study investigates the differences on test scores, cognitive load, and motivation after neuroanatomy learning using AR applications or using cross-sections of the brain. Prior to two practical assignments, a pretest (extended matching questions, double-choice questions and a test on cross-sectional anatomy) and a mental rotation test (MRT) were completed. Sex and MRT scores were used to stratify students over the two groups. The two practical assignments were designed to study (1) general brain anatomy and (2) subcortical structures. Subsequently, participants completed a posttest similar to the pretest and a motivational questionnaire. Finally, a focus group interview was conducted to appraise participants’ perceptions. Medical and biomedical students (n = 31); 19 males (61.3%) and 12 females (38.7%), mean age 19.2 ± 1.7 years participated in this experiment. Students who worked with cross-sections (n = 16) showed significantly more improvement on test scores than students who worked with GreyMapp-AR (P = 0.035) (n = 15). Further analysis showed that this difference was primarily caused by significant improvement on the cross-sectional questions. Students in the cross-section group, moreover, experienced a significantly higher germane (P = 0.009) and extraneous cognitive load (P = 0.016) than students in the GreyMapp-AR group. No significant differences were found in motivational scores. To conclude, this study suggests that AR applications can play a role in future anatomy education as an add-on educational tool, especially in learning three-dimensional relations of anatomical structures. 相似文献
100.
In many Western science systems, funding structures increasingly stimulate academic research to contribute to practical applications,
but at the same time the rise of bibliometric performance assessments have strengthened the pressure on academics to conduct
excellent basic research that can be published in scholarly literature. We analyze the interplay between these two developments
in a set of three case studies of fields of chemistry in the Netherlands. First, we describe how the conditions under which
academic chemists work have changed since 1975. Second, we investigate whether practical applications have become a source
of credibility for individual researchers. Indeed, this turns out to be the case in catalysis, where connecting with industrial
applications helps in many steps of the credibility cycle. Practical applications yield much less credibility in environmental
chemistry, where application-oriented research agendas help to acquire funding, but not to publish prestigious papers or to
earn peer recognition. In biochemistry practical applications hardly help in gaining credibility, as this field is still strongly
oriented at fundamental questions. The differences between the fields can be explained by the presence or absence of powerful
upstream end-users, who can afford to invest in academic research with promising long term benefits. 相似文献