全文获取类型
收费全文 | 18040篇 |
免费 | 261篇 |
国内免费 | 65篇 |
专业分类
教育 | 13113篇 |
科学研究 | 1257篇 |
各国文化 | 179篇 |
体育 | 1572篇 |
综合类 | 44篇 |
文化理论 | 106篇 |
信息传播 | 2095篇 |
出版年
2022年 | 121篇 |
2021年 | 214篇 |
2020年 | 261篇 |
2019年 | 407篇 |
2018年 | 588篇 |
2017年 | 609篇 |
2016年 | 574篇 |
2015年 | 360篇 |
2014年 | 501篇 |
2013年 | 3513篇 |
2012年 | 514篇 |
2011年 | 518篇 |
2010年 | 466篇 |
2009年 | 437篇 |
2008年 | 455篇 |
2007年 | 420篇 |
2006年 | 457篇 |
2005年 | 404篇 |
2004年 | 285篇 |
2003年 | 269篇 |
2002年 | 259篇 |
2001年 | 392篇 |
2000年 | 303篇 |
1999年 | 267篇 |
1998年 | 176篇 |
1997年 | 169篇 |
1996年 | 176篇 |
1995年 | 147篇 |
1994年 | 156篇 |
1993年 | 143篇 |
1992年 | 222篇 |
1991年 | 214篇 |
1990年 | 247篇 |
1989年 | 220篇 |
1988年 | 178篇 |
1987年 | 186篇 |
1986年 | 194篇 |
1985年 | 179篇 |
1984年 | 190篇 |
1983年 | 170篇 |
1982年 | 138篇 |
1981年 | 141篇 |
1980年 | 137篇 |
1979年 | 198篇 |
1978年 | 165篇 |
1977年 | 116篇 |
1976年 | 120篇 |
1975年 | 122篇 |
1973年 | 107篇 |
1971年 | 118篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
<正>确分析和评价专业镇竞争力,客观认识和了解专业镇发展现状及竞争优势,对专业镇的政策制定及转型发展具有重要现实意义。从专业镇竞争力的内涵及评价内容入手,从城镇竞争力、产业竞争力、企业竞争力、自主创新能力和环境竞争力五个方面构建出一套相对完整的专业镇竞争力评价指标体系以及与之相应的评价模型,为客观、全面、定量地评价和衡量专业镇竞争力提供理论支撑和实践依据。 相似文献
992.
Microfluidic devices allow for the production of physiologically relevant cellular microenvironments by including biomimetic hydrogels and generating controlled chemical gradients. During transport, the biomolecules interact in distinct ways with the fibrillar networks: as purely diffusive factors in the soluble fluid or bound to the matrix proteins. These two main mechanisms may regulate distinct cell responses in order to guide their directional migration: caused by the substrate-bound chemoattractant gradient (haptotaxis) or by the gradient established within the soluble fluid (chemotaxis). In this work 3D diffusion experiments, in combination with ELISA assays, are performed using microfluidic platforms in order to quantify the distribution of PDGF-BB and TGF-β1 across collagen and fibrin gels. Furthermore, to gain a deeper understanding of the fundamental processes, the experiments are reproduced by computer simulations based on a reaction-diffusion transport model. This model yields an accurate prediction of the experimental results, confirming that diffusion and binding phenomena are established within the microdevice. 相似文献
993.
[目的/意义]旨在提高我国公共图书馆文化服务效率,为公共图书馆文化服务发展提供参考。[方法/过程]以我国31个省份公共图书馆为数据,运用DEA-BCC模型和K-means聚类分析我国各区域文化服务的效率及差异。[结果/结论]我国公共图书馆文化服务效率整体较低,呈非均衡性,存在不同程度投入冗余和产出不足,最后针对我国公共图书馆文化服务提出相应的改进建议。 相似文献
994.
Steffen Pacholak Stefan Hochstein Alexander Rudert Christoph Brücker 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(2):176-194
The undulatory underwater sequence is one of the most important phases in competitive swimming. An understanding of the recurrent vortex dynamics around the human body and their generation could therefore be used to improve swimming techniques. In order to produce a dynamic model, we applied human joint kinematics to three-dimensional (3D) body scans of a female swimmer. The flow around this dynamic model was then calculated using computational fluid dynamics with the aid of moving 3D meshes. Evaluation of the numerical results delivered by the various motion cycles identified characteristic vortex structures for each of the cycles, which exhibited increasing intensity and drag influence. At maximum thrust, drag forces appear to be 12 times higher than those of a passive gliding swimmer. As far as we know, this is the first disclosure of vortex rings merging into vortex tubes in the wake after vortex recapturing. All unsteady structures were visualized using a modified Q-criterion also incorporated into our methods. At the very least, our approach is likely to be suited to further studies examining swimmers engaging in undulatory swimming during training or competition. 相似文献
995.
Guillaume Mornieux Dominic Gehring Patrick Fürst Albert Gollhofer 《Journal of sports sciences》2014,32(13):1255-1262
AbstractAnticipatory postural adjustments (APAs), i.e. preparatory positioning of the head, the trunk and the foot, are essential to initiate cutting manoeuvres during football games. The aim of the present study was to determine how APA strategies during cutting manoeuvres are influenced by a reduction of the time available to prepare the movement.Thirteen football players performed different cutting tasks, with directions of cutting either known prior to the task or indicated by a light signal occurring 850, 600 or 500 ms before ground contact.With less time available to prepare the cutting manoeuvre, the head was less orientated towards the cutting direction (P = 0.033) and the trunk was even more rotated in the opposite direction (P = 0.002), while the foot placement was not significantly influenced. Moreover, the induced higher lateral trunk flexion correlated with the increased knee abduction moment (r = 0.41; P = 0.009).Increasing lateral trunk flexion is the main strategy used to successfully perform a cutting manoeuvre when less time is available to prepare the movement. However, higher lateral trunk flexion was associated with an increased knee abduction moment and therefore an increased knee injury risk. Reducing lateral trunk flexion during cutting manoeuvres should be part of training programs seeking the optimisation of APAs. 相似文献
996.
This discussion focuses on how the rise of America's national sporting pastimes, during the period 1880–1920, was inextricably tied to the ambitions and outpourings of American print capitalism and a concomitant congealing of a sense of modern American nationhood. In examining this thematic, we explicate the manner in which American national sporting audiences during the period 1880–1920 were variously constituted through discourses of national and ethnic sporting difference or Otherness. Hence, we examine the popular representation of turn of the century rodeo practices (as narrated through the spectacle of the western showman William Frederick ‘Buffalo Bill’ Cody's Wild West show productions), the position of early-twentieth-century American baseball in relation to other sporting cultures (graphically depicted by Albert Goodwill, or A.G., Spalding's promotional publications, specifically the 1911 America's National Game) and the national and ethnic differences discerned within the global sporting landscape more generally (explicated within the 1919 National Geographic article ‘The Geography of Games’). These performances and representations of ethnic and national sporting Otherness played an important role in re-inscribing and legitimating the (White European American) normative core of American sport culture (as manifest within and through the dominant practices of playing and/or spectating of football, baseball and basketball). 相似文献
997.
Michael Krüger 《国际体育史杂志》2014,31(12):1425-1443
Erinnerungskultur (culture of remembrance) is a widely discussed notion in German historiography. First, the meaning of Erinnerungskultur, including the specific role of academic historiography of sport, is described and explained with respect to sport and sport historiography. One main objective is to reveal the diversity of cultures of sport history and the specific obligations of academic historiography. Second, the actors of sport memories and/or Traditionspflege (heritage) are characterised, and, third, some controversial and perennial debates that permeate German sports history are explained and interpreted, especially that of Carl Diem, internationally known as ‘Mister Olympics’ of 1936. All in all, the paper provides an overview of the mainstreams, cultures and politics of history in Germany with respect to sport. 相似文献
998.
999.
1000.