全文获取类型
收费全文 | 2044篇 |
免费 | 48篇 |
国内免费 | 3篇 |
专业分类
教育 | 1627篇 |
科学研究 | 133篇 |
各国文化 | 35篇 |
体育 | 143篇 |
文化理论 | 24篇 |
信息传播 | 133篇 |
出版年
2023年 | 19篇 |
2022年 | 22篇 |
2021年 | 37篇 |
2020年 | 67篇 |
2019年 | 101篇 |
2018年 | 148篇 |
2017年 | 125篇 |
2016年 | 120篇 |
2015年 | 63篇 |
2014年 | 96篇 |
2013年 | 389篇 |
2012年 | 84篇 |
2011年 | 80篇 |
2010年 | 80篇 |
2009年 | 66篇 |
2008年 | 55篇 |
2007年 | 52篇 |
2006年 | 60篇 |
2005年 | 46篇 |
2004年 | 35篇 |
2003年 | 43篇 |
2002年 | 31篇 |
2001年 | 25篇 |
2000年 | 17篇 |
1999年 | 21篇 |
1998年 | 16篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 16篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1926年 | 2篇 |
1924年 | 3篇 |
排序方式: 共有2095条查询结果,搜索用时 9 毫秒
31.
Andries van den Broek 《Cultural Trends》2013,22(1):46-53
Arts participation bears the threefold imprint of time: people's life stage (age), their earlier socializing imprint (cohort) and the historical circumstances of the moment (period). A proper understanding of these three effects is of great importance in understanding the present and future sizes and preferences of arts audiences. Such understanding implies disentangling those three effects properly, rather than overlooking or confusing them. An example of how that might be done is presented here with regard to arts participation in the US. 相似文献
32.
33.
34.
Desalination is a relatively new intervention in the field of conservation of architectural heritage. Especially the desalination of immovable objects, such as masonry structures, is still a trial-error practice. In the field, different desalination materials and methods are used, sometimes with unsatisfactory results. Better understanding of the desalination process is needed in order to support the conservator with clear guidelines for choosing a suitable desalination material and method. The research presented in this paper constitutes the first step towards the development of a modular system of poultices, which can be adapted, i.e. fine-tuned to different types of substrates. Starting point is to make use of advection, i.e. the transport of salt ions with water flow. This transport mechanism is faster than diffusion and the application on immovable objects is relatively easy. In order to optimize salt extraction, a poultice working by advection should have smaller pores than the substrate. Starting from this principle the pore sizes of different desalination materials (sand, cellulose, kaolin and bentonite) mixed in different proportions, have been measured. Interesting results were obtained, showing that the desalination materials commonly used in the field are often not the most suitable ones. On the basis of the results, recipes for poultices, adapted to a specific substrate, can be formulated. 相似文献
35.
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
36.
Virology Experts in the Boundary Zone Between Science,Policy and the Public: A Biographical Analysis
Erwin van Rijswoud 《Minerva》2010,48(2):145-167
This article aims to open up the biographical black box of three experts working in the boundary zone between science, policy
and public debate. A biographical-narrative approach is used to analyse the roles played by the virologists Albert Osterhaus,
Roel Coutinho and Jaap Goudsmit in policy and public debate. These figures were among the few leading virologists visibly
active in the Netherlands during the revival of infectious diseases in the 1980s. Osterhaus and Coutinho in particular are
still the key figures today, as demonstrated during the outbreak of novel influenza A (H1N1). This article studies the various
political and communicative challenges and dilemmas encountered by these three virologists, and discusses the way in which,
strategically or not, they handled those challenges and dilemmas during the various stages of the field’s recent history.
Important in this respect is their pursuit of a public role that is both effective and credible. We will conclude with a reflection
on the H1N1 pandemic, and the historical and biographical ties between emerging governance arrangements and the experts involved
in the development of such arrangements. 相似文献
37.
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
38.
Morgan E. Chaffin Kris E. Berg Jessica R. Meendering Tamra L. Llewellyn Jeffrey A. French Jeremy E. Davis 《Research quarterly for exercise and sport》2013,84(4):693-701
The purpose of this study was to determine if a difference in interleukin-6 (IL-6) and delayed onset muscles soreness (DOMS) exists in two different phases of the menstrual cycle. Nine runners performed one 75-min high-intensity interval running session during the early follicular (EF) phase and once during the midluteal (ML) phase of the menstrual cycle. Estrogen and progesterone levels were significantly reduced in the EF phase when compared to the ML phase. IL-6 levels increased from pre- to postexercise in the EF and ML phases (p < .001). There was no relationship between the IL-6 level and DOMS. The results suggest that menstruating female runners need not vary training throughout the month to reduce DOMS. 相似文献
39.
Abstract Rowers sit on a seat that slides relative to the boat/ergometer. If a rower lifts him or herself from this sliding seat at any time, the seat will move away from under them and the rowing action is disrupted. From a mechanical perspective, it is clear that the need for the rower to remain in contact with the sliding seat at all times imposes position-dependent constraints on the forces exerted at the oar handle and the footstretcher. Here we investigate if the mechanical power output during rowing, which is strongly related to these forces, might be improved if the contact with the sliding seat was of no concern to the rower. In particular, we examine if elimination of these constraints by strapping the rower to the sliding seat leads to an increase in performance during the start on a standard rowing ergometer. Eleven well-trained female rowers performed 5-stroke starts in normal and strapped conditions. Handle force, vertical seat force, footstretcher force, and handle kinematics were recorded, from which mechanical power and work output were calculated. Most of the relevant mechanical variables differed significantly between the normal and strapped conditions. Most importantly, mechanical power output (averaged over the 5-stroke start) in the strapped condition was 12% higher than in the normal condition. We conclude that strapping a rower's pelvis to the sliding seat allows more vigorous execution of the stroke phases, resulting in a substantial improvement in performance during the start of ergometer rowing. 相似文献
40.
Luce C. A. Claessens Jan van Tartwijk Anna C. van der Want Helena J. M. Pennings Nico Verloop Perry J. den Brok 《The Journal of educational research》2017,110(5):478-493
The authors voice teachers' perceptions of their interpersonal experiences with students in both positive and problematic relationships. Interview data from 28 teachers were examined by coding utterances on teacher and student interactions. Results indicate that teachers defined the quality of the relationship mostly by the level of communion (friendly vs. hostile), instead of by the level of agency (in control vs. powerless). Analyses of mentioned teacher and student behavior show a friendly interactional pattern for positive relationships and a hostile pattern for problematic ones. In teachers' perceptions, positive and problematic relationships also differed in context where encounters take place and topic of talk. Contrary to interactions in problematic relationships, encounters in positive relationships were mostly situated outside the classroom context and conversations during these encounters covered a wide range of topics. Implications for teacher education programs are discussed. 相似文献