全文获取类型
收费全文 | 4325篇 |
免费 | 28篇 |
国内免费 | 8篇 |
专业分类
教育 | 3090篇 |
科学研究 | 622篇 |
各国文化 | 16篇 |
体育 | 176篇 |
综合类 | 22篇 |
文化理论 | 95篇 |
信息传播 | 340篇 |
出版年
2023年 | 9篇 |
2022年 | 45篇 |
2021年 | 61篇 |
2020年 | 53篇 |
2019年 | 63篇 |
2018年 | 141篇 |
2017年 | 182篇 |
2016年 | 236篇 |
2015年 | 162篇 |
2014年 | 120篇 |
2013年 | 336篇 |
2012年 | 258篇 |
2011年 | 241篇 |
2010年 | 122篇 |
2009年 | 90篇 |
2008年 | 114篇 |
2007年 | 101篇 |
2006年 | 80篇 |
2005年 | 712篇 |
2004年 | 497篇 |
2003年 | 317篇 |
2002年 | 167篇 |
2001年 | 74篇 |
2000年 | 42篇 |
1999年 | 27篇 |
1998年 | 16篇 |
1997年 | 8篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1826年 | 1篇 |
排序方式: 共有4361条查询结果,搜索用时 15 毫秒
111.
Catherine B. Woods Kevin Volf Liam Kelly Blthín Casey Peter Gelius Sven Messing Sarah Forberger Jeroen Lakerveld Joanna Zukowska Enrique García Bengoechea PEN consortium 《运动与健康科学(英文)》2021,10(3):263-276
BackgroundDespite the well-established health benefits of physical activity (PA) for young people (aged 4–19 years), most do not meet PA guidelines. Policies that support PA in schools may be promising, but their impact on PA behavior is poorly understood. The aim of this systematic review was to ascertain the level and type of evidence reported in the international scientific literature for policies within the school setting that contribute directly or indirectly to increasing PA.MethodsThis systematic review is compliant with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Six databases were searched using key concepts of policy, school, evaluation, and PA. Following title and abstract screening of 2323 studies, 25 progressed to data synthesis. Methodological quality was assessed using standardized tools, and the strength of the evidence of policy impact was described based on pre-determined codes: positive, negative, inconclusive, or untested statistically.ResultsEvidence emerged for 9 policy areas that had a direct or indirect effect on PA within the school setting. These were whole school PA policy, physical education, sport/extracurricular PA, classroom-based PA, active breaks/recess, physical environment, shared use agreements, active school transport, and surveillance. The bulk of the evidence was significantly positive (54%), 27% was inconclusive, 9% was significantly negative, and 11% was untested (due to rounding, some numbers add to 99% or 101%). Frequency of evidence was highest in the primary setting (41%), 34% in the secondary setting, and 24% in primary/secondary combined school settings. By policy area, frequency of evidence was highest for sport/extracurricular PA (35%), 17% for physical education, and 12% for whole school PA policy, with evidence for shared use agreements between schools and local communities rarely reported (2%). Comparing relative strength of evidence, the evidence for shared use agreements, though sparse, was 100% positive, while 60% of the evidence for whole school PA policy, 59% of the evidence for sport/extracurricular PA, 57% of the evidence for physical education, 50% of the evidence for PA in classroom, and 50% of the evidence for active breaks/recess were positive.ConclusionThe current evidence base supports the effectiveness of PA policy actions within the school setting but cautions against a “one-size-fits-all” approach and emphasizes the need to examine policy implementation to maximize translation into practice. Greater clarity regarding terminology, measurement, and methods for evaluation of policy interventions is needed. 相似文献
112.
113.
114.
This paper analyzes the effects that the 2012 VAT rise in Spain had on household’ demand for cultural goods and services. Household’ demands are modeled as a two-stage QUAIDS. After estimating price and expenditure elasticities, and the pass-through parameter associated with the reform, our results show that the individual welfare loss and the increment in the tax bill increase, but less than proportionately, with income. Consequently, the reform can be considered as regressive. Relating the effects of the VAT reform to households’ incomes also implies a low quantitative effect, because of the low proportion of total household expenditure that cultural expenditure represents. From a social perspective, the size of the induced welfare loss would positively depend on society’s inequality aversion. Regardless of the latter, it cannot be concluded whether the reform would have increased or reduced inequality in the distribution of cultural spending. Our results prove qualitatively robust to alternative values of the pass-through parameter. 相似文献
115.
档案进入数据态管理模式,需要新的档案价值鉴定体系.在概述谢伦伯格文件双重价值理论的核心要点的基础上,分析档案管理模式改变、信息公开、电子文件以及档案数据对双重价值理论时序性假设和方便利用等假设的冲击,反思双重价值理论在信息时代存在的合理性.从多元性角度重构档案价值理论,提出档案价值多元模型、档案多元价值变化时间模型,对... 相似文献
116.
教育理论与实践的本然统一 总被引:14,自引:0,他引:14
解释学是哲学,而且是实践哲学。在实践哲学视野下,理论不再被概念所固化为抽象的认识,理论总是在实践中不断生成和实现自身。在此意义上,理论可以生动、鲜活,与丰富的实践具有本然统一的联系。从教育之作为实践的本性出发,在一个相当根本的层面上,教育理论可以有这样一种探索和建构:它属于实践哲学的范畴,作为实践的理论形态,完成并实现于教育实践活动之中,它并不与教育实践相对立、相分离,而是具有不可分割的本然联系。 相似文献
117.
Measurement and analysis of soil nitrogen and organic matter content using near-infrared spectroscopy techniques 总被引:2,自引:0,他引:2
Near infrared reflectance (N1R) spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen (N) and organic matter (OM) content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP (standard error of prediction) were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application. 相似文献
118.
IPv4, the workhorse protocol of the currently popular TCP/ IP protocol suite, is fast becoming obsolete. The exponential growth
of the Internet is the main reason that has required the creation of the next generation of Internet Protocol-IPv6. IPv6 is
much more flexible and promises to take care of the address space and security issues in the foreseeable future.
Part 1 of the paper lays the foundation of the various issues involved in designing the Internet Protocol and motivates the
need for an upgraded version of this protocol. 相似文献
119.
The study explores the consequences, for participating schools, of the implementation of a system for the identification and selection of academically talented students, in the context of an extracurricular enrichment program operating at Pontificia Universidad Católica de Chile. The participants were 73 students, 50 teachers, and seven members of the school administration, in seven schools. Data were collected through interviews and focus groups. The results indicated that the identification and selection processes have mostly positive effects on teachers and students. Some potentially negative effects were also detected for the classmates of the talented students, which relate mainly to the manner in which information was handled. Possible implications of these findings for this program for talented children and other similar programs are discussed. 相似文献
120.
Pedro Buendía 《Al-Masaq: Islam & the Medieval Mediterranean》2014,26(2):168-182
The history of ice in medieval Arab societies is obscured behind a mosaic of a variety of references and scholarly citations. Beyond al-Qalqashandī's reference to organised ice trafficking in fourteenth-century Mamluk Egypt, we do not have conclusive evidence on the origin and use of ice as a consumer product. In this paper we trace its presence based on three genres of references: historical and literary quotations, medicine and literature pertaining to food. These references allow us to consider the extent of ice consumption in the Arab world before the ninth century, as well as the existence of an organised trade throughout the Middle Ages from that time. However, contrary to the Persian world, with its well-documented Iranian yakhchals, we still know virtually nothing about ice-houses in medieval Arab societies. We also know very little about the profession of the thallāj or ice-seller, or whether the widespread consumption of ice that originated in Spain in the sixteenth century was in fact a legacy of an earlier trade in al-Andalus. 相似文献