全文获取类型
收费全文 | 588篇 |
免费 | 21篇 |
专业分类
教育 | 368篇 |
科学研究 | 64篇 |
各国文化 | 8篇 |
体育 | 103篇 |
综合类 | 1篇 |
文化理论 | 11篇 |
信息传播 | 54篇 |
出版年
2023年 | 3篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 25篇 |
2019年 | 34篇 |
2018年 | 54篇 |
2017年 | 49篇 |
2016年 | 46篇 |
2015年 | 22篇 |
2014年 | 22篇 |
2013年 | 106篇 |
2012年 | 28篇 |
2011年 | 21篇 |
2010年 | 19篇 |
2009年 | 15篇 |
2008年 | 28篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1903年 | 1篇 |
排序方式: 共有609条查询结果,搜索用时 15 毫秒
581.
This paper presents a study of relevance feedback in a cross-language information retrieval environment. We have performed an experiment in which Portuguese speakers are asked to judge the relevance of English documents; documents hand-translated to Portuguese and documents automatically translated to Portuguese. The goals of the experiment were to answer two questions (i) how well can native Portuguese searchers recognise relevant documents written in English, compared to documents that are hand translated and automatically translated to Portuguese; and (ii) what is the impact of misjudged documents on the performance improvement that can be achieved by relevance feedback. Surprisingly, the results show that machine translation is as effective as hand translation in aiding users to assess relevance in the experiment. In addition, the impact of misjudged documents on the performance of RF is overall just moderate, and varies greatly for different query topics. 相似文献
582.
Oliver Neumann Christian Matt Benedikt Simon Hitz-Gamper Lisa Schmidthuber Matthias Stürmer 《Government Information Quarterly》2019,36(4):101411
Creating public value is a key goal of public administrations, both in their daily business and in the growing field of smart government and smart cities, which focuses on IT-enabled innovations in the public sphere. However, many public administrations still struggle with such innovations due to complex technologies, high investments, and the numerous stakeholders involved. To address this issue, some local governments in continental Europe have turned to collaborative innovation approaches, partnering with (semi-)public utility companies in the hope that their additional innovation assets will boost innovativeness. Nevertheless, it remains unclear how exactly such collaborations should be governed to ensure that the focus remains on creating public value, as utility companies may have their own agendas. To explore this question, we conducted a comparative case study in the context of smart city initiatives with four cases in Swiss local governments. Drawing on agency and stewardship theory, we then propose a model of public-value-focused collaborative innovation, enabling us to explore various collaboration characteristics and their effects on public value creation. Our findings suggest that both agency- and stewardship-based collaborations increase innovativeness. However, while agency collaborations tend to produce smart city innovations that mainly serve the utility companies' business interests, stewardship relationships lead to innovations that are focused more on public value creation. As such, our study extends the literature on the effects of collaborative innovation on public value, and it provides practical recommendations on how such collaborative innovation should be designed. 相似文献
583.
Bittner Jenny V. Stamov Roßnagel Christian Staudinger Ursula M. 《International Journal for Educational and Vocational Guidance》2022,22(2):307-325
International Journal for Educational and Vocational Guidance - Self-regulation is crucial for learning and achievement in educational and occupational contexts. Educational self-regulation has... 相似文献
584.
Education and Information Technologies - Due to the advent of coronavirus disease in most nations throughout the world, the manner of education altered from traditional face-to-face to remote or... 相似文献
585.
Christian Roith 《Paedagogica Historica: International Journal of the History of Education》2014,50(5):631-650
After the revolution in 1918, many reformist teachers were convinced that they could put into practice their dreams of a free and independent school in a democratic republic. Four state schools in Hamburg became anti-authoritarian school communities, in which teachers, parents and students experimented with revolutionary concepts of education. For two schools, the experiment lasted until 1930, when they voluntarily gave up their status as experimental schools. The remaining two schools lost this status in 1933 after the National Socialist seizure of power. The experimental schools in Hamburg attracted the attention of educationalists worldwide, welcoming a large number of visitors during their existence and inspiring academic studies. The German–Swiss educationalist Robert Jakob Schmid presented a critical study on the Hamburg school communities in his doctoral thesis, published in French during his stay in Geneva in 1936. His work fell into oblivion for more than three decades, until it was reprinted in French and later translated into Spanish, German, Portuguese and Italian in the 1970s. The publishers of these editions were not interested in spreading Schmid’s critiques regarding the school communities and distorted his argumentation by different means, such as partial translations, shortening the most critical aspects or adding long introductions. In this way, they tried to use Schmid’s study as a tool to support their own argumentative interests in the educational discourse of the 1970s. 相似文献
586.
Jun LIN Wei-ying ZHENG Peng-ruo-feng LIU Ning ZHANG Hui-ping LIN Yi-jing FAN Xin-hua GU Oliver VOLLRATH Christian MEHL 《Journal of Zhejiang University. Science. B》2014,(7)
研究目的:评价含有酪蛋白磷酸肽-无定形磷酸钙(CPP-ACP)的再矿化剂Tooth Mousse(TM)的使用、不同玷污层的处理以及样本储存时间对牙本质粘接微拉伸性能的影响。研究方法:将牙本质样本分成保留玷污层组和用15%乙二胺四乙酸(EDTA)处理90秒去除玷污层组。每组根据是否使用TM处理再分亚组。每个亚组分别用三种不同的粘结剂(两步法自酸蚀Clearfil SE Bond(CSE)、一步法自酸蚀G-Bond(GB)和全酸蚀Adper Single Bond 2(SB))与牙本质样本粘接,分别经过3天和6个月的去离子水储存。样本进行切割微拉伸测试并通过扫描电镜分析断裂界面模式。重要结论:经过再矿化剂TM预处理,可以减少牙齿的敏感性,并且对于这三种粘结系统经过长时间储存后的粘结性能没有影响。EDTA的处理对于长期储存的粘结性能没有显著影响。额外的TM和EDTA对短期(3天)粘接力会有效应,但对长期(6个月)的粘接力没有影响。 相似文献
587.
Why space matters in technological innovation systems—Mapping global knowledge dynamics of membrane bioreactor technology 总被引:1,自引:0,他引:1
Studies on technological innovation systems (TISs) often set spatial boundaries at the national level and treat supranational levels as a geographically undifferentiated and freely accessible global technological opportunity set. This article criticizes this conceptualization and proposes instead to analyze relevant actors, networks and processes in TIS from a relational perspective on space. It develops an analytical framework which allows investigating innovation processes (or ‘functions’) of a TIS at and across different spatial scales. Based on social network analysis of a co-publication dataset from membrane bioreactor technology, we illustrate how the spatial characteristics of collaborations in knowledge creation vary greatly over relatively short periods of time. This finding suggests that TIS studies should be more reflexive on system boundary setting both regarding the identification and analysis of core processes as well as in the formulation of policy advice. 相似文献
588.
Racetubes, a conventional system employing hollow glass tubes, are typically used for monitoring circadian rhythms from the model filamentous fungus, Neurospora crassa. However, a major technical limitation in using a conventional system is that racetubes are not amenable for real-time gas perturbations. In this work, we demonstrate a simple microfluidic device combined with real-time gas perturbations for monitoring circadian rhythms in Neurospora crassa using bioluminescence assays. The developed platform is a useful toolbox for investigating molecular responses under various gas conditions for Neurospora and can also be applied to other microorganisms. 相似文献
589.
Jean Slawinski Raphaël Dumas Laurence Cheze Guy Ontanon Christian Miller Alice Mazure–Bonnefoy 《Journal of sports sciences》2013,31(3):256-263
Abstract Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis® system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments. 相似文献
590.
Elvir Rakovic Gøran Paulsen Christian Helland Ola Eriksrud 《Journal of sports sciences》2013,31(24):2802-2808
ABSTRACTThis study aimed to evaluate whether an individualised sprint-training program was more effective in improving sprint performance in elite team-sport players compared to a generalised sprint-training program. Seventeen elite female handball players (23 ± 3 y, 177 ± 7 cm, 73 ± 6 kg) performed two weekly sprint training sessions over eight weeks in addition to their regular handball practice. An individualised training group (ITG, n = 9) performed a targeted sprint-training program based on their horizontal force-velocity profile from the pre-training test. Within ITG, players displaying the lowest, highest and mid-level force-velocity slope values relative to body mass were assigned to a resisted, an assisted or a mixed sprint-training program (resisted sprinting in the first half and assisted sprinting in the second half of the intervention period), respectively. A control group (CG, n = 8) performed a generalised sprint-training program. Both groups improved 30-m sprint performance by ~1% (small effect) and maximal velocity sprinting by ~2% (moderate effect). Trivial or small effect magnitudes were observed for mechanical outputs related to horizontal force- or power production. All between-group differences were trivial. In conclusion, individualised sprint-training was no more effective in improving sprint performance than a generalised sprint-training program. 相似文献