New “magic carpet”: New Edition American Chemical Society,Vol. 18, No. 16     

Martin A. Pomerantz 《Journal of The Franklin Institute》1940,230(6):798-799

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The teaching of mathematics — A tragedy     

Martin Wagenschein 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1961,7(2):155-164

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LIBRARY SERVICE: A JOINT RESPONSIBILITY.     

J A Martin 《Bulletin of the Medical Library Association》1964,52(4):771-772

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On stochastic differential equations with non-white noise having small correlation times     

Menelaos Lambiris  Martin Leibowitz 《Journal of The Franklin Institute》1980,309(1):55-64

This is an extension of an earlier paper by the second author. In the previous work, an algorithm was derived for the moments of an homogeneous equation with noise similar to the white noise, but has small, finite correlation time. In the present work this algorithm is extended for an inhomogeneous equation with the same characteristics. Previous notation has been kept throughout the paper.  相似文献   

Secondary electron emission from oxide-coated cathodes     

Martin A. Pomerantz 《Journal of The Franklin Institute》1946,241(6):415-433

The secondary electron emission from alkaline-earth oxide-coated cathodes has been investigated under both continuous and pulsed bombardment. Various factors affecting the yield, such as dependence upon primary voltage, collecting voltage, temperature, time, and angle of incidence, are noted, and the present state of the theory is discussed.Experiments have been performed with three types of apparatus. Yield vs. Energy data reveal values of δ of 4–7 at room temperature, with a more or less flat maximum at approximately 1,000 volts primary energy.The yield increases with temperature in an exponential manner, and plots of log Δδ (i.e. δ_K° ? δ_300°K) vs. 1/T give straight lines. Values of Q₁ between 0.9 – 1.5 eV. are generally indicated, and from extrapolation of these curves, yields exceeding 100 at 850° C. are deduced. The secondary emission depends upon the degree of activation, and increases with enhancement of the thermionic emission characteristics. Short-time effects such as growth or decay of secondary current after the onset of primary bombardment or persistence after the cessation of bombardment have not been observed, and values of yield obtained by pulsed methods are in accord with those obtained under D.C. conditions. Tail phenomena reported by J. B. Johnson and interpreted as “enhanced thermionic emission” from oxidecoated cathodes become manifest only under experimental conditions characterized by certain space-charge effects, and have been effectively simulated by bombarding a tantalum target adjacent to an electron-emitting tungsten filament. Various measurements of the energy distribution of secondary electrons as a function of primary voltage and temperature have been obtained. It was observed that the average energy of the secondary electrons decreases with temperature at a rate which more than compensates for the increase in the number of secondaries emitted per incident primary. The mechanism of the observed dependence of yield upon temperature is not well understood. Various alternative explanations are discussed and, in the light of the present state of our knowledge, regarded as untenable.  相似文献   

I am sailing—towards a transactional analysis of ‘body techniques’     

Joacim Andersson  Leif Östman  Marie Öhman 《Sport, Education and Society》2015,20(6):722-740

In recent years there has been a growing interest in questions related to embodiment and learning. Within the field of ‘body pedagogics’ great efforts have been made to develop theory and methodology that can deal with the corporeal aspects of experience and knowledge without adopting any form of dualistic conceptions of body/mind and organism/environment. This article connects to this body of research. The purpose is to first present a synthesis of James' radical empiricism, Dewey's transactional understanding of experience and learning and Marcel Mauss' concept of ‘body techniques’ and the notion of education embedded in it. Against the background of this theoretical development, and with a Transactional Model of Analyzing Bodying (TMAB), we then show how we can analytically come to terms with different dualistic problems that research into ‘body pedagogics’ has to deal with. We use an empirical example of dinghy sailing to create knowledge about what we learn when learning embodied knowledge, and how this learning takes place. We argue that experience is an important concept for understanding the acting knowing human being, describing how experience is organized and developed and outlining how this organization can be understood as learning. We hold that situations where someone learns to embody certain knowledge are cases of overt actions, in which we can see what kinds of relations are created and how these relations become meaningful for further action.  相似文献   

Self-report vs. kinematic screening test: prevalence,demographics, and sports biography of yips-affected golfers     

Martin K. Klämpfl  Philipp B. Philippen  Babett H. Lobinger 《Journal of sports sciences》2015,33(7):655-664

The yips is considered a task-specific movement disorder. Its estimated prevalence, however, is high compared to similar neurological movement disorders, possibly resulting from previous studies’ restriction of samples based on skill level, and self-report bias. Alternatively, this high prevalence might be an indication of additional aetiologies, for example the influence of previously played racket sports. We estimated the prevalence of the putting yips across the skill range, using self-reports in one study and a screening test in a second study. We explored if previously played sports matter for the development of the yips. In study 1, yips prevalence (N = 1,306) and golfers’ sports biographies (n = 264) were examined via two online surveys, in which golfers indicated if they were yips-affected. In study 2, golfers (N = 186) putted in a standardised putting test while kinematic and performance measures were recorded. Prevalence was estimated via a kinematic threshold. Sports biographies (n = 119) were obtained via an online survey. Prevalence of currently yips-affected golfers was 22.4% in study 1 and 16.7% in study 2. In both studies, more yips-affected than unaffected golfers had experience in playing racket sports. Yips prevalence remained higher than previously estimated prevalence of other movement disorders but decreased when the whole skill range including professionals and novices was considered. Future studies should use the kinematic screening test instead of self-reports to detect the yips and further investigate the influence of previously played racket sports.  相似文献   

Impact of age on haematological markers pre- and post-marathon running     

Thomas G. Martin  Rachel W. Pata  Johanna D’Addario  Lauren Yuknis  Rebecca Kingston  Richard Feinn 《Journal of sports sciences》2015,33(19):1988-1997

This study investigated whether haematological markers differ between young and masters marathon participants, running at similar performance levels. Nine young (31.89 ± 4.96 years) and eight masters (63.13 ± 4.61 years) runners participated. At five time points (pre-race through 54 h post-race), a complete blood cell count, basic metabolic panel and creatine kinase (CK) isoenzyme panel were assessed. Race performance was standardised using the World Masters Association Age Grading Performance Tables. Total CK levels were elevated for all participants at all time points post-race (P < 0.001). The CK-isoenzyme MB% was elevated across groups at 6, 30 and 54 h post-race (P < 0.01, P < 0.01 and P < 0.05), with masters runners having a higher CK-MB% at 30 and 54 h (P < 0.05, P < 0.05). Total white blood cell and neutrophil counts were elevated through 6 h post-race (P < 0.001), with higher levels found in younger runners (P < 0.001). When considering all blood work, masters runners had a higher number of abnormal values at 6, 30 and 54 h post-race (P < 0.05, P < 0.01 and P < 0.05). In conclusion, masters runners demonstrated sustained CK-MB elevation, which may suggest greater cardiac stress. However, future studies using additional cardiac markers should be completed to confirm these findings. In addition, masters runners showed an increased number of laboratory values outside normal range, indicating the body’s reduced capacity to respond to marathon running.  相似文献   

Archives and Historians of Sport     

Martin Johnes 《国际体育史杂志》2015,32(15):1784-1798

Archives and the documents within them are at the heart of the practice of history and the occupational culture of historians. A majority of historical work has been characterized and defined by research in archives of varying kinds. Yet, the material within archives is both partial and political and using it is never straightforward. For historians of sport, the material available in archives can be especially limited but, with some careful reading between the lines, there is still much to learn from and interpret within traditional archives. This paper explores the different kinds of archives and archival material that historians of sport have used and the uses they have been and can be put to. Archives, however, are not static entities and the paper also discusses the impact and implication of digitization processes and programmes to popularize and legitimize traditional archives. Although sport has been seen as one of the ways of diversifying the content and audience of archives, the paper argues that the practical and interpretative challenges historians of sport face in archives are no different to those faced by other historians.  相似文献   

Big and open linked data analytics ecosystem: Theoretical background and essential elements   总被引：1，自引：0，他引：1  

Martin Lnenicka  Jitka Komarkova 《Government Information Quarterly》2019,36(1):129-144

Big and open linked data are often mentioned together because storing, processing, and publishing large amounts of these data play an increasingly important role in today's society. However, although this topic is described from the political, economic, and social points of view, a technical dimension, which is represented by big data analytics, is insufficient. The aim of this review article was to provide a theoretical background of big and open linked data analytics ecosystem and its essential elements. First, the key terms were introduced including related dimensions. Then, the key lifecycle phases were defined and involved stakeholders were identified. Finally, a conceptual framework was proposed. In contrast to previous research, the new ecosystem is formed by interactions of stakeholders in the following dimensions and their sub-dimensions: transparency, engagement, legal, technical, social, and economic. These relationships are characterized by the most important requisites and public policy choices affecting the data analytics ecosystem together with the key phases and activities of the data analytics lifecycle. The findings should contribute to relevant initiatives, strategies, and policies and their effective implementation.  相似文献