Dust showers     

Washington Jones  W Barnet Le Van  Tinius Olsen  William M Henderson  Wm.D Marks 《Journal of The Franklin Institute》1880,110(2):106-114

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The bourdon pressure gauge     

John D. Van Buren 《Journal of The Franklin Institute》1866,81(4):219-223

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Experiment station of the Bureau of Mines     

Van H. Manning 《Journal of The Franklin Institute》1920,189(2):251-252

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The relationship between peak height velocity and physical performance in youth soccer players   总被引：1，自引：1，他引：0  

Philippaerts RM  Vaeyens R  Janssens M  Van Renterghem B  Matthys D  Craen R  Bourgois J  Vrijens J  Beunen G  Malina RM 《Journal of sports sciences》2006,24(3):221-230

Longitudinal changes in height, weight and physical performance were studied in 33 Flemish male youth soccer players from the Ghent Youth Soccer Project. The players' ages at the start of the study ranged from 10.4 to 13.7 years, with a mean age of 12.2 +/- 0.7 years. Longitudinal changes were studied over a 5 year period. Peak height velocity and peak weight velocity were determined using non-smoothed polynomials. The estimations of peak height velocity, peak weight velocity and age at peak height velocity were 9.7 +/- 1.5 cm x year-1, 8.4 +/- 3.0 kg x year-1 and 13.8 +/- 0.8 years, respectively. Peak weight velocity occurred, on average, at the same age as peak height velocity. Balance, speed of limb movement, trunk strength, upper-body muscular endurance, explosive strength, running speed and agility, cardiorespiratory endurance and anaerobic capacity showed peak development at peak height velocity. A plateau in the velocity curves was observed after peak height velocity for upper-body muscular endurance, explosive strength and running speed. Flexibility exhibited peak development during the tear after peak height velocity. Trainers and coaches should be aware of the individual characteristics of the adolescent growth spurt and the training load should also be individualized at this time.  相似文献   

The Turin International Centre for Advanced Technical and Vocational Training     

Jan Bado Sperling 《Prospects》1976,6(2):271-275

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Three-axis platform simulation: Bond graph and Lagrangian approach     

M.J.L. Tiernego  J.J. Van Dixhoorn 《Journal of The Franklin Institute》1979,308(3):185-204

A bond graph model is derived for the geometric constraints of a three-axis flight table. Gimbal dynamics are easily added even in asymmetrical and unbalanced cases. A method is introduced to make the local dependent inertias computable. The bond graph compares favourably to the Lagrangian approach as to modelling effort and accessibility of intermediate variables as well as having computational advantages.  相似文献   

Book reviews     

Mary A. Anderson  Frank Bowles  C. O. Taiwo  Jan D. Beckmann  L. J. Lewis  James R. Liesch  Godfrey N. Brown  H. L. Elvin  Shib K. Mitra  Richard F. Behrendt  Graeme Kemelfield  Hugh W. R. Hawes  W. A. Dodd  A. L. Tibawi 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1971,17(2):220-251

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The electron mechanics of induction acceleration     

Jan A. Rajchman  William H. Cherry 《Journal of The Franklin Institute》1947,243(4):261-285

The radial and axial motions of electrons in the betatron are described by means of a potential function of forces. Previously reported conditions of equilibrium, stability and damping of oscillations are derived for the region of parabolic variation of the potential. Extension of the analysis to, non-parabolic regions gives an account of the injection in conventional instruments in better agreement with experiment, particularly in regard to higher voltages of injection.Space charge limitations are discussed with the help of the Laplacian of the potential of forces.By means of an additional radial electric field electrons can be introduced as in the magnetron, without any asymmetry inherent in the conventional betatron circumferential injector. The analysis of the conditions of equilibrium and stability, greatly facilitated in this case by the notion of potential, shows that no substantial improvement in space charge limitations can be expected and that the required variations between the flux linking the electron orbits and the magnetic and electric fields at the orbits are difficult to realize on account of their complexity and narrow tolerances. The X-ray output of a small experimental double yoke instrument was measured by a phototube multiplier viewing an irradiated fluorescent screen and gave evidence of multiple group electron capture.  相似文献   

Differential contribution of personality to the explanation of variance in achievement in the first language and mathematics at high school level     

Mechala Scott  Jan L. De K. Monteit 《Psychology in the schools》1987,24(1):78-83

This study assessed the differential contribution of personality to the explanation of variance in achievement in the mother tongue and mathematics at the high school level. The results indicated that personality, as measured by the HSPQ, aided the explication of variance in achievement in the mother tongue significantly, but had little influence on mathematics. Personality contributed as much to the explanation of variance in the mother tongue as did the composite cognitive variable. The influence of personality on achievement in mathematics was shown to be negligible. Some practical implications for the teaching of the first language are drawn.  相似文献   

The Interplay of Psychology and Mathematics Education: From the Attraction of Psychology to the Discovery of the Social     

Karen François  Kathleen Coessens  Jean Paul Van Bendegem 《Journal of Philosophy of Education》2012,46(3):370-385

It is a rather safe statement to claim that the social dimensions of the scientific process are accepted in a fair share of studies in the philosophy of science. It is a somewhat safe statement to claim that the social dimensions are now seen as an essential element in the understanding of what human cognition is and how it functions. But it would be a rather unsafe statement to claim that the social is fully accepted in the philosophy of mathematics. And we are not quite sure what kind of statement it is to claim that the social dimensions in theories of mathematics education are becoming more prominent, compared to the psychological dimensions. In our contribution we will focus, after a brief presentation of the above claims, on this particular domain to understand the successes and failures of the development of theories of mathematics education that focus on the social and not primarily on the psychological.  相似文献