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61.
A completely general three-dimensional dynamic model is presented for the motion of basketball shots that may contact the rim, the backboard, the bridge between the rim and board, and possibly the board and the bridge simultaneously. Non-linear ordinary differential equations with six degrees of freedom describe the ball angular velocity and ball centre position. The model includes radial ball compliance and damping and contains five sub-models: purely gravitational flight, and ball-rim, ball-bridge, ball-board, and ball-bridge-board contact. Each contact sub-model has both slipping and non-slipping motions. Switching between the sub-models depends on the reaction force at, and velocity of, the contact point. Although the model can be used to study shots from any point on the court, we here use it to study the sets of free throw release angle, velocity, angular velocity, and lateral deviation angle that result in success (capture), as well as underhand free throws and those using an under-inflated ball. Free throw shots with larger backspin, lower inflation pressures, and underhand release conditions are shown to result in larger capture percentages. 相似文献
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Richard H. Beyler 《Minerva》2006,44(3):251-266
In responding to incidents of internal ‘indiscipline’, the Kaiser Wilhelm Society many times asserted its authority, sometimes in cooperation with agencies of the Nazi regime. Following the Second World War, however, the KWS represented itself as having been intrinsically anti-Nazi. This essay describes the assumptions inherent in this view, and points to its wider implications for post-war German science. 相似文献
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开展学术争鸣弘扬科学精神--《热带地理》开辟"争鸣园地"栏目的体会 总被引：4，自引：3，他引：1
介绍《热带地理》开辟"争鸣园地"栏目的背景和指导思想,以及编辑在引导学术争鸣持续开展,扩大刊物知名度方面的做法、收获和体会. 相似文献
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From 1919 to 1951, Alan Gregg and his mentor, Richard Pearce, directed the Medical Education and Medical SciencesDivisions of the Rockefeller Foundation. Although they oversaw the expenditure of millions of dollars, today they are forgotten. Yet, the system that Gregg administered became the model for the funding of biomedical research after the Second World War. This paper draws on the records of the Rockefeller Foundation to assess Gregg and his impact on biomedicine and philanthropy. 相似文献
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The many challenges faced by health sciences libraries of all types and sizes often require innovative solutions. When an innovative solution involves calculated risk taking, the approach is called intrapreneurial. At the University of Miami School of Medicine, an intrapreneurial approach solved the fiscal problems of the biomedical communications unit. The Louis Calder Memorial Library inherited these problems when the Department of the Library and Biomedical Communications was created in the early 1980s. In this paper, two intrapreneurial programs are described, and the benefit and suitability of this management style to information services are demonstrated. 相似文献