Results 31 to 40 of about 6,311,407 (143)
A model of macroevolution with a natural system size [PDF]
, 1998 We describe a simple model of evolution which incorporates the branching and extinction of species lines, and also includes abiotic influences. A first principles approach is taken in which the probability for speciation and extinction are defined purely
Head, DA, Rodgers, GJ
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Ultraluminous X-ray Sources and Their Nebulae [PDF]
, 2008 One of the interesting features of Ultraluminous X-ray sources is that many of them are surrounded by luminous nebulae exhibiting diverse observational properties. In different cases the nebulae are photoionized or shock-powered.
Magnus Axelsson, Pavel Abolmasov
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The design and development of a spacecraft appendage tie down mechanism [PDF]
, 1985 The design and evolution is described of a spacecraft Appendage Tie Down Mechanism (ATDM). Particular emphasis is paid to the mechanical aspects of using dry lubricants to increase the efficiency of acme threads and worm gearing.
Head, R., Nygren, W. D.
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, 2018 Dipole moments are a simple, global measure of the accuracy of the electron density of a polar molecule. Dipole moments also affect the interactions of a molecule with other molecules as well as electric fields.
Hait, Diptarka, Head-Gordon, Martin
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How do government agencies use evidence? [PDF]
Executive summary: Significant research gaps remain in our understanding about what happens in side government agencies in relation to the production, commissioning, assessment and incorporation of research-based evidence into their policy advice and ...
Brian Head
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Active Space Pair 2-Electron Reduced Density Matrix Theory for Strong Correlation
, 2020 An active space variational calculation of the 2-electron reduced density matrix (2-RDM) is derived and implemented where the active orbitals are correlated within the pair approximation.
Head-Marsden, Kade, Mazziotti, David A.
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Head Tracking via Robust Registration in Texture Map Images [PDF]
, 1997 A novel method for 3D head tracking in the presence of large head rotations and facial expression changes is described. Tracking is formulated in terms of color image registration in the texture map of a 3D surface model.
Isidoro, John +2 more
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Water is not a Dynamic Polydisperse Branched Polymer
, 2019 The contributed paper by Naserifar and Goddard reports that their RexPoN water model under ambient conditions simulates liquid water as a dynamic polydisperse branched polymer, which they speculate explains the existence of the liquid-liquid critical ...
Head-Gordon, Teresa, Paesani, Francesco
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Capital Flows, Incomplete Markets, and the U.S. European Unemployment Gap [PDF]
This paper investigates the relationship of the ``unemployment gap'' between the United States and Europe to the opening of international capital markets.
Allen Head, Karlis Smits
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Computer program determines thermal environment and temperature history of lunar orbiting space vehicles [PDF]
, 1967 Program computes the thermal environment of a spacecraft in a lunar orbit. The quantities determined include the incident flux /solar and lunar emitted radiation/, total radiation absorbed by a surface, and the resulting surface temperature as a function
Head, D. E., Mitchell, K. L.
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