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991.
Eberhard M. Schröder 《Journal of Geometry》1993,46(1-2):177-185
Two pointsX, Y of a quadricF in an affine or projective space are called 0-distant, writtenX Y, if they coincide or if their connecting line is a subset ofF. In this paper, answers are given to the question under which conditions an arbitrary permutation ofF satisfyingX Y X
Y
X,Y F can be extended to a collineation of the given space.Dedicated to Rafael Artzy on the occasion of his 80th birthday 相似文献
992.
It is shown that various first and second order derivatives of the Fitzpatrick and Penot representative functions for a maximal
monotone operator T, in a reflexive Banach space, can be used to represent differential information associated with the tangent and normal cones
to the Graph T. In particular we obtain formula for the proto-derivative, as well as its polar, the normal cone to the graph of T. First order derivatives are shown to be useful in recognising points of single-valuedness of T. We show that a strong form of proto-differentiability to the graph of T, is often associated with single valuedness of T.
The second author’s research was funded by NSERC and the Canada Research Chair programme, and the first author’s by ARC grant
number DP0664423. This study was commenced between August and December 2005 while the first author was visiting Dalhousie
University. 相似文献
993.
994.
995.
Eberhard Kaniuth Anthony T. Lau Gü nter Schlichting 《Proceedings of the American Mathematical Society》2005,133(7):2157-2164
We investigate a certain topological Paley-Wiener property and show, for instance, that compact-free nilpotent groups and simply connected solvable groups share this property.
996.
997.
Inverse models for underactuated multibody systems are presented. The derivation of the inverse model is based on the transformation of the equation of motion into a nonlinear input–output normal–form. These inverse models often include a internal dynamics, for which different methods of solution are presented. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
998.
Particle layers tend to build up on wails in many filtration and separation processes, calling for periodic removal in order to keep the apparatus running. Important factors are the adhesion of the layer on the substrate and the cohesion of the particles in the layer. Models describing such layer detachment generally assume constant and homogeneous conditions for the forces acting on the layer. But in reality detachment is extremely non-stationary concerning place and time, primarily due to changing conditions of the detaching forces on the one hand and changes in the particle layer morphology on the other. This paper describes a model and a simulation based on this model considering such transient kinetic effects, for which some computing results are presented and discussed. 相似文献
999.
Eberhard Schmidt 《中国颗粒学报》2009,(1)
Particle layers tend to build up on walls in many filtration and separation processes, calling for periodic removal in order to keep the apparatus running. Important factors are the adhesion of the layer on the substrate and the cohesion of the particles in the layer. Models describing such layer detachment generally assume constant and homogeneous conditions for the forces acting on the layer. But in reality detachment is extremely non-stationary concerning place and time, primarily due to changing conditi... 相似文献
1000.
Granular materials are an integral part of our environment. Due to their wide variety of applications in industrial and technological processes, they have captured a great interest in the recent research, see [1] and [2]. The related studies are often based on numerical simulations and it is considered as challenging to investigate computational phenomena of dense granular systems. Particle screening is an essential technology in many industrial fields and important in granular studies. The particular problem of interest is the separation of round shape particles of different geometrical sizes using a rotating tumbling vertical cylinder. The concept of discrete element method (DEM) that considers the motion of each single particle individually is applied in this study. Particle-to-particle and particle-to-wall collisions will appear under the tumbling motion of the rotating structure. The normal and frictional forces between particles themselves and particles and surrounding walls of the structure are calculated according to the rules of a penalty method, which employs spring-damper models for this purpose. As a result of collisions, the particles will dissipate kinetic energy due to the normal and frictional contact losses. Particle distribution and sifting rate of the separated particles have been studied taking into consideration different rotational speeds of the machine, various damping and frictional coefficients and different sizes of holes in the sifting plates at different levels of the structure. In an attempt to better understand the mechanism of the particle transport between the different layers of the sifting system, different computational studies have been performed. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献