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101.
102.
M.K. Gupta Vijay Gupta Manoj Kumar 《Journal of Mathematical Analysis and Applications》2007,330(2):799-816
In the present paper we introduce a new family of linear positive operators and study some direct and inverse results in simultaneous approximation. 相似文献
103.
Recently, the authors have proposed a new necessary and sufficient condition for turnpike optimality in calculus of variations
with singular Euler equation. The method is based on a characterization of the value function and generalizes the well known
method based on the Green theorem. Furthermore, it allows the optimality of a competition between several turnpikes to be
characterized. For a class of such problems not enjoying the turnpike property, we give an explicit formula for the value
function and show how to characterize the optimal solution as the limiting solution of a family of perturbed problems satisfying
the turnpike property. The considered problems are scalar with infinite horizon. 相似文献
104.
José A. Anquela Teresa Cortés Miguel Gómez-Lozano Mercedes Siles-Molina 《Acta Mathematica Hungarica》2004,103(3):177-196
We investigate the basic properties of the different socles that can be considered in not necessarily semiprime associative
systems. Among other things, we show that the socle defined as the sum of minimal (or minimal and trivial) inner ideals is
always an ideal. When trivial inner ideals are included, this inner socle contains the socles defined in terms of minimal
left or right ideals.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
105.
New solitons and kink solutions for the Gardner equation 总被引:3,自引:1,他引:2
The Gardner equation, also called combined KdV–mKdV equation, is studied. New hyperbolic ansatze are proposed to derive solitons solutions. The tanh method is used as well to obtain kink solutions. 相似文献
106.
107.
Ricardo L. Mancera Michalis Chalaris Jannis Samios 《Journal of Molecular Liquids》2004,110(1-3):147-153
We have carried out a molecular dynamics study of dimethyl sulfoxide (DMSO) in water at 298 K at two different densities by simulating two different concentrations: 0.055 and 0.19 mole fraction. We have found an enhancement in the structure of water, an effect that becomes more pronounced as the concentration of DMSO increases. At both concentrations there is a well-defined hydration structure around the oxygen atom of DMSO, which is able to establish strong hydrogen bonds with surrounding water molecules. An increase in the concentration of DMSO depletes the solution of bulk water molecules, reducing the number of hydrogen bonds that water can have in the immediate vicinity of DMSO but increasing the strength of the hydrogen bonds made between the oxygen atom of DMSO and water. There is clear evidence of ‘hydrophobic’ hydration around the methyl groups of DMSO, which is enhanced as the concentration of DMSO increases. 相似文献
108.
魏嵬 《数学的实践与认识》2007,37(16):76-83
为给转炉设计提供依据,需要计算炉液倾动的重心.利用数学方法将实际问题进行简化,通过分析炉液倾动过程中变量间的相互关系,来确定每个倾动角度对应情况下的液面位置.利用数学中三重积分的有关应用,进一步得出转炉在每个倾动角度为α∈(0,π2)时的重心计算方法及相关结论,在理论上为工程计算重心的方法提供参考. 相似文献
109.
We show that the complex projection of a completely positive quaternionic map of quaternionic density matrices is a positive
map in the space of complex density matrices, and we briefly outline some of its properties. To illustrate this result, we
study the complex projection of a one-parameter quaternionic unitary dynamics of a spin-1/2 quantum system.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 151, No. 3, pp. 360–370, June, 2007. 相似文献
110.
Piotr Biler 《Reports on Mathematical Physics》2003,52(2):205-225
We study asymptotic properties of solutions to an extension to arbitrary dimensions of the astrophysical model proposed by Chavanis et al. to explain phenomena of gravitational collapse in clouds of self-gravitating particles. In particular, we show that in the two-dimensional case the solutions can be continued to global ones, while in three space dimensions large data of negative energy blow up in a finite time. Relations between isothermal, Streater's energy-transport and the present models are also studied. 相似文献