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1.
刘文斌 《高校应用数学学报(A辑)》1994,(2)
本文利用上、下解方法推广了M.Lees关于半线性边值问题的结果,给出了另一类边值问题解的存在唯一性的一个充分条件;并利用所得的结果证明了Thomas-Fermi方程的边值问题解的存在唯一性,从而推广了C.DLuning的结果. 相似文献
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二阶常微分方程及Thomas—Fermi方程的边值问题 总被引:1,自引:0,他引:1
刘文斌 《高校应用数学学报(A辑)》1994,(2):136-145
本文利用上、下解方法推广了M.Lees关于半线性边值问题的结果,给出了另一类边值问题解的存在唯一性的一个充分条件;并利用所得的结果证明了Thomas-Fermi方程的边值问题解的存在唯一性,从而推广了C.D.Luning的结果。 相似文献
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本文利用构造上、下解方法,研究奇异方程、(t)X''=f(t,x)的极限边值问题解的存在唯一性,证明了Thoms-Fermi方程对应于孤立中性原子型边值问题有唯一解,所得结果推广了A.Mambriani定理 相似文献
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本文利用构造上、下解方法、研究奇异方程ψ(t)x‘’=f(t,x)的极限边值问题解的存在唯一性,证明了Thoms-Fermi方程对应于孤立中性原子型边值问题有唯一解,所得结果推广了A.Mambriani定理。 相似文献
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1.引言多孔介质二相驱动问题的数学模型是偶合的非线性偏微分方程组的初边值问题.该问题可转化为压力方程和浓度方程[1-4].浓度方程一般是对流占优的对流扩散方程,它的对流速度依赖于比浓度方程的扩散系数大得多的Farcy速度.因此Darcy速度的求解精度直接影响着浓度的求解精度.为了提高速度的求解精度,70年代P.A.Raviat和J.M.Thomas提出混合有限元方法[5].J.DouglasJr,T.F.Russell,R.E.Ewing,M.F.Wheeler[1]-[4],[9],[12]袁… 相似文献
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J.Csirik与D.S.Johnson针对带k-箱限制的在线装箱问题提出了四种装入和关闭法则,并利用这些法则给出了四种相应的算法.其中BBFk,NkF和ABFk算法的紧界在文[1-3]中分别进行了很好的研究.但对算法AFBk来讲,其紧界仍是一个公开问题.本文给出了AFBk算法性能比的一个上界,即.同时,本文提出了一个新的关闭法则,对AFBk算法进行了修改,使修改后的算法AFBk的性能比不超过1.7(k3) 相似文献
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设n,s1,s2,…,sn为正整数及M(s1,s2,…,sn)={(x1,x2,…,xn)|0xisi,且xi为正整数}.若FM(s1,s2,…,sn)满足:对任何a,b∈F,都至少有t个i使ai∧bi=min(ai,bi)>0,则称F为M(s1,s2,…,sn)中的一个t-相交序列族.对x=(x1,x2,…,xn)∈M(s1,s2,…,sn),称r(x)=∑ni=1xi为x的秩.本文讨论并得到当s1=s2=…=sn时M(s1,s2,…,sn)中秩为k的有限序列最大相交族,从而获得了由Engel和Frankl提出的一个关于有限序列相交族的公开未解问题在kn+t-1情形下的解. 相似文献
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We construct a kinetic equation describing the behavior of quantum Fermi gases with the molecule collision frequency proportional to the molecule velocity. We obtain an analytic solution of the generalized Smoluchowski problem with the temperature gradient and the mass flow velocity specified away from the surface. We find exact formulas for jumps of the gas temperature, concentration, and chemical potential. Analysis of limit cases demonstrates a transition of the quantum Fermi gas to the classical or degenerate gas. 相似文献
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Vl. D. Mazurov M. Yu. Khachay M. I. Poberii 《Proceedings of the Steklov Institute of Mathematics》2008,263(2):93-107
In the paper, the computational and approximational complexity of the minimal affine separating committee problem, as well as of some important special cases of this problem, is investigated. 相似文献
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We discuss analytically the stationary viscous quantum hydrodynamic model including a barrier potential, which is a nonlinear system of partial differential equations of mixed order in the sense of Douglis–Nirenberg. Combining a reformulation by means of an adjusted Fermi level, a variational functional, and a fixed point problem, we prove the existence of a weak solution. There are no assumptions on the size of the given data or their variation. We also provide various estimates of the solution that are independent of the quantum parameters. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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General considerations about means and expectations are preceded by a short historical overview. The existing approaches to
the definition of means are classified into three groups: approximational, functional, and axiomatic. In some particular cases
all of them are equivalent. The problem of meaningfulness of means is discussed for ordinal data and for some important cases
of metric data. A survey of the main areas of applications: decision theory, group decision, insurance, economical equity
and inequality is also provided.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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The existence of a local classical solution to the Mullins-Sekerka problem and the convergence to the two-phase quasi-stationary
Stefan problem are proved when surface tension approaches zero. This convergence gives a proof of the existence of a local
classical solution of quasi-stationary Stefan problem. The methods work in all dimensions. 相似文献
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F. Poupaud 《Mathematical Methods in the Applied Sciences》1991,14(2):121-137
In semiconductors the distributions of electrons satisfy a non-linear Boltzmann–Vlasov equation. We consider the half-space problem arising in the study of boundary layers when the mean free path tends to zero. We prove the existence and the uniqueness of the solution for any prescribed entering distribution. We establish that this solution tends towards a Fermi–Dirac distribution exponentially fast. 相似文献
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Given a feasible solution, the inverse optimization problem is to modify some parameters of the original problem as little as possible, and sometimes also with bound restrictions on these adjustments, to make the feasible solution become an optimal solution under the new parameter values. So far it is unknown that for a problem which is solvable in polynomial time, whether its inverse problem is also solvable in polynomial time. In this note we answer this question by considering the inverse center location problem and show that even though the original problem is polynomially solvable, its inverse problem is NP–hard. 相似文献
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H.-D. Alber 《Journal of Mathematical Analysis and Applications》2009,349(1):156-164
Convergence of the solution to the exterior Robin problem to the solution of the Dirichlet problem, as the impedance tends to infinity, is proved. The rate of convergence is established. A method for deriving higher order terms of the asymptotics of the solution is given. 相似文献
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张瑰 《数学的实践与认识》2007,37(8):119-123
Couette问题的解已被前人利用格林函数方法推导出来,但是这个结果不够严格,在此按照同样的方法进行计算与修正,对所求的解进行验证,并将结果推广到一般的线性问题. 相似文献
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In this paper, we obtain a generalization of the method of regularizing multipliers for the solution of the Hilbert boundary-value problem with finite index in the theory of analytic functions to the case of an infinite power-behaved index. This method is used to obtain a general solution of the homogeneous Hilbert problem for the half-plane, a solution that depends on the existence and the number of entire functions possessing mirror symmetry with respect to the real axis and satisfying some additional constraints related to the singularity characteristic of the index. To solve of the inhomogeneous problem, we essentially use a specially constructed solution of the homogeneous problem whereby we reduce the boundary condition of the Hilbert problem to a Dirichlet problem. 相似文献