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951.
Some previous works show that symmetric fixed- and variable-stepsize linear multistep methods for second-order systems which do not have any parasitic root in their first characteristic polynomial give rise to a slow error growth with time when integrating reversible systems. In this paper, we give a technique to construct variable-stepsize symmetric methods from their fixed-stepsize counterparts, in such a way that the former have the same order as the latter. The order and symmetry of the integrators obtained is proved independently of the order of the underlying fixed-stepsize integrators. As this technique looks for efficiency, we concentrate on explicit linear multistep methods, which just make one function evaluation per step, and we offer some numerical comparisons with other one-step adaptive methods which also show a good long-term behaviour.
952.
L. D. Popov 《Central European Journal of Mathematics》2004,2(1):76-86
For a linear complementarity problem with inconsistent system of constraints a notion of quasi-solution of Tschebyshev type
is introduced. It’s shown that this solution can be obtained automatically by Lemke’s method if the constraint matrix of the
original problem is copositive plus or belongs to the intersection of matrix classes P
0 and Q
0. 相似文献
953.
Here we prove a limit theorem in the sense of the weak convergence of probability measures in the space of meromorphic functions
for a general Dirichlet series. The explicit form of the limit measure in this theorem is given.
Partially supported by Lithuanian Foundation of Studies and Science 相似文献
954.
In the paper the asymptotics for Dirichlet polynomials associated to certain cusp forms are obtained.
Partially supported by Lithuanian Foundation of Studies and Science 相似文献
955.
956.
M. B. Litvinova 《Journal of Applied Spectroscopy》2004,71(1):143-146
It has been established that undoped gallium crystals exhibit anti-Stokes radiation with energy corresponding to the interband recombination of these crystals. Its appearance is most probably determined by EL2 defects, and its intensity depends on the product of the cross sections for photoionization of electrons and the holes from these defects. 相似文献
957.
B Deva Prasad Raju 《Journal of Physics and Chemistry of Solids》2003,64(8):1339-1347
EPR spectra of VO2+ ions doped in KZnClSO4·3H2O single crystals have been studied at different temperatures. The EPR spectrum shows a well-resolved hyperfine and superhyperfine structure patterns. The angular variation of EPR spectra reveals the presence of more than three magnetic complexes, which correspond to distinct sites of VO2+ ion. From the angular variation EPR data, the spin-Hamiltonian parameters are evaluated and discussed. The optical absorption spectrum studied at room temperature shows bands corresponding to C4v symmetry. From the EPR and optical data, the molecular-orbital bonding coefficient ε2 and β2 are evaluated and discussed. The observed five-line superhyperfine structure has been attributed to four protons (with I=1/2) from the surrounding water molecules of one of the vanadyl sites. 相似文献
958.
I. V. Bodnar 《Technical Physics》2003,48(5):587-591
The thermal expansion coefficients and the thermal conductivity of Bridgman-grown crystals of CuGa1−x
InxTe2 solid solutions are investigated. It is found that the thermal expansion coefficient varies with x linearly, while the thermal conductivity is minimal when x=0.5. The Debye temperature and the rms dynamic atomic displacements are calculated from experimental data. It is shown that
the Debye temperature decreases and the rms displacements in the crystal lattice sharply increase as the In content in the
solid solutions grows. 相似文献
959.
E. Sh. Gutshabash 《JETP Letters》2003,78(11):740-744
The integration procedure based on the generalized Darboux transform is suggested for the Ishimori magnet model. Exact solutions are constructed for the model on the background of spiral structures. The possibility of phase transition in the system is hypothesized. 相似文献
960.
L. Yu. Kolotilina 《Journal of Mathematical Sciences》2004,121(4):2481-2507
In this paper, bounds and inequalities for the Perron root of a nonnegative matrix, extending and complementing the classical theorems of Frobenius and Ostrowski in terms of (deleted) row and column sums, are presented. All the results are derived by using the same approach, based on the monotonicity property of the Perron root. Bibliography: 12 titles. 相似文献