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91.
92.
B. Cameron Reed 《Central European Journal of Physics》2005,3(1):1-7
The ground-state energy of neutral helium is estimated variationally with a trial wavefunction of the form ϕ≈e
−γ(rA/a
o)ne−γ(rB/a
o)n. This model represents a modification of traditional textbook examinations of this problem via inclusion of the power “n”
as a second nonlinear variational parameter in addition to the usual effective nuclear charge γ and leads to an upper-limit
on the ground state energy of −2.86107 E
h
(E
h
=1 hartree) in comparison with the traditional (n=1) result of −2.84766 E
h
. This result represents a reduction of the percentage overestimate from the true ground-state energy (−2.90373 E
h
) of from 1.93 to 1.47. In comparison with the maximum accuracy obtainable from an uncorrelated trial wavefunction, −2.86168
E
h
, the present trial wavefunction reduces the percentage overestimate from 0.49 (n=1) to 0.021. The optimum values of (n, γ)
are determined to be ≈(0.897, 1.825). 相似文献
93.
F. F. Bulat 《International Applied Mechanics》2006,42(9):967-975
The milestones in geotechnical mechanics research conducted at the N. S. Polyakov Institute of Geotechnical Mechanics of the
National Academy of Sciences of Ukraine are listed. Solutions to the deep-mining challenges faced by the institute as a leading
research institution in the industry are outlined. The basic results on the subject achieved by the institute over the years
of its existence are summarized
To the Beginning of the Third Millennium
To the 40th Anniversary of the N. S. Polyakov Institute of Geotechnical Mechanics
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 9, pp. 3–15, September 2006. 相似文献
94.
95.
Exact ground states of Ising spin glasses: New experimental results with a branch-and-cut algorithm 总被引:4,自引:0,他引:4
C. De Simone M. Diehl M. Jünger P. Mutzel G. Reinelt G. Rinaldi 《Journal of statistical physics》1995,80(1-2):487-496
In this paper we study two-dimensional Ising spin glasses on a grid with nearest neighbor and periodic boundary interactions, based on a Gaussian bond distribution, and an exterior magnetic field. We show how using a technique called branch and cut, the exact ground states of grids of sizes up to 100×100 can be determined in a moderate amount of computation time, and we report on extensive computational tests. With our method we produce results based on more than 20,000 experiments on the properties of spin glasses whose errors depend only on the assumptions on the model and not on the computational process. This feature is a clear advantage of the method over other, more popular ways to compute the ground state, like Monte Carlo simulation including simulated annealing, evolutionary, and genetic algorithms, that provide only approximate ground states with a degree of accuracy that cannot be determineda priori. Our ground-state energy estimation at zero field is –1.317. 相似文献
96.
对于一个原子核模型系统在不同耦合强度、不同粒子数情况下的基态关联效应进行了研究,结果表明:当具有稳定的静态形变时,基态关联基本上可用基于静态上的零点振动来解释,因此,关于静态性质的自治场计算是至关重要的. 但在开始发生单极形变的临界点附近,它随控制参量的变化显得很复杂、很敏感. 看来,在滴线附近的轻核的进一步研究中,关联效应是需要注意考虑的. 相似文献
97.
Starting from Padmanabhan's fully conformally invariant action, we obtain gravity as a spontaneously broken theory. Newton's
constant and the cosmological constant follow from the breakdown of the conformal symmetry at the tree approximation. For
small oscillation of the scalar field about the fundamental state, the matter field degenerates into two decoupled fields. 相似文献
98.
For one-dimensional systems interacting via a two-body potential, the sequence of ground states is proved to converge to an infinite lattice, for a large open class of interactions, containing in particular the Lennard-Jones potential. 相似文献
99.
We consider a two-body potential which has only periodic ground states and prove that it can be perturbed, by an arbitrarily small perturbation, so as to have only aperiodic ground states.Research supported in part by NSF grant MCS 78-01520-A01. 相似文献
100.
We give an explicit formula for exponential decay properties of ground states for a class of quasilinear elliptic equations in the whole space .