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111.
Langevin approach implemented in the inelastic cross-sections measured for the low-energy electrons colliding with metallic
clusters points out that statical form of the polarizability dominate at energies less than 1.25 eV. The dynamical form comes
into play at energies around 1.3 eV. The form of the polarizabilities indicates that polarizability of the metallic clusters
is energy-dependent. 相似文献
112.
Klas Källström 《Tetrahedron letters》2006,47(42):7477-7480
An efficient chiral N-heterocyclic carbene ligand for the Ir-catalyzed asymmetric hydrogenation of largely unfunctionalized tri-substituted olefins has been developed. The Ir-NHC-thiazole catalyst is able to reduce a large variety of substrates with excellent conversions and good enantioselectivities with ee’s ranging from 34% to 90%, depending on the geometry around the double bond of the substrates. 相似文献
113.
A. Ádám 《Acta Mathematica Hungarica》1989,54(3-4):291-296
114.
In this paper, it is shown that some of the results of torus actions on Poincaré duality spaces, Borel’s dimension formula
and topological splitting principle to local weights, hold if ‘torus’ is replaced by ‘pro-torus’. 相似文献
115.
We give general conditions on a generator of a C0-semigroup (resp. of a C0-resolvent) on Lp(E,μ), p ≥ 1, where E is an arbitrary (Lusin) topological space and μ a σ-finite measure on its Borel σ-algebra, so that it generates a sufficiently
regular Markov process on E. We present a general method how these conditions can be checked in many situations. Applications to solve stochastic differential
equations on Hilbert space in the sense of a martingale problem are given.
Dedicated to Giuseppe Da Prato on the occasion of his 70th birthday 相似文献
116.
Screening of 400 Streptomyces strains for biotransformation of the natural lignan matairesinol led to the identification of Streptomyces sp. LS136, capable of producing a single metabolite in moderate yields. Isolation and purification by preparative HPLC, followed by structural analyses by LC-MS and NMR, established the structure as matairesinol-4-O-rhamnoside. This bacterial strain was also used for rhamnosylation of the abundant natural lignans, hydroxymatairesinol and secoisolariciresinol. 相似文献
117.
Kenneth Sörensen 《Central European Journal of Operations Research》2006,14(2):193-207
In this paper, we argue that vehicle routing solutions are often tactical decisions, that should not be changed too often
or too much. For marketing or other reasons, vehicle routing solutions should be stable, i.e. a new solution (when e.g. new customers require service) should be as similar as possible to a solution already in
use. Simultaneously however, this new solution should still have a good quality in the traditional sense (e.g. small total
travel cost). In this paper, we develop a way to measure the difference between two vehicle routing solutions. We use this
distance measure to create a metaheuristic approach that will find solutions that are “close” (in the solution space) to a
given baseline solution and at the same time have a high quality in the sense that their total distance traveled is small.
By using this approach, the dispatcher is offered a choice of Pareto-optimal solutions, allowing him to make a trade-off between
changing his existing solution and allowing a longer travel distance. Some experiments are performed to show the effectiveness
of the approach. 相似文献
118.
We consider an M/G/1 queue with symmetric service discipline. The class of symmetric service disciplines contains, in particular, the preemptive
last-come-first-served discipline and the processor-sharing discipline. It has been conjectured in Kella et al. [1] that the
marginal distribution of the queue length at any time is identical for all symmetric disciplines if the queue starts empty.
In this paper we show that this conjecture is true if service requirements have an Erlang distribution. We also show by a
counterexample, involving the hyperexponential distribution, that the conjecture is generally not true.
AMS Subject Classifications Primary—60K25; Secondary—90B22 相似文献
119.
120.
J. Fülöp 《Mathematical Methods of Operations Research》1991,35(1):1-13
This paper shows that any linear disjunctive program with a finite number of constraints can be transformed into an equivalent facial program. Based upon linear programming technique, a new, finite cutting plane method is presented for the facial programs.
Zusammenfassung Die Arbeit zeigt, daß jedes lineare disjunktive Optimierungsproblem mit endlich vielen Restriktionen in ein äquivalentes Fazetten-Problem transformiert werden kann. Auf der Grundlage von linearer Optimierungstechnik wird für das Fazetten-Problem ein neues, endliches Schnittebenenverfahren vorgestellt.相似文献