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991.
V. G. Maiorov A. I. Nikolaev B. Ya. Zil’berman V. M. Shcherbakov 《Russian Journal of Applied Chemistry》2007,80(6):874-878
A scheme for utilization of chloride solutions of complex composition with α-and β-activity of up to 35 and 28 kBq 1?1, respectively, is suggested. 相似文献
992.
993.
The coupling of visible nanosecond laser pulses to metallic targets irradiated in vacuum is studied. The expressions of the vapour and plasma ignition times are obtained. Two cases for vapour breakdown in the plasma ignition process are considered. The first case is that 40 generations of new electrons are born in vapour generation time before plasma formation as assumed in the literature. The second case is that 10 generations of new electrons are born in vapour generation time. Molybdenum (Mo), niobium (Nb) and aluminium (Al) targets are considered for illustrations of our results. The expression of the plasma ignition time for the Al target is substantially different from that reported in the literature. The vapour and plasma ignition threshold laser intensities are calculated and compared with those reported in the literature. Reasons for disagreement are discussed. The plasma ignition threshold estimated in the second case is noted to be in good agreement with the reported experimental result. 相似文献
994.
995.
996.
B.R. Nana Nbendjo R. Yamapi 《Communications in Nonlinear Science & Numerical Simulation》2007,12(8):1550-1559
We study in this paper the active control of a driven class of Van der Pol oscillator which exhibits three limit cycles. We begin by investigating the dynamics and stability analysis of the system under active control. We also analyze the effects of a time periodic perturbation included in the control process. In all these cases the domain of control gain parameters leading to a good control is obtained and verified numerically. 相似文献
997.
We consider some regression relations for record values X(n), n > 0, generated by a sequence of independent random variables
X1, X2, X3,... with a common continuous cumulative distribution function F(x). New characterizations of distributions based on regression
properties of record values are obtained. Bibliography: 7 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 339, 2006, pp. 5–14. 相似文献
998.
M B Wright 《The Journal of the Operational Research Society》2007,58(4):439-445
This case study paper describes a problem faced every year by the Devon Cricket League in England. Every league match requires two officiating umpires. There are various preferences relating to the deployment of umpires that fall short of being definite constraints. The requirement was to produce a computer system that would allocate umpires in a satisfactory manner without the need for human interaction, since the users of the system will be unqualified amateurs. This necessitated the construction of a very complex objective function, using imprecise and ill-defined information. The biggest challenge was thus one of problem formulation; the solution technique was relatively straightforward. The system has been put into successful use and it is expected that its use will continue indefinitely. The work raises ethical issues regarding work done for customers who are inexperienced amateurs. 相似文献
999.
The title of this paper states precisely what the subject is. The first part of the paper concerns the radially-symmetric
problem in the exterior of the unit ball. It is shown that in time the solution of the problem converges to one of two specific
self-similar solutions of the porous media equation, dependent upon the dimensionality of the problem. Moreover, the free
boundary of the solution converges to that of the self-similar solution. The critical space dimension is two, for which there
is no distinction between the self-similar solutions, and the form of the convergence is exceptional. The technique used is
a comparison principle involving a variable that is a weighted integral of the solution. The second part of the paper is devoted
to the problem in an arbitrary spatial domain with no conditions of symmetry. A special invariance principle and the results
obtained for the radially-symmetric case are used to determine the large-time behaviour of solutions and their free boundaries.
This behaviour is decidedly different from when the boundary data are fixed and not homogeneous. 相似文献
1000.
D. Boilley A. Marchix B. Jurado K. -H. Schmidt 《The European Physical Journal A - Hadrons and Nuclei》2007,33(1):47-52
We propose a new formula for the saddle-to-scission time that is more general that the one based on Kramers' approach. Its
validity and applicability is then studied in detail. Such a formula is useful for the evaluation of the fission time of very
heavy nuclei. 相似文献