T14N3

A.S. Berdnikov, A.N. Verentchikov, N.V. Konenkov

Two problems that are significant for mass spectrometry (namely, the model of chemical kinetics of formation of clusters and the model of the pseudopotential of stroboscopic samples of coordinates and ion velocities in quadrupole radio-frequency fields) are considered as the examples to investigate the relationship between discrete models with finite-difference equations and continual models with point derivatives. In constructing continuum models, integer indices are replaced by real parameters, and finite-difference relations are replaced by approximate relations involving the derivatives. It is shown that this procedure is not safe: the discrete model and the continuum model can diverge globally contrary to the a priori intuitive considerations. As a result, the transfer of the conclusions obtained on the basis of the approximate continuum model to the exact physical model can lead to conceptually significant errors and requires the investigator to be careful. In particular, considered as an example the continuous model of chemical kinetics of formation of clusters and the continuous model of the pseudopotential of stroboscopic samples of coordinates and ion velocities in quadrupole radio-frequency fields are both insolvent.

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Keywords: T14N3 дискретные модели диффузионная модель формирования кластеров квадрупольные радиочастотные поля конечно-разностные уравнения континуальные модели масс-спектрометрические модели модели кластерообразования модели химической кинетики псевдопотенциал радиочастотного электрического поля стробоскопическая модель псевдопотенциала

Categories: T14N3