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91.
Ivo Petráš 《Nonlinear dynamics》2009,57(1-2):157-170
This paper deals with a new fractional-order chaotic system. It is based on the concept of Volta’s system, where the mathematical model of Volta’s system contains fractional-order derivatives. This system has simple structure and can display a double-scroll attractor. The behavior of the integer-order and the fractional-order Volta’s system with total order less than three which exhibits chaos is presented as well. Computer simulations are cross-verified by the numerical calculation and the Matlab/Simulink models. 相似文献
92.
Anneli Kruve Koit Herodes Ivo Leito 《Rapid communications in mass spectrometry : RCM》2010,24(7):919-926
Optimization of both the ionization process and ion transportation in the mass spectrometer is of crucial importance in order to achieve high sensitivity and low detection limits and acceptable accuracy in liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) analysis. In this paper four optimization procedures of electrospray interface and quadrupole ion‐trap mass spectrometer parameters (ESI‐MS) (nebulizer gas and drying gas flow rate, end plate voltage, capillary voltage, skimmer voltage, octopoles direct current and radio frequency, trap drive and lens voltages) were studied on three pesticides – thiabendazole, aldicarb and imazalil. The results demonstrate that the methodology of optimization strongly influences the effectiveness of finding true optima of the operating parameters. Both eluent flow rate and composition during optimization have to mimic the situation during real analysis as closely as possible in order to achieve parameters giving the highest sensitivity. Therefore, post‐column addition of analyte to the mobile phase identical in composition to the one in which analyte elutes during real analysis combined with software‐based optimization was found to be the most effective and fastest method for achieving intensity maxima. The parameters most strongly affecting ion formation and transportation, hence sensitivity, were capillary voltage, direct current of the first octopole, trap drive and the second lens for all pesticides under study. In addition to sensitivity and detection limit matrix effect was considered in the optimization process. It was found that the matrix effect can be reduced but not eliminated by adjusting the ESI and MS parameters. The optimal parameters from the point of view of the matrix effect can only be found with factorial design. Parameters giving higher sensitivity tended to be more affected by matrix effect causing higher ionization suppression by co‐eluting compounds. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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97.
Ivo Düntsch 《Algebra Universalis》1987,24(3):197-203
We characterize the injective and projective regular double Stone algebras, and describe those regular double Stone algebras which are also projective in the category of double Stone algebras.Presented by Bjarni Jónsson. 相似文献
98.
Ivo Babu
ka 《Finite Elements in Analysis and Design》1987,3(4):341-354
This paper addresses the finite element method with a posteriori error estimation for elements of degree p = 1 and p = 2. It gives the formulae for the error indicators and error estimators. Basic mathematical characterizations of the estimators are given and it is shown that the estimators for p = 1 and p = 2 have different structures. Numerical examples show the effectivity of the approach and the high quality of the estimator. 相似文献
99.
Ivo Deiglmayr 《Fresenius' Journal of Analytical Chemistry》1909,48(2):122-123
Ohne Zusammenfassung 相似文献
100.
Ivo A. Hümmelgen 《Journal of Solid State Electrochemistry》2007,11(11):1463-1463