Showing papers by "National Cheng Kung University published in 1977"
TL;DR: The absorption spectrum of NO2 has been recorded in the energy region of the N1s and O1s excitations by the use of synchrotron radiation as discussed by the authors, and the spectra are interpreted with the help of the (Z + 1)-core analogy model on the basis of Cl calculations.
19 citations
TL;DR: In this article, a mathematical model has been proposed for an isotopic exchange reaction between the solid particles and ions in a solution of finite volume and a theoretical equation has been derived to predict the exchange fraction as a function of the dimensionless time T with the kinetic parameters ξ, ξ1 and final fractional uptake U as parameters for the exchange rate controlled by combined film diffusion, surface chemical reaction and intraparticle diffusion.
Abstract: A mathematical model has been proposed for an isotopic exchange reaction between the solid particles and ions in a solution of finite volume. A theoretical equation has been derived to predict the exchange fraction as a function of the dimensionless time T with the kinetic parameters ξ, ξ1 and final fractional uptake U as parameters for the exchange rate controlled by combined film diffusion, surface chemical reaction and intraparticle diffusion. The exchange fraction increases as the values of T, U, ξ and ξ, increase. Experimental results of the isotopic exchange systems CaCO3(s)Ca2+ (aq), CaC2O4(s)/ Ca2+ (aq) and Ca-form Dowex 50W-X8/Ca2+ (aq) agree well with the theoretical equation proposed in this study.
On a propose un modele mathematique dans le cas d'une reaction avec echange isotopique entre les particules solides et les ions dans une solution de volume fini. On a mis au point une equation theorique pour prevoir la fraction de l'echange, en fonction du temps sans dimensions T, dans laquelle les parametres cinetiques ξ et ξ1 ainsi que la prise fractionnelle et finale U etaient parametres pour le taux d'echange que contrǒlaient a la fois la diffusion en couche mince, la reaction chimique superficielle et la diffusion entre les particules. La fraction d'echange s'est accrue a mesure que les valeurs de T, U, ξ et ξ1 augmentaient. Les resultats experimentaux obtenus avec les systemes d'echange isotopique CaCO3(S)/Ca2+ (eau), CaC2O4(S)/Ca2+ (eau) et Ca-forme Dowex 50W-X8/Ca2+ (eau) ont bien concorde avec l'equation theorique proposee dans la presente etude.
13 citations
11 citations
TL;DR: In this paper, the authors investigated the permselectivity of cations in ion exchange membrane electrodialysis for NaCl-MgCl 2 and NaCl -CaCl 2 systems.
10 citations
TL;DR: In this article, the sydnone rings were condensed with formaldehyde to give diarylation in 4-position of the synone rings: 3,3′-diphenyl-4,4′-methylenedisydnone is obtained from 3-phenylsydnone in 61% yield.
Abstract: In the presence of H2SO4, the sydnone rings were condensed with formaldehyde to give diarylation in 4-position of the sydnone rings: 3,3′-diphenyl-4,4′-methylenedisydnone is obtained from 3-phenylsydnone in 61% yield, and 3,3′-di-p-methylphenyl-4, 4′-methylenedisydnone is obtained from 3-(4′-methylphenyl)sydnone in 70% yield. And the possible reaction mechanism is discussed.
3 citations
TL;DR: In this paper, a mathematical model has been proposed for a heterogeneous isotopic exchange reaction which involves film diffusion, surface chemical reaction and intraparticle diffusion, the exchange equation to predict the exchange fraction as a function of time for the spherical particles immersed in a solution of finite volume has been derived.
Abstract: A mathematical model has been proposed for a heterogeneous isotopic exchange reaction which involves film diffusion, surface chemical reaction and intraparticle diffusion. The exchange equation to predict the exchange fraction as a function of time for the spherical particles immersed in a solution of finite volume has been derived. The relations between the exchange fraction and dimensionless time are plotted with e(=akf/KDe, e1(=K1a2/De) and final fractional uptake as parameters. From the values of the kinetic parameters e and e1, the relative importance of each limiting step is discussed. Experimental results of the isotopic exchange reaction of calcium ion in both system CaCO3(s)/Ca2+(aq) and system calcium type resin Dowex 50W-X8/Ca2+(aq) are coincident with the theoretical equation proposed in this study.
2 citations
TL;DR: In this article, the effects of glass modifiers on the sheet resistivity is discussed in view of the ionic potential, Z R a, of the modifiers, for 40% (wt.) Tl2O3 resistors, can be obtained as a straight line.
2 citations
TL;DR: In this article, a general pertubation method for the analysis of the effect of Prandt1 number on the steady state heat transfer across laminar incompressible boundary layer is proposed.
TL;DR: The reaction of 4-methoxypyridine 1-oxide with ethyl bromoacetate was found to produce a high yield of ethyl glyoxylate, trimethylamine N-oxide and pyridine 2-oxide as discussed by the authors.
Abstract: The reaction of 4-methoxypyridine 1-oxide with ethyl bromoacetate was found to produce a high yield of ethyl glyoxylate, trimethylamine N-oxide and pyridine 1-oxide also afforded the glyoxylate but in lower yield in the reaction, and 4-nitropyridine 1-oxide was found to be inactive with bromoacetate. Pyridine 1-oxide and trimethylamine N-oxide exhibit the same stoichiometry, while 4-methoxypyridine 1-oxide follows a different course.