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991.
A generalized model that describes apparently "non-Nernstian" equilibrium responses of ionophore-based ion-selective electrodes (ISEs) is presented. It is formulated for primary and secondary ions of any charges that enter the membrane phase and independently form complexes with the ionophore, respectively. Equations for the phase boundary potential model were solved numerically to obtain whole response curves as a function of the sample activity of the primary ion, and analytical solutions could be obtained for apparently non-Nernstian response sections in these response curves. Ionophore-based ISEs can give three types of apparently non-Nernstian equilibrium responses, i.e., apparently "super-Nernstian", "inverted-Nernstian", and "sub-Nernstian" responses. The values of the response slopes depend on the charge numbers of the primary and secondary ions and on the stoichiometries of their complexes with the ionophore. The theoretical predictions for super-Nernstian responses agree well with the experimental results obtained with ISEs based on acidic ionophores or metalloporphyrin ionophores. Also, theoretical response curves with inverted-Nernstian slopes were found to be similar in character to the pH responses of Ca2+-selective electrodes based on organophosphate ionophores, which have been known to exhibit a so-called "potential dip". The quantitative understanding of apparently non-Nernstian response slopes presented here provides an insight into ionophore-analyte complexation processes in ISE membranes and should be helpful for the design of new ionophores. 相似文献
992.
Jun-ichi Shimoyama Koichi Kitazawa Keisuke Shimizu Shinya Ueda Shigeru Horii Noriko Chikumoto Kohji Kishio 《Journal of Low Temperature Physics》2003,131(5-6):1043-1052
Systematic studies on the irreversibility field H
irr, and anisotropy factor 2 of high temperature superconductors (HTSC) were performed using single crystals with high quality. The generic scaling law have been found to hold for all the HTSC systems examined, i.e., H
irr[Oe]=4×107–2 (1–T/T
c)1.5 at T0.7T
c. In addition, of each HTSC material is roughly expressed as 2=2 exp(0.78d[Å]) at the carrier optimally-doped state. Based on the generic scaling law, the behaviors of the variously doped superconductors, such as Bi(Pb)2212 and Hg(Re)1223, are discussed in terms of the critical current. 相似文献
993.
Shigeru Ueda Kazuki Morita Nobuo Sano 《Metallurgical and Materials Transactions B》1997,28(6):1151-1155
The thermodynamics of phosphorus in molten Si-Fe and Si-Mn alloys has been investigated at 1723 K by equilibrating the alloys
in a controlled phosphorus partial pressure. The activity coefficient of phosphorus in each alloy shows a maximum value at
a certain composition due to a strong interaction between silicon and iron and between silicon and manganese. Interaction
coefficients between phosphorus and iron in molten silicon were found to be ε
P
Fe
=7.43 and ρ
P
Fe
=−16.4 (0≦X
Fe≦0.65), and those between phosphorus and manganese were ε
P
Mn
=12.0 and ρ
P
Mn
=−22.2 (0≦X
Mn≦0.5). Further discussion has revealed that the Si-Fe-P and Si-Mn-P systems approximately conform to a regular solution within
the composition ranges investigated in the present work. 相似文献
994.
Masao Senuma Shigeru Kuwabara Kyoji Kaeriyama Fumio Hase Yukio Shimura 《应用聚合物科学杂志》1986,31(6):1687-1697
Copolymerization of sodium vinyl benzyl sulfonate (VBS) or vinyl benzyl trimethyl ammonium chloride (VBQ) with acrylonitrile (AN) gave polyelectrolytes of preferable solution viscosities. The blending of these two copolymers in N,N-dimethyl formamide (DMF) produced polymer complexes with ionic linkages, of which the following properties were examined. The maximum in the tan δ temperature was increased by complex formation. Freundlich-type dye adsorption and much better dyeability than on polyacrylonitrile was observed. Electric resistivity decreased with the introduction of ionic moiety. Permeability of water increased with the number of ionic sites. Homogeneous films could be cast from DMF and dimethyl sulfoxide (DMSO) solutions. 相似文献
995.
The solution to the conjugate heat transfer problem in an annulus with a heated (cooled) core and an insulated outside tube is presented. Three kinds of boundary conditions are considered for a chosen radius ratio. From the results of parametric calculation over a wide range, it is concluded that wall heat conduction in a core can have substantial effects on the heat transfer characteristics in the areas surrounding the beginning and the end of the heat transfer section. 相似文献
996.
Damage induced by very low energy (30 eV) Cl reactive ion beam etching (RIBE) and radical etching (RE) has been electrically
characterized. GaAs/n-AlGaAs two-dimensional electron gas heterostructures were used as damage sensitive probes. Sheet carrier
concentrations and Hall mobilities were measured at 77 K, under dark as well as illuminated conditions. By carefully designing
the sample structure, the damaged layer thickness could be estimated by comparing dark and illuminated data. In case of RE,
no degradation was detected at depths as shallow as 25 nm from the etched surface. For 30 eV-RIBE, the damage was detected
but found to be reasonably small (38% decrease in electron mobility) and shallow (<50 nm). Electrical and optical damage are
compared briefly. 相似文献
997.
The plasma etching durability of O2 and CCl4 was investigated for copolymer and polymer blend of poly(methyl methacrylate) (PMMA) and poly(α-methylstyrene) (PMSt) as a function of MSt content. Further, the effects of crosslinking on plasma etching were studied by incorporating N-methylolated methacrylamide into the copolymer as a crosslinkable site during prebaking. The plasma-etching resistance of PMMA was largely improved by incorporating or adding only a small amount of MSt. Especially in the case of the CCl4 plasma etching, the copolymer and the polymer blend with 10 mol% of MSt showed etching resistance as great as that of PMSt homopolymer. Stabilization of the polymers against the plasma etching can be explained by the sponge effect, the energy migration followed by the quenching by the phenyl ring. The polymer blend offered similar etching resistance as the copolymer, indicating an effective occurrence of the energy migration between the polymer chains. Etching resistance was also improved by crosslinking, also due to the enhancement of the sponge effect. 相似文献
998.
Akio Ishiguro Takeshi Furuhashi Shigeru Okuma Yoshiki Uchikawa Muneaki Ishida 《Electrical Engineering in Japan》1991,111(5):117-126
A new output voltage control method for PWM-controlled cycloconverters with space vectors is proposed in this paper. Results are as follows:. (1) The classification and the systematic behavior of the space vectors of PWM-controlled cycloconverters are clarified through the analysis. (2) A new output voltage control method that makes excellent output voltage waveforms is proposed using the results of this analysis. (3) Feasibility of the proposed output voltage control method is confirmed by simulation. (4) Output voltage waveforms of the PWM-controlled cycloconverters are compared with those of the PWM-controlled inverters, using the performance index of variance of time-integral of higher harmonic components. Therefore, the proposed control method may reduce both acoustic noise and torque ripple of induction motors. 相似文献
999.
1000.