On Solutions of the q-Hypergeometric Equation with q N = 1

We consider the q-hypergeometric equation with q ^N = 1 and , , . We solve this equation on the space of functions given by a power series multiplied by a power of the logarithmic function. We prove that the subspace of solutions is two-dimensional over the field of quasi-constants. We get a basis for this space explicitly. In terms of this basis, we represent the q-hypergeometric function of the Barnes type constructed by Nishizawa and Ueno. Then we see that this function has logarithmic singularity at the origin. This is a difference between the q-hypergeometric functions with 0 < |q| < 1 and at |q| = 1.     

Role of Al or Eu on thermoluminescence of Al- and/or Eu-doped SiO2 crystals

Although SiO₂ crystals have been used in electroluminescence devices and thermoluminescence (TL) dosimeters, the emission mechanism of TL has not yet been clearly explained. Recently, as we could get amorphous and highly pure SiO₂ prepared by the sol-gel method, we have investigated the TL emission mechanism using Al³⁺- and/or Eu³⁺-doped SiO₂ crystalline samples prepared by the heat-treatment under much lower temperature that the melting point of SiO₂. The TL spectrum of the Eu³⁺-doped sample displayed several peaks, including two main peaks due to the electron transitions from ⁵D₂ to ⁷F₅ (ca. 570 nm) and from ⁵D₀ to ⁷F₂ (ca. 610 nm). As doping concentration increased, all the peak intensities reduced from maximum values except that due to the electron transition from ⁵D₀ to ⁷F₂. These observations are thought to result from a cross-relaxation process due to the lack of inversion symmetry at the Eu³⁺ site.     

Preconcentration of trace silver with yeast for river water analysis

A new preconcentration method with yeast is presented. The method was evaluated for the determination of trace silver in river waters by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for preconcentration of silver was 1.75 mg ml-1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 25 degrees C. Under optimal conditions, silver in aqueous sample was concentrated to 6.9-fold by yeast. The detection limit was 4.6 pg ml-1 (3S/N) for silver in river water. The yeast preconcentration method was applied to the determination of silver in river waters. The recovery of spiked silver was in the range of 89 to 110%. By the preconcentration, it was found that ultra trace silver in river waters could be determined without interferences of matrix elements, after only the cultivation and with no chemical treatment.     

Nickel-catalyzed intermolecular coupling of 1,3-dienes and aldehydes via transmetalation of nickelacycles with diisobutylaluminum acetylacetonate

Intermolecular coupling reactions of 1,3-dienes and aldehydes via transmetalation of nickelacycle intermediate with (i)Bu(2)Al-acac were investigated. In the reactions, a linear adduct or a branched adduct was produced, depending upon the nature of 1,3-dienes and aldehydes, via two nickelacycles that were relatively stable among the four possible nickelacycles because of the equilibrium with pi-allynickel forms.     

First total synthesis of artepillin C established by o,o'-diprenylation of p-halophenols in water

We have demonstrated that prenylation of p-halophenols was dependent on the solvent effect and succeeded in o,o'-diprenylation of p-halophenols in water. Following the Mizoroki-Heck coupling of the diprenyl-p-iodophenol 3c with methyl acrylate and then hydrolysis, we first synthesized artepillin C [3-(4-hydroxy-3,5-di(3-methyl-2-butenyl)phenyl)-2(E)-propenoic acid] (1), which is a biologically active constituent of propolis. These reactions may be applicable to the synthesis of various useful natural products such as 2,4,6-trisubstituted phenol derivatives.     

Sorption and diffusion of water vapor in polyimide films

Sorption and diffusion of water vapor are investigated gravimetrically for polyimide films. The activity dependence of the solubility and diffusion coefficients, S and D, respectively, is classified under four types: (1) constant S and D type, (2) dual-mode sorption and transport type, (3) dual-mode type followed by a deviation due to a plasticization effect at high vapor activity, and (4) constant S and D type followed by a deviation due to water cluster formation at high activity. For the dual-mode type, the Henry's law component is much larger than the Langmuir component except at low activity, and therefore deviation in behavior from the first type is small. S is larger for polyimides with higher content of polar groups such as carbonyl, carboxyl, and sulfonyl. D is larger for polyimides with a higher fraction of free space, with some exceptions. The polyimide from 3,3′,4,4′-biphenyltetracarboxylic dianhydride and dimethyl-3,7-diaminodibenzothiophene-5, 5-dioxide belongs to the third type and displays both large S and large D. The polyimide from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride and 4,4′-oxydianiline belongs to the fourth type, and has the largest D but rather small S because of the hydrophobic C(CF₃)₂ groups. © 1992 John Wiley & Sons, Inc.     

One-dimensional perturbations of the shift

The structure of isometries on a Hilbert space are well studied. In this paper we study contractions which are one-dimensional perturbations of isometries, in particular, perturbations of the shift operator onH ².     

Determination of strontium in biological samples by atomic emission spectrometry with electrothermal atomization

Summary Strontium showed a high atomic emission in a molybdenum microtube. The addition of hydrogen in the argon gas atmosphere served to increase the atomic emission. No interferences from less than 5 ng of potassium, calcium and magnesium were found. Other elements also had no interferences at the concentration levels usually found in biological samples. Samples were digested with nitric acid in a Uni-Seal decomposition vessel. The results obtained showed good agreement with the certified values. Atomic emission spectrometry with a molybdenum microtube atomizer permits a simple and sensitive determination of strontium in biological samples (coefficient of variation 2.5% for 10 pg Sr).

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Strontiumbestimmung in biologischem Material durch Atomemissions-Spektrometrie mit elektrothermischer Atomisierung

Zusammenfassung Eine hohe Atomemission wurde für Strontium bei Verwendung einer Molybdän-Mikroröhre beobachtet. Durch Wasserstoffzusatz zum Argon konnte sie noch weiter erhöht werden. Weniger als 5 ng K, Ca und Mg verursachen keine Störung. Andere Elemente stören nicht in den Konzentrationsbereichen, wie sie üblicherweise in biologischen Materialien vorkommen. Der Aufschluß der Proben wurde mit Salpetersäure in Uni-Seal-Gefäßen vorgenommen. Die erhaltenen Werte stimmten gut mit zertifizierten Daten überein. Die vorgeschlagene Methode ermöglicht eine einfache und empfindliche Strontiumbestimmung in biologischen Proben (Variationskoeffizient 2,5% bei 10 pg Sr).

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This work was supported by the Ministry of Education, Science and Culture of Japan through a Grant-in-Aid for Special Project Research.     

Discrimination of the geometrical isomers of 2,3-, 2,5-, and 2,6-dimethylpiperazines based on 1 H?Nmr spectral data

¹ H-Nmr spectra of cis and trans isomers of 2,3-, 2,5-, and 2,6-dimethylpiperazines were taken at various temperatures. The spectra of geometrical isomers bearing the ae or ea dimethyl groups showed broadening at lower temperatures. It was clarified that the measurement of the spectra at lower temperatures is useful for the discrimination of the geometrical isomers of dimethylpiperazines.