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131.
132.
Adolf Jesih Primo? Benki? Ljup?o Pejov Vladimir M. Petruševski 《Journal of solid state chemistry》2004,177(12):4482-4493
A systematic study of N2H5[M(N2H3COO)3]·H2O (M∈{Co, Zn}) type of compounds, which are typical model systems for transition metal complexes with α-amino acids (the latter are not obtainable in crystalline form), was carried out. The crystal structures of these compounds were solved by X-ray crystallographic methods. FTIR spectra at room and low temperature (∼100 K) as well as Raman spectra at room temperature were recorded, and analyzed in details. Also, the geometries of the Zn(N2H3COO)3− and N2H5+ species were fully optimized at ab initio HF and B3LYP/6-31+G(d,p) level of theory, and subsequent vibrational analyses were performed on the basis of which several important reassignments of the IR and Raman bands were proposed. In order to study the binding energetics and the ligand-cation charge-transfer interactions within the Zn(N2H3COO)3− complex, NBO analysis was carried out, employing the second-order perturbation theory analysis of the Fock matrix (i.e., its Kohn-Sham analog) within the NBO basis. 相似文献
133.
Emil Sko
ir Anica Pe
avar Adolf Kranja Mirko Proek 《Journal of separation science》1993,16(4):243-246
The quantitative CE analysis of fluorine and monofluorophosphate in toothpastes is described. Separation is performed using a Waters CIA-Pak chemistry kit with Waters Electro Osmotic Flow Modifiers on a CE instrument from Spectra Physics (Spectra-phoresis 500) at elevated temperatures up to 40 °C and at a low temperature of 10 °C. The quantitative results and the simplicity are compared for the CE method, the existing standard GC procedure described in the Official Journal of the European Communities, and the procedure employing a fluoride-ion-specific electrode. 相似文献
134.
Adolf Hildebrand 《Monatshefte für Mathematik》1986,102(2):103-114
It is known that for fixedk2 and every sufficiently large primep there exists an integerr such thatr andr+1 are bothk'th power residues modulop. It has been conjectured that the least positiver with this property is bounded in terms ofk only. We prove this conjecture in the casek is a prime, and a weaker result in the general case.Dedicated to Professr E. Hlawka on the occasion of his sevetiethSupported by NSF grant MCS-8108814(A04). 相似文献
135.
Miklavc A 《The Journal of chemical physics》2004,121(3):1171-1174
Hydrogen kinetic isotope effect with values of alpha identical with ln(kH/kT)/ln(kD/kT)>3.3 which are generally ascribed to quantum tunneling of hydrogen are shown to arise in O+HCl(DCl,TCl) reactions due to the effects of rotational excitation on the distribution of encounters with the critical dividing surface. At higher rotational excitations these distributions are shifted towards the regions of the critical dividing surface with low barrier energies which can lead to a large enhancement of the barrier crossing. This effect depends strongly on the hydrogen isotope involved in the reaction and, at some temperatures, gives rise to alpha much larger than 3.3. It can be readily seen that the effect should arise also in condensed molecular systems, due to internal rotations or other vibrations "perpendicular" to the reaction coordinate. 相似文献
136.
Iwao?KatayamaEmail author Adolf?Mikula Toshio?Oishi 《Monatshefte für Chemie / Chemical Monthly》2005,136(10):1715-1725
Summary. Gallium activity in the B2 (CsCl-type) phase of ternary Co–Ga–X (X = Ge, Ni, and Fe) alloys was measured by the EMF method with a stabilized zirconia solid electrolyte. The temperature range
was 1050–1250 K and the concentrations of the added elements were 2–6 at-% Ge and Ni, and 1–3 at-% Fe. The reference electrodes
were Fe,FexO or Ga,Ga2O3. The effect on the activity of gallium in the B2 phase with the addition of other elements was found to be the largest with
Ge and the smallest in the case of Ni. 相似文献
137.
Adolf Emil Siegrist Hans Rudolf Meyer Peter Gassmann Serge Moss 《Helvetica chimica acta》1980,63(5):1311-1334
Preparation of Styryl and Distyryl Derivatives of Pyridine 2,4-, 2,5- and 2,6-Dimethylpyridines react with anils of aromatic aldehydes in the presence of dimethylformamide and potassium hydroxide to yield the corresponding distyrylpyridines (‘anil synthesis’). Under the same reaction conditions (4-methylstyryl)pyridines are converted to (stilbenylvinyl)pyridines. Similarly, the Schiff's base derived from pyridine-3-carbaldehyde and p-chloroaniline on treatment with methyl- and p-tolyl-substituted aromatic heterocycles gives the corresponding (heteroaryl-styryl)pyridines, whereas with the Schiff's bases derived from pyridine-2- and -4-carbaldehyde side reactions, such as dimerization followed by disproportionation predominate. 相似文献
138.
Zusammenfassung Ein neues Gerät zur selektiven Sauerstoffbestimmung in kleinen Gasmengen, das direkt elektrisch den Prozentgehalt anzeigt, wird beschrieben. Das Meßprinzip besteht darin, daß eine sauerstoffdepolarisierte Kohleelektrode in einem Element Kohle/Kalilauge/Zink entsprechend dem Sauerstoffgehalt des zugeführten Gases eine verschiedene Leistung an einen Belastungskreis abgibt. Die rasche und reproduzierbare Einstellung wird durch eine neuartige Kohleelektrode ermöglicht. Die Analyse ist sowohl in strömendem Gas, wie in einem abgeschlossenen Volumen möglich. Automatische Daueranalysen und selbsttätige Regelung bei Schwankungen von ± 0,01% im Sauerstoffgehalt sind ausführbar.
Mit 4 Abbildungen. 相似文献
Summary A new apparatus is described for the selective determination of oxygen in small amounts of gas; it gives a direct electrical indication of the percentage content. The measuring principle is that an oxygen-depolarized carbon electrode in a carbon/potassium hydroxide/zinc cell delivers current to a loading circuit in amounts which vary with the oxygen content of the gas introduced. The rapid and reproducible standardization is made possible by a new type of carbon electrode. Analyses can be carried out in the streaming gas as well as in closed vessel. Automatic continuous analyses and self regulation with variations of ± 0.01% in oxygen content are practicable.
Résumé On décrit un nouvel appareil pour le dosage sélectif de l'oxygène qui en donne électriquement, directement dans les petites quantités de gaz, la teneur en pour cent. Le principe de la mesure repose sur le fait qu'une électrode de carbon dépolarisée à l'oxygène dans la pile charbon/lessive de potasse/zinc, communique un rendement variable dans le circuit de charge suivant la teneur en oxygène du gaz soumis à l'expérience. La mise au point rapide est bien reproductible et rendue possible grâce à une électrode de charbon d'un nouveau type. L'analyse est possible aussi bien dans un courant gazeux que dans un espace clos. Des essais automatiques d'endurance et d'auto-réglage sont réalisables avec des variations de 0,01% dans la teneur en oxygène.
Mit 4 Abbildungen. 相似文献
139.
Ohne Zusammenfassung 相似文献
140.
A. Adam F. Schmidt B. Tollens Marchand Grote F. Soxhlet Szombathy A. Wynter Blyth Boorhoeve Ph. du Roi F. Clausnizer Adolf Mayer N. Gerber und P. Radenhausen 《Fresenius' Journal of Analytical Chemistry》1880,19(1):362-368
Ohne Zusammenfassung 相似文献