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1.
Cs. Vértes I. Czakó-Nagy W. Meisel M. Kolonits F. Horkai A. Vértes 《Journal of Radioanalytical and Nuclear Chemistry》1990,144(3):179-187
A stacking Mössbauer technique, MMS has been applied for studying thin surface layers. The surface layers formed on the57Fe film in aqueous solutions of corrosion inhibitors, such as zinc phosphate and barium metaborate, and in distilled water was studied by this method. It has been found that the corrosion is much slower in the presence of zinc phosphate and barium metaborate. XPS analysis suggests the formation of a mixed iron zinc phosphate on the surface of the57Fe film after corrosion in a zinc phosphate solution. 相似文献
2.
The molecular structure of 4,4′-sulfanidyl-bis-thiophenol (C12H10S3) has been determined by gas electron diffraction. Assuming identical geometry and D2h local symmetry for ---SC6H4S--- moieties, the following bond lengths (rg) and bond angles were obtained: C---H = 1.101 ± 0.005, S---H = 1.388 ± 0.019, (C---C)mean = 1.400 ± 0.003, (S---C)mean = 1.778 ± 0.004 Å, Car---S---Car = 103.5 ± 1.3, C---C(S)---C = 120.4 ± 0.3, C(H)---C(H)---H = 119.1 ± 0.9 and C---S---H = 94.6 ± 3.1°. Two ratational forms were found to reproduce the experimental data, characterized by dihedral angles of the benzene rings with respect to the CarSCar plane; 1 = 67.8 ± 2.0°, 2 = 4.5 ± 7.2°, and 1 = 69.4 ± 2.0δ, 2 = −26.6 ± 7.1°. Identical signs of 1 and 2 indicate that the two benzene rings are rotated in the same direction about the respective Scentral---C axes. 相似文献
3.
Mátyás Milen László Hazai Pál Kolonits György Kalaus Lajos Szabó Ágnes Gömöry Csaba Szántay 《Central European Journal of Chemistry》2005,3(1):118-136
Transformation of β-carboline derivatives into optically active entities were studied and the de and ee values of the resulted compounds were detected.
Dedicated to Professor Károly Lempert on his 80th birthday. 相似文献
4.
Sándor Balogh Ede Kolos Gaszton Gáll und Pál Kolonits 《Fresenius' Journal of Analytical Chemistry》1975,276(3):201-204
Zusammenfassung Es wurden die Möglichkeiten für die titrimetrische Bestimmung von dimerem Glykolaldehyd (Fp: 94–96° C) und dl-Glycerinaldehyd (Fp: 138–141° C) untersucht. Die systematischen Fehler der auf Grund verschiedener funktioneller Gruppen durchführbaren Messungen sind von der Stabilität ihrer cyclischen Halbacetale sowie von den ihrer Depolymerisation folgenden weiteren Gleichgewichten bestimmt. Das aus dem dl-Glycerinaldehyd gebildete Halbacetal besitzt höhere Stabilität als dasjenige aus dem Glykolaldehyd.Mit der Hydrogensulfit-Methode werden 95–96%, mit der Hydroxylamin-Methode dagegen 98–99% vom wahren Wert gefunden.In Wasser gelöst zersetzt sich der Glykolaldehyd verhältnismäßig rasch, und das Gleichgewicht kann durch beide Aldehydreaktionen quantitativ gegen die Monomerenform verschoben werden.Unsere Untersuchungen ergaben, daß die Hydroxylamin-Methode zur Bestimmung der in Form cyclischer Halbacetale kristallisierenden, dimeren Hydroxyaldehyde Vorteile gegenüber der Hydrogensulfit-Methode bietet.Frau Dipl.-Ing. Eva Varsányi-Kiss danken wir für die derivatographischen Aufnahmen und deren Auswertung. 相似文献
5.
Melinda Fekete Pál Kolonits Ngo Thi Hien Lajos Novák 《Central European Journal of Chemistry》2005,3(4):792-802
New tryptamine 5, 7 and β-carboline derivatives 3 were preparated by palladium-catalyzed coupling reaction of 5-bromotryptamine 1 with aryl boronic acids.
Dedicated to Professor András Lipták on his 70th birthday. 相似文献
6.
The structural parameters of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), (CH2NNO2)3, 1,3-dinitro-1,3-diazacyclopentane (DDCP), CH2(CH2NNO2)2, andN-nitropyrrolidine (NP), (CH2)4NNO2, have been determined by electron diffraction.The six-membered ring of RDX has a chair form with axial positions of the nitro groups and close to planar bond geometry of the amine nitrogen atoms. The overallC
3 symmetry of the molecule is in agreement with the experimental data.The conformation of the five-membered ring in DDCP is a half-chair ofC
2 symmetry, while that in NP is an envelope ofC
S symmetry. The nitro groups are in equatorial positions in both molecules. The conformations of pyrrolidine and imidazolidine cycles show interesting features.The pyramidal geometry of the amine nitrogen atom bonds flattens in going from pyrrolidine andN-chloropyrrolidine to NP and DDCP and then to RDX and to dimethylnitramine (DMNA), (CH3)2NNO2. 相似文献
7.
V. Kolonits 《Colloid and polymer science》1968,226(1):40-45
Zusammenfassung Bei der Herstellung dünner Kunststoffschichten (1–7 m) aus Lösungen untersuchten wir die Trocknung dieser Lösungsfilme unter verschiedenen Bedingungen. Dieser Bericht diskutiert die Rolle der Feuchtigkeit der Umgebung auf die Struktur des Films bei und nach dessen Bildung. In deren Laufe war es bei der als Modell ausgewählten Celluloseacetobutyrat-Lösungen nachweisbar ein Ausfällprozeß, der mit dem Erscheinen einer groben Oberflächenstruktur zusammengeht. Die Erscheinung und Entwicklung dieses Prozesses ist sehr abhängig von den verwendeten Lösungsmitteln. Der Feuchtigkeitsgehalt der Umgebung hat einen ähnlichen — aber kleineren — Einfluß auf die schon ausgebildete Polymeroberfläche.Summary The drying of thin polymer films was investigated at various conditions. This paper shows the influence of the atmospheric relative humidity on the structure of the forming and the formed films alike. When we availed ourselves of cellulose-acetobutyrate solution models a precipitation could be demonstrated in the influence of the humid atmosphere, which precipitation was joint to the formation of a rough surface-structure Appearance and development of this structure proved to be a function of the solving material applied. The environment-humidity shows also a similar but less influence on the formed polymer films.
Mit 13 Abbildungen und 5 Tabellen 相似文献
Mit 13 Abbildungen und 5 Tabellen 相似文献
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9.
The purpose of the present study was to provide a reliable value for the specific grain-boundary resistivity ρSGBR of Ni metal. New results are presented on the room-temperature electrical resistivity of nanocrystalline (nc) Ni metal samples produced by electrodeposition with various grain sizes. These resistivity data were compared with previous reports on nc-Ni and all results were analysed according to the procedure of Andrews [Phys. Lett. 19, 558 (1965)] who found that the resistivity increment due to grain boundaries is proportional to the grain-boundary surface area per unit volume which is, on the other hand, inversely proportional to the grain size. It is pointed out that the grain size directly accessible by transmission electron microscopy imaging is the relevant parameter for the evaluation of ρSGBR whereas the crystallite size deduced from X-ray diffraction line broadening leads to an underestimation of ρSGBR because coherency-breaking intragrain defects not contributing significantly to the resistivity also cause a line broadening. From the evaluation of the nc-Ni resistivity data at room temperature, we find that 4.45·10?16?Ω·m2?ρSGBR(Ni)?6.2·10?16?Ω·m2 and our upper bound agrees exactly with the most recent calculated value in the literature. 相似文献
10.
The molecular structure of BiBr3 was determined by gas-phase electron diffraction. The principal geometrical parameters are r
(Bi—Br) = 2.567 ± 0.005 Å and 221D;Br—Bi—Br = 98.6 ± 0.2°. The force field of the molecule was obtained by a normal coordinate analysis utilizing both experimental vibrational frequencies and electron diffraction mean amplitudes of vibration. The variation of bond lengths and bond angles within the Group 15 trihalides is consistent with the expected trend, except that all bismuth trihalide bond angles appear to be somewhat large. 相似文献