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81.
Calculations on the cation-induced shifts in the UV spectrum of the terphenyl mononegative ion suggest that the spectra of the ions of alternant hydrocarbons, as compared with those of the molecules, are rather insensitive to electric field perturbations. This feature only shows up if one includes enough (doubly) excited configurations to allow for the polarization of the excited states involved in the optical transitions.
Zusammenfassung Berechnungen über die von Kationen verursachten Verschiebungen im UV-Spektrum des mononegativen Terphenylions deuten darauf hin, daß die Spektren der Ionen alternierender Kohlenwasserstoffe im Vergleich zu denen der Molekeln gegen vom elektrischen Feld hervorgerufene Störungen ziemlich unempfindlich sind. Dies kommt nur dann zum Ausdruck, wenn man in den Berechnungen genügend (doppelt) angeregte Konfigurationen mit einbezieht, um auch die Polarisation der an den optischen Übergängen beteiligten Anregungszustände zu erfassen.

Résumé Des calculs sur les déplacements — provoqués par le cation — dans le spectre ultraviolet de l'ion mononégatif de terphényle indiquent que les spectres des ions d'hydrocarbures alternants, à côté de ceux des molécules, sont assez insensibles aux perturbations du champ électrique. On ne trouve ce résultat que dans le cas où l'on introduit un nombre suffisant de configurations excitées (doublement) pour tenir compte de la polarisation des états excités liés aux transitions optiques.
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82.
Base induced 1.4-elimination of pyridine·HI from 1-(2-phenyl-2-phenylhydrazono-ethyl)-pyridinium iodide (6) yields 1.3.6-triphenyl-6-phenylazo-1.4.5.6-tetrahydropyridazine (8) the (4+2)-cyclodimer of the intermediate 1-phenyl-1-phenylazoethylene (7).8 can also be obtained by intramolecular oxidative cyclisation (with KMnO4) of 1.4-diphenylbutane-1.4-dione bisphenylhydrazone (12). Spectroscopic data (ms,1H-nmr, uv and ir/Raman) confirm the structure of8.  相似文献   
83.
The infrared spectra of thiocyanato-copper(II) complexes of the type Cu(NCS)2 L 2 with all isomeric picolines and lutidines (L) as well as those of the type Cu(NCS)2 L 3 withL=3- and 4-picoline, 3,4- and 3,5-lutidine were measured. The behaviour of the (CN) stretching vibrations of the Cu(NCS)2 L 2 complexes led to conclusions on the different kind of coordination of the NCS groups in dependence on the ligandL. The mutually conditioned strength of the Cu–NCS and Cu–N(L) bonds in the equatorial plane, especially in the presence of ligandsL with the steric effect, was determined from the frequency shift of the Cu–NCS and Cu–N(L) stretching vibrations with regard to the vibrations for Cu(NCS)2(pyridine)2.

Mit 1 Abbildung  相似文献   
84.
The mass spectra of the pyrrolidides of some long-chain carboxylic acids with alicyclic residues attached to their ω-end are discussed and compared with the spectra of the corresponding esters. Fragmentation triggered by the pyrrolidide group generates a series of peaks, which clearly exhibits the size and the structure of the carbon chain.  相似文献   
85.
We give the continuum wave function solutions to the Schrödinger equation for an electron moving field of two point nuclei, as an expansion in terms of one centre Coulomb wave functions in a prolate elliptical coordinate system. These solutions may be chosen to have a convenient asymptotic behaviour, and tend to the conventional solutions of the Helmholtz equation in the limit that the nuclear charge goes to zero. In symmetric systems, where both nuclei have the same charge the angular wave functions are found to be identical with those occurring in the free case, and the expansion coefficients for the corresponding radial solutions are given for selected values of electron energy and nuclear separation.[/p]  相似文献   
86.
X-ray diffraction and morphology of crystalline,hard, elastic materials   总被引:2,自引:0,他引:2  
Summary X-ray diffraction and electron microscopic results on several crystalline polymers which demonstrate elastic properties (polypropylene, Celcon®, poly-4-methyl-pentene) are reported. Photographic small angle X-ray diffraction techniques provided considerable qualitative information, concerning the morphological features of these elastic materials both as extruded, annealed and during extension. Lamellar thickness, thickness distribution and perfection of lamellae could be estimated. Lateral order features and orientation of the lamellar structures were obtainable from the sharpness and length of the equatorial wide angle diffraction arcs. Electron microscopic results essentially confirm the morphological features postulated on the basis of the X-ray results. These morphological features are discussed in terms of a general structural model which appears consistent with the mechanical properties of these materials.
Zusammenfassung Röntgenbeugung und elektronenmikroskopische Daten von einigen kristallinen Polymerprodukten mit elastischen Eigenschaften (Polypropylen, Celcon, Poly-4-methylpenten) werden berichtet. Die photographische Röntgen-Kleinwinkelmethode liefert wichtige qualitative Messungen der morphologischen Struktur dieser elastischen Materialien in den Zuständen sowohl wie hergestellt als auch nach Tempern und während des Dehnungsprozesses. Die Dicke der Lamellen, ihre Dikkenverteilung und die Güte der Lamellen konnten abgeschätzt werden. Die laterale Ordnung und die Orientierung der Lamellen kann aus Weitwinkelbeugungsdaten abgeleitet werden. Die Elektronenmikroskopie bestätigt die Morphologie, die aus Röntgendaten folgt. Ein allgemeines Strukturmodel dieser Morphologie, das im Einklang mit den mechanischen Eigenschaften dieser Produkte steht, wird diskutiert.
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87.
In previous papers many different classes and constructions of greedoids have been defined and studied. This paper documents inclusion relations among all subclasses of greedoids which are known so far. It will be shown that all inclusion relations are proper and that all but one subclasses of interval greedoids are distinct.
Zusammenfassung In früheren Arbeiten wurden viele verschiedene Klassen und Konstruktionen für Greedoide eingeführt und studiert. In dieser Arbeit werden alle bekannten Inklusionsbeziehungen zwischen Unterklassen von Greedoiden dokumentiert. Es wird gezeigt, daß alle Inklusionsbeziehungen echt und alle Unterklassen mit einer Ausnahme tatsächlich verschieden sind.


Supported by the joint research project Algorithmic Aspects of Combinatorial Optimization of the Hungarian Academy of Sciences (Magyar Tudományos Akadémia) and the German Research Association (Deutsche Forschungsgemeinschaft, SFB 21). Part of this research was done while the first author was visiting the Department of Combinatorics and Optimization, University of Waterloo.  相似文献   
88.
The influence of solvents on the redox behaviour of bistriphenylphosphinomercury perchlorate has been investigated by polarographic, voltammetric and potentiometric methods. The electrode process was found to be reversible in acetonitrile, propylene carbonate, N,N-dimethylformamide and dimethyl sulfoxide. An irreversible process was observed in nitromethane employing the dropping mercury electrode as well as in N,N-dimethylthioformamide and N-methyl-2-thiopyrrolidinone employing the rotating platinum electrode. Half wave potentials and diffusion coefficients have been measured. A linear relationship between theE 1/2 and the donor number (DN) of the solvent has been found for the reversible electrode reactions. Ligand replacement occurs in N,N-dimethylthioformamide and N-methyl-2-thiopyrrolidinone.

Mit 1 Abbildung  相似文献   
89.
Liu LD  Liu Y  Wang HY  Sun Y  Ma L  Tang B 《Talanta》2000,52(6):991-999
Spectrophotometric determination of procaine hydrochloride is described. The procaine hydrochloride reacts with p-dimethylaminobenzalhyde in glacial acetic acid to form an Schiff base which is a yellow compound, and its maximum absorption wavelength is at 455nm, 455=3.46×104. The absorbance for procaine hydrochloride from 0.2 to 15 μg ml−1 obeys Beer's law. The linear regression equation of the calibration graph is C=5.866A−0.02, with a linear regression correlative coefficient is 0.9994 and relative standard deviation (RSD) of 1.7%; the detection limit is 0.1 μg ml−1; recovery is from 92.0 to 110.0%. Effects of reaction medium, temperature, gentamycin, beneylpenicillin, kanamycin, streptomycin, foreign ions, and stand for time on the determination of procaine hydrochloride have been examined. The results obtained by this method agreed with those by the official method (dead-stop titration). This method is rapid and simple, and can be used for the determination of procaine hydrochloride in injection solution of procaine hydrochloride.  相似文献   
90.
Palladium[0]-mediated Ullmann cross-coupling of 1-bromo-2-nitrobenzene (1 R = H) and its derivatives with a range of beta-halo-enals, -enones, or -esters readily affords the corresponding beta-aryl derivatives, which are converted into the corresponding quinolines, 2-quinolones, phenanthridines, or 6(5H)-phenanthridinones on reaction with dihydrogen in the presence of Pd on C or with TiCl(3) in aqueous acetone. [reaction: see text]  相似文献   
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