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101.
The effect of ultraviolet light on a methanol-water solution of 1-methyl-4-ethoxycarbonylpyridinium iodide has been studied. It has been established that the 225 nm irradiation of air-saturated solution initiates the formation of species which absorb at 358 nm. The 280 nm irradiation of a solution containing newly formed particles causes a reverse process of a gradual diminuation of the concentration of the complex formed.
Über das photochemische Verhalten von 1-Methyl-4-ethoxycarbonylpyridiniumjodid (Kurze Mitteilung)
Zusammenfassung Die Wirkung des Ultraviolettlichtes auf eine methanolisch-wäßrige Lösung von 1-Methyl-4-ethoxycarbonylpyridiniumjodid wurde studiert. Es wurde festgestellt, daß die Belichtung der luftgesättigten Lösung bei 225 nm eine Bildung von Spezies, die bei 358 nm absorbieren, hervorruft. Die Belichtung einer Lösung, die die neugebildeten Partikel enthält, verursacht bei 280 nm einen Rückgang bzw. eine allmähliche Abnahme der Konzentration des gebildeten Komplexes.相似文献
102.
B. V. Unkovskii N. P. Shulaev Yu. F. Malina O. D. Saralidze 《Chemistry of Heterocyclic Compounds》1971,4(4):481-484
In order to synthesize stereoisometric 4-acyl(benzoyl)-1, 3-dimethyl and-1, 2, 5-trimethyl-4-piperidinols, the reaction of the geometrical isomers of 4-cyano-1, 3-dimethyl- and -1, 2, 5-trimethyl-4-piperidinols and the amines and imidic esters corresponding to them with some alkyl- and arylmagnesium halides, leading to the corresponding isomeric piperidinic -ketols, has been studied. The dependence of the reactivity of the geometrical isomers of the compounds studied on the spatial orientation of their functional groups has been shown. 相似文献
103.
Malina Raileanu Monica Popa Jose Maria Calderon Moreno Lia Stanciu Lacramioara Bordeianu Maria Zaharescu 《Journal of membrane science》2002,210(2):320-207
Two types of unsupported zeolites (silicalite-1 and silicalite-2) and porous alumina discs supports were prepared by the hydrothermal sol–gel synthesis method. The influence of the raw materials used as SiO2 source, the temperature of the thermal treatment and the presence of the ceramic support on the crystallization of zeolites were studied. The reaction products were characterized by X-ray diffraction (XRD), IR spectroscopy (IR) and scanning electron microscopy (SEM) studies. The SiO2 source had a significant effect on the final zeolite obtained: the use of colloidal silica sol (ZCS) as SiO2 source in the synthesis led to ZSM-11 (silicalite-2) crystals, while the sodium silicate solution (ZSS) produced the ZSM-5 (silicalite-1) type. The presence of the alumina support influences the crystallization process of ZSM-5, as it improves nucleation and the ordering of the crystals. 相似文献
104.
We developed and implemented an approximation of the state-specific Brillouin-Wigner coupled-cluster method with singles, doubles, and triples, called MRBWCCSDT-alpha, for a general number of closed- and open-shell reference configurations. The accuracy of the method is assessed on the calculation of the oxygen molecule in the X3sigma(g-), a1delta(g), and b1sigma(g+) states and the results of this multireference treatment are compared with previous MRBWCCSD results and with those obtained by the doubly ionized similarity transformed equation-of-motion CCSD and multireference configuration interaction methods and with experimental spectroscopic data. Explicit tests of the size-extensivity of the MRBWCCSDT-alpha method with iterative size-extensivity correction are also performed. 相似文献
105.
Binary and ternary potassium, rubidium and caesium glasses were irradiated by an electron beam with energy varying from 10
to 50 keV. Alkali ion X-ray decays were recorded and afterward incubation periods were determined. The incubation period versus
electron energy curves revealed thresholds, which are typical for each alkali species. The threshold ratios are proportional
to the mass of the alkali species, consistent with the suggested elastic scattering assisted hopping mechanism. 相似文献
106.
T. D. Sokolova K. I. Romanova Yu. F. Malina B. V. Unkovskii 《Chemistry of Heterocyclic Compounds》1975,11(12):1391-1394
The corresponding stereoisomeric p-nitrobenzoates were obtained by reaction of the geometrical isomers of 1,3-dimethyl-, 1,2,5-trimethyl-, and 1-tert-butyl-3-methyl-4-hydroxypiperidines with p-nitrobenzoyl chloride. The stereoisomers of the corresponding benzoates were also synthesized from the geometrical isomers of 1,3-dimethyl-4-hydroxypiperidines. The primary conformations of the investigated compounds in solution were established by means of their PMR spectra. 相似文献
107.
Luboš Jankovič Karol Végsö Peter Šiffalovič Ondrej Šauša Lubomír Čaplovič Mária Čaplovičová 《International Journal of Polymer Analysis and Characterization》2016,21(6):524-536
Three different polymer nanocomposites were prepared using clay modified with tetraoctylammonium (4C8) surfactant. The dispersion of clay silicate layers was studied using X-ray diffraction and small-angle scattering. Free-volume cavity sizes were studied with positron annihilation lifetime spectroscopy. Scattering methods confirmed disruption of all polymer lamellae organization upon organoclay addition and the creation of partially intercalated systems for polyamide and polycaprolactone. The presence of organoclay in the polymers enlarges the lower value of average positronium lifetime τ3 of polyamide and reduces the higher value of τ3 for polycaprolactone and polyethylene. 相似文献
108.
Ondrej Kurka 《Proceedings of the American Mathematical Society》2008,136(12):4467-4473
We show that the sets of Fréchet subdifferentiability of Lipschitz functions on a Banach space are Borel if and only if is reflexive. This answers a question of L. Zajíček.
109.
Poterya V Votava O Fárník M Oncák M Slavícek P Buck U Friedrich B 《The Journal of chemical physics》2008,128(10):104313
We report on the first observation of the organoxenon HXeCCH molecule in the gas phase. This molecule has been prepared in a molecular beam experiment by 193 nm photolysis of an acetylene molecule on Xe(n) clusters (n approximately 390). Subsequently the molecule has been oriented via the pseudo-first-order Stark effect in a strong electric field of the polarized laser light combined with the weak electrostatic field in the extraction region of a time-of-flight spectrometer. The experimental evidence for the oriented molecule has been provided by measurements of its photodissociation. For comparison, photolysis of C(2)H(2) on Ar(n) clusters (n approximately 280) has been measured. Here the analogous rare gas molecule HArCCH could not be generated. The interpretation of our experimental findings has been supported by ab initio calculations. In addition, the experiment together with the calculations reveals information on the photochemistry of the HXeCCH molecule. The 193 nm radiation excites the molecule predominantly into the 2 (1)Sigma(+) state, which cannot dissociate the Xe-H bond directly, but the system evolves along the Xe-C coordinate to a conical intersection of a slightly nonlinear configuration with the dissociative 1 (1)Pi state, which then dissociates the Xe-H bond. 相似文献
110.
Ondrej F. K. Kalenda Kenneth Kunen 《Proceedings of the American Mathematical Society》2005,133(2):425-429
Assuming the consistency of the existence of a measurable cardinal, it is consistent to have two Banach spaces, , where is a weak Asplund space such that (in the weak* topology) in not in Stegall's class, whereas is in Stegall's class but is not weak* fragmentable.