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991.
The homotopic method has been used to analyze the kinetic model of three-stageCO oxidation on two nonuniform surface patches conjugated byCO 2 spillover. Diagrams of steady states depending on the portion of surface patchm 1 at various temperatures and pressure ratiosP(O 2)/P(CO) have been constructed. The ratios of different type patches corresponding to the maximum overall reaction rate have been found.  相似文献   
992.
Thick (≈0.2–1 μm) layers of octaorganylsilsesquioxanes [RSiO1.5]8, where R is CH3, C2H3, and C2H5, were obtained by vacuum deposition and studied by X-ray diffractometry (DRON-3M, R=192 mm, CuKα radiation). Irrespective of the type of support, the layers are ideally oriented polycrystalline films with the [001] texture axis. Structural arrangement of the layers is analyzed on the basis of the crystal data. Orientation of the terminal atomic groups on the surface of the layer is established. It is shown that it is possible to adjust the scale of the layer pattern. Two-layer compositions— Cu(II) β-diketonates and phthalocyanines on octaorganylsilsesquioxane supports and vice versa — with preserved orientations of the films were obtained. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 5, pp. 923–928, September–October, 1996. Translated by L. Smolina  相似文献   
993.
By the use of complete orthonormal sets of -exponential-type orbitals, where ( = 1, 0, –1, –2,...) the multicenter electronic attraction (EA), electric field (EF) and electric field gradient (EFG) integrals of nonscreened and Yukawa-like screened Coulomb potentials are expressed through the two-center overlap integrals with the same screening constants and the auxiliary functions introduced in our previous paper (I.I. Guseinov, J. Phys. B, 3 (1970) 1399). The recurrence relations for auxiliary functions are useful for the calculation of multicenter EA, EF and EFG integrals for arbitrary integer and noninteger values of principal quantum numbers, screening constants, and location of slater-type orbitals. The convergence of the series is tested by calculating concrete cases.  相似文献   
994.
Emission from an atmospheric-pressure glow discharge with alkali metal chloride solutions used as the cathode was studied. The relation between the discharge emission and the cathode sputtering process leading to the transfer of solution components to the plasma zone was analyzed. It was assumed that the appearance of neutral alkali metal atoms and halogens in the plasma zone is due to the dissociation of halide molecules from a covalently bound state, since the transition to this state becomes possible as a result of excitation of sputtered molecules to high vibrational levels.  相似文献   
995.
A series of papers devoted to the synthesis of tryptamines and related structures (tryptophols, homotryptamines, eserines, azatryptamines, etc.) from halocarbonyl compounds and arylhydrazines are correlated. The data on the mechanism of the reaction can be successfully applied to the Fischer indole synthesis.  相似文献   
996.
The liquid-liquid extraction of rare-earth elements (REE) by 0.75 M di-(2-ethylhexyl) phosphoric acid (HDEHP) in cyclohexane from perchloric acid (1–12M) has been investigated. At moderate perchloric acid molarities (1–6 M), the distribution coefficient, E, has an inverse third-power dependency upon the acid concentration in the aqueous phase. However, at higher perchloric acid concentrations, the slope of the resulting curve is about +18, which means a change in the extraction mechanism. In 12 M perchloric acid medium, REE are quantitatively and selectively extracted from apatite minerals, in the organic phase. In order to strip out all the lanthanides, back-extractions were carried out with 9 M hydrochloric acid solutions.  相似文献   
997.
Benzindoles     
A large amount of structural similarity between 4,5-benzindole and naphthalene and between 6,7-benzindole and indole was detected on a basis of a comparison of the absorption, fluorescence, and phosphorescence spectra of isomeric benzindoles with the spectra of indole and naphthalene. A great analogy between indole and 6,7-benzindole as compared with 4,5-benzindole is also observed during the formation of hydrogen bonds, as indicated by the shift in the absorption band of the NH group in the IR spectra of the investigated compounds in the presence of various proton acceptors.  相似文献   
998.
Monophenylhydrazones were prepared from three monochloro derivatives of arylaliphatic 1,5-diketones, and some their transformations were investigated. The monophenylhydrazones formed regiospecifically, and the direction of the reaction was governed by the substituent attached to C3 atom in the initial chlorodiketones. Formerly unknown products of transformations suffered by monophenylhydrazones obtained were described: 2-amino-1,3-diphenyl-3-(2-phenylindolyl-3)-propan-1-one, 3-benzoyl-2,4,6-triphenyl-2,3,4,5-tetrahydropyridazine, and 3-methyl-1,5-diphenyl-5-phenylazopent-4-en-1-one.  相似文献   
999.
Steroid polyols from the Far-Eastern starfish Henricia sanguinolenta   总被引:2,自引:0,他引:2  
A new polyhydroxylated steroid (20R,24S)-5-cholestane-3,6,15,24-tetraol and a known glycoside, laeviuscoloside G, was isolated from the Far-Eastern starfish Henricia sanguinolenta, collected in the sea of Okhotsk, and characterized.  相似文献   
1000.
The borling temperatures of perfluoro-2,4,6,9,11,13-hexaoxy-n-tetradecane, perfluoro-2,4,6,8,11,13,15,17-octaoxy-n-octadecane, and perfluoro-2,4,6,8,11,13,15,17,19,21-decaoxy-n-docosane were determined by comparative ebulliometry over the saturated vapor pressure range 6.2–101.6 kPa. The heat capacity of perfluoro-2,4,6,8,11,13,15,17-octaoxy-n-octadecane was studied by adiabatic calorimetry over the temperature range 5.3–371.2 K. The densities of the substances at 296–338 K were measured in quartz pycnometers. The data obtained were used to calculate the normal boiling points, enthalpies of vaporization, critical parameters, and thermodynamic functions (entropy, enthalpy, and Gibbs energy) of the polyethers studied.  相似文献   
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