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951.
4-Phenyl- and 4-methylthiazolylhydrazones were brominated in chloroform and acetic acid. The use of 1.5 equivalents of bromine led to the exclusive formation of the 5-halo derivatives. Effects of substituents on the thiazole ring and of the hydrazone fragment aromatic ring on the course of the reaction were discovered.Urals State Technical University-UPI, 620002 Yekaterinburg. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 991–995, July, 1995. Original article submitted March 1, 1995. 相似文献
952.
R. Buccellato M. M. Michaelis C. A. Dempers A. Prause P. F. Cunningham 《Optics & Laser Technology》1993,25(4)
The concept of a pulsed gas lens is proposed. Potential applications are envisaged and preliminary experiments with pulsed ray refraction are reported. 相似文献
953.
An FFT method is described for the solution of Poisson's equationover a rectangular region with Robbins boundary conditions oneither one or two sides of the region, together with suitableconditions on the rest of the boundary. In contrast to earlierapplications of the FFT technique, the equations for the Fourierharmonic amplitudes do not decouple into simpler independentsystems and an effective iterative scheme is developed for thesolution of these equations. A theoretical convergence analysisis shown generally to support the results obtained from practicalcomputation. For the test problems considered the method isfound to take between 3 and 4 times the execution time for problemssoluble directly by the FFT technique. 相似文献
954.
Recent observations of a direct reaction between adsorbates and hydrogen atoms incident from the gas phase are interpreted in terms of an Eley-Rideal reaction. A detailed comparison of the experimental data for the HD/Cu(111) system with quantum mechanical model calculations corroborates such an interpretation. The peculiar isotope effect observed can be understood from the different dynamical implications of appropriately rescaled potential energy surfaces. The width of the measured time-of-flight spectrum is explained from the overlapping contributions of the populated vibrational levels. The angular distributions are rationalized by contributions both from ‘indirect’ events, where the incident atoms make several bounces in the surface well prior to reaction, and ‘direct’ reactive events. 相似文献
955.
We study extension of operators T: E→ L0([0, 1]), where E is an F–function space and L0([0, 1]) the space of measurable functions with the topology of convergence in measure, to domains larger than E, and we study the properties of such domains. The main tool is the integration of scalar functions with respect to stochastic
measures and the corresponding spaces of integrable functions.
Partially supported by D.G.I. #MTM2006-13000-C03-01 (Spain). 相似文献
956.
Electrochemical oxidation of thio/carbohydrazide and their hydrazone derivatives Benzaldehyde thiocarbohydrazone [BTCH] diacetylene
thiocarbohydrazone [DATCH] have been studied in Brit-ton Robinson buffer in aqueous and nonaqueous media at a glassy carbon
electrode. The effects of pH, sweep rate, concentration, temperature and surfactants have been studied. The complex bis (carbo/thiocabohydrazide) Zn(II) chloride was also subjected to voltammetric analysis in order to understand the reactivity
both in free and metal bound states. The reaction conditions were optimized for the determination of above compounds in micrograms
quantities by differential pulse voltammetry, analytical utility of this investigation is also highlighted. 相似文献
957.
N. Barrier P. Gall P. Gougeon 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):i102-i104
Trisamarium molybdenum heptaoxide, Sm3MoO7, is isomorphous with Ln3MoO7 (Ln = La and Pr). The crystal structure consists of chains of corner‐linked MoO6 octahedra running parallel to the b axis and separated from each other by seven‐ or eight‐coordinate Sm–O polyhedra. In contrast to La3MoO7 and Pr3MoO7, a splitting of one Sm site into two positions is observed. 相似文献
958.
L. P. Eksperiandova A. I. Fedorov Ya. N. Makarovskaya 《Journal of Analytical Chemistry》2007,62(12):1163-1166
A series of quasi-solid emitters is proposed for the X-ray fluorescence determination of bromine in different bromine-containing compounds. It is shown that sucrose-based glasses are the best emitters for analyzing alkali solutions of halogenated organic compounds, saccharose-based glasses and polymer films are best for analyzing powder samples, and organic gels offer most promise for analyzing liquid (at normal conditions) samples. It is noted that the proposed method can expand the possibilities of commercially produced element analyzers, which are currently intended for determining only C, H, O, N, and S in organic compounds and cannot be used for determining halogens. 相似文献
959.
K.P.B. Moosad P. Krishnakumar G. Chandrashekar R.M.R. Vishnubhatla 《Applied Acoustics》2007,68(10):1280-1285
Class IV flextensional transducers (FTs) are the best-known FTs in literature. These are light-weight projectors (compared to the conventional Tonpilz designs) with capability for high power delivery at low frequencies. The resonance frequencies of this type of transducers are known to be dominantly dependent on the characteristics of the outer shell than on the driver stack. Consequently, the method of achieving fine-tuning of the transducer by modifying the characteristics of the stack, as practiced in the case of Tonpilz designs, is not very effective. This paper describes a method for fine-tuning of the frequency of a Class IV FT, which involves only a modification of a pair of small components used for coupling the stack to the transducer. The effectiveness of the method is examined by finite element modelling using the package ATILA, in the case of a 3 kHz aluminium shell transducer. Experimental results are also presented. 相似文献
960.
I. A. Belogorokhov M. N. Martyshov E. V. Tikhonov M. O. Breusova V. E. Pushkarev P. A. Forsh A. V. Zoteev L. G. Tomilova D. R. Khokhlov 《JETP Letters》2007,85(12):655-657
The Raman spectra have been obtained and the temperature dependence of the conductivity of organic semiconductor structures based on butyl-substituted erbium monophthalocyanine and erbium triphthalocyanine has been studied. It has been found experimentally that the activation energy decreases dramatically and the Raman spectra exhibits four new peaks in the region of large Raman shifts as the molecular structure of the samples becomes more complicated. 相似文献