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991.
Conductive films of gold were assembled on flexible polymer substrates such as Kapton and polyethylene using a solution-based process. The polymer substrates were modified by using argon plasma and subsequent coupling of silanes with amino- or mercapto- terminal groups. These modified surfaces were examined by X-ray photoelectron spectroscopy and contact angle measurements. Colloidal gold was assembled onto the silane-modified surface from solution. The gold particles are attached to the surface by covalent interactions with the thiol or amine group. Formation of a conductive film is achieved by increasing the coverage of gold by using a "seeding" method to increase the size of the attached gold particles. Field emission scanning electron microscopy was used to follow the growth of the film. The surface resistance of the films, measured using a four-point probe, was about 1 Omega/sq. 相似文献
992.
O. A. Filippov V. V. Posokh T. I. Tikhomirova E. N. Shapovalova G. I. Tsizin O. A. Shpigun Yu. A. Zolotov 《Journal of Analytical Chemistry》2002,57(9):788-793
Conditions of the preconcentration of phenol on a microcolumn filled with MN-200 hypercrosslinked polystyrene were determined using the linear sorption dynamics model. Conditions of the on-line determination of phenol and its chloro derivatives by reversed-phase high-performance liquid chromatography with amperometric detection were optimized. The detection limit of phenol and chlorophenols for preconcentration from 30 mL of a sample was 3 and 15 ng/L, respectively. The proposed procedure was used for the determination of phenols in tap and river water. 相似文献
993.
V. V. Lapachev O. A. Zagulyaeva S. F. Bychkov V. P. Mamaev 《Chemistry of Heterocyclic Compounds》1978,14(11):1257-1260
The tautomeric properties of 4-pyrimidinylmethanes were studied in the case of 2-CH3- and 2-CF3-4-pyrimidinylcyanoacetic esters, 2-CH3-4-pyrimidinylnitromethane, and 4-pyrimidinylnitromethane. It was shown by 1H and 13C NMR spectroscopy that an equilibrium with the participation of three tautomeric forms — pyrimidine form A and pyrimidinylidene forms B and C with o- and p-quinoid orientations of the double bonds in the heteroring — may be realized in aprotic dipolar solvents (dimethyl sulfoxide).See [1, 2] for communications I and II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1544–1548, November, 1978. 相似文献
994.
A simplified micro-method for the quantitative analysis of urinary polyamines is described. After acid hydrolysis of urine, the polyamines are converted to fluorescent 1-dimethylaminonaphthalene-5-sulfonyl (Dns; dansyl) derivatives and separated by means of thin-layer chromatography. Dns-NH2, which has been reported to interfere with the determination of putrescine, is well separated from di-Dns-putrescine. Putrescine, spermidine and spermine are quantitated by in situ scanning of their fluorescent spots on the chromatogram. The present method is both sensitive and reproducible. It eliminates a number of time-consuming steps and thus reduces preparative losses. Yet an adequate chromatographic resolution is obtained. Representative polyamine analyses of urine from normal volunteers and from cancer patients are reported. Elevated levels occur in the urines of pregnant women and of patients with various types of cancer. 相似文献
995.
New ionization potential values are reported for sixteen aromatic molecules. They are obtained from CT spectra of a new electron acceptor, 3,5-dinitro-phthalic anhydride with the aromatic electron donors in 1,2-dichloroethane. The results are correlated with molecular electronic structure using perturbation theory. 相似文献
996.
Prof. Dr. O. Hromatka D. Binder K. Eichinger 《Monatshefte für Chemie / Chemical Monthly》1974,105(1):123-126
The synthesis of 5-(o-trifluoromethylphenyl)-1H-thieno-[3,4-e]1,4-diazepin-2(3H)-one (7) and its nitration and chlorination in pos. 8 are described. 相似文献
997.
O. B. Bondarenko A. Yu. Gavrilova M. A. Kazantseva V. N. Tikhanushkina E. E. Nifant’ev L. G. Saginova N. V. Zyk 《Russian Journal of Organic Chemistry》2006,42(2):249-255
A reaction of monoarylcyclopropanes with nitrosyl chloride activated by sulfur (IV) oxide gave in good yields 5-arylisoxazolines. The reaction is of electrophilic character. A scheme of the reaction was suggested. 相似文献
998.
F. J. Krug L. C. R. Pessenda E. A. G. Zagatto A. O. Jacintho B. F. Reis 《Analytica chimica acta》1981,130(2):409-413
A flow injection procedure is described for the spectrophotometric determination of chloride in ethanol, based on the mercury(II) thiocyanate—iron(III) reaction. Effects of reagent composition and ethanol content of the sample are investigated in detail. The proposed system can analyse 120 samples of ethanol (94–100% v/v) per hour, with a relative standard deviation lower than 1%, when the chloride content ranges from 0.1–6.0 ppm. Recoveries of ca. 96% are found. 相似文献
999.
A. I. Druzhinina O. V. Krol’ A. A. Efimova R. M. Varushchenko L. L. Gervits 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(11):1742-1748
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
1000.
O. R. Sergeeva V. V. Chenets V. G. Lipovich 《Reaction Kinetics and Catalysis Letters》1982,19(3-4):411-414
Kinetic isotope effect (KIE) measurements in the trans-alkylation of toluene and benzene with ethylbenzene in hexane in the presence of AlBr3 at 313 K indicate that deuterium in the toluene methyl group causes a small inverse KIE characteristic for a -complex transiton state. The small direct KIE found for the reaction with C2D5C6H5 does not agree with a mechanism involving alkyl-and -phenylalkyl cations.
() - AlBr3 313 . , , - C2D5C6H5 , - -.相似文献