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941.
A quantitative compressed pellet infrared method used together with a micro-distillation to effect separation of the isomer has been developed and reported here for the analysis of ortho-, meta-, and para-terphonyl. The terphenyl content is determined on fractions isolated by distillation from radiation damaged samples. The compressed pellet infrared method is preferred instead of the more conventional solution technique since smaller quantities of isolated terphcnyl are required. The pellet method is applicable also to polyphenyls higher than the terphenyls. The solution technique is not due to the insolubility of the polyphenyls. It is expected that the compressed pellet spectral method developed here might well find application in the analysis of compounds other than polyphenyls. Results presented here appear to be the, first quantitative infrared data reported in the literaturu on polyphenyl compounds. 相似文献
942.
T. Ya. Safonova N. S. Gulyukina Yu. V. Novakovskaya E. A. Astaf'ev G. N. Bondarenko O. A. Petrii G. A. Tsirlina I. P. Beletskaya 《Russian Journal of Electrochemistry》2002,38(5):457-466
The conditions for electrochemical hydrogenation and anodic oxidation of -phenylvinylphosphonic acid and its 4-chloro- and 4-methyl-substituted derivatives on palladized platinum electrodes in aqueous sulfuric-acid solutions are found. It is shown that, in the system under study, the products of strong chemisorption are not the intermediates of the electrocatalytic hydrogenation. The reactant molecules are modeled by quantum-chemical methods in terms of the restricted Hartree–Fock approximation. The calculated charge distributions in reactant molecules are used for estimating the electrostatic components of works of approach and the orientation distributions in the reaction layer. 相似文献
943.
Chris Mussell Céline S. J. Wolff Briche Chris Hopley Gavin O’Connor 《Accreditation and quality assurance》2007,12(9):469-474
The method used at LGC for analysis of “total” 19-norandrosterone (19-norandrosterone glucuronide plus “free” 19-norandrosterone)
in urine for the Comité Consultatif pour la Quantité de Matière Pilot Study (CCQM-P68) is described. The analytical method
used was a modified version of the method developed at the National Measurement Institute of Australia, which used a hydrolysis
and derivatisation procedure first described by the German Sports University. This method is routinely used by World Anti-Doping
Agency-accredited laboratories for sports drug testing. The main modifications made to the method were the use of 19-norandrosterone
glucuronide as a calibration standard and 19-norandrosterone glucuronide-d4 as an isotopically labelled internal standard,
and the use of a bench-top quadrupole gas chromatograph–mass spectrometer. The results produced by LGC (2.14 ± 0.15 ng g−1 expanded uncertainty, coverage factor k = 2) were in excellent agreement with those from other participating national metrology institutes and thus further validates
the exact-matching isotope-dilution mass spectrometric procedures used at LGC for a wide range of reference measurement applications,
including measurement of ng g−1 levels of steroids in a biological matrix. 相似文献
944.
The possible routes of deactivation of electronically excited states of 4-methyl-7-hydroxy-2-quinolone and its protolytic forms were analyzed. The relative contribution of radiative and nonradiative deactivation channels of electronic excitation energy was determined, and the rate constants of photophysical processes (internal conversion and intersystem crossing) occurring upon light absorption by these forms were estimated. 相似文献
945.
Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsikiicheskikh Soedinenii, No. 4, pp. 435–473, April, 1995. Original article submitted February 22, 1995. 相似文献
946.
O. V. Konopatskii O. G. Chernitskii A. I. Tripol'skii 《Theoretical and Experimental Chemistry》1994,29(5):300-304
A study has been carried out on the kinetics of the temperature-programmed desorption of O2, HCl, and H2O from the surface of cobalt chromite. A mathematic model was obtained for the kinetics of the thermal desorption and a method was developed for determining the kinetic constants. The kinetic parameters of the desorption of O2, HCl, and H2O were calculated using these experimental data.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 5, pp. 449–455, September–October, 1993. 相似文献
947.
Conclusions The S-2-hydroxyalkyl esters of cyclic P(V) thioacids, which were obtained by reacting a cyclic phosphorus monothioacid with an alkylene oxide, are converted to the 2-mercaptoalkyl esters of cyclic phosphorus acids independent of the size of the ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2594–2596, November, 1980. 相似文献
948.
V. M. Mastikhin O. P. Krivoruchko B. P. Zolotovskii R. A. Buyanov 《Reaction Kinetics and Catalysis Letters》1982,18(1-2):117-120
The possible use of the27Al-NMR method with sample rotation at a magic angle to study the local environment and cation distribution of Al(III) ions in the oxide lattice are exemplified by -, -, -, -Al2O3 and commercial A-1 A1(III) oxide.
-, , -, -Al2O3 Al(III) A-1 27 Al Al(III) ë .相似文献
949.
950.
L. V. Borisova Yu. N. Dubrov O. D. Prasolova 《Russian Journal of Inorganic Chemistry》2006,51(12):1869-1871
The mechanism of the reaction of the rhenium(VI) dithiolate complex ReIV(TDT)3 with some electron-donating organic reagents in nonaqueous solvents is studied by the spin trap method combined with electron paramagnetic resonance. The reaction products are stable complex rhenium(V) anions, ReV(TDT)3-, and short-lived radicals forming long-lived adducts with spin traps as probed by EPR. The possibility of using the radical processes for analytical purposes is discussed. 相似文献