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891.
892.
The possibilities and the limitations of 2D NMR for the structural characterization of paramagnetic metalloproteins are reviewed. We survey the general strategies for 2D1H NMR investigations of hyperfine shifted signals. Careful adaptation of classical 2D NMR experiments to fast relaxing systems results in the detection of previously not observed scalar and dipolar connectivities, thus leading to the specific assignment of selected resonances. The approach is of general applicability for paramagnetic metalloproteins. We report here on the application of the application of the method to an iron sulfur protein and a heme protein. In both cases specific assignment of several hyperfine shifted signals, corresponding to active site protons, were obtained; this allowed significant insight into the structure-function relationships of these metalloproteins. 相似文献
893.
I. Yu. Chudinovich 《Mathematical Methods in the Applied Sciences》1993,16(3):217-227
This work considers the methods for solving approximately the four types of boundary equations arising when the third initial boundary value problem of the theory of elasticity is solved with the help of retarded elastic potentials. The convergence of these methods is proved. 相似文献
894.
A. I. Podgorny 《Radiophysics and Quantum Electronics》1996,39(11-12):912-915
We have developed the Peresvet program for numerical simulation of energy accumulation above active regions. This program solves 3D MHD equations for the compressible plasma with allowance for the dissipative terms. It is shown that the energy can be stored in a layer of current by focusing the photospheric disturbances. 相似文献
895.
M. U. Belyi N. E. Bartnitskaya I. F. Mel'nik B. A. Okhrimenko S. M. Yablochkov 《Journal of Applied Spectroscopy》1995,62(3):564-567
T. Shevchenko Kiev University, 252022 Kiev, Pr. Akad. Glushakova, 6, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 62, No. 3, pp. 192–196, May–June, 1995. 相似文献
896.
The dehydration of molybdic acid, MoO3---H2O, was studied by thermal analysis, X-ray diffractometry and FTIR spectroscopy. The results show that an intermediate phase, MoO3-2/3H2O is formed at 216 °C and the monoclinic form of MoO3 is grown above 350 °C. The mechanism of dehydration and structural rearrangement were confirmed by the features of the infrared spectra showing formation of corner-shared MoO6 octahedra. 相似文献
897.
Methods are proposed for determining the diffusion coefficients of adsorbed molecules and the adsorption isotherms from given concentrations of the solutes in the external solution. The methods are based on a comparison of experimental data with the numerical results produced by a mathematical model of internal-diffusion kinetics of adsorption from a constant bounded volume.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 66, pp. 41–46, 1988. 相似文献
898.
A. V. Kibal'nyi Yu. A. Nikolyukin V. I. Dulenko 《Chemistry of Heterocyclic Compounds》1994,30(8):895-900
Summary The reaction of acyl perchlorates with 1 phenacylskatole affords the previously unknown 1-R-lamethyl-3phenylindolo[2,1-c1-1,4oxazinium salts, which undergo recyclization by the action of ammonia to the corresponding indolo[2,1-alpyrazines. It is found that the salts (R = CHj, CZHS) also form dimers of their anhydro bases. The perchlorate (R = Ph) is converted to indolo[2,141-1, 2, S-triazepine by the action of hydrazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1041-1047, August, 1994. 相似文献
899.
The magnified cross-section of the LDV probe volume fringe field created on a far screen (image plane) with an imaging lens is examined both analytically and experimentally. It is shown that measurements of the image plane fringe field can be used to quantitatively determine the fringe field existing within the probe volume. Because the fringe spacing in the magnified image is more accessible experimentally, both longitudinal- and lateral-coordinate variations in fringe spacing can be determined, permitting a complete mapping of the fringe field. The detailed knowledge of the fringe field thus obtained allows beam quality, alignment, and fringe uniformity to be evaluated with greater precision than is possible with other techniques.The authors would like to acknowledge C. F. Edwards and R. L. Schmitt for the loan of the beam profiler and for many helpful discussions. This work was performed at the Combustion Research Facility, Sandia National Laboratories, and was supported by the U.S. Department of Energy, Office of Industrial Technologies, Advanced Industrial Concepts Division. 相似文献
900.
J.-M. Colmont B. Bakri G. Wlodarczak G. Cazzoli C. Puzzarini 《Journal of Molecular Spectroscopy》2005,231(2):171-187
For atmospheric purposes, the N2- and O2-, or Air-broadenings of selected transitions of ozone have been investigated in the 195-300 K temperature range. More precisely, the following 13 transitions in the 280-345 GHz frequency range have been studied: the 22,0 ← 21,1 (279.5 GHz), 242,22 ← 241,23 (286.2 GHz), 32,2 ← 31,3 (286.3 GHz), 52,4 ← 51,5 (293.2 GHz), 134,10 ← 143,11 (300.7 GHz), 140,14 ← 131,13 (301.8 GHz), 72,6 ← 71,7 (303.2 GHz), 262,24 ← 261,25 (315.9 GHz), 53,3 ← 62,4 (317.2 GHz), 201,19 ← 200,20 (320.0 GHz), 266,20 ← 275,23 (343.2 GHz), 262,24 ← 253,23 (343.2 GHz), and 43,1 ← 52,4 (343.5 GHz) lines. Systematic errors are known to be the principal error source and recent intercomparisons of line-broadening coefficients showed differences up to 20%, thus a large effort in minimizing systematic error sources has been taken and cross check measurements with different techniques have been carried out. The conclusion of the intercomparison performed indicates an excellent agreement of the results and that an uncertainty less than 3%, which also takes into account the systematic errors, can be claimed for the line-broadening parameters. 相似文献