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W. Grüebler Ronald E. Brown F.D. Correll R.A. Hardekopf Nelson Jarmie G.G. Ohlsen 《Nuclear Physics A》1979,331(1):61-74
A previous phase-shift analysis of the d + α system had indicated that the solution obtained might not describe the backward-angle tensor analyzing powers very well above about 10 MeV. We have measured differential cross sections and all four analyzing powers Ay, Axx, Ayy and Axz at deuteron bombarding energies of 12, 14, 15 and 17 MeV, with some emphasis on the backward-angle region. The discrepancy with the previous phase-shift analysis was confirmed, and we have studied the changes in the phase parameters necessary to improve the fit to our new measurements. 相似文献
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MW Spectra of 3- and 4-fluoronitrobenzene in several torsional states and of 2- and 2,4,6-trifluoronitrobenzene in the ground state have been obtained. The inertial defects have been used to show that the 3- and 4-substituted molecules are planar and to find their twofold barriers (1428 cm?1 and 1213 cm?1 respectively). The 2- and 2,4,6-substituted molecules have very large negative inertial defects indicating non-planarity. The out-of-plane angles have been calculated (32° and 57° respectively). 相似文献
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In the Chesapeake Bay Region, acidic atmospheric deposition has deleterious effects on watershed and freshwater ecosystems. One of the associated effects is the disappearance of fish from the streams. 相似文献
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MULTIPLE CHROMOPHORE SPECIES IN PHYTOCHROME*,†,‡ 总被引:2,自引:0,他引:2
David L. Correll John L. Edwards W. Shropshire Jr. 《Photochemistry and photobiology》1968,8(5):465-475
Abstract— Buffered aqueous solutions of pure phytochrome, when irradiated at 730 nm, had a main absorption band at about 660 nm and a shoulder or secondary band at 580–600 nm. When irradiated at 660 nm, these absorption bands bleached and a pair of bands at 670 and 725–730 nm appeared. When 660 nm irradiated samples were placed in the dark the 730 nm absorption slowly bleached and the 670 nm absorption band shifted to 660 nm. The kinetics of the bleaching indicated that two populations of PFR existed initially. These two populations decayed by first order kinetics with k's of 4.8 × 10-4 sec-1 and 3.1 × 10--5 sec-1at 25°. While the bleaching of PFR was occumng, the appearance of the 660 nm and 580–600 nm absorption bands characteristic of PR took place. The kinetics of the increase in the 580 and 660 nm absorption bands indicated that it was arising from two populations of reactants by two first order reactions with k's of 6.4 × 10-4 sec-1 and 3.1 × 10-5sec-1 at 25°. When the sodium chloride concentration of the solvent was changed the proportions of the kinetically different populations were altered. In some conditions, especially in the presence of air. reversible but non-reciprocal changes in the four absorption bands were observed. These effects were evident after the lapse of many hours in the dark. When native phytochrome was treated with sodium dodecyl sulfate all absorption bands but the 580–600 nm absorption band were bleached and photoreversibility was lost. When native phytochrome was treated with glutaraldehyde, the 730 nm absorption band was bleached but photoreversibility was retained. It was concluded that at least four species of chromophore exist in phytochrome with absorption maxima at 580, 660 , 670 and 730 nm. Each chromophore is capable of being bleached by appropriate irradiation or in the dark by chemical reactions rather than photochemical reactions. The reactions are probably coupled redox reactions between the 580–660 nm pair and the 670–730 pair of chromophores. Discrepancies observed in the reciprocity of the absorption changes in these paired bands are probably due to various degrees of uncoupling and secondarily to the redox potential of the solvent when such uncoupling occurs. 相似文献
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Sascha Correll Norbert Stock Wolfgang Schnick 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):321-324
A systematic investigation of tri- and tetrametaphosphimates based on single-crystals is reviewed and results of a conformation analysis of the cyclic six- and eight-membered P-N rings of the (PO2NH)3 3- and (PO2NH)4 4- ions are given. 相似文献
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