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991.
Munenori Sumiyoshi Hiroko Kuritani Keiji Shingu Masazumi Nakagawa 《Tetrahedron letters》1980,21(30):2855-2856
The recently assigned diastereomeric configuration of 3,8-di-t-butylspiro[4.4]nonane-1,6-dione has been revised based on the X-ray analysis. 相似文献
992.
The microwave spectra of ethaneselenol and its deuterated and 13C-substituted species were measured and assigned for the gauche and trans isomers. The double minimum splittings in the gauche isomers were directly observed for the species having a symmetry plane in the frame part. The rotational constants and the torsional splitting of the gauche isomer of the parent species were determined to be A = 27 148.86 ± 0.05, B = 3 623.68 ± 0.01, C = 3 399.21 ± 0.03, and Δν = 1 083.33 ± 0.04 MHz. From the torsional splittings of the parent and SeD species together with the vibrational frequencies already reported by Durig and Bucy, the Fourier coefficients of the selenol internal rotation potential function were determined to be V1 = ?44 ± 17, V2 = ?260 ± 3, V3 = 1202 ± 16, and V6 = ?43 ± 9 cal/mole. From the rotational constants obtained, the rs structural parameters of the gauche and trans isomers were determined. The structural parameters in the skeletal part for the gauche isomer are , , , α(CCSe) = 113°31′, α(CSeH) = 93°05′, and the dihedral angle τ(CCSeH) = 61°39′. Those for the trans isomer are , , , α(CCSe) = 108°43′, and α(CSeH) = 93°30′. These parameters were compared with the corresponding ones of ethanethiol. 相似文献
993.
994.
A broad peak was systematically observed at about 10 MeV above the Gamow-Teller resonance in the 90Zr, 120Sn, 140Ce, 208Pb (p,n) reactions at Ep = 41 MeV. The angular distribution shapes of these peaks support the interpretation that they they correspond to ΔL = 1 state. The data are compared with TDA-DWBA calculations. 相似文献
995.
The mechanism which was formerly used to obtain neutrino masses is generalized to all light fermions. Correspondingly, several sets of superheavy fermions are introduced. Assignments under a horizontal symmetry group are arranged such that the heaviest among the light fermions acquire their masses, not from the ordinary Higgs-Yukawa couplings, but from couplings to the heavy fermions. Masses of the other light fermions are then obtained through horizontal gauge interactions. Accordingly, the resulting light fermion masses exhibit a hierarchical generation structure. Because of the construction, light Higgs fields do not induce dangerous flavor-changing neutral-current interactions. 相似文献
996.
Styrene-divinylbenzene copolymer resins containing a series of diethylenetriamine derivatives have been prepared and characterized. The multidentate ligands are covalently bound to the polymer matrix without causing inter- and intrastrand bridging structures. The properties of the present chelating resins have been examined with respect to the uptake of transition metal ions. 相似文献
997.
998.
Ohne Zusammenfassung 相似文献
999.
1000.
M Nakagawa T Harada A Hara T Nakayama H Sawada 《Chemical & pharmaceutical bulletin》1989,37(10):2852-2854
Two major and two minor forms of dihydrodiol dehydrogenase with similar molecular weights of around 36000 were purified from monkey liver cytosol. All the forms oxidized trans-dihydrodiols of benzene and naphthalene and reduced aromatic aldehydes, but showed differences in charge, specificity for other substrates and inhibitor sensitivity. One major (pI 8.7) and one minor (pI 7.9) form of the enzyme exhibited high activity for alicyclic alcohols and sensitivity to o-phenanthroline. The other major form (pI 6.2) oxidized 3 alpha-hydroxysteroids and was inhibited by dexamethasone and indomethacin, whereas the other minor form (pI 5.8) showed high reductase activity for aldehydes including D-glucuronate and sensitivity to barbital and sorbinil, and cross-reacted with human aldehyde reductase. The results indicate that the multiple forms of monkey liver dihydrodiol dehydrogenase are indanol dehydrogenases, 3 alpha-hydroxysteroid dehydrogenase and aldehyde reductase. 相似文献