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151.
A new method for assignment of the absolute configuration of the asymmetric carbon atom attached to an amino or imino group using rac.-3-hexadecanoyl-4-methoxycarbonyl-1,3-thiazolidine-2-thione (rac.-HDMTT) () is described. 相似文献
152.
Structure-reactivity indices for the hydrolysis of diol epoxides of polycyclic aromatic hydrocarbons
Several different computational parameters have been used in an attempt to predict relative reactivity of carcinogenic bay-region diol epoxides. The correlation of experimentally observed hydrolytic reactivity with these parameters is described. 相似文献
153.
The emission and excitation spectra of P-doped Cd1?xMgxTe (x ? 0.45) mixed crystals have been measured over the temperature range of 300 ~ 4.2 K to reinvestigate the photoluminescence process of two broad emission bands; the 690 nm band of the as- grown crystals and the 610 nm band of the annealed crystal. The excitation spectrum of each band has a characteristic peak at 550 nm near the absorption edge of this crystal. Together with the data of the decay characteristic and the halfwidth of each band, we discuss the difference in the recombination process when the crystal is excited under two different radiation at 365 and 570 nm (close to the 550 nm radiation). It is concluded that both emission bands arise from donor-acceptor pairs and a localized center or self- activated center; the associated pair is VCd-interstitial P in the as-grown and VTe ? PTe in the annealed crystal. 相似文献
154.
Yoshio Iwakura Fujio Toda Hideaki Suzuki Norihisa Kusakawa Kohji Yagi 《Journal of polymer science. Part A, Polymer chemistry》1972,10(4):1133-1148
Methods of preparing new monomers, 2-vinyl and 2-isopropenyloxazoles and 2-isopropenyl-1,3,4-oxadiazoles are described. New methods were developed to synthesize monomers containing an isoxazole or a thiazole ring. Radical homopolymerization and copolymerization with styrene of these monomers were carried out by using AIBN as an initiator. Monomer reactivity ratios r1, r2 and Alfrey-Price Q–e values were determined by the Fineman-Ross and the Mayo-Lewis methods. The localization energy of the β-carbon was calculated by a HITAC-5020 computer, and the monomer reactivity is discussed in terms of Lβ. 相似文献
155.
The reactions ATe(p, t)A?2Te have been studied with even-A targets using 51.9 MeV protons. Three or more strongly excited triton peaks were observed in the spectra of the A-2Te nuclei at energies of ≈ 2–3 MeV excitation. Angular distributions are analyzed using DWBA theory. The lowest octupole (3?1) states of five Te isotopes are strongly excited. The lowest 3? state in 120Te is established at 2.09 ±0.02 MeV. The systematics of excitation energies and cross sections for the lowest 5? and 7? states are interpreted by a quasiparticle model. 相似文献
156.
157.
Abstract. 1-Hydroxy-5-oxo-5H-pyrido [3,2 a ] phenoxazine-3-carboxylic acid was found to be reduced when it was irradiated with visible light in the presence of certain electron donors such as tetramethyl ethylenediamine and reduced glutathione. Upon illuminating this compound with either of the above electron donors under aerobic conditions, the coexisting nitroblue tetrazolium was reduced. The reduction was inhibited by superoxide dismutase, which indicated that superoxide anion was generated during the photoinduced reaction. 相似文献
158.
Extracts from recent results of ultra-high-vacuum in-situ electron microscopy of growth processes of epitaxial thin films are given. As a modified monolayer-by-monolayer mode, the growth process in Fe/(111)Au of the initial Frank-van der Merwe type, followed by the intrinsic γ → α transformation of Fe is mentioned. For the nucleation and growth mode, a systematic selection of epitaxial orientation according to interfacial lattice fitting, nucleation and coalescence features, the validity of Cabrera's suggestion extending Frank and van der Merwe's idea, the cluster mobility and effects of grown-in dislocations in substrate crystals are discussed on the basis of the observations. 相似文献
159.
160.
The Brillouin scattering measurement in KH3(SeO3)2 above the transition temperature shows a large anomaly in hypersonic velocity of the transverse wave with the wave vector q = [010] and the polarization ξ = [001], which indicates acoustic phonon softening. 相似文献