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61.
Akiko Sekihara Hidekazu Honma Tadahiro Fukuju Kiminori Maeda Hisao Murai 《Research on Chemical Intermediates》1998,24(8):859-877
Photooxidation (charge transfer) reactions of carbazole derivatives by maleic anhydride (MA) in alcoholic media are studied
by a time-resolved cw-ESR (TRESR) and Fourier transform ESR (FTESR) techniques. The CIDEP spectra observed in the systems
(methyl-, ethyl-, and phenyl-substituted carbazoles with MA) remarkably depend on the MA concentration. Under the high concentration
conditions, an emissive TM (triplet mechanism) polarization with a slight A/E (absorption/emission) pattern of the RPM (radical
pair mechanism) is observed. In the low concentration of MA, a TM-like absorptive polarization is superimposed on the A/E
pattern of the RPM. Since this reaction takes place exclusively through the triplet state, this spectral phase reveals that
the singlet state of the radical-ion pair (RIP) has an energy higher than that of the triplet state, in other words, the sign
of the apparent exchange interaction of the present RIP systems is positive. The total absorptive polarization observed in
the low concentration of MA is tentatively explained by the polarization transfer from the excited triplet state of carbazoles
in thermal equilibrium. 相似文献
62.
63.
Within the framework of nonrelativisitic quantum electrodynamics we consider a single nucleus and N electrons coupled to the radiation field. Since the total momentum P is conserved, the Hamiltonian H admits a fiber decomposition with respect to P with fiber Hamiltonian H(P). A stable atom, respectively ion, means that the fiber Hamiltonian H(P) has an eigenvalue at the bottom of its spectrum. We establish the existence of a ground state for H(P) under (i) an explicit bound on P, (ii) a binding condition, and (iii) an energy inequality. The binding condition is proven to hold for a heavy nucleus and the energy inequality for spinless electrons. 相似文献
64.
65.
Yoichi Asada Keith Slevin Tomi Ohtsuki 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):228
Electron transport phenomena in disordered electron systems with spin–orbit coupling in two dimensions and below are studied numerically. The scaling hypothesis is checked by analyzing the scaling of the quasi-1D localization length. A logarithmic increase of the mean conductance is also confirmed. These support the theoretical prediction that the two-dimensional metal in systems with spin–orbit coupling has a perfect conductivity. Transport through a Sierpinski carpet is also reported. 相似文献
66.
Jing Chen Masahiro Ueda Katsuhiko Asada Keiji Taniguchi 《Optics and Lasers in Engineering》1998,29(1):221
An optical method to measure the weight density of raw glass wool has been developed for use in a manufacturing plant. The method is based on the light attenuation theory. The system consists of the usual white light as a light source, a solar cell as a light-sensitive receiver, an amplifier, a personal computer with an A/D converter for data acquisition and a monitor for display of the data. The accuracy of the system was found to be above 98% and the system can be effectively applied to practical use in the factory. The system may be further applied for quality control in manufacturing raw glass wool. 相似文献
67.
An inductively coupled plasma is extracted into a quartz vacuum chamber through an orifice to observe optical characteristics of the extracted afterglow. The Mach disk, the barrel shock and the zone of silence, which are familiar in supersonic molecular beam experiments with neutral gases, are clearly observed. Axial profiles of the emission of various lines are measured with a photodiode array spectrometer. Intensities of ionic lines as well as atomic lines are stronger at the Mach disk than in the zone of silence. The location of the Mach disk with varying chamber presure is in conformity with an experimental equation obtained in supersonic molecular beam experiments. 相似文献
68.
Hiroyoshi Kamogawa Yuichiro Haramoto Yukihiro Misaka Yasuhiro Asada Yumiko Ohno Masato Nanasawa 《Journal of polymer science. Part A, Polymer chemistry》1985,23(5):1517-1526
p-Styrenesulfonate esters of primary and secondary perfume alcohols and phenols, including citronellol, 1-menthol, borneol, β-phenethyl alcohol, eugenol, p-anisyl alcohol, cinnamyl alcohol, and geraniol, and herbicide alcohols such as 2,4-dichloro- and 2,4,5-trichlorophenoxy-ethanols were synthesized using p-styrenesulfonyl chloride in the presence of bases such as pyridine, triethylamine, sodium hydrogen carbonate, and sodium hydride. The hydrolytic behavior of sulfonate ester monomers and their copolymers with N-vinyl-2-pyrrolidone to liberate perfume and herbicide alcohols was structure-dependent, thereby affording chemical release control. 相似文献
69.
Two new triterpenoid saponins, ardisimamilloside G (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-13beta,28-epoxy-16-oxo-oleanan-3beta,30-diol and ardisimamilloside H (2), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-alpha-L-arabinopyranosyl]-3beta-hydroxy-13beta,28-epoxy-16-oxo-oleanan-30-al, were isolated from the roots of Ardisia mamillata HANCE. Structure assignments were established on the basis of spectral data and chemical evidence. 相似文献
70.
Terai T Osakabe K Katai M Sakaguchi K Narama I Matsuura T Katakawa J Tetsumi T 《Chemical & pharmaceutical bulletin》2003,51(3):351-353
Novel 9alpha and 9beta-hydroxy grayanotoxin II derivatives were prepared by photo-sensitized oxygenation of iso-grayanotoxin II and oxidation of grayanotoxin II tetraacetate with selenium dioxide respectively. The lethal dosage of 9alpha and 9beta-hydroxy grayanotoxin II were lower than that of grayanotoxin II. In addition, the lethal dosage of 9beta-hydroxy-dihydro grayanotoxin II was higher than that of dihydro grayanotoxin II. 相似文献