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251.
252.
253.
Motoo Tori Aki Watanabe Yasuko Okamoto Shigeru Takaoka Chiaki Kuroda Ryo Hanai 《Tetrahedron》2008,64(19):4486-4495
Twenty-six eremophilane-type sesquiterpenoids, including six new compounds, were isolated from the title species. One of the new compounds, kanaitzensol, suggested the presence of an enzyme for the conversion of eremophil-7(11)-en-8-one derivative to furanoeremophilanes. The plant was collected at 15 locations in Yunnan Province of China and found to be diverse with respect to its sesquiterpenoid composition. DNA sequencing also revealed a large intraspecific diversity of the plant. 相似文献
254.
T. Okamoto T. Omori K. Yoshihara 《Journal of Radioanalytical and Nuclear Chemistry》1984,85(4):245-251
The chemical species of carrier-free technetium, which were extractable into a TTA-benzene solution on reduction of96TcO
4
–
either with NaBH4 or concentrated HCl, were studied by means of silica gel chromatography. Elution peaks ascribed to the formation of Tc/tta/4 and Tc/tta/3 type complexes were observed. The latter complex was also synthesized by recoil effect of Ru/, p/Tc reactions in -irradiated Ru/tta/3. 相似文献
255.
256.
Takakazu Kojima Takuzo Kurotu Ken-Ichi Masuda Yoshinobu Hosaka 《Journal of polymer science. Part A, Polymer chemistry》1985,23(2):343-349
The thermal decomposition of poly(sec-amyl methacrylate) is studied by simultaneous thermogravimetry–gas chromatography–mass spectrometry and by pyrolysis–gas chromatography. The TG curve has four distinct breaks and a plateau. Results of the identification of the evolved gas at the individual breaks by GC–MS techniques lead to the conclusion that these breaks correspond to the individual processes in the decomposition mechanism like that of poly(tert-butyl methacrylate): the first break, the depolymerization initiated at the unsaturated chain ends; the second break, the depolymerization initiated at the saturated chain ends; the third break, the ester decomposition; the plateau, the inhibition of decomposition by the formation of poly(methacrylic anhydride); the fourth break, the decomposition of poly(methacrylic anhydride). The extent of ester decomposition is related to the substituent constants based on Hammett equation. The ester decomposition product is separated into three pentene isomers by pyrolysis–gas chromatography: trans-2-pentene, cis-2-pentene, and 1-pentene. As raising decomposition temperature, the composition ratio of trans-2-pentene decreases and becomes constant above 620 K, and the composition ratios of cis-2-pentene and 1-pentene increase and also become constant above 620 K. These results are accounted for by mobility of atoms included in the substituent at forming a ring transition state. 相似文献
257.
K Torizumi S Okamoto M Yasui Y Okamoto T Tuda K Ota F Oka H Sagawa K Yabe A Okuyama 《Radioisotopes》1988,37(11):623-626
The bone metabolic markers showed the significant differences in age and sex of the hemodialysis patients with renal insufficiency. It is likely that the evaluations of bone change and biochemical metabolic markers should be based on serum estradiol level, sex and age of the renal hemodialysis patients. 相似文献
258.
Sound attenuattion constants are calculated for the one-dimensional ferro- and antiferromagnetic systems at finite temperatures. Their frequency dependences, in both cases, turn out to be , where ωc is a “cut-off” frequency related to the three-dimensional anisotropic interactions. 相似文献
259.
Ken-Ichi Okamoto Akira Itaya Shigekazu Kusabayashi 《Journal of Polymer Science.Polymer Physics》1976,14(5):869-877
The photoconductivity of poly(N-acryloylcarbazole) (PACz), with the pendant carbazolyl group only a short distance from the skeletal chain of the polymer but separated from it by a carbonyl group, is investigated and compared with that of poly(N-vinylcarbazole) (PVCz). There is no significant difference between PACz and PVCz in the temperature, light intensity, and spectral dependences of the photocurrent. The photoconductivity of PACz, however, is much inferior to that of PVCz and even to that of poly(N-carbazolylethylvinylether), a representative vinyl polymer with pendant carbazolyl groups far from the skeletal chain. The poor photoconductivity of PACz is discussed in relation to the intensity of the electronic interaction between neighboring carbazolyl groups in the polymer chain and to singlet exciton migration. It is attributed mainly to an extremely low efficiency of extrinsic carrier generation via a singlet exciton, which is due to the poor electron-donating character and the extremely short lifetime of a singlet exciton in the presence of the carbonyl group. 相似文献
260.
Bone metabolic markers were investigated in the male hemodialysis patients within and over 60 years old and the female hemodialysis patients within and over 50 years old. Our results indicated that bone metabolic markers were more increased in the lower values of serum estradiol in the male patients, but inversely were more enhanced in higher values of serum estradiol in the female patients. 相似文献