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71.
He I (584 Å) photoelectron spectra and photoionization cross sections of atomic chlorine and bromine
Well-resolved He I photoelectron spectra of atomic chlorine and bromine have been obtained without serious background electrons, giving rise to relative photoelectron intensities associated with differential photoionization cross sections at an angle of 90° with respect to the incident 584 Å radiation. 相似文献
72.
Riki Seki Etsuko Kimura Toshiyuki Takahashi Nagao Ikeda 《Journal of Radioanalytical and Nuclear Chemistry》1990,138(1):17-31
The concentration of129I in soil in Japan was determined by neutron activation analysis. For the activation analysis, pre-irradiation chemical separation of the iodine was carried out by acid decomposition and distillation and post-irradiation treatment was performed by ion exchange and solvent extraction. The concentration of stable iodine and137Cs were also determined and compared with the behavior of129I in soil.Soil samples from Ibaraki, Fukui, Fukushima, and Nagasaki Prefectures were analyzed and129I was detected in amounts ranging from 10–7 to 10–5 Bq/g soil in uncultivated surface soil. There are apparently small variations in the129I concentrations in each of the regions analyzed.From depth profile studies in sandy soil, the iodide form of129I was found to migrate downward at a relatively rapid rate while other species remain longer in the surface soil. 相似文献
73.
Yasuo Kimura Takashi Hamasaki Hiromitsu Nakajima Akira Isogai 《Tetrahedron letters》1982,23(2):225-228
Aszonalenin () has been isolated from together with LL-S490β () and the structure of has been established by spectroscopic evidences and chemical transformation. 相似文献
74.
Cordonier CE Satake K Atarashi M Kawamoto Y Okamoto H Kimura M 《The Journal of organic chemistry》2005,70(9):3425-3436
[reaction: see text] The reaction of 2-methoxy-3H-azepines, in the presence or absence of a nucleophile, with N-bromosuccinimide (NBS) gave a regioselective 1,4-adduct from which the corresponding 2H-azepine derivatives were formed via base-promoted hydrogen bromide elimination, generally in moderate to quantitative yield. Competitive formation of 4-bromo-2-methoxy-3H-azepine by electrophilic substitutuion or 3H-azepin-2-yl 2H-azepin-2-yl ether by transetherification was minimized at lower reaction temperatures. Quantitative substitution of 2-(2',4',6'-trichlorophenoxy)-2H-azepine derivatives, formed in moderate yield from the respective 3H-azepine and NBS in the presence of 2,4,6-trichlorophenol (TCP), by various nucleophiles gave the corresponding 2-substituted 2H-azepine. Among these nucleophiles were alkanethiol and alkylamine that are not tolerated in the reaction of 3H-azepine and NBS. 相似文献
75.
Novel thermally crosslinkable fluorine‐containing poly(arylene ether ketone)s comprised of 2,3,5, 6‐tetrafluoro‐1,4‐phenylene moiety were synthesized by the termination of polymer chain ends with propargyl ether groups in order to improve solvent resistance. Crosslinking reaction occurred over 250°C through the formation of both chromen ring and polyene structure. This structure change brought about not only the outstanding solvent resistance but also the increase in glass transition temperature (Tg). The cured films also exhibited excellent thermal stability, transparency and hydrophobicity derived from fluorine atoms. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
76.
Raman spectra of stilbene mono- and di-negative ions in tetrahydrofuran solution were obtained by Ar+ laser exciting lines. A considerable frequency shift was observed for several vibrations in the successive steps: stilbene → (stilbene)? → (stilbene)2?. The observed shift is discussed in a simple VB scheme, particularly in comparison with the results on anthracene negative ions. The resonance Raman effect was striking for both ions with intensity maxima at the exciting wavelengths close to the absorption maxima. 相似文献
77.
Kawahara K Sekiguchi A Kiyoki E Ueda T Shimamura K Kurosaki Y Miyaoka S Okabe H Miyajima M Kimura J 《Chemical & pharmaceutical bulletin》2003,51(3):336-338
Newly formulated cationic liposomes (TRX-liposomes) with four different mean diameters were injected into twelve male rats via the lateral tail vein in order to evaluate the effect of liposomal size on pharmacokinetic parameters. TRX-liposomes disappeared from the blood according to the one-compartment model and demonstrated maximum and minimum half-lives of ca. 14 h (mean diameter of 114.3 nm) and ca. 5 h (mean diameter of 285.9 nm), respectively. This prolonged half-life tended to decrease at the boundary of 114.3 nm mean diameter. The optimal size (114.3 nm) for prolonged circulation of TRX-liposomes was consistent with that of pegylated liposomes such as Doxil((R)), however, the half-life was different among these liposomes. The electric charge of the TRX-liposomal surface is assumed to be responsible for this difference. The results of the present study will be very useful in the design of long-circulating cationic liposomes. 相似文献
78.
Keiichi Kimura Masayuki Kaneshige Hideo Tokuhisa Masaaki Yokoyama 《Journal of polymer science. Part A, Polymer chemistry》1993,31(11):2809-2813
Copolymers of bis[4-(N,N-dimethylamino)phenyl]-4-vinylphenylmethanenitrile (vinyl Malachite Green leuconitrile) with methyl methacrylate or ω-methoxyoligo(oxyethylene) methacrylate have been synthesized, aiming at designing one-component-type organic polymers for photoswitchable ion-conducting films. The triphenylmethanenitrile copolymers with ω-methoxyoligo(oxyethylene) methacrylate were found to undergo ionic-conductivity switching by turning on and off UV light at ambient temperature, owing to their low glass transition temperature. © 1993 John Wiley & Sons, Inc. 相似文献
79.
Shizuko Kobayashi Makoto Takehana Chiharu Tohyama 《Photochemistry and photobiology》1996,63(1):106-110
Abstract— The protective effect of administration of glutathione (GSH) isopropyl ester on photodamage, such as lipid peroxidation, inflammation and tumorigenesis induced by UV exposure (290–400 nm, max. 312 nm), was investigated using hairless mice. Pretreatment with 20 mg/kg GSH isopropyl ester prevented the increases of thiobarbituric acid-reactive substance (TBARS) formation in skin and serum sialic acid, indices of lipid peroxidation and inflammatory reaction, respectively, which were caused by a single dose (15 kj/m2 ) of UV irradiation. The level of epidermal GSH in skins of the GSH ester-treated mice was maintained within normal limits. When mice were exposed to UV at a dose of 2 kj/m2 , three times weekly, skin tumors developed in all of them after 25 weeks. The formation of skin tumors was significantly inhibited by administration of 10 mg/kg GSH ester prior to each UV irradiation for 25 weeks. Moreover, the increases of cutaneous TBARS and serum sialic acid in the tumor-bearing mice were also prevented by continuous pretreatment with GSH ester. Even after 24 weeks, the epidermal GSH content of the pretreated mice was mostly retained compared to nonirradiated mice. However, administration of GSH prior to acute or chronic UV irradiation had no effect on the UV-induced damage. The present results suggest that the protection from photo-damage afforded by pretreatment with GSH ester is due to maintenance of a normal GSH level. 相似文献
80.
Naomi Masuda Yatsuhisa Nagano T. Kimura 《Journal of Thermal Analysis and Calorimetry》2005,81(3):533-535
Summary The standard molar enthalpy of formation of methyl methylthiomethyl sulfoxide, CH3(CH3SCH2)SO, at T=298.15 K in the liquid state was determined to be -199.4±1.5 kJ mol-1 by means of oxygen rotating-bomb combustion calorimetry. 相似文献