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排序方式: 共有591条查询结果,搜索用时 0 毫秒
31.
Beta-ray skin dose due to the fission fallout from the Hiroshima atomic bomb is potentially related to the epilation in the black rain area. The absorbed dose to the skin from beta-rays emitted by fission fallout has been estimated for an initial 13?Cs deposition of 1 kBq m?2 on the ground at 0.5 h after the explosion. The estimated skin dose takes into account both external exposure from fission fallout radionuclides uniformly distributed in 1 mm of soil on the surface of the ground and from a 26 μm thickness of contaminated soil on the skin, using the Monte Carlo radiation transport code MCNP-4C. The cumulative skin dose for 1 month after the explosion is taken as the representative value. The estimated skin dose for an initial 13?Cs deposition of 1 kBq m?2 was determined to be about 500 mSv. 相似文献
32.
33.
Kinetic Study of the Prooxidant Effect of α-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical 总被引:1,自引:0,他引:1
Aya Ouchi Masaharu Ishikura Kensuke Konishi Shin-ichi Nagaoka Kazuo Mukai 《Lipids》2009,44(10):935-943
A kinetic study of the prooxidant effect of α-tocopherol was performed. The rates of allylic hydrogen abstraction from various
unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by α-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order
rate constants (k
p) obtained are <1 × 10−2 M−1 s−1 for 1, 1.90 × 10−2 M−1 s−1 for 2, 8.33 × 10−2 M−1 s−1 for 3, 1.92 × 10−1 M−1 s−1 for 4, and 2.43 × 10−1 M−1 s−1 for 5 at 25.0 °C. Fatty acid esters 3, 4, and 5 contain two, four, and six –CH2– hydrogen atoms activated by two π-electron systems (–C=C–CH2–C=C–). On the other hand, fatty acid ester 2 has four –CH2– hydrogen atoms activated by a single π-electron system (–CH2–C=C–CH2–). Thus, the rate constants, k
abstr/H, given on an available hydrogen basis are k
p/4 = 4.75 × 10−3 M−1 s−1 for 2, k
p/2 = 4.16 × 10−2 M−1 s−1 for 3, k
p/4 = 4.79 × 10−2 M−1 s−1 for 4, and k
p/6 = 4.05 × 10−2 M−1 s−1 for 5. The k
abstr/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of α-tocopherol in edible oils, fats, and low-density lipoproteins
may be induced by the above hydrogen abstraction reaction. 相似文献
34.
Yasutaka Nagai Kazuhiko Dohmae Kentaro Teramura Tsunehiro Tanaka Gemma Guilera Kazuo Kato Masaharu Nomura Hirofumi Shinjoh Shinichi Matsumoto 《Catalysis Today》2009,145(3-4):279
Two main pivotal subjects of research in automotive catalysts were studied by modern X-ray absorption analysis techniques. One is oxygen storage/release behaviour, and the other is sintering inhibition of Pt particles. First, three types of CeO2–ZrO2 (Ce:Zr = 1:1 molar ratio) compounds with different oxygen storage/release capacities and different structural properties were prepared, and the valence change of Ce as a function of temperature during oxygen release/storage processes was investigated. The reduction of surface Ce mainly occurred in the range 100–170 °C, and the reduction of bulk Ce progressed at high temperatures of 170 °C and above. The Ce reduction behaviour depended not only on the homogeneity of the Ce and Zr for bulk reduction at high temperatures but also on the particle size of the CeO2–ZrO2 samples for surface reduction at low temperatures. Secondly, sintering inhibition of Pt in Pt/Al2O3, Pt/MgO and Pt/ceria-based catalysts after 800 °C ageing in air was studied. We found that the Pt–O–M (M = Mg, Ce) bond acted as an anchor and inhibited the sintering of Pt particles on MgO or ceria-based oxide. Especially, it was noteworthy that the Pt–O–Ce4+ bond on the ceria-based support breaks easily through the reduction of Ce (Ce4+ → Ce3+) during the usual stoichiometric and reducing conditions. 相似文献
35.
Jianming Zhu Dr. Jing Wang Kai Cheng Hui Chen Dr. Ran An Dr. Yaping Zhang Prof. Makoto Komiyama Prof. Xingguo Liang 《Chembiochem : a European journal of chemical biology》2020,21(6):785-788
High-resolution melting (HRM) analysis has been improved and applied for the first time to quantitative analysis of enzymatic reactions. By using the relative ratios of peak intensities of substrates and products, the quantitativity of conventional HRM analysis has been improved to allow detailed kinetic analysis. As an example, the ligation of sticky ends through the action of T4 DNA ligase has been kinetically analyzed, with comprehensive data on substrate specificity and other properties having been obtained. For the first time, the kinetic parameters (kobs and apparent Km) of sticky-end ligation were obtained for both fully matched and mismatched sticky ends. The effect of ATP concentration on sticky-end ligation was also investigated. The improved HRM method should also be applicable to versatile DNA-transforming enzymes, because the only requirement is that the products have Tm values different enough from the substrates. 相似文献
36.
Masaharu Mizumoto 《Information Sciences》1982,27(3):183-209
This paper shows that the majority of fuzzy inference methods for a fuzzy conditional proposition “If x is A then y is B,” with A and B fuzzy concepts, can infer very reasonable consequences which fit our intuition with respect to several criteria such as modus ponens and modus tollens, if a new composition called “max-⊙ composition” is used in the compositional rule of inference, though reasonable consequences cannot always be obtained when using the max-min composition, which is used usually in the compositional rule of inference. Furthermore, it is shown that a syllogism holds for the majority of the methods under the max-⊙ composition, though they do not always satisfy the syllogism under the max-min composition. 相似文献
37.
Using the instrumented fuel assemblies (IFA) installed in the Japan Power Demonstration Reactor (JPDR)-II core, fluctuations of the inlet and outlet channel flow rates were observed under both conditions of at-power operation and cold core flow circulation. The correlation analysis revealed that the flow fluctuations in any IFA channel showed almost uncorrelated cross-covariance function with other IFA channel flow. To explain the mechanism of the channel flow fluctuations, some hypothetical idea is introduced. 相似文献
38.
39.
Kenji Yura Kazumasa Ohashi Masaru Nakajima Masataka Yoshimura Masaharu Ota Katsundo Hitomi P.E. Econ 《Computers & Industrial Engineering》1994,27(1-4):127-130
A method of developing strategic CIM is described. Relationship between CIM and firm's competitive power is clarified, and a fundamental planning procedure for CIM is developed for enhancing the competitiveness. In the procedure, the system configuration of CIM is analyzed using 0–1 goal programming techniques. A numerical example is also demonstrated to show the effectiveness of the procedure. 相似文献
40.
These days, the number of pharmaceutical patent applications which do not specify the principal active ingredient in the form of a chemical name or structure is increasing. These patents are difficult to retrieve in retrospective on-line searches using chemical structures or keywords. Furthermore, even if you could find them, the situation with regard to patentability is obscure and this causes considerable problems for the experts in charge of the patent search. If you are a searcher for a large pharmaceutical company, you might already be apprehensive of infringing such patents. We, the JFA,* gathered these patents together and studied the differences between their patentability in Japan, the US and the EPO. 相似文献