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41.
Simeon Reich Alexander J. Zaslavski 《Journal of Fixed Point Theory and Applications》2010,8(2):395-403
We use the concept of porosity in order to establish a generic stable convergence theorem for infinite products of nonexpansive
mappings in Banach spaces. 相似文献
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Carvalho Andrade Carolina M. M. Aguiar Wilson Bucker Antranikian Garo 《Applied biochemistry and biotechnology》2001,91(1-9):655-669
Xylanases (EC3.2.1.8) catalyze the hydrolysis of xylan, the major constituent of hemicellulose. The use of these enzymes could
greatly improve the overall economics of processing lignocellulosic materials for the generation of liquid fuels and chemicals.
The hyperthermophilic archaeon Pyrodictium abyssi, which was originally isolated from marine hot abyssal sites, grows optimally at 97°C and is a prospective source of highly
thermostable xylanase. Its endoxylanase was shown to be highly thermostable (over 100 m in at 105°C) and active even at 110°C.
The growth of the deep-sea archaeon P. abyssi was investigated using different culture techniques. Among the carbohydrates used, beech wood xylan, birch wood glucuronoxylan
and the arabinoxylan from oats pelt appeared to be good inducers for endoxylanase and β-xylosidase production. The highest
production of arabinofuranosidase, however, was detected in the cell extracts after growth on xylose and pyruvate, indicating
that the intermediate of the tricarboxylic acid cycle acted as a nonrepressing carbon source for the production of thi enzyme.
Electron microscopic studies did not show a significant difference in the cell surface (e.g., xylanosomes) when P. abyssi cells were grown on different carbohydrates. The main kinetic parameters of the organism have been determined. The cell yield
was shown to be very low owing to incomplete substrate utilization, but a very high maximal specific growth rate was determined
(μmax=0.0195) at 90°C and pH 6.0. We also give information on the problems that arise during the fermentation of this hyperthermophilic
archaeon at elevated temperatures. 相似文献
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Maria Carolina de CeglieLeonardo Degennaro Aurelia FalcicchioRenzo Luisi 《Tetrahedron》2011,67(48):9382-9388
‘Gear-like’ rotations of simple C-C bonds have been observed in some aziridine methanol derivatives. These restricted rotations have been studied by dynamic and multinuclear magnetic resonance experiments, and the barrier for rotations of Csp3-Csp3 and Csp3-Csp2 bonds have been calculated. The role of an intramolecular hydrogen bond on the stereodynamics has also been demonstrated. 相似文献
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In this paper, we continue the study of semitotal domination in graphs in [Discrete Math. 324, 13–18 (2014)]. A set \({S}\) of vertices in \({G}\) is a semitotal dominating set of \({G}\) if it is a dominating set of \({G}\) and every vertex in \({S}\) is within distance 2 of another vertex of \({S}\). The semitotal domination number, \({{\gamma_{t2}}(G)}\), is the minimum cardinality of a semitotal dominating set of \({G}\). This domination parameter is squeezed between arguably the two most important domination parameters; namely, the domination number, \({\gamma (G)}\), and the total domination number, \({{\gamma_{t}}(G)}\). We observe that \({\gamma (G) \leq {\gamma_{t2}}(G) \leq {\gamma_{t}}(G)}\). A claw-free graph is a graph that does not contain \({K_{1, \, 3}}\) as an induced subgraph. We prove that if \({G}\) is a connected, claw-free, cubic graph of order \({n \geq 10}\), then \({{\gamma_{t2}}(G) \leq 4n/11}\). 相似文献
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